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    Nanotechnologies for

    Textiles, Clothing andFootwear

    Dr. Jimmy LamInstitute of Textiles & Clothing

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    Agenda Introduction Applications

    Nano-fibres Nano-composite fibres Carbon nano-tubes Nano-coated fibres

    Future Prospects

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    Introduction Nano is derived from the Greek word,nanos, meaning dwarf, and in SI units,the prefix nano is used as a factorindicating 10-9.

    One nanometer (nm) is 0.000000001m By comparison, the diameter of single

    human hair is 80,000nm, and human redblood cell is 7000nm wide and a watermolecule is almost 0.3nm.

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    Nano-science and

    nano-technology Both nano-science and nano-technology are

    concerned with materials that are very small.

    Nano-scale has generally been taken to liefrom 0.2nm (atom) to 100nm.

    Nano-science is defined as the study ofphenomena and manipulation of materials at

    atomic, molecular and macro-molecularscales, where the properties of materialsdiffer markedly from those at larger scale.

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    Nano-science and

    nano-technology2 Nano-technologies, on the other hand, refer

    to the design, characterisation, production

    and application of structures, devices andsystems, by controlling shape and size at thenano-metre scale.

    Nano-technologies may be considered as a

    range of methods of manufacturing materialsalong the lines of atomic assembly.

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    Nano-science and

    nano-technology3 Atoms, molecules and nano-sized

    materials are thereby manipulated in a

    thorough, precise and controlledmanner to produce novel materials withinnovative and different properties to

    those obtained by conventional materialengineering at the micro-scale.

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    Nano-science and

    nano-technology4 Nano-technology has been termed a bottom-up technology because of the use of suchsmall scale building units.

    Conventional materials engineering at themacro-scale is, by contrast, considered as atop-down approach.

    The use of nano-science and nano-technology

    to control the internal structure of amaterial at nano-scale is considered to leadto materials with fewer defects and henceof a higher quality.

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    Application of nano-technogies for textile

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    Three approaches1. For nano-materials that are nano-scale inone dimesion, application of very thinsurface coating (2nm-100nm) to textile

    materials.2. Nano-fibres and nanotubes are esentiallynano-scale in two dimensions and theirutilization in many forms of compositematerials offers opportunities for improve

    the mechanical properties, alteringelectrical, optical or biologicalcharacteristics.

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    Three approaches3. The third approach involves the useof nano-particles (nano-scale in three

    dimensions) for incorporation infibres, coating, films to provide amyriad of possibilities such asimparting antimicrobial, flameretardant and chemical softeningeffects to textiles and clothing.

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    Example 1:

    nanofibres Nano-fibres are generally taken to be fibres with adiameter less than 1m (100nm).

    Electrospinning is the major fibre production

    method used to make nano-fibres. In this method a polymer fluid (melt or soloution) ischarged with a high electrical voltage and extrudedthrough a spinneret of 0.1-1nm in diameter, theextruded polymer jet being drawn towards an

    earthered collector. By manipulation of the electro-spinning conditions,

    micro-filaments can be produced with differentdiameters.

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    Electro-spinning

    Nano-fibres

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    Example1:

    nanofibres 2 Nano-fibres produced from syntheticfibre materials can be formed with ahigh surface area to volume ratio andsmall pores sizes in fabric form.

    The potential end uses for such nano-fibres are in filtration, wound

    dressings, tissue engineering, nano-composites, drug delivery devices andsensors.

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    Example2:

    nano-composites fibres Nano-composite fibres consist of nano-fibres containing particles with onedimension in the nano-metre range.

    The particles may be spheres, fibrils and byvarying the amounts, their alignment, anddistribution within the nano-fibre

    improvements in the mechanical, electrical,optical or biological properties may beobtained.

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    Nano-composite fibres

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    Example3:

    Carbon nano-tubes The carbon nano-tubes essentially consistof tiny shells of graphite rolled up intocylinders, either as single tubes or multiple

    tubes joined together. The carbon nano-tubes exhibit remarkableproperties: a tensile strength some one hundred times that

    of steel at one sixth of the weight.

    A thermal conductivity superior to all but thepurest diamond;

    Electrical conductivity similar to copper but withan ability to carry much higher electricalcurrents.

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    Carbon Nano-tubes

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    Example4:

    Nano-coated fibres Nano-coating the surfaces of textiles,clothing and textiles for footwear is oneapproach to the production of highly

    effective anti-microbial treatments forkilling the bacteria that can lead tomalodour formation. electrical currents.

    The nano-coating is held on the fibresurface by strong electrostatic and

    hydrogen bonds and punctures the bacterialwall, killing bacteria that can accumulate intextiles and clothing through the retentionof human respiration exuded throughphysical activity and wear.

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    Example4:

    Nano-coated fibres2 Nano-coating of textile fabrics,complete finished garments or shoes

    can be obtained by plasma polymertreatment.

    Plasma is the fourth state of matter

    (after solid, liquids and gases) whichwas proposed by Sir William Crookers,as a result of experiments in thepassage of electricity through gases.

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    Nano-coating

    Plasma Treatment

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    Example4:

    Nano-coated fibres3 A plasma generated by electrical dischargethrough gas consists of a mixture ofpositive and negative ions, electrons, free

    readicals, ultraviolet radiation, and manydifferent electronically excited molecules. By vary the conditions of the plasma

    treatment and the nature of the specificgas presents, a variety of surface

    treatments can be produced that changethe chemical or physical nature of the fibresurface, thereby radically altering alltreatments that depend upon fibreadhesion, eg coating, lamination and bonding.

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    Future prospects

    The main trust in nano-technologies applied totextiles, clothing and footwear will be to: Improve the properties and performance of existing

    materials;

    Develop smart and intelligent textiles with novelfunctions;

    Greatly increase the use of fibres in technical textiles,biomedical and healthcare options; and

    Open up new opportunities for fibres as sensors.

    Overall, nano-technologies offer great potentialfor the future and could radically changeconsumer perception of what constitutes astandard apparel fabric.

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    References Nano-technologies for Textile,Clothing, and Footwear by Ian Holme,

    Textile Magazine 2005, Vol.32, No. 1,p.7.