Nano coated fibres2 Nano coating of textile fabrics

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					Nanotechnologies for
Textiles, Clothing and
          Dr. Jimmy Lam
  Institute of Textiles & Clothing
• Introduction
• Applications
  –   Nano-fibres
  –   Nano-composite fibres
  –   Carbon nano-tubes
  –   Nano-coated fibres
• Future Prospects
• Nano is derived from the Greek word,
  nanos, meaning dwarf, and in SI units,
  the prefix nano is used as a factor
  indicating 10-9.
• One nanometer (nm) is 0.000000001m
• By comparison, the diameter of single
  human hair is 80,000nm, and human red
  blood cell is 7000nm wide and a water
  molecule is almost 0.3nm.
      Nano-science and
• Both nano-science and nano-technology are
  concerned with materials that are very small.
• Nano-scale has generally been taken to lie
  from 0.2nm (atom) to 100nm.
• Nano-science is defined as the study of
  phenomena and manipulation of materials at
  atomic, molecular and macro-molecular
  scales, where the properties of materials
  differ markedly from those at larger scale.
      Nano-science and
• Nano-technologies, on the other hand, refer
  to the design, characterisation, production
  and application of structures, devices and
  systems, by controlling shape and size at the
  nano-metre scale.
• Nano-technologies may be considered as a
  range of methods of manufacturing materials
  along the lines of atomic assembly.
     Nano-science and
• Atoms, molecules and nano-sized
  materials are thereby manipulated in a
  thorough, precise and controlled
  manner to produce novel materials with
  innovative and different properties to
  those obtained by conventional material
  engineering at the micro-scale.
      Nano-science and
• Nano-technology has been termed a “bottom-
  up” technology because of the use of such
  small scale building units.
• Conventional materials engineering at the
  macro-scale is, by contrast, considered as a
  “top-down” approach.
• The use of nano-science and nano-technology
  to control the internal structure of a
  material at nano-scale is considered to lead
  to materials with fewer defects and hence
  of a higher quality.
 Application of nano-
technogies for textile
     Three approaches
1. For nano-materials that are nano-scale in
   one dimesion, application of very thin
   surface coating (2nm-100nm) to textile
2. Nano-fibres and nanotubes are esentially
   nano-scale in two dimensions and their
   utilization in many forms of composite
   materials offers opportunities for improve
   the mechanical properties, altering
   electrical, optical or biological
     Three approaches
3. The third approach involves the use
   of nano-particles (nano-scale in three
   dimensions) for incorporation in
   fibres, coating, films to provide a
   myriad of possibilities such as
   imparting antimicrobial, flame
   retardant and chemical softening
   effects to textiles and clothing.
             Example 1:
• Nano-fibres are generally taken to be fibres with a
  diameter less than 1μm (100nm).
• Electrospinning is the major fibre production
  method used to make nano-fibres.
• In this method a polymer fluid (melt or soloution) is
  charged with a high electrical voltage and extruded
  through a spinneret of 0.1-1nm in diameter, the
  extruded polymer jet being drawn towards an
  earthered collector.
• By manipulation of the electro-spinning conditions,
  micro-filaments can be produced with different
        nanofibres 2
• Nano-fibres produced from synthetic
  fibre materials can be formed with a
  high surface area to volume ratio and
  small 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 and
 nano-composites fibres
• Nano-composite fibres consist of nano-
  fibres containing particles with one
  dimension in the nano-metre range.
• The particles may be spheres, fibrils and by
  varying the amounts, their alignment, and
  distribution within the nano-fibre
  improvements in the mechanical, electrical,
  optical or biological properties may be
Nano-composite fibres
     Carbon nano-tubes
• The carbon nano-tubes essentially consist
  of tiny shells of graphite rolled up into
  cylinders, either as single tubes or multiple
  tubes joined together.
• The carbon nano-tubes exhibit remarkable
  – a tensile strength some one hundred times that
    of steel at one sixth of the weight.
  – A thermal conductivity superior to all but the
    purest diamond;
  – Electrical conductivity similar to copper but with
    an ability to carry much higher electrical
Carbon Nano-tubes
    Nano-coated fibres
• Nano-coating the surfaces of textiles,
  clothing and textiles for footwear is one
  approach to the production of highly
  effective anti-microbial treatments for
  killing the bacteria that can lead to
  malodour formation. electrical currents.
• The nano-coating is held on the fibre
  surface by strong electrostatic and
  hydrogen bonds and punctures the bacterial
  wall, killing bacteria that can accumulate in
  textiles and clothing through the retention
  of human respiration exuded through
  physical activity and wear.
   Nano-coated fibres2
• Nano-coating of textile fabrics,
  complete finished garments or shoes
  can be obtained by plasma polymer
• Plasma is the fourth state of matter
  (after solid, liquids and gases) which
  was proposed by Sir William Crookers,
  as a result of experiments in the
  passage of electricity through gases.
Plasma Treatment
   Nano-coated fibres3
• A plasma generated by electrical discharge
  through gas consists of a mixture of
  positive and negative ions, electrons, free
  readicals, ultraviolet radiation, and many
  different electronically excited molecules.
• By vary the conditions of the plasma
  treatment and the nature of the specific
  gas presents, a variety of surface
  treatments can be produced that change
  the chemical or physical nature of the fibre
  surface, thereby radically altering all
  treatments that depend upon fibre
  adhesion, eg coating, lamination and bonding.
        Future prospects
• The main trust in nano-technologies applied to
  textiles, clothing and footwear will be to:
   – Improve the properties and performance of existing
   – Develop smart and intelligent textiles with novel
   – 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 potential
  for the future and could radically change
  consumer perception of what constitutes a
  “standard” apparel fabric.
• Nano-technologies for Textile,
  Clothing, and Footwear by Ian Holme,
• Textile Magazine 2005, Vol.32, No. 1,

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