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O R I G I N A L P A P E R
Amino-functionalized nanocrystalline cellulose
as an adsorbent for anionic dyes
Liqiang Jin . Weigong Li . Qinghua Xu .
Qiucun Sun
Received: 7 January 2015 / Accepted: 3 May 2015
Springer Science+Business Media Dordrecht 2015
Abstract In this present work, amino-functionalized
nanocrystalline cellulose (ANCC) was prepared by a
process involving, (1) extraction of nanocrystalline
cellulose (NCC) from fully bleached hardwood kraft
pulp by sulfuric acid hydrolysis, (2) sodium periodate
oxidation of NCC to yield the corresponding C-2/C-3
dialdehyde nanocellulose (DANC) and (3) grafting
with ethylenediamine to obtain ANCC through a
reductive amination treatment. Properties of DANC
and ANCC were characterized by conductometric
titration, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction and atomic force microscopy. It
was found that the primary amine groups of ANCC
(0.77–1.28 mmol g-1) increased with the increase of
ethylenediamine dosage. The successful grafting was
further evidenced by Kaiser test and FT-IR analysis.
Zeta potential measurements showed that ANCCs
were amphoteric, and their isoelectric points were
between pH of 7–8. Chemical modifications of the
cellulose nanowhiskers reduced the crystallinity but
the initial cellulose I polymorph was retained. The
cross-sectional dimension of nanowhiskers was
slightly decreased from about 5–10 to 3–8 nm after
the oxidation, and a better dispersibility was observed.
ANCC sample was then applied as an adsorbent to
remove anionic dyes in aqueous solutions. It demon-
strated the maximum removal efficiency at acidic
conditions. The acid red GR adsorption on ANCC
fitted well with the Langmuir model, with a maximum
theoretical adsorption capacity of 555.6 mg g-1. The
adsorption of congo red 4BS, acid red GR and reactive
light yellow K-4G followed pseudo second order
kinetics, indicating a chemisorption nature.
Keywords Nanocellulose Periodate oxidation Amino-functionalization Adsorption Anionic dyes
Introduction
More than 10,000 different dyes and pigments are used
in chemical industries, such as textile, plastic, paper,
printing, carpet, cosmetic and food industries toprovide color to their products (Bhattacharyya and
Ray 2015; Yagub et al. 2014). However, around
15 wt% of dyes remains in industrial wastes and are
discharged to water body (Kayranli 2011). The
presence of dyes, not only imparts waste water
undesirable visual pollution, but also reduces water
reoxygenation capacity, resulting in acute and chronic
toxicities and difficulties in water treatment by
conventional methods (Piccin et al. 2012). Due to
L. Jin (&)
School of Chemistry and Pharmaceutical Engineering,
Qilu University of Technology, Jinan 250353, China
e-mail: [email protected]
W. Li Q. Xu Q. SunKey Laboratory of Paper Science and Technology of
Ministry of Education, Qilu University of Technology,
Jinan 250353, China
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DOI 10.1007/s10570-015-0649-4
Cellulose (2015) 22:2443–2456
/ Published online: 1 ay 20150 M
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the increasing use of dyes, the dye wastewater is
becoming an environmental threat, and the removal of
these pollutants from wastewater has been a challenge
(El-Zahhar et al. 2014).
Various processes such as coagulation/flocculation,
membrane treatment, ion exchange, electrodialysis,
electrolysis, and adsorption (Pearce et al. 2003) areused for removal of these non-biodegradable dyes
from water. Adsorption has been found to be superior
to other techniques in terms of flexibility and
simplicity of design, initial cost, insensitivity to toxic
pollutants and ease of operation and is considered an
ideal method for removing dyes or other pollutants
(Crini 2006; Deng et al. 2012; Unuabonah and Taubert
2014). The adsorbents used in water treatment may be
mineral, organic or biological in origin, including
activated carbons, zeolites, clays, silica beads, bio-
mass and polymeric resins (Murphy et al. 2008;Unuabonah et al. 2012). In order to provide cost-
effective, greener and more sustainable solutions for
dye removal, there has been a strong desire to develop
adsorbents from low cost agriculture, wood and
shellfish byproducts or wastes (Pei et al. 2013). Most
adsorptions of contaminants rely on the surface
interactions between adsorbents and adsorbates, there-
fore, the functional groups on the adsorbents surface
play an important role in determining the effective-
ness, capacity, selectivity and reusability of the
adsorbent material (Dural et al. 2011; Karim et al.2014). Furthermore large surface area and abundance
of adsorption sites are essential for adsorption and
removal of contaminants from wastewater (Liu et al.
2014). Nanomaterials, due to their good adsorption
efficiency, higher surface area and greater active sites
for interaction with pollutants, are increasingly used in
dye removal (Savage and Diallo 2005). It is desirable
to develop nanomaterial adsorbents to enhance the
adsorption capacity, adsorption rate and shorten the
reaction time (Yagub et al. 2014).
Cellulose has been considered to be an idealcandidate for the removal of dyes owing to the facts
that cellulose is the most abundant organic raw
materials on the earth, and it is inexpensive, renew-
able, biodegradable and biocompatible (Roy et al.
2009). Nanocellulose, extracted from cellulosic fibers
by applying mechanical, chemical, physical or biolo-
gical methods, demonstrates excellent properties,
including high aspect ratio, large specific surface area,
reactive surface of -OH groups, and high Young’s
modulus. The unique properties may impart nanocel-
lulose high adsorbability for dyes. By enzymatic or
chemical pretreatments of wood pulp fiber, the energy
consumption of the subsequent mechanical treatment
could be lowered for producing cellulose nanofibers
(Fujisawa et al. 2011; Isogai et al. 2011), thus facilitate
the production at a larger scale, which encouraged usto develop nanocellulose based dye adsorbents with
high adsorption capacity (Pei et al. 2013). Ma et al.
(2012) developed a multilayered nanofibrous micro-
filtration (MF) membrane, by impregnating ultrafine
cellulose nanowhiskers into an electrospun polyacry-
lonitrile (PAN) nanofibrous scaffold supported by a
poly(ethyleneterephthalate) (PET) nonwoven sub-
strate. The impregnated CNCs possessed very high
negative surface charge density and thus provided
high adsorption capacity to remove positively charged
dyes, i.e. crystal violet dye. Karim et al. (2014)reported a fully biobased composite membrane for
water purification fabricated with cellulose nanocrys-
tals (CNCs) as functional entities in chitosan matrix
via freeze-drying process followed by compacting.
The membranes removed 98, 84 and 70 % of
positively charged dyes like Victoria Blue 2B, Methyl
Violet 2B and Rhodamine 6G, respectively. The
removal of dyes was expected to be driven by the
electrostatic attraction between the negatively charged
CNCs and the positively charged dyes.
Cellulose tends to exhibit a high adsorptioncapacity for pollutant after suitable chemical modifi-
cation on its surface with the aim of incorporating
molecules that contain basic groups, particularly those
that are rich in nitrogen, sulfur and oxygen (Musyoka
et al. 2011). Pei et al. (2013) prepared quatinized
cellulose nanofibrils (Q-NFC) by mechanical disinte-
gration of wood pulp fibers which were pretreated
through a reaction with glycidyltrimethylammonium
chloride. The Q-NFC nanofibrils possessed high
anionic dye adsorption capability. Silva et al. (2013)
reported the surface modification of cellulose withaminoethanethiol in the absence of solvent to improve
its adsorbability. The modified cellulose showed
superior performance in the adsorption of a reactive
red dye.
Different approaches have been explored to
chemically modify the nanocellulose, such as esterifi-
cation, oxidation, silylation and polymer grafting
(Habibi et al. 2010; Ifuku et al. 2007; Missoum et al.
2013; Pahimanolis et al. 2011; Zaman et al. 2012).
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Most of covalent modifications predominantly oc-
curred on the primary hydroxyl groups at the C-6
position of the cellulose backbone. Periodate oxida-
tion offers a facile method for functionalization of
hydroxyl groups in cellulose nanowhiskers (Li et al.
2009; Lu et al. 2014; Pan and Ragauskas 2014). The
resulted dialdehyde nanocellulose can act as a reactiveintermediate for further derivatization and opens
possibilities for many other chemical reactions (Cheng
et al. 2014; Dash et al. 2012; Sirviö et al. 2014), thus
widening the potential application of nanocellulose
(Kalaskar et al. 2010). A chemical pretreatment for
producing CNCs with periodate oxidation and reduc-
tive amination was reported by Visanko et al. (2014).
The butylamino-functionalized CNCs were obtained
after the pretreatment and the subsequent mechanical
homogenization, which could be utilized in stabilizing
the o/w emulsions due to its amphiphilic nature. Dashand Ragauskas (2012) prepared a novel nanometric
carrier molecule by grafting for amine-containing
biologically active molecules and drugs employing
functionalized cellulose nanowhiskers. The nanowhis-
kers were grafted with a spacer molecule, gamma
aminobutyric acid, using a periodate oxidation and
Schiff’s base condensation reaction sequence.
The aim of the present study is to incorporate
primary amine groups onto the surface of cellulose
nanowhiskers, and then evaluate its dye removal
efficiency. Nanocrystalline cellulose was firstly oxi-dized by sodium periodate to yield the corresponding
C-2/C-3 dialdehyde nanocellulose (DANC), and then
grafted with ethylenediamine to obtain amino-func-
tionalized NCC (ANCC) with free primary amino
groups through a reductive-amination treatment.
Properties of DANC and ANCC were characterized
by FT-IR, XRD and AFM. Furthermore, adsorption
capacity and kinetics of ANCC for anionic dyes were
investigated.
Experimental
Materials
Fully bleached aspen kraft pulp with a cellulose
content of 84.3 %, a hemicelluloses content of
10.9 %, and a weight average fiber length of
0.755 mm, as an original material used for preparation
of the nanocrystalline cellulose, was provided by the
Silver Star Paper Co. Ltd, Jinan, China. Ethylenedi-
amine and sodium periodate were purchased from
Sigma-Aldrich Co. Ltd. The following commercial
anionic dyes, acid red GR (acid dye), congo red 4BS
(direct dye), and reactive light yellow K-4G (reactive
dye) were supplied by Tianjin Ruiji Chemical Co. Ltd
and their chemical structures are shown in Fig. 1.
Preparation of NCC
Nanocrystalline cellulose (NCC) were prepared by
sulfuric acid hydrolysis of fully bleached kraft pulp
according to the method by Lu and Hsieh (2012)
Aspen kraft pulp was firstly ground using a Wiley mill
(mini mill, Thomas Scientific, USA) at a speed of
approximately 1700 rpm to pass through a 20-mesh
screen, and the fraction passing through was collected
for the hydrolysis step. 10 g (o.d.) of the milled pulpwas hydrolyzed by using 85 ml of 64 wt% sulfuric
acid for 30 min at 45 C. At the end of the reaction, the
suspensions were then centrifuged to remove the acid,
and then diluted with deionized water and washed via
centrifugation. The acquired precipitate was trans-
ferred onto a cellulose dialysis membrane with a
molecular weight cut-off of 12,000–14,000 and
dialyzed against deionized water for 4 days until the
suspension became homogeneous and the pH value
became constant. NCC with a yield of about 30 % was
acquired, and stored at a temperature of 5 C as itsoriginal wet state.
Sodium periodate oxidation of cellulose
nanowhiskers
250 ml of cellulose nanowhiskers (0.4 wt%) and
various amounts of sodium periodate, corresponding
to 1.5, 3, 6 and 9 mmol g-1 NCC, were mixed and
stirred for 48 h in the absence of light at 40 C. The
residual sodium periodate was then removed by
adding 10 ml of ethylene glycol. The product wasdialyzed against deionized water for 3 days using a
dialysis membrane with a molecular weight cut-off of
12,000–14,000. The acquired dialdehyde nanocrys-
talline cellulose (DANC) was stored at temperature of
5 C as its original wet state. The dialdehyde content
of DANC was determined by the Schiff base reaction
between aldehyde groups and hydroxylamine hy-
drochloride (Kim et al. 2004). The dialdehyde content
(DC) of each sample was calculated through Eq. (1),
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DC ðmmol g1Þ ¼C ðV 2 V 1Þ
mð1Þ
where, V 1 is the amount of sodium hydroxide for
DANC titration, ml; V 2 is the amount of hydrochloric
acid for control titration in ml; C is the concentration
of sodium hydroxide, mol l-1 and m is the weight of each sample, g.
Preparation of amino-functionalized
nanocrystalline cellulose (ANCC)
200 ml of DANC suspension (0.5 wt%) was ultra-
sonicated for 5 min, and then various amounts of
ethylenediamine were added. The mixture was con-
tinuously stirred for 6 h at 30 C, followed by the
in situ reduction of the resulting imine intermediate at
room temperature employing 0.58 g of NaBH4. After
stirring for 3 h, the product was dialyzed (MWCO:
12,000–14,000) against deionized water until it
reached a neutral pH to obtain ANCC. The content
of amine groups was determined by conductometric
titration according to the literature (Filpponen and
Argyropoulos 2010). The pH of ANCC suspension
was adjusted to 3 by HCl at room temperature and
stirred for 15 min. The suspension was subsequently
titrated with NaOH (0.01 mol l-1) solution until the
pH was 12. The conductivity of the suspension was
recorded. The amine group content was calculated
based on the following Eq. (2),
AGC ¼C ðV 2 V 1Þ
mð2Þ
where, AGC is the amino group content, mmol g-1;
C is the concentration of NaOH solution; V 1 and V 2 are
the minimum and maximum consumptions of NaOH
in the lowest conductivity (ml), respectively and m is
the freeze dried content of ANCC.
Characterization
Kaiser test
Kaiser test was performed according to the literature
(Hemraz et al. 2013). A few drops of phenol (about80 % in ethanol), KCN in water/pyridine, and ninhy-
drin (6 % in ethanol) solutions were added to a few
milligrams of NCC, DANC and ANCC samples in test
tubes. The mixture was then heated at 120 C for
5 min, and any change in color was noted.
FT-IR
FT-IR spectra of cellulose nanowhiskers were con-
ducted on an IRPrestige-21 Fourier transform infrared
spectrometer (Shimadzu Company, Japan). The sam-ples were freeze-dried before preparing the KBr
tablets. The spectra were recorded with width ranging
from 400 to 4000 cm-1, and resolution of 2 cm-1.
X-ray diffraction analysis
X-ray diffraction (XRD) analyses were performed
with a D8 Powder X-ray Diffractometer (Bruker AXS,
Germany), which was equipped with a CuXa X-ray
tube. The crystallinity index (CrI) was calculated
based on the Eq. (3) below (Segal et al. 1959),
CrI ¼ I 002 I am
I 002ð3Þ
where, CrI is the crystallinity index; I 002 is the intensity
of the crystalline peak at the maximum at 2h between
22 and 23 for cellulose I, and I am is the intensity at
minimum at 2h between 18 and 19 for cellulose I.
The crystal size was calculated according to the
Scherrer formula as below,
Fig. 1 Chemical structures of dyes a acid red GR; b congo red 4BS and reactive light yellow K-4G
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D ¼ 0:89 k
b1=2 cos h ð4Þ
where, k is the radiation wavelength of X ray,
0.154056 nm; h is the Bragg diffraction angle, corre-
sponding to the (002) plane in this case, and b1/2 is the
full width of the diffraction peak measured at half maximum height (FWHM) of the instrument corrected
line profile.
AFM
A Mutimode 8 Nanoscope V System AFM (Bruker
Corporation, Germany) was used to characterize the
surface morphology of NCC, DANC and ANCC
samples. A drop of dilute nanocellulose suspension
was deposited onto a clean mica surface and air dried
overnight at ambient conditions. Images from severaldifferent places on the samples were scanned.
Adsorption of anionic dyes
The freeze dried ANCC were mixed with 100 mg l-1
dye solution and continuously stirred at 180 rpm.
Samples were withdrawn at periodic time intervals
from the reaction mixture. The nanocellulose adsorbed
with dyes was then removed by centrifugation at
4000 rpm for 5 min. The adsorption of the supernatant
was measured using a UV–visible spectrometer (8453,
Angilent). The residual dye concentration could be
obtained using a standard curve derived from a series
of dye solutions with known dye content. The
adsorbed amount of dyes was calculated according
to the following Eq. (5),
qt ¼ðC 0 C tÞV
m ð5Þ
where, qt is the adsorbed amount after time t, C 0 and C tare initial concentration and concentration of the
adsorbate after time t, respectively, mg l-1; V is the
volume of the solution, l, and m is the weight of the
ANCC used, g.
The percentage removal of the dye was calculated
using the following Eq. (6),
%removal ¼C 0 C t
C 0 100 ð6Þ
The study of pH influence was performed by
varying the pH between 4 and 9.
Results and discussions
Characterization of ANCC
Nanocrystalline cellulose was extracted from fully
bleached hardwood kraft pulp by sulfuric acid hy-
drolysis and then oxidized by sodium periodate toyield the corresponding C-2/C-3 dialdehyde nanocel-
lulose (DANC). The effect of sodium periodate
amount on the aldehyde group content of DANC is
shown in Fig. 2. It was shown that the aldehyde
content was increased with the increased dosage of
NaIO4, and reached the maximum (8.81 mmol g-1)
when NaIO4 addition was 9 mmol/g. This is in
consistent with the results of Cheng et al. (2014),
who prepared 2,3-dialdehyde cellulose films using
regenerated cellulose films by periodate oxidation. It
was reported by Sirviö et al. (2011) that periodateoxidation can be improved by using elevated tem-
perature and metal salts as oxidation activators.
The oxidized nanowhiskers with aldehyde group
content of 8.81 mmol g-1 were then grafted with
ethylenediamine to obtain ANCC employing a reduc-
tive amination treatment. The schematic pathway for
sodium periodate oxidation and reductive amination
of nanocellulose is shown in Scheme 1. During the
reaction, one of the amine groups reacts with the
aldehyde group of DANC to generate an imine bond
and then reduced to C–N bond by NaBH 4, while theother one remains as a free primary amine.
The relationship between ethylenediamine addition
and amino group amount is shown in Fig. 3. It was
demonstrated that the primary amine groups were
Fig. 2 The relationship between the amount of sodium
periodate and aldehyde group content
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successfully grafted onto the surface of nanowhiskers,
and the amino group content increased with the
increase of ethylenediamine addition. The amino
group content was higher than that reported by Way
et al. (2012), who prepared NCC-NH2 through a three-
step procedure. NCC obtained via HCl hydrolysis of
tunicate was firstly oxidized by TEMPO/NaClO/
NaBr, then the resulted NCC-COOH reacted with an
excess (25 equiv) of mono Boc-protected ethylene
diamine using standard peptide coupling techniques.
The higher amino group content may probably
because more aldehyde groups formed during the
periodate oxidation than the carboxylic moieties
(310 mmol/kg) by TEMPO/NaBr/NaClO oxidation.
The presence of the free primary amine group on the
nanowhiskers surface was also confirmed by the
Kaiser test, which is shown in Fig. 4. The appearance
of a dark blue color was a strong indication for the free
amines.
The zeta potential of ANCCs versus pH values is
shown in Fig. 5. Obviously, the zeta potential of
ANCCs was significantly affected by the pH value of
the solution. It was positive at low pH due to the
protonation of amines (NCC-NH3?). With the in-
crease of the pH value, the zeta potential decreased
and became negative in the alkaline region, resulting
from the deprotonation of amine groups (NCC-NH2)
and dissociation of sulfate groups on the surface. The
results indicated an amphoteric property of ANCC and
rendered it pH responsive, which can widen its
potential industrial application. The zeta potential
reached zero at pH of about 7–8, that is to say, the
isoelectric points of the ANCC samples are between
pH of 7–8. It was noted that with the increase of
ethylenediamine addition, the isoelectric point in-
creased. It may probably because more amine groups
were introduced onto the nanowhiskers surface.
The FT-IR spectra of NCC, DANC and ANCC
samples are presented in Fig. 6. Compared with the
spectrum of unmodified NCC (Fig. 6a), two new
absorption bands at around 1731 and 885 cm-1
appeared in the spectrum of DANC (Fig. 6b),
NaIO4 NaIO3+H2O+
O
O
OX
OH
HO
OO
OX
OO
X = H, SO3H
O
O
OX
NCH2CH2 NH2H2 NH2CH2CN
2 H2 N
C H2 C H2 NH2
NaBH4
O
O
OX
NHCH2CH2 NH2H2 NH2CH2CHN
Scheme 1 Sodium periodate oxidation and amination reaction of cellulose nanowhiskers
Fig. 3 Effect of ethylenediamine addition on amino group
content
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corresponding to the characteristic absorption peaks of
the aldehyde group (C=O) and hemiacetal bonds
between newly achieved aldehyde groups and their
neighboring hydroxyl groups, respectively. This result
indicated that the hydroxyl groups on the molecularchain of NCC were partially oxidized to aldehyde
groups, resulting in the dialdehyde NCC. The band at
1731 cm-1 was absent in the spectrum of ANCC
(Fig. 6c), which supported the successful reaction of
DANC with ethylenediamine. FT-IR spectra of ANCC
gave a new adsorption band at 1583 cm-1, which was
corresponded to N–H bending vibration (Barazzouk
and Daneault 2012; Oh et al. 2005). The two bands in
the region of 3300 cm-1 typical for N–H of primary
amines were not observed, they may probably overlap
with the strong broad O–H stretching band, aspreviously reported by Hemraz et al. (2013).
The wide angle X-ray diffraction patterns of freeze-
dried NCC, DANC and ANCC are demonstrated in
Fig. 7. The peaks at 2h = 14–18, 22.5 and 34.5
were characteristic of the structure of cellulose I
(Klemm et al. 2005). The CrI and crystallite size of
NCC, DANC and ANCC are calculated and shown in
Table 1. Compared with that of NCC (63.0 %), the
crystallinity index of DANC was reduced to 56.3 %. It
was found that the cellulose I polymorphic form was
retained after the oxidation, although the initialcrystallinity was reduced. The results were consistent
with those of Lindh et al. (2014) and Lu et al. (2014),
who also found the crystallinity decrease during the
nanocellulose periodate oxidation. The loss of crys-
tallinity is considered to result from the opening of
glucopyranose rings and destruction of their ordered
packing (Kim et al. 2000; Varma and Chavan 1995).
The crystallite size of nanowhiskers before and after
chemical modification decreased insignificantly.
Fig. 4 Kaiser test of NCC, DANC and ANCC samples
Fig. 5 Zeta potential of ANCC samples at varied pH
Fig. 6 FT-IR spectra of a NCC; b DANC and c ANCC (with 20
equiv of ethylenediamine)
Fig. 7 X-ray diffraction patterns of a NCC; b DANC and
c ANCC (with 20 equiv of ethylenediamine)
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Surface morphology and size distribution of the
cellulose nanowhiskers were characterized by AFM.
The AFM height images for the NCC, DANC and
ANCC are shown in Fig. 8 (upper part). It was
observed that the functionalization did not significant-
ly affect the surface morphology characteristic of
nanowhiskers. The dispersibility of nanowhiskers
after chemical modification (Fig. 8b, c) were im-
proved compared to that of the NCC (Fig. 8a), maybedue to the incorporation of relatively hydrophilic
groups on the surface (Dash et al.2012; Sabzalian et al.
2014).
The height profile of the line along the length of the
cellulose whiskers was plotted, as shown in Fig. 8
(lower part), which revealed that the width of
nanowhiskers was slightly decreased from about
5–10 to 3–8 nm after the oxidation. The results agree
well with that of Sabzalian et al. (2014), who showed
that the diameter of periodate oxidized fibers became
smaller than that of the original fibers.
Adsorption of dyes
Effect of solution pH
ANCC sample prepared with 20 equiv of ethylenedi-
amine per glucose unit was used as an adsorbent to
remove the acid red GR in the aqueous solution.
pH is one of the most important process variables
when considering dye adsorption. The solution pH
determines the level of electrostatic or molecular
interaction between the adsorbent and the adsorbate
owing to the charge distribution on the material (Nair
et al. 2014). In the present study, the effect of pH on
the dye removal percentage was evaluated at a pHrange of 4.0–9.0, as shown in Fig. 9. From Fig. 9
(inset), it is clear that the isoelectric point (pHpzc)of
ANCC is about 8.0, which means that at pH\8.0, the
surface of ANCC is positively charged, while
negatively charged at pH more than 8.0. It is obvious
that under acidic region (pH 4.7), the percentage
removal of dye was 67.3 % (qt = 134.7 mg g-1),
higher than the percentage removal of 52.2 %
Table 1 Crystallinity index and crystallite size of cellulose
nanowhishkers
Samples Crystallinity
index (%)
Crystallite
size (nm)
NCC 63.0 3.68
DANC 56.3 3.35
ANCC 59.8 3.26
Fig. 8 Dimensional dynamic AFM images for of a NCC; b DANC and c ANCC (with 20 equiv of ethylenediamine). Z-profile graph
was taken across the image from an arbitrary horizontal line
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(qt = 104.5 mg g-1) in the neutral region (pH 6.7).
This demonstrates that at acidic conditions, the
interaction between the protonated amine and the
anionic site of the dye enhanced the adsorption of dyes
onto the ANCC. At a pH of 9, the dye percentage
removal was only 31.3 % (qt = 62.6 mg g-1). In the
alkaline region, the ANCC surface charge became
negative, consequently limiting the chemical interac-
tion between ANCC surface and the anionic site of the
dye due to electrostatic repulsion. The results demon-
strated that surface characteristics of ANCC, whichshowed a direct dependence on the zeta-potential,
affected the adsorption efficiency greatly. The results
were consistent with literatures reported before
(Ibrahim et al. 2010; Liu et al. 2012), which found
that due to the presence of functional groups, anionic
dye adsorption was favored at pH\pHpzc where the
surface became positively charged, whereas cationic
dye adsorption was favored at pH[pHpzc.
The adsorption characteristics of ANCC are due to
the hydroxyl (-OH) and primary amine (-NH2)
groups that act as highly active adsorption sites. Theseare similar with chitosan, a well known natural
biopolymer with high adsorption capacity and low
cost for the removal of dyes (Vakili et al. 2014). For
acidic dyes, both ANCC and chitosan show better
adsorption in the acidic conditions due to protonation
of amino groups. However, chitosan is apt to dissolute
in acidic solution, which will limit its adsorption
performance (Nair et al. 2014). Compared to chitosan,
ANCC in this study has high specific surface area
(with a BET surface area of 12.5 m2 g-1) and is more
stable in acidic solutions.
Adsorption isotherm
Adsorption isotherm models is used to described the
interaction between the adsorbate and adsorbent. Theadsorption of acid red GR onto the ANCC was
evaluated using classic isotherm models, Langmuir
and Freundlich models. The Langmuir isotherm model
is based on a monolayer adsorption onto a surface with
a finite number of adsorption sites of uniform adsorp-
tion energies (Nair et al. 2014). It can be expressed in
the following linear form,
1
qe¼
1
qmaxþ
1
K L qmaxC e
where, C e is the equilibrium concentration of adsor-bate in the solution, mg l-1; qe is the amount of solute
adsorbed per mass of adsorbent, mg g-1; K L is the
Langmuir adsorption equilibrium constant, l g-1 and
qmax is the maximum adsorption capacity for mono-
layer formation.
The Freundlich isotherm model is an empirical
equation, which is utilized to understand adsorption on
heterogeneous surfaces adsorption capacity and mul-
tiple adsorption layers (Silva et al. 2013). It can be
expressed by the following equation,
ln qe ¼ ln K f þ ð1=nÞ ln C e
where, qe and Ce have the same meaning as in the
Langmuir equation; K f and 1/n are the two Freundlich
constants.
Figure 10 shows the Langmuir isotherm for adsorp-
tion of acid red GR on ANCC. The high correlation
coefficient (R2 = 0.992) demonstrated that the model
provided a good theoretical correlation to the adsorp-
tion equilibrium. However, the fit of Freundlich model
with experimental data was poor with an R2 of 0.882,
indicating that the adsorption followed the monolayersurface coverage model of Langmuir under the dye
concentration range studied. The theoretical maximum
adsorption capacity (555.6 mg g-1) matched well with
the experimental values (516.1 mg g-1).
Adsorption kinetics
The adsorption of different anionic dyes, congo red
4BS (direct dye), acid red GR (acid dye) and reactive
Fig. 9 Effect of initial solution pH on acid red GR removal
(dye conc. = 100 mg l-1; adsorbent dosage = 0.5 g l-1) (inset
the zeta potential of different pH for ANCC with 20 equiv of
ethylenediamine)
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light yellow K-4G (reactive dye) on ANCC wereevaluated and shown in Fig. 11. It was noted that the
percentage removal of Congo red 4BS (about 100 %,
qt = 199.5 mg g-1) was more compared to other
dyes. This was mainly due to strong electrostatic and
chemical interaction of the anionic and amine groups
present on congo red 4BS with the amine and hydroxyl
groups on ANCC. The removal efficiency of acid red
GR and reactive light yellow K-4G were 68
(qt = 134.7 mg g-1) and 91 % (qt = 183.0 mg g
-1),
respectively, which demonstrated that ANCC can be
utilized for the adsorption of different anionic dyes at alow dosage.
The adsorption kinetics of congo red 4BS, acid red
GR and reactive light yellow K-4G by ANCC were
investigated to describe the dye adsorption rate and
eventually explore the mechanism of adsorption and
the rate limiting steps involved. The most commonly
used kinetic models for investigating solid–liquid
interactions are pseudo first order and pseudo second
order models, which are based on adsorption capacity
(Zhou et al. 2014). In first order model, adsorption is
controlled by diffusion and mass transfer of theadsorbate to the adsorption site, whereas in a second
order model, chmisorption is the rate limiting step (El-
Zahhar et al. 2014). The pseudo second order model
considers that the limiting stage of the adsorption
process involves valence forces through the sharing or
exchange of electrons between the adsorbent and the
adsorbate (Vargas et al. 2012).
The first and second order rate equations are
expressed as follows,
First order kinetic model: log qe qt ð Þ¼ log qe k 1t =2:303
Second order kinetic model: t
qt ¼
1
k 2q2eþ
1
qet
where, qe and qt are the amount of adsorbed dye per
unit mass of adsorbent (mg g-1) at equilibrium and at
time t, respectively; k 1 is the pseudo first order sorption
rate constant (h-1), and k 2 is the rate constant of
pseudo second order adsorption (g mg-1 h-1).
The linear plot of log (qe - qt) versus t and t/qt
versus t were plotted and shown in Fig. 12 and 13,respectively. The kinetic parameters were calculated
by the intercepts and slopes of the lines, which were
listed in Table 2. R2 for the second order model were
greater than 0.99 for all the three dyes, while R2 for the
first order model were between 0.872 and 0.968.
Moreover, the calculated equilibrium adsorption val-
ues from pseudo first order model were much lower
than the experimental values. The values of qe cal by
the second order model and qe exp matched well, which
confirmed that the kinetics of adsorption by ANCC for
the three anionic dyes was best described by thepseudo second order model. This indicated that
adsorption of anionic dyes onto ANCC was mainly
controlled by chemisorption behavior. Second order
kinetics of dye adsorption was also observed for
biosorbents such as modified cellulose (Wang and Li
2013), chitosan/lignin composite (Nair et al. 2014),
tannery solid waste (Piccin et al. 2012), and lignocel-
lulose originating from biodiesel production (Ma-
griotis et al. 2014). It was also clear from Table 2 that
Fig. 10 Langmuir isotherm for adsorption of acid red GR on
ANCC (adsorbent dosage = 0.5 g l-1
; t = 7 h) (inset linear
Langmuir plot of adsorption)
Fig. 11 Percentage removal of different anionic dyes using
ANCC (dye conc. = 100 mg l-1
; adsorbent dosage = 0.5 g l-1
)
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the rate constant, k 2, for the adsorption of acid red GR
and reactive light yellow K-4G, was much lower than
that for congo red 4BS, which qualifies the higher
efficiency of ANCC for the adsorption of congo red
4BS.
Conclusions
In this study, nanocrystalline cellulose, extracted fromfully bleached hardwood kraft pulp by sulfuric acid
hydrolysis, was firstly oxidized by sodium periodate to
yield the corresponding C-2/C-3 DANC. The oxidized
nanowhiskers were then grafted with ethylenediamine
to obtain amino-functionalized NCC (ANCC) through
reductive amination reaction. The free primary amine
groups of ANCCs increased with the increase of
ethylenediamine addition. The presence of the free
amine group on the nanowhiskers surface was also
confirmed by the Kaiser test and FT-IR analysis. Zeta
potential of ANCCs was significantly affected by thepH value. It was positive at low pH and became
negative in the alkaline region, indicating an ampho-
teric property of ANCC and rendered it pH responsive,
which can widen its potential industrial application.
The isoelectric points of the ANCC samples are
between 7 and 8. The crystallinity indices were
reduced after periodate oxidation and amino-function-
alization, while the structure of cellulose I was
maintained. AFM analysis revealed that the function-
alization did not significantly affect the surface
morphology characteristic of nanowhiskers. Thewidth of nanowhiskers was slightly decreased from
about 5–10 to 3–8 nm after the oxidation. ANCC was
applied as an adsorbent to remove the anionic dyes in
the solution, and showed high adsorption capability. It
demonstrated the maximum removal efficiency at
acidic conditions. The adsorption isotherms of ANCC
could be well described by Langmuir model. ANCC
Fig. 12 Pseudo first order sorption rate plot for sorption of dyes by
ANCC (dye conc. = 100 mg l-1
; adsorbent dosage = 0.5 g l-1
)
Fig. 13 Pseudo second order sorption rate plot for sorption of
dyes by ANCC (dye conc. = 100 mg l-1
; adsorbent
dosage = 0.5 g l-1
)
Table 2 Pseudo first and
second order parameters for
the adsorption of dyes onANCC
Dyes Acid red GR Congo red 4BS Reactive light yellow K-4G
First order
K 1 (h-1
) 1.1345 1.1784 0.8735
qe cal (mg g-1) 38.74 0.83 71.48
R2 0.944 0.872 0.968
Second order
K 2 (g mg-1
h-1
) 0.065 3.575 0.030
qe cal (mg g-1
) 138.9 200 188.7
R2
0.999 1.000 0.999
qe exp (mg g-1
) 137.1 199.5 183.0
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can be utilized for the adsorption of different anionic
dyes. The removal percentage of direct dye was more
than those of acid and reactive dyes. The adsorption of
the anionic dyes onto ANCC followed pseudo second
order kinetics, indicating that dye adsorption on
ANCC was mainly controlled by chemisorption
behavior.
Acknowledgments The authors would like to thank the
National Natural Science Foundation of China (Grant No.
31370581), Shandong Provincial Outstanding Youth Scholar
Foundation for Scientific Research (Grant Nos. 2009BSB01053
and BS2010CL041), and the funding of Shandong provincial
Science and Technology Development Project (Grant No. 13fz02).
References
Barazzouk S, Daneault C (2012) Amino acid and peptide im-mobilization on oxidized nanocellulose: spectroscopic
characterization. Nanomaterials 2:187–205. doi:10.3390/
nano2020187
Bhattacharyya R, Ray SK (2015) Removal of congo red and
methyl violet from water using nano clay filled composite
hydrogels of poly acrylic acid and polyethylene glycol.
Chem Eng J 260:269–283. doi:10.1016/j.cej.2014.08.030
Cheng YM, Lu JT, Liu SL, Zhao P, Lu GZ, Chen JH (2014) The
preparation, characterization and evaluation of regenerated
cellulose/collagen composite hydrogel films. Carbohydr
Polym 107:57–64. doi:10.1016/j.carbpol.2014.02.034
Crini G (2006) Non-conventional low-cost adsorbents for dye
removal: a review. Bioresour Technol 97:1061–1085.
doi:10.1016/j.biortech.2005.05.001Dash R, Ragauskas AJ (2012) Synthesis of a novel cellulose
nanowhisker-based drug delivery system. RSC Adv 2:3403–
3409. doi:10.1039/c2ra01071b
Dash R, Elder T, Ragauskas AJ (2012) Grafting of model pri-
mary amine compounds to cellulose nanowhiskers through
periodate oxidation. Cellulose 19:2069–2079. doi:10.1007/
s10570-012-9769-2
Deng C, Liu J, Zhou W, Zhang YK, Du KF, Zhao ZM (2012)
Fabrication of spherical cellulose/carbon tubes hybrid ad-
sorbent anchored with welan gum polysaccharide and its
potential in adsorbing methylene blue. Chem Eng J
200–202:452–458. doi:10.1016/j.cej.2012.06.059
Dural MU, Cavas L, Papageorgiou SK, Katsaros FK (2011)
Methylene blue adsorption on activated carbon prepared
from Posidonia oceanica (L.) dead leaves: kinetics and
equilibrium studies. Chem Eng J 168:77–85. doi:10.1016/j.
cej.2010.12.038
El-Zahhar AA, Awwad NS, El-Katori EE (2014) Removal of
bromophenol blue dye from industrial waste water by
synthesizing polymer-clay composite. J Mol Liq
199:454–461. doi:10.1016/j.molliq.2014.07.034
Filpponen I, Argyropoulos DS (2010) Regular linking of cel-
lulose nanocrystals via click chemistry: synthesis and for-
mation of cellulose nanoplatelet gels. Biomacromolecules
11:1060–1066. doi:10.1021/bm1000247
Fujisawa S, Okita Y, Fukuzumi H, Saito T, Isogai A (2011)
Preparation and characterization of TEMPO-oxidized cel-
lulose nanofibril films with free carboxyl groups. Carbo-
hydr Polym 84:579–583. doi:10.1016/j.carbpol.2010.12.
029
Habibi Y, Lucia LA, Rojas OJ (2010) Cellulose nanocrystals:
chemistry, self-assembly, and applications. Chem Rev
110:3479–3500. doi:10.1021/cr900339w
Hemraz UD, Boluk Y, Sunasee R (2013) Amine-decorated
nanocrystalline cellulose surfaces: synthesis, charac-
terization, and surface properties. Can J Chem 91:974–981.
doi:10.1139/cjc-2013-0165
Ibrahim S, Fatimah I, Ang HM, Wang SB (2010) Adsorption of
anionic dyes in aqueous solution using chemically mod-
ified barley straw. Water Sci Technol 62:1177–1182.
doi:10.2166/wst.2010.388
Ifuku S, Nogi M, Abe K, Handa K, Nakatsubo F, Yano H (2007)
Surface modification of bacterial cellulose nanofibres for
property enhancement of optically transparent composites:
dependence on acetyl-group DS. Biomacromolecules
8:1973–1978. doi:10.1021/bm070113b
Isogai A, Saito T, Fukuzumi H (2011) TEMPO-oxidized cel-lulose nanofibers. Nanoscale 3:71–85. doi:10.1039/
C0NR00583E
Kalaskar DM, Ulijn RV, Gough JE, Alexander MR, Scurr DJ,
Sampson WW, Eichhorn SJ (2010) Characterisation of
amino acid modified cellulose surfaces using ToF-SIMS
and XPS. Cellulose 17:747–756. doi:10.1007/s10570-010-
9413-y
Karim Z, Mathew AP, Grahn M, Mouzonb J, Oksmana K (2014)
Nanoporous membranes with cellulose nanocrystals as
functional entity in chitosan: removal of dyes from water.
Carbohydr Polym 112:668–676. doi:10.1016/j.carbpol.
2014.06.048
Kayranli B (2011) Adsorption of textile dyes onto iron based
waterworks sludge from aqueous solution: isotherm, ki-netic and thermodynamic study. Chem Eng J 173:782–791.
doi:10.1016/j.cej.2011.08.051
Kim UJ, Kuga S, Wada M, Okano T, Kondo T (2000) Periodate
oxidation of crystalline cellulose. Biomacromolecules
1:488–492. doi:10.1021/bm0000337
Kim UJ, Kuga S, Wada M (2004) Solubilizaton of dialdehyde
cellulose by hot water. Carbohydr Polym 56:7–10. doi:10.
1016/j.carbpol.2003.10.013
Klemm D, Heublein B, Fink HP, Bohn A (2005) Cellulose:
fascinating biopolymer and sustainable raw material.
Angew Chem Int Ed 44:3358–3393. doi:10.1002/anie.
200460587
Li J, Wan YZ, Li LF, Liang H, Wang JH (2009) Preparation and
characterization of 2,3-dialdehyde bacterial cellulose for
potential biodegradable tissue engineering scaffolds. Mater
Sci Eng 29:1635–1642. doi:10.1016/j.msec.2009.01.006
Lindh J, Carlsson DO, Strømme M, Mihranyan A (2014) Con-
venient one-pot formation of 2,3-dialdehyde cellulose beads
via periodate oxidation of cellulose in water. Biomacro-
molecules 15:1928–1932. doi:10.1021/bm5002944
Liu WJ, Yao C, Wang MH, Ji JL, Ying L, Fu CY (2012) Kinetics
and thermodynamics characteristics of cationic yellow
X-GL adsorption on attapulgite/rice hull-based activated
carbon nanocomposites. Environ Prog Sustain Energy
32:655–662. doi:10.1002/ep.11680
1 3
2454 Cellulose (2015) 22:2443–2456
http://dx.doi.org/10.3390/nano2020187http://dx.doi.org/10.3390/nano2020187http://dx.doi.org/10.1016/j.cej.2014.08.030http://dx.doi.org/10.1016/j.carbpol.2014.02.034http://dx.doi.org/10.1016/j.biortech.2005.05.001http://dx.doi.org/10.1039/c2ra01071bhttp://dx.doi.org/10.1007/s10570-012-9769-2http://dx.doi.org/10.1007/s10570-012-9769-2http://dx.doi.org/10.1016/j.cej.2012.06.059http://dx.doi.org/10.1016/j.cej.2010.12.038http://dx.doi.org/10.1016/j.cej.2010.12.038http://dx.doi.org/10.1016/j.molliq.2014.07.034http://dx.doi.org/10.1021/bm1000247http://dx.doi.org/10.1016/j.carbpol.2010.12.029http://dx.doi.org/10.1016/j.carbpol.2010.12.029http://dx.doi.org/10.1021/cr900339whttp://dx.doi.org/10.1139/cjc-2013-0165http://dx.doi.org/10.2166/wst.2010.388http://dx.doi.org/10.1021/bm070113bhttp://dx.doi.org/10.1039/C0NR00583Ehttp://dx.doi.org/10.1039/C0NR00583Ehttp://dx.doi.org/10.1007/s10570-010-9413-yhttp://dx.doi.org/10.1007/s10570-010-9413-yhttp://dx.doi.org/10.1016/j.carbpol.2014.06.048http://dx.doi.org/10.1016/j.carbpol.2014.06.048http://dx.doi.org/10.1016/j.cej.2011.08.051http://dx.doi.org/10.1021/bm0000337http://dx.doi.org/10.1016/j.carbpol.2003.10.013http://dx.doi.org/10.1016/j.carbpol.2003.10.013http://dx.doi.org/10.1002/anie.200460587http://dx.doi.org/10.1002/anie.200460587http://dx.doi.org/10.1016/j.msec.2009.01.006http://dx.doi.org/10.1021/bm5002944http://dx.doi.org/10.1002/ep.11680http://dx.doi.org/10.1002/ep.11680http://dx.doi.org/10.1021/bm5002944http://dx.doi.org/10.1016/j.msec.2009.01.006http://dx.doi.org/10.1002/anie.200460587http://dx.doi.org/10.1002/anie.200460587http://dx.doi.org/10.1016/j.carbpol.2003.10.013http://dx.doi.org/10.1016/j.carbpol.2003.10.013http://dx.doi.org/10.1021/bm0000337http://dx.doi.org/10.1016/j.cej.2011.08.051http://dx.doi.org/10.1016/j.carbpol.2014.06.048http://dx.doi.org/10.1016/j.carbpol.2014.06.048http://dx.doi.org/10.1007/s10570-010-9413-yhttp://dx.doi.org/10.1007/s10570-010-9413-yhttp://dx.doi.org/10.1039/C0NR00583Ehttp://dx.doi.org/10.1039/C0NR00583Ehttp://dx.doi.org/10.1021/bm070113bhttp://dx.doi.org/10.2166/wst.2010.388http://dx.doi.org/10.1139/cjc-2013-0165http://dx.doi.org/10.1021/cr900339whttp://dx.doi.org/10.1016/j.carbpol.2010.12.029http://dx.doi.org/10.1016/j.carbpol.2010.12.029http://dx.doi.org/10.1021/bm1000247http://dx.doi.org/10.1016/j.molliq.2014.07.034http://dx.doi.org/10.1016/j.cej.2010.12.038http://dx.doi.org/10.1016/j.cej.2010.12.038http://dx.doi.org/10.1016/j.cej.2012.06.059http://dx.doi.org/10.1007/s10570-012-9769-2http://dx.doi.org/10.1007/s10570-012-9769-2http://dx.doi.org/10.1039/c2ra01071bhttp://dx.doi.org/10.1016/j.biortech.2005.05.001http://dx.doi.org/10.1016/j.carbpol.2014.02.034http://dx.doi.org/10.1016/j.cej.2014.08.030http://dx.doi.org/10.3390/nano2020187http://dx.doi.org/10.3390/nano2020187
-
8/18/2019 Amino-functionalized Nanocrystalline Cellulose
13/14
Liu P, Sehaqui H, Tingaut P, Wichser A, Oksman K, Mathew
AP (2014) Biobased nanomaterials for capturing silver ions
(Ag?) from water via surface adsorption. Cellulose
21:449–461. doi:10.1007/s10570-013-0139-5
Lu P, Hsieh YL (2012) Preparation and characterization of
cellulose nanocrystals from rice straw. Carbohydr Polym
87:564–573. doi:10.1016/j.carbpol.2011.08.022
Lu TH, Li Q, Chen WH, Yu HP (2014) Composite aerogels
based on dialdehyde nanocellulose and collagen for po-
tential applications as wound dressing and tissue engi-
neering scaffold. Compos Sci Technol 94:132–138. doi:10.
1016/j.compscitech.2014.01.020
Ma H, Burger C, Hsiao BS, Chu B (2012) Nanofibrous micro-
filtration membrane based on cellulose nanowhiskers.
Biomacromolecules 13:180–186. doi:10.1021/bm201421g
Magriotis ZM, Vieira SS, Saczk AA, Santos NAV, Stradiotto
NR (2014) Removal of dyes by lignocellulose adsorbents
originating from biodiesel production. J Environ Chem
Eng 2:2199–2210. doi:10.1016/j.jece.2014.09.012
Missoum K, Belgacem MN, Bras J (2013) Nanofibrillated cel-
lulose surface modification: a review. Materials 6:1745–
1766. doi:10.3390/ma6051745Murphy V, Hughes H, McLoughlin P (2008) Comparative study
of chromium biosorption by red, green and brown seaweed
biomass. Chemosphere 70:1128–1134. doi:10.1016/j.
chemosphere.2007.08.015
Musyoka SM, Ngila JC, Moodley B, Petrik LA (2011) Syn-
thesis, characterization, and adsorption kinetic studies of
ethylenediamine modified cellulose for removal of Cd and
Pb. Anal Lett 44:1925–1936. doi:10.1080/00032719.2010.
539736
Nair V, Panigrahy A, Vinu R (2014) Development of novel
chitosan–lignin composites for adsorption of dyes and
metal ions from wastewater. Chem Eng J 254:491–502.
doi:10.1016/j.cej.2014.05.045
Oh SY, Yoo DI, Shin Y, Kim HC, Kim HY, Chung YS, Park WH, Youk JH (2005) Crystalline structure analysis of
cellulose treated with sodium hydroxide and carbon diox-
ide by means of X-ray diffraction and FT-IR spectroscopy.
Carbohydr Res 340:2376–2391. doi:10.1016/j.carres.2005.
08.007
Pahimanolis N, Hippi U, Johansson LS, Saarinen T, Houbenov
N, Ruokolainen J, Seppala J (2011) Surface functional-
ization of nanofibrillated cellulose using click-chemistry
approach in aqueous media. Cellulose 18:1201–1212.
doi:10.1007/s10570-011-9573-4
Pan SB, Ragauskas AJ (2014) Enhancement of nanofibrillation
of softwood cellulosic fibers by oxidation and sulfonation.
Carbohydr Polym 111:514–523. doi: 10.1016/j.carbpol.
2014.04.096
Pearce CI, Lloyd JR, Guthrie JT (2003) The removal of colour
from textile wastewater using whole bacterial cells: a re-
view. Dyes Pigment 58:179–196. doi:10.1016/j.cej.2011.
12.013
Pei A, Butchosa N, Berglund LA, Zhou Q (2013) Surface
quaternized cellulose nanofibrils with high water ab-
sorbency and adsorption capacity for anionic dyes. Soft
Matter 9:2047–2055. doi:10.1039/C2SM27344F
Piccin JS, Gomes CS, Feris LA, Gutterres M (2012) Kinetics
and isotherms of leather dye adsorption by tannery solid
waste. Chem Eng J 183:30–38. doi:10.1016/j.cej.2011.12.
013
Roy D, Semsarilar M, Guthrie JT, Perrier S (2009) Cellulose
modification by polymer grafting: a review. Chem Soc Rev
38:2046–2064. doi:10.1039/B808639G
Sabzalian Z, Alam MN, Van de Ven TGM (2014) Hydropho-
bization and characterization of internally crosslink-rein-
forced cellulose fibers. Cellulose 21:1381–1393. doi:10.
1007/s10570-014-0178-6
Savage N, Diallo MS (2005) Nanomaterials and water purifi-
cation: opportunities and challenges. J Nanopart Res
7:331–342. doi:10.1007/s11051-005-7523-5
Segal L, Creely JJ, Martin AE Jr, Conrad CM (1959) An em-
pirical method for estimating the degree of crystallinity of
native cellulose using X-ray diffractometer. Text Res J
29:786–794. doi:10.1177/004051755902901003
Silva LS, Lima LCB, Silva FC, Matos JME, Santos MRMC,
Santos LS Jr (2013) Dye anionic sorption in aqueous so-
lution onto a cellulose surface chemically modified with
aminoethanethiol. Chem Eng J 218:89–98. doi:10.1016/j.
cej.2012.11.118
Sirviö J, Hyväkkö U, Liimatainen H, Niinimäki J, Hormi O (2011)Periodate oxidation of cellulose at elevated temperatures us-
ing metal salts as cellulose activators. Carbohydr Polym
83:1293–1297. doi:10.1016/j.carbpol.2010.09.036
Sirviö JA, Kolehmainen A, Visanko M, Liimatainen H, Niin-
imäki J, Hormi OE (2014) Strong, self-standing oxygen
barrier films from nanocelluloses modified with re-
gioselective oxidative treatments. ACS Appl Mater Inter-
faces 6:14384–14390. doi:10.1021/am503659j
Unuabonah EI, Taubert A (2014) Clay-polymer nanocomposites
(CPNs): adsorbents of the future for water treatment. Appl
Clay Sci 99:83–92. doi:10.1016/j.clay.2014.06.016
Unuabonah EI, El-Khaiary MI, Olu-Owolabi BI, Adebowale
KO (2012) Predicting the dynamics and performance of a
polymer-clay based composite in a fixed bed system for theremoval of lead (II) ion. Chem Eng ResDes 90:1105–1115.
doi:10.1016/j.cherd.2011.11.009
Vakili M, Rafatulah M, Salamatinia B, Abdullah AZ, Ibrahim
MH, Tan KB, Gholami Z, Amouzgar P (2014) Application
of chitosan and its derivatives as adsorbents for dye re-
moval from water and waste water: a review. Carbohydr
Polym 113:115–130. doi:10.1016/j.carbpol.2014.07.007
Vargas AMM, Cazetta AL, Martins AC, Moraes JCG, Garcia
EE, Gauze GF, Costa WF, Almeida VC (2012) Kinetic and
equilibrium studies: adsorption of food dyes acid yellow 6,
acid yellow 23, and acid red 18 on activated carbon from
flamboyant pods. Chem Eng J 181–182:243–250. doi:10.
1016/j.cej.2011.11.073
Varma AJ, Chavan VB (1995) A study of crystallinity changes
in oxidized celluloses. Polym Degrad Stab 49:245–250.
doi:10.1016/0141-3910(95)87006-7
Visanko M, Liimatainen H, Sirviö J, Heiskanen J, Hormi O, Ni-
inimäki J (2014) Amphiphilic cellulose nanocrystals from
acid-free oxidative treatment: physico-chemical characteris-
tics and use as an oil-water stabilizer. Biomacromolecules
15:2769–2775. doi:10.1021/bm500628g
Wang LJ, Li J (2013) Adsorption of C.I. Reactive red 228 dye
from aqueous solution by modified cellulose from flax
shive: kinetics, equilibrium, and thermodynamics. Ind
1 3
Cellulose (2015) 22:2443–2456 2455
http://dx.doi.org/10.1007/s10570-013-0139-5http://dx.doi.org/10.1016/j.carbpol.2011.08.022http://dx.doi.org/10.1016/j.compscitech.2014.01.020http://dx.doi.org/10.1016/j.compscitech.2014.01.020http://dx.doi.org/10.1021/bm201421ghttp://dx.doi.org/10.1016/j.jece.2014.09.012http://dx.doi.org/10.3390/ma6051745http://dx.doi.org/10.1016/j.chemosphere.2007.08.015http://dx.doi.org/10.1016/j.chemosphere.2007.08.015http://dx.doi.org/10.1080/00032719.2010.539736http://dx.doi.org/10.1080/00032719.2010.539736http://dx.doi.org/10.1016/j.cej.2014.05.045http://dx.doi.org/10.1016/j.carres.2005.08.007http://dx.doi.org/10.1016/j.carres.2005.08.007http://dx.doi.org/10.1007/s10570-011-9573-4http://dx.doi.org/10.1016/j.carbpol.2014.04.096http://dx.doi.org/10.1016/j.carbpol.2014.04.096http://dx.doi.org/10.1016/j.cej.2011.12.013http://dx.doi.org/10.1016/j.cej.2011.12.013http://dx.doi.org/10.1039/C2SM27344Fhttp://dx.doi.org/10.1016/j.cej.2011.12.013http://dx.doi.org/10.1016/j.cej.2011.12.013http://dx.doi.org/10.1039/B808639Ghttp://dx.doi.org/10.1007/s10570-014-0178-6http://dx.doi.org/10.1007/s10570-014-0178-6http://dx.doi.org/10.1007/s11051-005-7523-5http://dx.doi.org/10.1177/004051755902901003http://dx.doi.org/10.1016/j.cej.2012.11.118http://dx.doi.org/10.1016/j.cej.2012.11.118http://dx.doi.org/10.1016/j.carbpol.2010.09.036http://dx.doi.org/10.1021/am503659jhttp://dx.doi.org/10.1016/j.clay.2014.06.016http://dx.doi.org/10.1016/j.cherd.2011.11.009http://dx.doi.org/10.1016/j.carbpol.2014.07.007http://dx.doi.org/10.1016/j.cej.2011.11.073http://dx.doi.org/10.1016/j.cej.2011.11.073http://dx.doi.org/10.1016/0141-3910(95)87006-7http://dx.doi.org/10.1021/bm500628ghttp://dx.doi.org/10.1021/bm500628ghttp://dx.doi.org/10.1016/0141-3910(95)87006-7http://dx.doi.org/10.1016/j.cej.2011.11.073http://dx.doi.org/10.1016/j.cej.2011.11.073http://dx.doi.org/10.1016/j.carbpol.2014.07.007http://dx.doi.org/10.1016/j.cherd.2011.11.009http://dx.doi.org/10.1016/j.clay.2014.06.016http://dx.doi.org/10.1021/am503659jhttp://dx.doi.org/10.1016/j.carbpol.2010.09.036http://dx.doi.org/10.1016/j.cej.2012.11.118http://dx.doi.org/10.1016/j.cej.2012.11.118http://dx.doi.org/10.1177/004051755902901003http://dx.doi.org/10.1007/s11051-005-7523-5http://dx.doi.org/10.1007/s10570-014-0178-6http://dx.doi.org/10.1007/s10570-014-0178-6http://dx.doi.org/10.1039/B808639Ghttp://dx.doi.org/10.1016/j.cej.2011.12.013http://dx.doi.org/10.1016/j.cej.2011.12.013http://dx.doi.org/10.1039/C2SM27344Fhttp://dx.doi.org/10.1016/j.cej.2011.12.013http://dx.doi.org/10.1016/j.cej.2011.12.013http://dx.doi.org/10.1016/j.carbpol.2014.04.096http://dx.doi.org/10.1016/j.carbpol.2014.04.096http://dx.doi.org/10.1007/s10570-011-9573-4http://dx.doi.org/10.1016/j.carres.2005.08.007http://dx.doi.org/10.1016/j.carres.2005.08.007http://dx.doi.org/10.1016/j.cej.2014.05.045http://dx.doi.org/10.1080/00032719.2010.539736http://dx.doi.org/10.1080/00032719.2010.539736http://dx.doi.org/10.1016/j.chemosphere.2007.08.015http://dx.doi.org/10.1016/j.chemosphere.2007.08.015http://dx.doi.org/10.3390/ma6051745http://dx.doi.org/10.1016/j.jece.2014.09.012http://dx.doi.org/10.1021/bm201421ghttp://dx.doi.org/10.1016/j.compscitech.2014.01.020http://dx.doi.org/10.1016/j.compscitech.2014.01.020http://dx.doi.org/10.1016/j.carbpol.2011.08.022http://dx.doi.org/10.1007/s10570-013-0139-5
-
8/18/2019 Amino-functionalized Nanocrystalline Cellulose
14/14
Crops Prod 42:153–158. doi:10.1016/j.indcrop.2012.05.
031
Way AE, Hsu L, Shanmuganathan K, Weder C, Rowan SJ
(2012) pH-Responsive cellulose nanocrystal gels and
nanocomposites. ACS Macro Lett 1:1001–1006. doi:10.
1021/mz30030061
Yagub MT, Sen TK, Afroze S, Ang HM (2014) Dye and its
removal from aqueous solution by adsorption: a review.
Adv Colloid Interface J 209:172–184. doi:10.1016/j.cis.
2014.04.002
Zaman M, Xiao HN, Chibante F, Ni YH (2012) Synthesis and
characterization of cationically modified nanocrystalline
cellulose. Carbohydr Polym 89:163–170. doi:10.1016/j.
carbpol.2012.02.066
Zhou CJ, Wu QL, Lei TZ, Negulescu II (2014) Adsorption ki-
netic and equilibrium studies for methylene blue dye by
partially hydrolyzed polyacrylamide/cellulose nanocrystal
nanocomposite hydrogels. Chem Eng J 251:17–24. doi:10.
1016/j.cej.2014.04.034
1 3
2456 Cellulose (2015) 22:2443–2456
http://dx.doi.org/10.1016/j.indcrop.2012.05.031http://dx.doi.org/10.1016/j.indcrop.2012.05.031http://dx.doi.org/10.1021/mz30030061http://dx.doi.org/10.1021/mz30030061http://dx.doi.org/10.1016/j.cis.2014.04.002http://dx.doi.org/10.1016/j.cis.2014.04.002http://dx.doi.org/10.1016/j.carbpol.2012.02.066http://dx.doi.org/10.1016/j.carbpol.2012.02.066http://dx.doi.org/10.1016/j.cej.2014.04.034http://dx.doi.org/10.1016/j.cej.2014.04.034http://dx.doi.org/10.1016/j.cej.2014.04.034http://dx.doi.org/10.1016/j.cej.2014.04.034http://dx.doi.org/10.1016/j.carbpol.2012.02.066http://dx.doi.org/10.1016/j.carbpol.2012.02.066http://dx.doi.org/10.1016/j.cis.2014.04.002http://dx.doi.org/10.1016/j.cis.2014.04.002http://dx.doi.org/10.1021/mz30030061http://dx.doi.org/10.1021/mz30030061http://dx.doi.org/10.1016/j.indcrop.2012.05.031http://dx.doi.org/10.1016/j.indcrop.2012.05.031