thao nguyen-hand cleaner
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Bachelor Thesis Hand Cleaner
Huynh Thi Thao Nguyen Page i
HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY
FACULTY OF CHEMICAL ENGINEERING
DEPARTMENT OF ORGANIC CHEMICAL TECHNOLOGY
……………………………………………………………
BACHELOR THESIS
HAND CLEANER WITH ESSENTIAL OIL
Supervisor: Dr. Le Thi Hong Nhan
Student: Huynh Thi Thao Nguyen
Student code: 60501871
Ho Chi Minh City, 01/2010
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Acknowledgments
During the research and writing of this thesis, many people have helped me and their
contributions were invaluable. Although I might have missed mentioning some of their
names in these acknowledgements, they all deserve my special thanks.
Firstly, my deepest appreciations go to my supervisors Ms.Vuong Ngoc Chinh and Dr. Le
Thi Hong Nhan, who have supported me in many ways. Their excellent, patient guidance
and encouragement have opened and directed me towards a new study field, hand clea ner
with essential oil.
I wish to thank to all friends for their encouragement and motivation to carry on striving.
Last but not least are my deepest thanks to my dear family. The support I have received
from them in all my life is inestimable.
Huynh Thi Thao Nguyen
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Abstract
This thesis applied natural essential oil into hand cleaner. Product with essential oil and
product with chemical synthetic substances were compared to anti-bacteria ability, cleaned
capacity and some factors to evaluate ability of essential oil to apply to personal care
products.
Suitable components for basic formula were chosen, included: distillated water, sodium
laundry sulfate (SLS), Carbopol aqua, TEA, CDE, ethanol, CAPB. Among them, ratio of
SLS and Carbopol were very important because they affected on quality of product. After
surveying, the suitable fraction for SLS was 10%wt and 6% for Carbopol aqua 30%.
Citronella and lemon were popular materials and there were many previous researches
showed them had a good anti-bacteria agent. So, this thesis chose essential oils of lemon
and citronella for final products. Essential oils were extracted by indirect steam distillation
at 2atm. The yeild of distillation were 1.65% for citronella and 3.51% for lemon.
To compare activity of essential oil and Triclosan, three final products were prepared,
included: SP1 with Triclosan, SP2 with lemon’s essential oil and SP3 with citronella’s
essential oil. By comparing quantity of remain bacteria after using products and after using
water, the suitable ratio of anti-bacteria agents were chosen (essential oils / Triclosan) as
follows:
- SP1 with 0.3 % Triclosan, killed 98.18% bacteria
- SP2 with 0.6% lemon’s essential oil killed 91.71% bacteria
- SP3 with 0.5% citronella’s essential oil killed 94.17% bacteria.
While activity of SP1 didn’t not change follow time, activity of SP2 and SP3 were reduced
because of decaying and evaporation. The odor of SP2 and SP3 could make comfortable
and relax, so two products were accepted by customers.
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List of Figures Figure 2-1: Structure of human skin .................................................................................... 5
Figure 2-2: Scanning electron microscopy of some kinds of harmful microbe ................... 9
Figure 2-3: Triclosan structure ............................................................................................ 11
Figure 2-4: Some commercial products using Triclosan ..................................................... 11
Figure 2-5: Some popular materials of essential oils in Vietnam........................................ 17
Figure 2-6: Many bacteria on hands .................................................................................... 22
Figure 2-7: Six steps to wash hands .................................................................................... 24
Figure 2-8: Some hand cleaner products on market ............................................................ 25
Figure 3-1: Experimental orientation of this thesis ............................................................. 28
Figure 4-1: Zahn cup ........................................................................................................... 30
Figure 4-2: Bacteria counting chambers .............................................................................. 30
Figure 4-3: Indirect steam distillating system ..................................................................... 31
Figure 4-4: Zoom in image of Bacteria counting chambers ................................................ 34
Figure 4-5: Procedure for preparation of hand cleaner product .......................................... 39
Figure 4-6: Procedure for preparation of distillating essential oils ..................................... 43
Figure 4-7: Diagram of preparing SP1 ............................................................................... 44
Figure 5-1: Cross- link structure of Carbopol polymer ........................................................ 50
Figure 5-2: The two dimensional structure of CMC polymer ............................................ 51
Figure 5-3: Temperature effect on density of products ....................................................... 55
Figure 5-4: Temperature effect on viscosity of products..................................................... 56
Figure 5-5: Temperature effect on turbidity of products ..................................................... 57
Figure 5-6: Centrifugation effect on density of products .................................................... 59
Figure 5-7: Centrifugation effect on viscosity of products................................................. 59
Figure 5-8: Lemongrass essential oil and lemon essential oil ............................................. 61
Figure 5-9: Effect of anti-bacteria agents on the rate of killed bacteria .............................. 64
Figure 5-10: Time effect on bio-activity of final products .................................................. 65
Figure 5-11: Three final products after preparing ............................................................... 67
Figure 5-12: Result of investigating viewpoint of customers in final products .................. 68
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List of Tables
Table 4-1: Components of basic formula and their utility................................................... 29
Table 4-2: Viscosity conversion chart for Zahn cup number 3 and Zahn cup number 5 .... 32
Table 4-3: Evaluated factors of evaluating product and their ratio (mi).............................. 35
Table 4-4: Points range of evaluating product..................................................................... 35
Table 4-5: The questionnaire to surveying viewpoint of customers about products ........... 37
Table 4-6: Formulae for investigating effect of SLS material............................................. 40
Table 4-7: Formulae for investigating effect of Carbopol aqua material ............................ 40
Table 4-8: Formulae for investigating effect of CMC material........................................... 40
Table 4-9: The targeted product and its ingredients ............................................................ 41
Table 4-10: Materials for essential oil distillation ............................................................... 42
Table 4-11: Serials of products to evaluating effect of anti-bacterial agents on activity of
products ........................................................................................................................ 45
Table 4-12: Price of materials.............................................................................................. 47
Table 4-13: Price of some hand cleaners on market ............................................................ 47
Table 5-1: Result of surveying ratio of SLS ........................................................................ 48
Table 5-2: Viscosity of Carbopol aqua samples .................................................................. 49
Table 5-3: Viscosity of CMC samples................................................................................. 50
Table 5-4: Formulae of semi-product .................................................................................. 52
Table 5-5: Temperature effect on semi-product and targeted product ................................ 54
Table 5-6: Centrifugation effect on properties of semi-product and targeted product ........ 58
Table 5-7: Characteristics of Lemon and lemongrass essential oil ..................................... 61
Table 5-8: Surveying the suitable fraction of anti-bacteria agents in final products ........... 63
Table 5-9: Effect of time on anti-bacteria capacity of products .......................................... 65
Table 5-10: Characteristics of three final products.............................................................. 66
Table 5-11: Result of investigating viewpoint of customers ............................................... 68
Table 5-12: Cost of product SP1 ......................................................................................... 69
Table 5-13: Cost of product SP2 ......................................................................................... 70
Table 5-14: Cost of product SP3 ......................................................................................... 71
Table 6-1: Summary of product SP1 ................................................................................... 73
Table 6-2: Summary of product SP2 ................................................................................... 74
Table 6-3: Summary of product SP3 ................................................................................... 75
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Table of Contents Acknowledgments..............................................................................................................................i
Abstract...........................................................................................................................................iii
List of Figures.................................................................................................................................. iv
Table of Contents ............................................................................................................................. v
CHAPTER 1: INTRODUCTION...................................................................................................... 1
CHAPTER 2: LITERATURE REVIEW .......................................................................................... 3
2.1. SKIN ..................................................................................................................................... 3
2.1.1. Introduction ..................................................................................................................... 3
2.1.2. Skin components .............................................................................................................. 3
2.1.3. Hygiene and skin care ...................................................................................................... 5
2.2. BACTERIA AND PARASITIC DISEASE ON SKIN ............................................................ 6
2.2.1. Introduction ..................................................................................................................... 6
2.2.2. Some kinds of microbes on human skin ............................................................................. 6
2.2.2.1. The bacteria ............................................................................................................. 6
2.2.2.2. Candida Albican....................................................................................................... 7
2.2.2.3. Mould Aspergillus .................................................................................................... 7
2.2.2.4. Dermatophyte........................................................................................................... 7
2.2.3. Anti-bacteria mechanisms of human body.......................................................................... 9
2.3. ANTI-BACTERIAL AGENTS ............................................................................................ 10
2.3.1. Anti-bacteria definition and classification ........................................................................ 10
2.3.2. Useful and harmful effect of anti-bacteria agents .............................................................. 10
2.3.3. Triclosan ....................................................................................................................... 11
2.3.3.1. Using Triclosan ...................................................................................................... 11
2.3.3.2. Health concerns ..................................................................................................... 12
2.4. ESSENTIAL OILS .............................................................................................................. 12
2.4.1. Value of essential oils ..................................................................................................... 13
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2.4.1.1. Lemon.................................................................................................................... 13
2.4.1.2. Lemon Eucalyptus .................................................................................................. 14
2.4.1.3. Citronella............................................................................................................... 14
2.4.1.4. Betel ...................................................................................................................... 15
2.4.1.5. Curcuma ................................................................................................................ 15
2.4.2. Essential oil separation ................................................................................................... 18
2.4.2.1. Expression ............................................................................................................. 18
2.4.2.2. Solvent extraction ................................................................................................... 18
2.4.2.3. Distillation ............................................................................................................. 19
2.4.3. Some matters when using essential oil ............................................................................. 19
2.5. REVIEWS OF SOME PREVIOUS STUDIES ..................................................................... 20
2.6. HAND CLEANER PRODUCTS.......................................................................................... 22
2.6.1. Some matters about washing hands ................................................................................. 22
2.6.2. Some hand cleaners on market ........................................................................................ 24
2.6.3. Some formulae of hand cleaners...................................................................................... 25
CHAPTER 3: OBJECTIVES & EXPERIMENTIAL ORIENTATION.......................................... 27
CHAPTER 4: EXPERIMENTALS................................................................................................. 29
4.1. MATERIALS AND EQUIPMENT............................................................................... 29
4.1.1. Materials ....................................................................................................................... 29
4.1.2. Equipment ..................................................................................................................... 29
4.2. METHODS.......................................................................................................................... 31
4.3. PREPARING SEMI-FORMULA ........................................................................................ 38
4.3.1. General procedure for preparation of hand cleaner............................................................ 38
4.3.2. Effect of components in semi-formula ............................................................................. 39
4.3.3. Preparing and evaluating semi-product ............................................................................ 41
4.4. DISTILLATING AND EVALUATING ESSENTIAL OIL.................................................. 42
4.4.1. Distillating essential oil .................................................................................................. 42
4.4.2. Evaluating essential oils................................................................................................ 44
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4.5. PREPARING FINAL PRODUCTS ..................................................................................... 44
4.5.1. Preparing final product........................................................................................................... 44
4.5.2. Effect of anti-bacteria agents on activity of final products ........................................................ 45
4.6. EVALUATING FINAL PRODUCTS .................................................................................. 46
4.6.1. Evaluating characteristics of final products............................................................................ 46
4.6.2. Evaluating commercial ability of final products .................................................................... 46
4.6.2.1. Surveying viewpoint of customers about products ..................................................... 46
4.6.2.2. Preliminary estimating price of products.................................................................. 46
CHAPTER 5: RESULTS AND DISCUSSION ................................................................................ 48
5.1. PREPARING AND EVALUATING SEMI FORMULA ...................................................... 48
5.1.1. Preparing semi-formula........................................................................................................ 48
5.1.1.1. Effect of components in semi-formula....................................................................... 48
5.1.1.2. Formulae of semi-product ....................................................................................... 51
5.1.2. Evaluating semi-formula ..................................................................................................... 53
5.2. DISTILLATING AND EVALUATING ESSENTIAL OIL.................................................. 60
5.3. PREPARING AND EVALUATING FINAL PRODUCTS .................................................. 63
5.3.1. Preparing final products ...................................................................................................... 63
5.3.2. Evaluating final products..................................................................................................... 66
5.3.2.1. Evaluating characteristics of final products.............................................................. 66
5.3.2.2. Evaluating commercial ability of final products ........................................................ 67
CHAPTER 6: CONCLUSION & INTENDING WORKS............................................................... 72
6.1. CONCLUSION.................................................................................................................... 72
6.1.1. Essential oil distillation ....................................................................................................... 72
6.1.2. The final products ............................................................................................................... 72
6.2. EVALUATING FEASIBILITY OF STUDY........................................................................ 75
6.3. INTENDING WORKS ........................................................................................................ 76
REFERENCES............................................................................................................................... 78
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CHAPTER 1
INTRODUCTION
Hands are the most dynamic organ in our body, taking part in all activity directly, example
holding, touching … In particular, in the hospitals, medical workers always get in touch
with patients, devices that cause diseases easily. In order, in the food or seafood
manufactories, hands always contact the environment, which has many disease germs.
Thus, hands are the most enable contaminated organ as well as the most protected organ.
Most of present hand cleaner products use mainly some synthetic anti-bacterial agents,
such as Triclosan, Chlorhexidine gluconate, Alcolhols…These substances have initially
promoted good effects and had a part in protecting our health. In recent times, there have
been many clear evidences to prove some bad effects on human and environment of these
substances. According to a report (announced on 14/04/2005) of Virginia University
(USA), Triclosan in toothpastes and detergents can combine with Chlor in tap water to
form Chloroform, which can cause cancers for human. [11]
Thus, a demand of modern detergent products is finding out an anti-bacterial agent that is
not only friendly with environment, safe for human but also bring into play its good effect.
One of attended tendencies is using natural essential oils. Many researches on the world
have proved good effects of essential oils on human health. In Vietnam, essential oils have
also been interested. Many products with essential oils have gradually appeared in market.
However, adding of essential oils to detergent products is not simple, because these
substances are decayed easily. For this reason, requirement is finding out a suitable
process, which can combine essential oils with other ingredients of detergent products.
The climate of Vietnam takes advantage of development of Citrus groups (as oranges,
lemons, pomelos…). These trees have a great reserve of essential oil. This essential oil is
good for skin and can sterilize. Most essential oils of citrus are in peels, which are waste.
Thus, using up this raw material not only solves agricultural sewage but also brings high
economic efficiency.
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With learning of market’s demand, knowledge of lemon’s essential oils as well as
reference of previous researches about hand cleaner, I hope that I can find out a suitable
process to make a hand cleaner that responds demand of most laborers.
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CHAPTER 2
LITERATURE REVIEW
2. This chapter provides a general introduction about some matters of human skin,
microorganism, useful and harmful effects of synthetic anti-antibacterial agents in
personal care products and detergents. This chapter also presents values of essential
oil for our health and some previous related researches …This definition and basic
properties are vital fundamental knowledge and necessary to understand and
approach the experimental, results and discussion aspects of this project.
2.1. SKIN
Skin is object of personal care products, includes hand cleaners. Thus, studying about skin
is necessary. Followed part will present some basic matters about skin.
2.1.1. Introduction
Skin is the outer covering of living tissue. It is the largest organ of the integumentary
system made up of multiple layers of epithelial tissues, and guards under lying muscles,
bones, ligaments and internal organs. For the average adult human, skin has a surface area
of between 1.5 to 2.0 square meters, most of it is between 2-3 mm of thickness. The
average square inch (6.5 cm²) of skin holds 650 sweat glands, 20 blood vessels, 60000
melanocytes and more than a thousand nerve endings. One of the main functions of skin is
protection. It protects the body from external factors such as bacteria, chemicals and
temperature….[12]s
2.1.2. Skin components
Skin has three discrete layers, include:
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Epidermis: is the thinnest layer with thickness of 0.1 mm. It contains no blood vessels and
cells in the deepest layers are nourished by diffusion from blood capillaries extending to
the upper layers of the dermis.
Cells are formed through mitosis at the basal layer. The daughter cells (see cell division)
move up the strata changing shape and composition as they die due to isolation from their
blood source. The cytoplasm is released and the protein keratin is inserted. They
eventually reach the corneum and slough off (desquamation). This process is called
keratinization and takes place within about 27 days. This keratinized layer of skin is
responsible for keeping water in the body and keeping other harmful chemicals and
pathogens out, making skin a natural barrier to infection. [12] [1]
Dermis: is the layer of skin beneath the epidermis that consists of connective tissue and
cushions the body from stress or strain. The dermis is tightly connected to the epidermis by
a basement membrane. It also harbors many Mechanoreceptor/nerve endings that provide
the sense of touch and heat. It contains the hair follicles, sweat glands, sebaceous glands,
apocrine glands, lymphatic vessels and blood vessels. The blood vessels in the dermis
provide nourishment and waste removal to its own cells as well as the Stratum basale of
the epidermis. [12; 1]
Hypodermis: The hypodermis is not part of the skin, and lies below the dermis. Its purpose
is to attach the skin to bone and muscle as well as supplying it with blood vessels and
nerves. It consists of loose connective tissue and elastin. The main cell types are
fibroblasts, macrophages and adipocytes (the hypodermis contains 50% of body fat). Fat
serves as padding and insulation for the body. [1]
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Figure 2-1: Structure of human skin [12]
2.1.3. Hygiene and skin care
Proper skin hygiene is important because unclean skin favors development of pathogenic
organisms. The dead cells that continually slough off the epidermis mix with secretions of
sweat, sebaceous glands and dust found on the skin form a filthy layer on its surface. If not
washed away, the slurry of sweat and sebaceous secretions mixed with dirt and dead skin
is decomposed by bacterial flora, producing a foul smell. Functions of skin are disturbed
when it is excessively dirty; it becomes more easily damaged, release of antibacterial
compounds decreases and dirty skin is more prone to develop infections.
In daily actions, sometimes we forget that there are many bacteria and virus can attach and
cause diseases for us. Hands are an intermediary role to get germs into body. Our hands
have billions of bacteria, each time we shake hands with somebody or touch any thing as
door handle, faucet… hands surely are contaminated bacteria. Thus, easy way to protect
our body is washing hands frequently.
Many researches have shown that washing hands with soap and water within 15 seconds
can decrease 35% of the risk of getting diarrhoea, 17-45% of infecting our respiratory
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system, even deadly disease as H5N1, SARS. Washing hands is considered a cheap
vaccine but get good effect on preventing bacteria
In general, skin is a shield, helps body prevent from outer harmful effects as bacteria and
virus. Therefore, skin protection is very important. Nowadays, to respond this demand,
skin products are researched and developed strongly. Although there are various kinds of
skin products, all of them have common purpose that makes skin clean and comfortable.
Besides, protect skin from harmful effects, correct and strengthen nutriments for skin…,.
Hand products are also produced for these demands.
2.2. BACTERIA AND PARASITIC DISEASE ON SKIN
Microorganisms are tiny creatures can cause some diseases for our. There are many kinds
of microorganisms in environment. This part will introduce some kinds of microorganisms
popularly on human skin and their harmful effects.
2.2.1. Introduction
A microorganism is an organism that is microscopic. They are very diverse; include
bacteria, fungi, archaea and protists. Microorganisms live in all parts of the biosphere, such
as liquid water, soil, ocean floor, high in the atmosphere and deep inside rocks within the
Earth's crust.
There are approximately ten times as many microbe cells as human cells in the human
body. The vast majority of the microbes in the body are rendered harmless by the
protective effects of the immune system, a few are even beneficial. However, some species
of microbe are pathogenic hazard and cause infectious diseases, including cholera,
syphilis, anthrax, leprosy and bubonic plague...[3]
Diseased mechanism : bacteria take food from their owner (especially assimilated food)
and secrete a poisonous substance that causing traumas. They also stimulate and transport
new germs into human body.[3]
2.2.2. Some kinds of microbes on human skin
2.2.2.1. The bacteria
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Bacteria are a large group of unicellular microorganisms. They have a wide range of
shapes, ranging from spheres to rods and spirals. Bacteria do not have chlorophyll so that
most of them are heterotrophy and a few autotrophies. Most o f heterotrophy are parasitize
and using existing organic. The autotrophies can synthesize the organic by energy of a
oxygenated inorganic process. [3]
There are two groups usually found on skin:
Resident bacteria: include Commensal and Anaerobic Gram-positive coccus as
Staphylococcus epidermis, Corynebacteria and Micrococcus species… Normally, the
resident bacteria do not cause diseases [3]
Temporary bacteria: include Pseudomonas spp (from environment), Streptocoques group
A, Enterococcus spp, Staphylococcus aureus. This group can cause harmfull diseases for
human heath.[3]
2.2.2.2. Candida Albican
Candida Albican is single celled fungal yeast. It presents normally on skin and in mucous
membranes such as vagina, mouth or rectum. Fungus also can travel through the blood stream
and affect throat, intestines, and heart valves. However, antibiotics easily destroyed them. If
taking an overdose of antibiotics, the Candida Albicans yeast will grow out of control,
producing chemicals that are toxic to human health. [4]
2.2.2.3. Mould Aspergillus
Aspergillus presents everywhere, some spices are often met: A.fumigatus, A.flavus, A.niger.
Besides Aspergillus, there are Penicillium and Fusarium. They often causes green, yellow,
brown or black mold on old organic substances. Aspergillus contaminate by respiratory
system, causes some diseases as bronchitis, pneumonia… [4]
2.2.2.4. Dermatophyte
Dermatophytes cause infections of skin, hair and nails due to their ability to obtain nutrients
from keratinized material. Dermatophytes do not cause splanchnopathy diseases. Some
diseases are caused by Dermatophytes: ringworm, purulent scabies, impetigo… [4]
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Candida Albicans
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Aspergillus
Dermatophytes
Figure 2-2: Scanning electron microscopy of some kinds of harmful microbe [14]
2.2.3. Anti-bacteria mechanisms of human body
Our healthy body has self-defense mechanisms against bacteria’s encroachment. There are
two main mechanisms:
Non-specific mechanisms: make a physiological barrier with sweat and mucilage that
have acid to inhibit, prevent and kill harmful microbes. In addition, the helpful
resident bacteria on skin not only fight against harmful microbes in food but also emit
poisons to inhibit the harmful microbes. [4] [3]
Specific mechanisms: human body is protected from diseases by immunity. This is
depend on kind of microbe, human heredity factors and age … [4]
In short, harmful effects of microbes are unable to avoid. To protect our body, we should
hygiene to prevent and kill harmful microbes. Nowadays, there are many hygienic products
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to clean and protect our body from harmful microbes. Hygienic products for hands are also
been researching and developing for common demand.
2.3. ANTI-BACTERIAL AGENTS
According to above part, microbes can be killed by anti-bacterial agents. Hence, synthetic
anti-anti-bacterial agents are used popularly in hygienic products. This chapter will clear up
about good and bad effects of these agents for human health.
2.3.1. Anti-bacteria definition and classification
In the broadest definition, an anti-bacterial agent is substance that interferes with growth and
reproduction of bacteria. Anti-bacterial agents are now most commonly agents used to
disinfect surfaces and eliminate potentially harmful bacteria. Anti-bacterial agents may be
divided into two groups according to their speed of action and residue production:
Non-residue-producing: contains those that act rapidly to destroy bacteria, but quickly
disappear (by evaporation or breakdown) and leave no active residue behind.
Examples of this type are the alcohols, chlorine, peroxides and aldehydes. [15]
Residue- producing: consists mostly of newer compounds that leave long-acting
residues on the surface to be disinfected and thus have a prolonged action. Common
examples of this group are triclosan, triclocarban and benzalkonium chloride. [15]
2.3.2. Useful and harmful effect of anti-bacteria agents
Anti-bacterial agents are definitely effective in killing bacteria. However, there is
considerable controversy surrounding their health benefits. The non-residue producing
agents have been used for many years and continue to be effective agents for controlling
diseased organisms in a wide variety of healthcare and domestic settings. When using under
strict guidelines of application, the residue-producing agents can affect on controlling
bacterial and fungal infection. [15]
Some hygienic products have demonstrated effectiveness for specific conditions, such as anti-
bacterial toothpaste helps control periodontal (gum) disease; anti-bacterial deodorants
suppress odor-causing bacteria, and anti-dandruff shampoos help control dandruff. [15]
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When using directly for external surfaces, anti-bacterial agents are considered non-toxic.
However, some may cause skin and eye irritation and all have the potential for causing harm
if not stored or used properly. Furthermore, evaluations of risk are based on single agents and
do not consider the effects of multiple uses or multiple compounds. Recently, some harmful
effects of Triclosan in surface waters, sewage treatment plants, the bile of fish and breast
milk… has been reported.
2.3.3. Triclosan
Triclosan (IUPAC name: 5-chloro-2-(2,4-dichlorophenoxy)phenol) is a potent wide spectrum
anti-bacterial and anti- fungal agent. Thus, it is used as the most common anti-bacteria agent
now. It is a polychloro phenoxy phenol.
Figure 2-3: Triclosan structure
2.3.3.1. Using Triclosan
Triclosan is found in soaps (0.10-1.00%), deodorants, toothpastes, shaving creams, mouth
washes and cleaning supplies... Triclosan has been shown to be effective in reducing and
controlling bacterial contamination on the hands and on treated products.
Figure 2-4: Some commercial products using Triclosan
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2.3.3.2. Health concerns
Reports have suggested that Triclosan can combine with chlorine in tap water to form
chloroform gas, which the United States Environmental Protection Agency classifies as a
probable human carcinogen. As a result, Triclosan was the target of a UK cancer alert.
Triclosan reacts with the free chlorine in tap water to also produce lesser amounts of other
compounds, like 2,4-dichlorophenol. Most of these intermediates convert into dioxins upon
exposure to UV radiation (from the sun or other sources). Although small amounts of dioxins
are produced, there is a great deal of concern over this effect because some dioxins are
extremely toxic and are very potent endocrine disruptors. They are also chemically very
stable, so that they are eliminated from the body very slowly (they can bio-accumulate to
dangerous levels), and they persist in the environment for a very long time. [16]
For long-time, chemical anti-bacterial agents have used popularly in hygienic products. They
have promoted their positive ability and contributed to protect our health. Nowadays, because
of the strict environmental requirement in industrial production and discovery of anti-
bacterial agent’s weak points, it is necessary to find out a new kind of anti-bacterial agent,
which friendlier with environment and safer for our health, can replace chemical anti-
bacterial agents. One of these trends is taking interest in natural essential oil.
2.4. ESSENTIAL OILS
For hundreds years, essential oils have been referred to a natural treasure. They have been
used as a therapeutic method, health care and making beauty. In the middle of 19 th century,
essential oils were focused on research and became a total therapeutic method, which have
been popularized at many countries as China, Korea, Japan, U.K and France …
Scientists estimated that essential oils have the power and vitality, which stronger 100 times
than dried medicinal herbs. However, essential oil content of plant is very little. To have 10
ml of essential oil, we have to extract from many kinds of the same plants and maintain
carefully. The essential oils of medicinal herbs have no any toxins and chemical preservative
substances, so they are completely pure.
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2.4.1. Value of essential oils
For long time ago, essential oils have been used to take care of health and beauty. Nowadays,
beauty products, which content essential oils, are sold popularly. Some kinds of essential oils
treat xeroderma and make hair smooth and strong. They are also relaxant and moisten agent
for dry skin, especially it can deodorize body’s odor…
Besides, essential oils are also good for health. They are useful for breathing and circulation
of blood, intensifying and supporting the action of digestive system, keeping blood circulate
to the surface of skin.
In addition, essential oils help body and skin excrete toxin, get a healthy body and a good
skin. They also make our nervous system, endocrine system and immune system operate
well, balance mental sense, help us relax, reduce stress, headache, anxiousness and sadness.
Some kinds of essential oil that are common and easy to find out in Vietnam will be mention
in followed part:
2.4.1.1. Lemon
Lemon is a flowering plant, originated from the tropics and the subtropical regions as North
Africa, South America, China, India and Southeast Asia…
Lemon’s essential oil contents 90% of limonene, terpinene, phellandrene and pinene; 4-6% of
aldehyde converted to citral. Besides, there are others as citronellal, geranylacetat and
sesquiterpene.
Main contents of essential oil of lemon’s leaves are aldehyde: neral (7.6-22.5%), geranial
(14.5-31.8%), citronellal (1.9-3.7%); alcols: linalol, nonanol, geraniol, nerol (3.3-10.5%) and
esters of these alcols (>10%). [1]
Using lemon’s essential oil for massage reduces congestion and blister. Its odor makes low
blood pressure and lessens stress. This essential oil is a good disinfectant, cleans died cells
and brings a clean skin, improves the small bloodlines that are broken on our face’s skin.
Using it for fumigation gets temperature down; treats influenza, headache and makes you
comfortable.
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In cosmetic products, the lemon odor is used in toothpastes, mouthwash… In addition, it is
used as aromatizer in cream, powder and specially skin lotion…[17]
2.4.1.2. Lemon Eucalyptus
Lemon Eucalyptus is planted in Brazil, Guatemala, Seychelles... In Vietnam, they are planted
in South
Essential oil of Lemon Eucalyptus is volatile and recovered from fresh leaves by steam
distillation. This essential oil contents 70-75% of citronellal, 13% of isopulegol and 5-6% of
citronellol. Besides, it has geraniol, β-caryophylen, citronellyl acetate, cineol, terpineol and
pinen. [8]
With pasteurize and deodorize ability, this essential oil is used to clean air, prevent from
infectious diseases. This odor can drive mosquitoes away, so these trees are planted in
swamps to improve environment, decrease paludism. In addition, it is used to steam when
catch a chill, its smell makes our sense comfortable. Massage with this essential oil reduces
rheumatism, arthritis and increases blood’s volume to the massaged region. [17]
In field of aromatizer, Lemon Eucalyptus essential oil is used much to procedure perfume and
aromatic substances have natural odor.
2.4.1.3. Citronella
Citronella has 120 species, are planted popularly in tropics and subtropics as countries in
Asia and Africa. Citronella are planted in spring and harvested after 5-6 months.
On market, Citronella oils are classified into two chemotypes:
Ceylon type (obtained from Cymbopogon nardus Rendle) consists of geraniol (18-
20%), limonene (9-11%), methyl isoeugenol (7-11%), citronellol (6-8%), and
citronellal (5-15%).[1]
Java type (obtained from Cymbopogon winterianus Jowitt) consists of citronellal
(32-45%), geraniol (11-13%), geranyl acetate (3-8%), limonene (1-4%). The higher
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proportions of geraniol and citronellal in the Java type make it a better source for
perfumery derivatives... [1]
Citronella’s essential oil has therapeutic properties as an antiseptic, deodorant, insecticide,
parasitic. It is also role as tonic and stimulant. It will also be contained in soaps and candles
and has common applications in massage. This essential oil can help with minor infection,
but it is more commonly known for ability to assist in combating colds and flu. Citronella can
also be used for excessive perspiration and for conditioning oily skin and hair. [17]
2.4.1.4. Betel
The Betel was planted initially at South and South East Asia (India, Srilanka, Vietnam and
Malaysia…)… This is a spice whose leaves have medicinal properties.
The active ingredients of betel oil, which is obtained from the leaves, are primarily a class of
allylbenzene compounds. Though particular emphasis has been placed on chavibetol (betel-
phenol; 3-hydroxy-4-methoxyallylbenzene), it also contains chavicol (p-allyl-phenol; 4-allyl-
phenol), estragole (p-allyl-anisole; 4-methoxy-allylbenzene), eugenol (allylguaiacol; 4-
hydroxy-3-methoxy-allylbenzene; 2-methoxy-4-allyl-phenol), methyl eugenol (eugenol
methyl ether; 3,4-dimethoxy-allylbenzene) and hydroxycatechol (2,4-dihydroxy-
allylbenzene). [8]
Betel is used to cure worms. According to traditional, chewing areca nut and betel leaf is a
good remedy against bad breath. They are also used to treat headaches, arthritis, relieve
toothache, harden the gums, preserve the teeth, sweeten the breath and improve voice. They
are used specifically as being stimulating, carminative, aromatic and antiseptic. [17]
Essential oil of Betel leaf can also be used in soap, lotions, massage oils, pot-pourri, scent, air
fresheners, body fragrance, perfume oils, aromatherapy products, bath oils, towel scenting,
spa's, incense, light rings, laundry, facial steams, hair treatments and more… [17]
2.4.1.5. Curcuma
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Curcumas are grown popularly in South Asia as India, Bangladesh, Taiwan and China…
There are 18 kinds of curcumas in Vietnam. Some of them have researched, some are
mentioned but unsearchable. Otherwise, some are found out but non- identify.
Curcuma content mainly water, essential oil and Curcuminoids compound. The most active
component in curcuma is Curcumin- element makes color in curcuma, aroma and flovour.
Curcuminoids and curcumin make Curcuma’s biological activity. [8]
Curcuma is known with a lot of various values; especially in India and many countries, it is
used as drugs to treat all diseases. Curcumin is a substance is strongest to destroy cancer’s
cell.
In food industry, Curcumin is used to get color of food, prevent from oxidation. Curcuma’s
powder is bitter and peppering, has mustard’s smell and used as flavoring.
In cosmetic products, Curcuma is used for skin and hair. It can remove freckles, prevent
wrinkles, alopecia, obeseness, make beautiful skin; harmonize air, cure scalds and protect
skin from harmful sunshine …[17]
In general, the natural material sources that are recommended above are very familiar. They
are used for a long time as popular drugs with good biological activity, do not cause damage
for our health and can take place of the chemical substances.
Furthermore, these above materials are easy to find out and cheap. Using these materials so
help develop agricultural regions, get profit for Vietnam economy.
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Java Citronella Lemongrass
Figure 2-5: Some popular materials of essential oils in Vietnam
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2.4.2. Essential oil separation
Depending on kinds of material and condition, essential oils can be separated by various
methods.
Some requirements of essential oil’s separation:
- Essential oils are kept the original natural odor.
- Methods are suitable, easy and fast.
- Essential oils are separated thoroughly. In producing, the less essential oils
content of residue are, the better they get
- The original cost of producing is at least
Some common methods of essential oil’s separation:
2.4.2.1. Expression
Most citrus peel oils are expressed mechanically or cold-pressed. Due to the large quantities
of oil in citrus peel and the relatively low cost to grow and harvest the raw materials, citrus-
fruit oils are cheaper than most other essential oils. Lemon or sweet orange oils that are
obtained as by-products of the citrus industry are even cheaper. [1]
2.4.2.2. Solvent extraction
Most flowers contain too little volatile oil to undergo expression and their chemical
components are too delicate and easily denatured by the high heat used in steam distillation.
Instead, a solvent such as hexane or supercritical carbon dioxide is used to extract the oils.
Extracts from hexane and other hydrophobic solvent are called concretes, which is a mixture
of essential oil, waxes, resins, and other lipophilic (oil soluble) plant material. Another
solvent, often ethyl alcohol, which only dissolves the fragrant low-molecular weight
compounds, is used to extract the fragrant oil from the concrete. The alcohol is removed by a
second distillation, leaving behind the absolute.
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Supercritical carbon dioxide is used as a solvent in supercritical fluid extraction. This method
has many benefits, including avoiding petrochemical residues in the product and the loss of
some “top notes” when steam distillation is used. It does not yield an absolute directly. The
supercritical carbon dioxide will extract both the waxes and the essential oils that make up
the concrete.[1] [17]
2.4.2.3. Distillation
Today, most common essential oils, such as lavender, peppermint and eucalyptus… are
distilled. Raw plant material, consisting of the flowers, leaves, wood, bark, roots, seeds, or
peel, is put into an alembic (distillation apparatus) over water. As the water is heated the
steam passes through the plant material, vaporizing the volatile compounds. The vapors flow
through a coil where they condense back to liquid, which is then collected in the receiving
vessel.
The recondensed water is referred to as a hydrosol, hydrolat, herbal distillate or plant water
essence, which may be sold as another fragrant product. Popular hydrosols are rose water,
lavender water, lemon balm and orange blossom water. The use of herbal distillates in
cosmetics is increasing. [1]
2.4.3. Some matters when using essential oil
Because of their concentrated nature, essential oils generally should not be applied directly to
the skin in their undiluted or "neat" form. Some can cause severe irritation, or provoke an
allergic reaction. Instead, essential oils should be blended with vegetable-based "carrier" oil
before being applied. Common carrier oils include olive, almond, hazelnut and grape seed.
Only neutral oils should be used. [17]
Some essential oils, including many of the citrus peel oils, are photo-sensitizers (i.e.,
increasing the skin's vulnerability to sunlight, making it more likely to burn), are not used
directly under sunshine.
Industrial users of essential oils should consult the material safety data sheets (MSDS) to
determine the hazards and handling requirements of particular oils. Person, who used
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essential oils on the first time, should have a test within 24 h before using to avoid
stimulating on skin. [17]
In short, the natural essential oils with precious properties can take place of the common
antibacterial agents. The procedure is easy, less cost and do not cause environmental
pollution, concurrently it makes develop home agriculture. However, essential oil’s content is
very little , so that it is necessary to find out and choose a materials with good biological
activity, high content, easily find and available.
2.5. REVIEWS OF SOME PREVIOUS STUDIES
From some matters mentioned above, it can be seen that essential oils not only have similar
activity with the chemical synthetic agents but also be friendly with environment. Nowadays,
researching and applying essential oil to cosmetic is new tendency. There are many
researches at home and aboard about this precious materials.
In previous reviews, Dr. Le Ngoc Thach and his co-workers carried out research about
essential oil in the South of Vietnam. The research used some classical and modern methods
to extract, define chemical components and physiochemical factors of essential oils in area.
They separated out main components of essential oils to be used for feedstock of semi-
synthetic reactions. The research applied new organic synthetic methods as non-solvent, solid
carrier, microwave, ultrasound, enzyme, salt effect… for these semi-synthetic reactions to
protect environment and increase productivity of these reactors for a short time. The
biological activity of products was tested on anti-bacteria capacity, insect inducement and
stimulating the plant’s growth…
In addition, Dr. Nguyen Dinh Nga and her partners researched about anti-bacterial and anti-
fungus ability of some essential oil and extract of plants. Raw materials of the research were
periwinkles, gingers, piper lolots, turmerics, trunk and leaves of persicarias, alpinias and
betel’s leaves… which were extracted with ethanol, methanol solvents. Each of drugs,
essential oils and their mixture was separately tested on yeasts, moulds and cutaneous
funguses. According to the study, some results were got: six of ten antifungal drugs from
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Alpinias had effect on Aspergillus with MIC=12.5÷15.75mg drug/ml, on Candida albicans
with MIC=40mg drug/ml. Other essential oils affected mainly on cutaneous fungus.
Ability of essential oil has also researched widely on aboard, such as research about Effects of
Citrus essential oil on growth and morphogenesis of Aspergillus niger (L.)Osbeck of Neeta
Sharma, University of Lucknow, India. The research showed that the essential oils had anti-
microbial activity, especially effects on growth and morphogenesis of Aspergillus. The
fungitoxicity of oil did not change even at exposure to 100 °C and autoclaving. The main
changes observed under light and scanning electron microscopy after oil treatment were loss
of cytoplasm in fungal hyphae, and budding of hyphal tip. The hyphal wall and its diameter
became markedly thinner, distorted and resulted in cell wall disruption. The flattened and
empty hyphal tips bifurcated into bud like structures. GC-MS studies of the oil revealed the
presence of 10 chemical constituents. Limonene has been found to be major component
(84.2%).[20]
Value of citrus peels essential oil was proved by Medvedev. The invention related to
composition comprising an activated citrus peel extract (ACPE) prepared by an activation
method which includes exposure of citrus peels to at least one plant or animal pathogen. The
ACPE comprises at least one of the following: oligosaccharides, short peptides, flavonoid
glycosides, fatty acids, and triglycerides. Compositions comprising the ACPE have been
shown useful as dermatological compositions for the treatment of various skin conditions.
They have also been shown to be useful in preserving food, beverages and cosmetics. [20]
Overall, there have been many researches about essential oil separation and have many
valuable evidences about their good effects for our health. With these precious properties,
essential oils have been researching to add to many products, especially cosmetics and
personal care products.
Products, with essential oil contents, have more dominant effect than products with synthetic
chemical substances. Nowadays, through many home and aboard researches, applying
essential oils to products is very popular. This is the new tendency of cosmetic industry to
make cosmetics, which are not only good for health but also friendly with environment.
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2.6. HAND CLEANER PRODUCTS
Keeping hand clean is important to prevent some dangerous diseases that are caused by
bacteria. Now, many hand cleaners have been produced to keep hand clean. This part will
discuss some notes when washing hands and some matters of hand cleaner.
2.6.1. Some matters about washing hands
Our hands have billions of bacteria, each time we shake hands with somebody or touch any
thing as door handle, faucet… hands surely are contaminated bacteria. Thus, easy way to
protect our body is washing hands frequently.
Figure 2-6: Many bacteria on hands
Hands are never sterilized completely even if we apply any way to wash hands. If we wash
hands too many times, there also will a few bacteria on hands. The purpose of washing hands
is cleanup visible and invisible dirty. Thus, in below cases, you should wash hands:
- Before and after eating.
- Before washing your eyes and nasal line.
- Before repairing the meal.
- Before and after taking care of babies, example: changing diapers…
- Before and after caring for sores
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- Before and after getting in touch with patients
- Before and after doing an unclean work, as doing the garden…
- After going to the toilette
- After getting in touch with animal or dirty things, as cats, dogs, faucets and door
block…
There are two ways of cleaning hands: using water and soap; using hand cleaners content
alcohol and unwanted water (alcohol-based hand sanitizer).
Cleaning hands uses water and soap
Many people think that it is unnecessary to study the way of washing hands because it is very
easy. Nevertheless, if you want to wash hands effectively, you will notice some points:
- To put hands into warm water faucet, rub soap into the hollows of our hands to make
foam
- To rub time and again two hands carefully about 10-15s
- To rub everywhere on hands, especially reverse side and among fingers as well as
nails
- To wash carefully by water
- To dry by clean handkerchief
- When using public toilet, you should not use our clean hands (hands after washing) to
turn off the water tap. You should dry hands and use tissue to block the water tap.
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Figure 2-7: Six steps to wash hands
Cleaning hands by alcohol based hand sanitizers, unwanted water
In recent years, hand cleaners with alcohol that do not need to wash again by water are used
more popularly. A little hand cleaner are put into hands, rub repeatedly two hands carefully
until hands dry. Reading carefully directions for use before using
However, if your hands are too dirty to can see clearly dirt, you should use soap and water to
clean hands instead of using these products.
2.6.2. Some hand cleaners on market
Nowadays, there are more and more specialized products for cleaning hands on market. Most
of customers take interest in them not only cheap, high quality but also easy to use
Although imported products were present at market earliest, but recently, home products that
made in Vietnam have been held 1/3 of total number. According to Maximark supermarket
and Minimark Super Bowl supermarket, there are 70% Vietnam’s hand cleaner products sold
every week.
The main components of hand cleaner include mandatory substances are surfactants, anti-
bacteria agents…to deodorize and resist to bacteria. Besides, there are others to get odor,
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smoothness. In Handsoap product of Singapore is added to vegetable extracts, makes fragrant
odor, aloe extracts makes cool skin. Lifebuoy with milk extract makes nourish hand skin.
Linen Rose of U.K has neutral pH ratio, keep natural acid film on skin to protect skin from
bacteria…
Figure 2-8: Some hand cleaner products on market
2.6.3. Some formulae of hand cleaners
Any hand cleaner have three main components:
- Surfactants: used for cleanness
- Main active substances: anti-bacterial agents, nutrients for hand skin…
- Additions: preservative substance, pH correct substance, coloring matter and
odor…
Some formulas of hand cleaner:
Formula 1: Antibacterial Hand wash [10]
Ingredients Wt %
- Water 44.3
- Ammonium Lauryl Sulfate (28%) 23.0
- Sodium Laureth-2 Sulfate (26%) 21.5
- Promidium CO 3.5
- Monateric LMAB 3.0
- Phospholipid CDM 2.5
- Pricerine 9083 1.0
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- Triclosan 0.2
- Monamate RMEA-40 0.7
- Disodium EDTA 0.2
- Citric acid 0.1
Formula 2: Clear liquid hand soap with suspended mineral oil beads [10]
Ingredient Wt%
- Water 68.0
- Carbopol ETD 2020 0.9
- Glyceryl 2.0
- Triethanolamine (30%) 0.2
- Ammonium lauryl sulfate (40%) 20.0
- Lauryl ether sulfosuccinate 2.0
- Disodium EDTA 0.1
- Propylene glycol 2.0
- Triclosan 0.5
- DMDM hydantoin 0.7
- Triethanolamine 0.6
- Cocamidopropyl betain (35%) 2.0
- Mineral oil beads 1.0
In short, washing hands is simple but helps us prevent from many deadly diseases. To get
result on washing hands, we should notice some above notes. Today, many hand cleaner have
supplied for washing hands. Besides imported products, home products have been more and
more popular with customers. There are various kinds of hand cleaners (lotion, creams or
milk…) with various ingredients (essential oils, mineral oils…) can satisfied multiform
demands of customers.
With above matters, this chapter supplied basic knowledge for me to determine object and
orientation of my thesis.
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3. CHAPTER 3
4. OBJECTIVES &
EXPERIMENTIAL ORIENTATION
3. When living standard of people is increasing, high hygienic standard are also required. This is
good condition for developing of hygienic products, include products for washing hands. As
summary in Chapter 2, it can be seen that chemical anti-bacteria agents have been used more
and more. This is long-term hazard for customer heath. So, this is necessary to find out
substances can take place of chemical anti-bacteria agents which not only friendlier with
environment but also safer for human heath. Natural essential oils with high anti-microbial
activity are one of choices for hygienic products in future.
From this real requirement, this thesis is focused on studying and forming a hand cleaner
formula which using essential oils as anti-bacteria agents. This formula needs to satisfy
requirements about hygienic standards, suitable process and low cost. Besides, essential oils
require high activity and are popular in Vietnam.
With above requirements, the experimental orientation of my thesis was as followed:
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Characteristic
Stability
Characteristic
Anti-bacteria
capacity
Chance of joining market
Final product
Evaluating semi-product
Preparing final-product
Evaluating final product
Preparing materials
of essential oil
Distillating essential oil
Evaluating essential oil
Essential oil
Initial formula
Investigating effect of components
Semi-formula
Preparing semi-product
Main surfactant
Thickener
Semi-product
Figure 3-1: Experimental orientation of this thesis
Anti-bacteria agents
(Essential oils/Triclosan)
Essential oils
Evaluating essential
oils
Distillating essential
oils
Preparing materials of
essential oils
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CHAPTER 4
EXPERIMENTALS
4. This chapter presents initial materials, methods, equipment and instrumental procedures
for making up a basic formula, distillation of essential oil and surveying combination of
essential oil with the basic formula.
4.1. MATERIALS AND EQUIPMENT
4.1.1. Materials
From selections, ingredients of basic formulae could be proposed as follows:
Table 4-1: Components of basic formula and their utility
Ingredients Original resources Utility
Distilled Water Distilled water at lab Dispersed phase
Sodium lauryl sulfate (SLS)
Commercial product
(from Kim Bien
market)
Primary surfactant
Cocamido propyl betain (CAPB) 30% Secondary surfactant
Carbopol aqua or Carboxy methyl
cellulose (CMC) Thickener
Triethanolamine (TEA) Neutralizer
Coconut Diethanolamine (CDE) Co-surfactant and
thickener
Ethanol Freshcolate & anti-
bacterial agent
Glycerin Humectant
4.1.2. Equipment
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Because of equipment limitation, this thesis was carried out with followed equipment of
laboratory:
Electric stirrer: Stuart Scientific SS10 (made in UK) and glass stirring blade
Viscometer: Zahn cup number 3 with code CNDB-3 and Zahn cup number 5 with
code CNDB-5 (made in China).
Figure 4-1: Zahn cup
Spectrophotometer: Herios Epsilon VIS.
Centrifuge: Hermle Z200A.
Bacteria counting chambers: Petroff-Hausser (made in Germany).
Figure 4-2: Bacteria counting chambers
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Indirect steam distillating system at high pressure.
Figure 4-3: Indirect steam distillating system
Beakers, gage glasses, pycnometer, two numbers scale and four numbers scale…
With above materials and equipment, procedure of preparing products is presented in next
parts.
4.2. METHODS
This part presents methods which used in experimental.
Measuring viscosity of liquid
Zahn cup is used to determine viscosity of liquid products. Each cup has a 12- inch loop
handle to allow the cup to be dipped by hand into a liquid container. At the center of this
handle is a finger-ring for holding the cup in a vertical position during use.
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The cup was been sink in product. It was lifted slowly. When lip of cup just left the free
surface of liquid, time that liquid get out the cup completely was counted. Then, time was
compared with data of Viscosity Conversion Chart to determine the viscosity of liquid.
Table 4-2: Viscosity conversion chart for Zahn cup number 3 and Zahn cup number 5
Viscosity (Centipoise)
Time (second)
Zahn 3 Zahn 5
90 10
100 12
120 14
140 16
160 18
180 20
200 23 10
220 25 11
240 28 12
260 30 13
280 32 14
300 34 15
320 36 16
340 39 17
360 41 18
380 43 19
400 46 20
420 48 21
440 50 22
460 52 23
480 54 24
500 57 25
550 63 27
600 68 30
700 35
800 40
900 45
1000 49
1100 55
Measuring turbidity of liquid
Turbidity of liquid was measured by using Herios Epsilon VIS spectrophotometer. Turbidity
of sample was determined at λ = 546nm with blank solution was water.
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Surveying effect of shocking on properties of sample by using Centrifuge Hermle
Z200A.
This machine could control speed and time. In this thesis, samples were contained in
centrifuge tubes and surveyed at 3000 rpm within 10-50minutes.
Measuring density of liquid: using a 10ml pycnometer
Evaluating pH index: using pH meter
A little liquid was dropped on pH paper. Then, color of pH paper was compared to
chromaticity diagram to estimate pH index of liquid.
Counting quantity of microbe: by using Bacteria counting chambers
This equipment had two 3millimeters squares on two sides. Each square was divided into 5
groups as followed Figure 4-4
Firstly, a bowl of sterilized water was prepared. Hand of a test people was washed within 30s.
Then, hand was dipped in the bowl within 30s.
After that, a little water in the bowl was dropped on one of two 3millimeters squares of
Bacteria counting chambers and observed by Microscope to count quantity of microbe on the
central square millimeter
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Figure 4-4: Zoom in image of Bacteria counting chambers
Distillating essential oils: by using Indirect steam distillating system at high pressure.
Steam from pressure tank came to material tank and pulled essential oil out. Steam and
essential oil were evaporated and condensed by pipe cooler. Essential oil was upper and
separated. Water was circulated to take all remain essential oil.
Surveying effect of main surfactant to property of product
To evaluate the ratio of SLS 30%, four factors were examined as follows:
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Table 4-3: Evaluated factors of evaluating product and their ratio (mi)
Evaluated factor mi (%)
Coolness 25
Foaming capacity 25
Cleansing power 25
Washout rate 25
Factors were evaluated by points range as Table 4-4
Table 4-4: Points range of evaluating product
Rate of evaluation Point Symbol
Very good 5 ++
Good 4 +
Satisfy 3 0
Bad 2 _
Very bad 1 _ _
Four factors were evaluated as follows:
Coolness: A little of sample was put on wet hands. Hands were rubbed and washed.
Rate of coolness needed to be felt in all process.
Making cool None making cool
0 + -
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Foaming capacity
- Preparing five glass tubes
- Adding 2ml of H2O and 0.02ml of sample to each tube
- Shaking tubes within 30s
-Measuring height of foam column on top of tubes
Cleaning power: A little of sample was put on wet hands. Hands were rubbed and
washed. Cleanness of hands was evaluated after washing.
Washout rate: A little of sample was put on wet hands. Hands were rubbed and
washed. Time and quantity of water which were used to reach feeling about cleanness
were evaluated.
Easy Hard
0 + -
clean unclean
0 + -
0
A lot of foam A little foam
+ -
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Surveying the viewpoint of customers about final products
Table 4-5: The questionnaire to surveying viewpoint of customers about products
Criterions SP1 SP2 SP3
1. Cleansed
capacity
A. Clean
B. Normal
C. Not clean
A. Wash out quickly
B. Wash out lowly
2. Foaming
capacity
A. Numerous, fine foam
B. Numerous, big foam
C. A bit of foam
3. Odor
A. Fragrant, make comfortable
B. Normal
C. Pungent, make uncomfortable
4. Feelling after
using
A. Smooth skin, make comfortable
B. Normal
C. Make dry skin, uncomfortable
5. Skin irritation
A. Not make irritate
B. Make irritate
6. Acceptance A. Accept
B. Not accept
Surveyed people chose only one answer for a question. The answers were converted to
points, as follows:
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- The question had three
selections:
+ choosing the answer A: 5 points
+ choosing the answer B: 3 points
+ choosing the answer C: 1 point
- The question had two
selections:
+ choosing the answer A: 5 points
+ choosing the answer B: 1 point
There are all methods were used in experimental. The followed part will present procedure to
form a hand cleaner.
4.3. PREPARING SEMI-FORMULA
This study was carried out at Organic Chemical Engineering Department, Hochiminh City
University of Technology.
4.3.1. General procedure for preparation of hand cleaner
The preparation of the hand cleaner product is presented in Figure 4-5
Firstly, SLS was dissolved in water at 70oC and stirred until SLS dissolved completely. Then,
solution cooled down to room temperature. Water, Ethanol, CDE and Cocamide propyl
betain were added in SLS solution and stirred at room temperature at rate of 750rpm until
reaching homogeneous. After that, thickener was added in solution. If Carbopol aqua was
used as thickener, TEA would gradually drop to neutralize Carbopol solution. The mixture
was stirred until it turned transparent.
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Figure 4-5: Procedure for preparation of hand cleaner product
4.3.2. Effect of components in semi-formula
In this part, the studies focused on effects of main surfactant and thickener on characteristics
of products.
Main surfactant: Sodium lauryl sulfate (SLS)
Five samples were prepared as follows:
Stirring
SLS Water
Water CDE
CAPB 30%
Ethanol
Semi-product
SLS solution 30%
Stirring
Stirring
Stirring
Stirring
Stirring
Thickener
Stirring TEA (if
using
Carbop
ol as
thicken
er)
to=70oC
Room temperature
Speed of stirring: 750rpm
Time: 15 minutes
TEA (if using Carbopol as thickener)
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Table 4-6: Formulae for investigating effect of SLS material
Ingredients Sample 1 Sample 2 Sample 3 Sample 4 Sample 5
SLS (% wt) 5.0 7.5 10.0 12.5 15.0
CAPB 1.00
CDE 0.06
Ethanol 2.00
Glycerin 1.00
H2O (% wt) to 100
Each sample was investigated four factors: coolness, cleaning power, foaming capacity and
washout rate. These tests were evaluated by the evaluating system which was presented in
Section 4.2
Thickener
With each thickener, five samples with five different ratio of thickener were prepared
Table 4-7: Formulae for investigating effect of Carbopol aqua material
%wt Sample 1 Sample 2 Sample 3 Sample 4 Sample 5
Carbopol aqua 30% 5.0 5.5 6.0 6.5 7.0
TEA 1.0 1.1 1.2 1.3 1.4
Water To 100
Table 4-8: Formulae for investigating effect of CMC material
% wt Sample 1 Sample 2 Sample 3 Sample 4 Sample 5
CMC 5.0 5.5 6.0 6.5 7.5
Water To 100
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Each sample was measured viscosity by using a Zahn cup and compared to a target product
(The targeted product was “Dr. Clean” hand cleaner, a commercial product). After 3 days,
viscosity of each sample was measured again for evaluating durability.
After determining semi-formula and preparing semi-product, the nest task was evaluating
semi-product and comparing it to a targeted product.
4.3.3. Preparing and evaluating semi-product
From previous results, the basic formula was obtained. It is used to prepare the semi product.
The semi-product was evaluated stability against temperature and shocking and compared to
a targeted product.
Targeted product: “Dr.Clean hand cleaner”
Table 4-9: The targeted product and its ingredients
Ingredients
Water, Sodium Laureth Sulfate,
Glycerin, Cocaamide propyl betain,
Coamide DEA, PEG-7, Glyceryl,
Cocoate, Fragrance, Polysorbate 20,
Triclosan,
Methylcloroisothiazolinone and
Methylisothiazolinone
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Effect of temperature on property of semi- product
Seven samples of semi-product were left at seven different temperatures (30oC, 40oC, 50oC,
60oC, 70oC, 80oC and 90oC) for 30 minutes. After that, the samples were examined pH index,
viscosity, density and turbidity. Similar tests with the targeted product were carried out.
Effect of centrifugation on semi- product
Six samples of semi-product were left at 3000rpm for 0min, 10min, 30min, 40min and
50min. This test was carried out by using centrifugal. After that, the samples were examined
pH index, viscosity, density and turbidity. Similar tests with the targeted product were
carried out.
After having semi-product, the next task was preparing anti-bacteria agents for final products
4.4. DISTILLATING AND EVALUATING ESSENTIAL OIL
4.4.1. Distillating essential oil
Essential oils were extracted by indirect steam distillation at high pressure. Lemon’s peels
and leaves of lemongrass were cut into small pieces. Then, materials were distillated at
pressure of 2 atm.
Table 4-10: Materials for essential oil distillation
Material Source Used section Weight of each batch (g) Humidity (A%)
Lemon Tien Giang Peel 100 76.04
Lemongrass Long An Trunk and leaves 200 79.51
Procedure for isolating essential oil is shown in Figure 4-6
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Figure 4-6: Procedure for preparation of distillating essential oils
Separating
Dehydrating
Separating
Essential oil
Essential oils and water
Water
Raw essential oils
Na2SO4
Na2SO4.5H2O
Condensing
Separating
Water
Cutting
Distilling (P=2at, t=2h)
Raw materials
(Lemon &Lemongrass)
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4.4.2. Evaluating essential oils
After distillating, yield of distillation was calculated and essential oil was evaluated by
sensible evaluation about:
- Appearance & color: Essential oil was put on a transparent beaker and
observed about appearance, color and precipitate.
- Odor: essential oil was dropped into a filter paper and smelled about odor
(fragrant, pungent or uncomfortable…) and its intensity (mild or prolonged…).
- Density of essential oil: using pycnometer.
4.5. PREPARING FINAL PRODUCTS The last step was adding anti-bacteria agents (Triclosan or essential oils) into semi-product.
4.5.1. Preparing final product
To investigate effect of essential oil to anti-bacterial capacity of products, three serials of
final products were prepared as follows:
- SP1 with Triclosan
- SP2 with lemon essential oil
- SP3 with lemongrass essential oil
Preparing SP1
Triclosan was dissolved in ethanol first. Then, solution was added SLS, CAPB, CDE, water,
Carbopol aqua and TEA as Figure 4-5
Preparing SP2 and SP3
Two products had a similar process. Because essential oils were oxidized and decayed easily,
SP2 and SP3 were added methyl paraben (0.25%wt) and propyl paraben (0.25 %wt) as
preservative substance.
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Essential oils and preservative agents was added into solution included SLS, CAPB, CDE,
ethanol and water. After that, Carbopol aqua and TEA were added into mixture. Procedure
was similar with Figure 4-5.
4.5.2. Effect of anti-bacteria agents on activity of final products
General principle was counting quantity of bacteria after washing only by sterilized water and
compared with number of bacteria after washing by products. From there, the suitable content
was chosen. This survey was carried out at Bio-Technology Laboratory.
Each serial of product SP1, SP2 and SP3 was prepared with seven different concentrations of
active agents:
Table 4-11: Serials of products to evaluating effect of anti-bacterial agents on activity of products
Sample 1 2 3 4 5 6 7
SP1 Triclosan
(%wt)
0.1 0.2 0.3 0.4 0.5 0.6 0.7
SP2 Lemon essential oil
(%wt)
0.1 0.2 0.3 0.4 0.5 0.6 0.7
SP3 Lemongrass essential oil
(%wt)
0.1 0.2 0.3 0.4 0.5 0.6 0.7
This test was carried out by using Bacterial counting chambers. After that, suitable ratio of
each anti-bacterial agent for each product was chosen.
Each chosen sample was counted again quantity of bacteria once a week within three weeks
to investigating effect of time on stability of active agents.
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4.6. EVALUATING FINAL PRODUCTS
This part would evaluate characteristics and chance to join market of final products.
4.6.1. Evaluating characteristics of final products
Each final product was evaluated about: density, viscosity, pH, color, odor and quantity of
bacteria (tested on Candida albicans, S.aureus and Aerophil in Institute Pasteur).
4.6.2. Evaluating commercial ability of final products
Evaluating final products based on viewpoint of customers and price in comparison to
products on the market.
4.6.2.1. Surveying viewpoint of customers about products
Sensible tests were executed to determine feeling of customers for SP1, SP2 and SP3. These
tests based on feeling of customers to evaluate pleasance, acceptance and enjoyment.
Products were evaluated 6 criterions by 30 customers (both men and women). The
questionnaire with selective questions was presented in Section 4-2. Result was converted to
points and determined the pleasance, acceptance of customers. The point was as high as well.
4.6.2.2. Preliminary estimating price of products
From price of materials and their ratio in products, the price of products was estimated. After
that, the products were reduced a finish product unit which its volume similar with
commercial products and compared price with commercial products.
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Table 4-12: Price of materials
Substances Price/weight
Distillated water 2,000VND/kg
SLS 45,000VND/kg
Carbopol aqua 127,000VND/kg
TEA 45,000VND/kg
Cocamide propyl betain 60,000VND/kg
Coconut Diethanolaamine 60,000VND/kg
Ethanol 16,000VND/kg
Triclosan 900,000VND/kg
Lemon’s essentisl oil 7,000,000VND/kg
Citronella’s essential oil 6,500,000VND/kg
Glycerin 20,000VND/kg
Methyl paraben 1,100,000VND/kg
Propyl paraben 1,000,000VND/kg
Table 4-13: Price of some hand cleaners on market
Some marked products Volume of a unit Price
Hand cleaner Dr. Clean 500ml 32,500VND
Hand cleaner Lifebouy 200ml 11,000VND
Hand cleaner Linen Rose 500ml 39,600VND
Hand cleaner Hand soap 250ml 24,000VND
Hand cleaner Pril 375ml 28,500VND
Hand cleaner Kleen 320ml 20,500VND
There are all experimental of thesis. Results of above tests are presented in next chapter
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CHAPTER 5
RESULTS AND DISCUSSION
5. This chapter represents results of those above studying and discussed phenomenon
occurred when surveying.
5.1. PREPARING AND EVALUATING SEMI FORMULA
5.1.1. Preparing semi-formula
5.1.1.1. Effect of components in semi-formula
Main surfactant and thickener were most important components in basic formula. They
affected on cleaning power, foaming capacity and thickness of product
Effect of SLS
After surveyed four factors: coolness, foaming capacity, cleaned power and washout rate of
five samples, result was got as follows:
Table 5-1: Result of surveying ratio of SLS
Target standard mi(%) Sample 1 Sample 2 Sample 3 Sample 4 Sample 5
Coolness 25 + + + + +
Foaming capacity 25 _ + ++ ++ ++
Cleaned power 25 _ _ ++ ++ ++
Washout rate 25 ++ + + _ _ _
Sum of points 325 350 450 400 375
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The main surfactant was the most important agent in any cleaned product. It influenced on
cleaning power of product at most. If fraction of main surfactant were low, cleaning power
would be obviously weak. Otherwise, high fraction of main surfactant was waste, made
difficulty and greasy feeling when washing out.
With the above result, sample 3 with 10 %wt of SLS had the highest scores. So, that was the
suitable ratio of main surfactant in basic formula.
Effect of thickener
Content of thickener was very important. It influenced on homogeny, thickness and durability
of product. If fraction of thickener were low, product would be watery and non-durable.
Furthermore, the watery product also affected to the sense organs of customers, it made
customers feel that cleaning power of product was weak.
Thus, the thickness of product was chosen a suitable value to guarantee durability, homogeny
of product and accommodate to packing (for example: product could flow in container’s
faucet).
The result of viscosity of samples as follows:
Table 5-2: Viscosity of Carbopol aqua samples
Sample
1
Sample
2
Sample
3
Sample
4
Sample
5
Targeted
product
Carbopol aqua 30% (%wt) 5.0 5.5 6.0 6.5 7.0
Viscosity(cP) 310.18 367.26 418.6 476.42 548.15 417
Viscosity after 3 days (cP) 313.25 372.14 421.51 480.23 552.64
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Table 5-3: Viscosity of CMC samples
Sample
1
Sample
2
Sample
3
Sample
4
Sample
5
Targeted
product
CMC (%wt) 5.0 5.5 6.0 6.5 7.0
Viscosity (cP) 226.35 286.15 327.54 376.83 411.15 417
Viscosity after 3 days (cP) 197.83 251.16 296.34 328.67 382.82
According to Table 5-2 and Table 5-3, viscosity of sample 3 with 6.0%wt of Carbopol aqua
and sample 5 with 7.0%wt of CMC closed to targeted product.
But after 3 days, the viscosity of CMC decreased quickly. Meanwhile, the viscosity of
Carbopol aqua increased a bit. The reason was the different structure of each thickener.
Carbopol was a polymer with cross- link structure.
Figure 5-1: Cross- link structure of Carbopol polymer
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Thus, they made a stable three dimensional form when swelling in water. The viscosity of
Carbopol solution increased just because of evaporation of water.
Otherwise, CMC had a laminated structure
Figure 5-2: The two dimensional structure of CMC polymer
CMC formed a two dimensional structure when swelling in water. Besides, CMC was
derivation of cellulose, it was decayed by microbes easily. So, the viscosity of CMC solution
was lower than viscosity of Carbopol solution and its viscosity decreased follow time.
In short, Carbopol aqua was chosen as thickener with its suitable fraction was 6.0%wt.
5.1.1.2. Formulae of semi-product
With those results, ingredients of semi-formulae were as Table 5-4:
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Table 5-4: Formulae of semi-product
Ingredients Content
(%wt)
Sodium lauryl sulfate (SLS)
30%
33.33
Cocamide propyl betain
(CAPB) 30%
1.00
CDE 0.06
Glycerin 1.00
Ethanol 2.00
Carbopol aqua 30% 6.0
TEA 1.2
Water To 100
Beside SLS and Carbopol aqua, other agents had different roles to improve product.
- Cocoamide propyl betain (CAPB): was a synthetic surfactant derived from coconut
oil. It was a medium strength surfactant which most often does not irritate skin or
mucous membranes. It is compatible with other cationic, anionic, and nonionic
surfactants. So, the role of CAPB in this product was reducing irritation main
surfactants would cause.[18]
- Coconut Diethanolaamine (CDE): was a fatty acid of coconut oil. It was a nonionic
surfactant. In this product, its role was making mild the skin and stable foam. But, it
was used with a small quantity (0.06%) because of its high viscosity. With higher
volume, it could cause cloudy product and greasy felling when washout.[18]
- Glycerin: was used as humectants because of its three hydrophilic hydroxyl groups.
High volume of glycerin also could cause greasy felling when washout.
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- Ethanol: was co-surfactant which made product transparent. Besides, it also dissolved
Triclosan and essential oils and brought a cool felling when washing. But, the high
quantity of ethanol could cause dried skin after washing.
- TEA: neutralized Carbopol to make Carbopol swelled to maximum limit
Contents of above ingredients were chosen from documents and small experimental which
not mentioned in chapter 3.
The semi-product was very important. It was background to adding anti-bacterial agents.
After preparing the semi-product, the next task was evaluating the semi-product about its
stability against temperature and shocking.
5.1.2. Evaluating semi-formula
Some properties of semi- product at room temperature (30oC):
- That was an odorless and transparent liquid.
- Viscosity: 418.6cP
- Density: 1.0231 g/ml
- pH: 5-6
Because of equipment limitation, there were just surveying stability of semi-product against
temperature and shocking. Two effects were important because they helped manufacturer
chose the suitable storage condition and transportation to keep good state of product.
After surveying stability of the semi-product and the target product, the result was presented
as follows:
Effect of temperature on semi- product and target product
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Table 5-5: Temperature effect on semi-product and targeted product
Temperature
(oC)
Density
(g/ml)
Viscosity
(cP)
Turbidity
(Ao)
pH
Semi-
products
30 1.0231 418.59 0 5-6
40 1.0229 392.19 0.004 5-6
50 1.0221 363.55 0.013 5-6
60 1.0219 279.13 0.026 5-6
70 1.0167 217.64 0.054 5-6
80 1.0128 182.46 0.083 5-6
90 1.0118 152.36 0.112 5-6
Targeted
products
30 1.0219 428.86 0
5-6
40 1.0212 358.43 0.001
5-6
50 1.0168 236.85 0.006
5-6
60 1.0147 170.59 0.019
5-6
70 1.012 142.85 0.063
5-6
80 1.011 113.68 0.092
5-6
90 1.0097 95.329
0.107
5-6
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Targeted product and semi-product have a similar of pH, density, viscosity and turbidity.
When raising temperature, the density of both was decreased because of forming tiny foams
in liquid.
Figure 5-3: Temperature effect on density of products
According to Table 5-5 and Figure 5-3, we could see that:
- The semi-product: When temperature raised from 60oC to 70oC, its density became
changing much (from 1.0219g/ml at 60oC down to 1.0167g/ml at 70oC)
- The targeted product: period of temperature began to have large changing of density
was 40oC-50oC (from 1.0212g/ml at 40oC down to 1.0168g/ml at 50oC).
The reason was different thickener of each product. With targeted product, Cocoamide propyl
betain and Coamide DEA were also thickeners. Formula of these chemicals was
CH3(CH2)nC(=O)N(CH2CH2OH)2, where n can vary depending on the source of fatty acids.
The long length of carbon chains in the molecules made the thickener of product. Binding of
these chemicals and other ingredients of product was weak.
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In the other hand, Carbopol aqua was thickener of semi-product. The three dimensional
structure of Carbopol was more stable than others. So, semi-product could keep its state
better than targeted product when raising temperature.
However, temperature effect on density was not much and it wasn’t as important as
temperature effect on viscosity.
Figure 5-4: Temperature effect on viscosity of products
The viscosities of those products also were decreased when raising temperature. That is
suitable with Arrhenius model:
Where: T was temperature, μ0 was a coefficient, E was the activation energy and R was the
universal gas constant.
- Semi-product: period from 50oC to 60oC began to have a fast decreasing of
viscosity.
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-
- Targeted product: the viscosity began to have a fast decreasing when
temperature decreased from 40oC to 50oC
This phenomenon’s reason also was different thickeners of each product. The change of
viscosity was very important because it affected on sensible evaluation of customers.
Figure 5-5: Temperature effect on turbidity of products
Turbidity of products increased because of tiny bubbles in product. But, this change was
realized clearly at high temperature (over 70oC)
According above results, limit storage temperature of semi-product was 50oC and 40oC for
targeted product to maintain their state in good condition.
Effect of centrifugation on semi- product
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Table 5-6: Centrifugation effect on properties of semi-product and targeted product
Time of
centrifugation
(min)
Density
(g/ml)
Viscosity
(cP)
Turbidity
(Ao)
pH
Semi-
product
0 1.0231 418.59 0 5-6
10 1.0232 425.13 0 5-6
20 1.0233 431.56 0 5-6
30 1.0237 438.75 0 5-6
40 1.0240 441.69 0 5-6
50 1.0243 444.24 0 5-6
Targeted
product
0 1.0219 428.86 0 5-6
10 1.0221 436.67 0 5-6
20 1.0223 446.24 0 5-6
30 1.0224 455.58 0 5-6
40 1.0229 461.15 0 5-6
50 1.0232 467.12 0 5-6
Under centrifugation’s effect, density, viscosity of both products had a little change. Their
turbidity had no change.
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Figure 5-6: Centrifugation effect on density of products
Under centrifugation, molecules in solution were compressed that made volume of solution
was decreased. So, the density of both products was increased a bit. The difference of
thickener of each product caused density of targeted product changed more than semi-
product’s.
Figure 5-7: Centrifugation effect on viscosity of products
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Otherwise, viscosity of products was increased because of the compression of molecules in
solution. Follow time, compression was more increased, so density and viscosity of products
increased by time.
Temperature and shocking did not affect on pH. pH of products was 5-6 which was limitation
for skin safeness.
In short, the centrifugation’s effect did not make change the properties of products so much.
Thus, products could stand shock of transportation.
In conclusion, semi-product had similar physical characteristics with targeted product.
Besides, with three dimensional structure of Carbopol, semi-product could stand effect of
shocking and temperature better than targeted product. It was important background to mix
anti-bacterial agents afterwards.
5.2. DISTILLATING AND EVALUATING ESSENTIAL OIL
Indirect steam distillation could make good some weak points of direct steam distillation,
such as: avoid burning material, have good color and quality of essential oil…
Besides, this method could control and adjust pressure and flow of steam to raise yield of
distillation and quality of essential oil. However, too high pressure could destroy essential oil.
Thus, this was necessary to choose a suitable pressure of distillation.
According to some documents, major agent of lemon essential oils was 90% limonene with
boiling point was 176oC, lemongrass essential oil had 85-97% geraniol with boiling point was
229oC. So, the suitable pressure chosen was 2atm (about 120oC) to preserve those agents
from decaying.
Productivity of distillation and physiochemical properties of essential oils as follows:
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Table 5-7: Characteristics of Lemon and lemongrass essential oil
Lemongrass essential oil Lemon essential oil
Color Light yellow, transparent Light yellow, transparent
Odor Citronella odor Lemon odor
Average volume of
essential oil (ml)
0.7375
0.9625
Density (g/ml) 0.912 0.874
Yeild (weight of essential
oil/ weight of dried
material)
1.64%
3.51%
Figure 5-8: Lemongrass essential oil and lemon essential oil
Lemongrass essential oil Lemon essential oil
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Lemongrass essential oil:
During distillating, a non- desired phenomenon was some agent of essential oil dissolved into
water and caused losses essential oil (for example: solubility of Lina lool was 0.16g/100ml
water). To reduce this phenomenon, circulation of water was necessary.
However, some harmful agents of essential oil could be output. Borneol (a component of
citronella’s essential oil) was an eye, skin, and respiratory irritant; and was harmful if
swallowed. Density of Borneol was 1.011g/ml. So, it was got out essential oil and settled
down water. This was very useful when using lemongrass essential oil into skin product.
According to documents, density of this essential oil was 0.885-0.9g/ml [1] and yield of
distillation was 0.4-1.6%. But, in table 4-7, density and yield were higher than theory’s
because water mixed into essential oil. Essential oil had many hydroxyl functions. So, they
could make hydro binding with water and kept water into essential oil. Besides, a
shortcoming of study was non-absolute dehydrating. However, quantity of water mixed into
essential oil was little and didn’t affect on product when using this essential oil as anti-
bacteria agent.
Lemon essential oil:
The non-absolute dehydrating and hydro bindings of hydroxyl functions with water made
water mixed into essential oil. So, its density was higher than theory’s (0.849-0.855g/ml).
The same as citronella’s distillation, mixing into water and settling down water of some
agents were non-desired phenomenon and caused losses essential oil. According to
document, yield of distillation was 14.3-18.8% and higher than productivity of this study
so much. The reason was non-suitable method of distillation.
Lemon had a high content of essential oil. So, the suitable method was compression.
After compression, lemon was distillated to take all remain essential oil. Because of
equipment deprivation, the study only used distillation. Thus, the obtainable essential oil
wasn’t as more as compression.
Essential oils of lemon and lemongrass were stored at cold temperature.
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In conclusion, quantity of essential oil in material was very little and it was stored
carefully after extraction to avoid evaporation, decaying…That was drawback of using
essential oil in reality. Steam distillation was a simple method, low cost and suit with
locally production. But, this method wasn’t suit with all materials. Choosing suitable
pressure and steam flow was important to ensure quality and volume of essential oil.
5.3. PREPARING AND EVALUATING FINAL PRODUCTS
5.3.1. Preparing final products
Effect of anti-bacteria agents
Rate of number of remained bacteria when washing by sterilized water and using product was
displayed in below table
Table 5-8: Surveying the suitable fraction of anti-bacteria agents in final products
Rate of number of killed bacteria (%)
Sample Fraction of anti-bacteria
agent (%)
SP1 SP 2 SP 3
1 0.1 86.70 56.80 72.63
2 0.2 95.94 70.85 73.63
3 0.3 98.18 76.26 82.11
4 0.4 98.13 82.33 89.27
5 0.5 98.03 85.79 94.17
6 0.6 98.00 91.71 93.72
7 0.7 98.04 91.71 94.18
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Figure 5-9: Effect of anti-bacteria agents on the rate of killed bacteria
According to table 5-9, the suitable content of Triclosan in SP1 was 0.3%, 0.6% lemon
essential oil in SP2 and 0.5% lemongrass essential oil in SP3.
The bio-activity of SP1 was highest, the second was SP3 and the last was SP2. It means
Triclosan had best bio-activity, at 0.3% wt, it could kill 98.18% bacteria. This was a strong
point of synthetic anti-bacteria agents. Thus, manufactures usually use them in almost
hygienic products.
Anti-bacteria capacity of lemongrass essential oil was better than lemon’s essential oil’s.
Although both essential oils were used with higher contents than Triclosan, their anti-bacteria
capacity were lower than Triclosan. Concentration of essential oils could not rise because the
higher concentration of essential oils caused irritation for skin. This was another weak point
of essential oil when using in personal care products.
After choosing the suitable concentration of anti-bacteria agents for three products, they were
surveyed effect of time on bio-activity. The result was presented as follows:
(%)
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Table 5-9: Effect of time on anti-bacteria capacity of products
Ratio of number of killed bacteria (%)
Week 1 Week 2 Week 3 Week 4
SP1(with 0.3% Triclsan) 98.18 98.05 97.57 98.41
SP2 (with 0.6% lemon’s essential oil) 91.71 86.63 79.48 75.40
SP3 (with 0.5% citronella’s essential oil) 94.17 87.50 85.15 79.59
Figure 5-10: Time effect on bio-activity of final products
While the activity of SP1 almost not changed, the bio-activity of SP2 and SP3 decreased
follow time. When storing SP2 and SP3, a part of essential oils at surface evaporated and a
another part could be decayed by microbe or sunlight…That caused the concentration of
essential oils in SP2 and SP3 decreased, so the activity of SP2 and SP3 also decreased follow
time.
Essential oils could been wrap into polymer bag to protect them from loosing and maintain
bio-activity of products
(%)
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In short, bio-activity of SP1 was higher than SP2 and SP3. Besides, the bio-activity of SP2
and SP3 was decreased follow time because of lighting and microbe…So, SP2 and SP3 were
storage carefully. That was a limitation of nature essential oil as compare with chemical
synthetic substances.
5.3.2. Evaluating final products
After choosing the suitable contents of anti-bacterial agent for each product, the final
products were prepared. After that, they were evaluated about characteristics and commercial
ability.
5.3.2.1. Evaluating characteristics of final products
Table 5-10: Characteristics of three final products Characteristics S1
(Triclosan)
S2
(lemon essential oil)
S3
(lemongrass essential
oil)
Color & odor Odorless and
transparent gel
Light yellow gel with
lemon essential oil odor
Light yellow gel with
lemongrass essential oil odor.
Density (g/ml)
1.0238 1.0242 1.0246
Density (g/ml)
1.0238 1.0242 1.0246
pH
5-6 5-6 5-6
Viscosity (cP)
419.23 417.75 420.17
Bacterial infection (100g product)
-Candida albicans<10 -S.aureus <10
-Aerophils <10
-Candida albicans <10 -S.aureus <10
-Aerophils <10
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Figure 5-11: Three final products after preparing
SP1 with Triclosan was a ordorless and transparent gel. It was similar with semi-
product because Triclosan was colourless and odorless when soluting into ethanol.
SP2 with lemon essential oil and SP3 with lemongrass essential oil
Essential oil was good environment for development of microbe, so SP2 and SP3 were
surveyed quantity of bacteria. Because some limits, SP2 and SP3 were just surveyed on three
most popular misrobe, such as: Candida albicans, S.aureus and Aerophils.
SP3 with lemongrass essential oil: was light yellow gel with citronella odor
Three final products satisfied basic standards of hygienic product. Besides, SP2 and SP3 had
natural odor and unwanted to use synthetic odor.
5.3.2.2. Evaluating commercial ability of final products
Investigating viewpoint of customers about products
SP1 SP2 SP3
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Table 5-11: Result of investigating viewpoint of customers
Sum of points
Criterions SP1 SP2 SP3
Cleansed capacity 150 150 150
Wash out capacity 146 126 130
Foaming capacity 78 112 128
Odor 90 146 92
Feelling after using 126 150 150
Skin irritation 150 150 150
Acceptance 118 142 90
Figure 5-12: Result of investigating viewpoint of customers in final products
According to Figure 5-12, SP2 had the most of customer acceptances because its odor made
comfortable. Although SP3 had the higher anti-bacteria capacity, it wasn’t accepted much
because citronella’s smell wasn’t popular. So, odor of personal care was very important. The
wrong choosing of odor could go to the failure product.
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Although there were some drawbacks, hand cleaners with essential oils (SP2 and SP3) had
some strong points in comparison to products with chemical synthetic substance (SP1).
Especially, products with essential oil could restrict some harmful effect of product with
chemical synthetic substance for customer health.
Preliminary estimating price of products
Price of each final product were reduce price of 350g product.
Table 5-12: Cost of product SP1
Component Content (%) Weigh per 100g product (g) Price (VND)
Distillated water 78.44 78.44 156.88
SLS 10.00 10.00 450
CAPB 30% 1.00 1.00 60
Carbopol aqua 6.00 6.00 762
TEA 1.20 1.20 54
Ethanol 2.00 2.00 32
CDE 0.06 0.06 3.6
Glycerin 1.00 1.00 20
Triclosan 0.30 0.30 270
Cost of material per 100g product 1 808.48
Cost of material per 350g product 6 329.68
Production cost of 350g product (200% material’s cost) 12 659.36
Cost of 350g product 18 989.04
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Table 5-13: Cost of product SP2
Component Content (%) Weigh per 100g product (g) Price (VND)
Distillated water 79.04 79.04 158.08
SLS 10.00 10.00 450
CAPB 30% 1.00 1.00 60
Carbopol aqua 6.00 6.00 762
TEA 1.20 1.20 54
Ethanol 2.00 2.00 32
CDE 0.06 0.06 3.6
Lemon’s essential oil 0.6 0.60 4 200
Methyl paraben 0.05 0.05 55
Propyl paraben 0.05 0.05 50
Cost of material per 100g product 5 824.68
Cost of material per 350g product 20 386.38
Production cost of 350g product (200% material’s cost) 40 772.76
Cost of 350g product 61 159.14
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Table 5-14: Cost of product SP3
Component Content (%) Weigh per 100g product (g) Price (VND)
Distillated water 79.14 79.14 158.28
SLS 10.00 10.00 450
CAPB 30% 1.00 1.00 60
Carbopol aqua 6.00 6.00 762
TEA 1.20 1.20 54
Ethanol 2.00 2.00 32
CDE 0.06 0.06 3.6
Citronella’s essential oil 0.5 0.50 3 450
Methyl paraben 0.05 0.05 55
Propyl paraben 0.05 0.05 50
Cost of material per 100g product 5 074.88
Cost of material per 350g product 17 762.08
Production cost of 350g product (200% material’s cost) 35 524.16
Cost of 350g product 53 286.24
Because price of essential oils was higher than price of Triclosan so much, price of SP2 and
SP3 was higher than price of SP1 and price of commercial products. However, price of
materials was counted follow price of chemicals for laboratory, so it was very high. In real
production, materials were industrial chemicals and were bought by a bulk, so the price
would reduce a lot. Besides, if essential oil would be distillated by own producer, the price
was lower than essential oil was bought in market. Combining with improvement in
production would make the price of products reduce and their commercial ability would be
higher.
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CHAPTER 6
CONCLUSION AND
INTENDING WORKS
6. This last chapter will conclude the results which got during the study. Besides, there
were some proposals for followed researches in this field.
6.1. CONCLUSION
6.1.1. Essential oil distillation
Essential oils were distillated by indirect steam distillation at high pressure (2atm). This was
a simple method, low cost and accommodated with local production. However, this method
also had some weak points; such as essential oil dissolved in water, decayed by
heat…Important thing of this method was choosing the suitable pressure and flow of water’s
circulation to get maximum essential oil with best quality.
Among agricultural materials, lemon and citronella were the most popular in Vietnam. Many
previous researches proved activity of their essential oil, so this was important reason to
choose two essential oils.
Reservation of lemon’s essential oil was more than citronella’s. But anti-bacteria capacity of
citronella’s essential oil was higher. Both of them had special odor. Odor of lemon’s essential
oil was accepted more because it brought relax and comfortable feeling when using.
Citronella odor wasn’t accepted more. Thus, odor was very important thing when choosing
kind of essential oil to use in personal care products.
6.1.2. The final products
SP1 with Triclosan
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Table 6-1: Summary of product SP1
Formulae Mixing condition Characteristics
Component Content (%)
Distillated water 78.44 - room temperature
- time: 15min/batch
- speed of stirring:
750rpm
-transparent gel
pH= 5.5-6.5
- anti-bacteria
-washing out quickly
-not make skin irritation
SLS 10.00
CAPB 30% 1.00
Carbopol aqua 6.00
TEA 1.20
Ethanol 2.00
CDE 0.06
Glycerin 1.00
Triclosan 0.30
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SP2 with lemon’s essential oil
Table 6-2: Summary of product SP2
Formulae Mixing condition Characteristics
Component Content (%)
Distillated water 78.64 - room temperature
- time: 15min/batch
- speed of stirring:
750rpm
-light yellow gel
pH= 5.5-6.5
lemon odor
- anti-bacteria, deodorize
-make foaming
-washing out quickly
-not make skin irritation
SLS 10.00
CAPB 30% 1.00
Carbopol aqua 6.00
TEA 1.20
Ethanol 2.00
CDE 0.06
Lemon’s essential
oil
0.6
Methyl paraben 0.25
Propyl paraben 0.25
SP3 with citronella’s essential oil
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Table 6-3: Summary of product SP3
Formulae Mixing condition Characteristics
Component Content (%)
Distillated water 78.74 - room temperature
- time: 15min/batch
- speed of stirring:
750rpm
-light yellow gel
pH= 5.5-6.5
Citronella odor
- anti-bacteria, deodorize
-washing out quickly
-make foaming
-not make skin irritation
SLS 10.00
CAPB 30% 1.00
Carbopol aqua 6.00
TEA 1.20
Ethanol 2.00
CDE 0.06
Citronella’s essential
oil
0.5
Methyl paraben 0.25
Propyl paraben 0.25
6.2. EVALUATING FEASIBILITY OF STUDY
The study based on real demand of customers and followed the new tendency which was
green production and using safe product from natural source. Washing hand has become a
daily habit. Society has got interest in it with many programs, such as washing hand program
to protect heath of Lifebouy-Unilever or a lot of hygienic programs to take care of heath of
local governments…Thus, demand of anti- bacteria hand cleaner is very high. Nowadays,
there aren’t any anti- bacteria products with natural essential oil (they just used natural
substances or natural derivation as aromatic). So, this study accommodated with new
tendency and can respond the high hygienic demand of customers.
Essential oils in market are high cost because of high requirement and expensive materials.
This study focused on essential oils had high reservation, easy growth and have many popular
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applications. Besides, essential oils were extracted from agricultural waste (lemon’s peel and
citronella’s trunk). So, the cost was reduced so much.
Hand cleaner had a simple formulae and easy procedure (components were stirred follows
time, unwanted temperature). It satisfied requirements of hygienic product, such as anti-
bacteria, making lot of foam, getting moisture for skin and odor of nature essential oil made
comfortable. Especially, essential oil helped customers prevented some harmful effects which
chemical synthetic substances got.
According to above considerations, this study can apply in reality to have a part in increasing
value of Vietnam’s essential oil, developing agriculture and supplying the new product
family which was not only safe for user but also friendly with environment.
6.3. INTENDING WORKS
Within the enable framework, this study just surveyed some basic properties of essential o il
and products. Follow studies should improve requirements, as follows:
For essential oil:
Finding out the best method for each essential oil to get essential oil with higher
quality and lower cost.
For essential oils of lemon and citronella, it should be tested activity on various
bacteria to develop anti-bacteria and anti- fungus range of their. It should be
determined MIC for each bacteria and fungus to have exactly concentration of using.
Surveying other materials, for example: orange’s peel, pomelo’s peel, ginger…
For hand cleaner product:
Surveying some parameters can affect on quality of product, such as: time of stirring,
speed of stirring, temperature of stirring, kind of stirring arm, changing some
components of formulae…
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Testing technical and consume criteria, such as: heavy metal content, time and
condition of storage, irritation and safeness for customers.
Evaluating product base on viewpoint of every kind of customers and taking advice of
experts.
In the future, essential oils would be applied into various products to diversify products
and increase values of essential oils.
This is also my proposal for followed researchers about this yield.
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REFERENCES
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[5] Louis Ho Tan Tai. "Detergent products".
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[16]. Ph.D. M. Angela McGhee, Biology and Marine Sciences. "Triclosan." from
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[18] Ph.D. Kuo-Yann Lai. "Liquid detergent". (1996). Colgate-Palmolive Company’s Global
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