Transcript Nano-technologies for textile and clothing

Nanotechnologies for
Textiles, Clothing and
Footwear
Dr. Jimmy Lam
Institute of Textiles & Clothing
Agenda
• Introduction
• Applications
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Nano-fibres
Nano-composite fibres
Carbon nano-tubes
Nano-coated fibres
• Future Prospects
Introduction
• 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
nano-technology
• 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-technology2
• 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
nano-technology3
• 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-technology4
• Nano-technology has been termed a “bottomup” 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 nanotechnogies 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
materials.
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
characteristics.
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:
nanofibres
• 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
diameters.
Electro-spinning
Nano-fibres
Example1:
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 nanofibres are in filtration, wound
dressings, tissue engineering, nanocomposites, drug delivery devices and
sensors.
Example2:
nano-composites fibres
• Nano-composite fibres consist of nanofibres 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
obtained.
Nano-composite fibres
Example3:
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
properties:
– 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
currents.
Carbon Nano-tubes
Example4:
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.
Example4:
Nano-coated fibres2
• Nano-coating of textile fabrics,
complete finished garments or shoes
can be obtained by plasma polymer
treatment.
• 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.
Nano-coating
Plasma Treatment
Example4:
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
materials;
– Develop smart and intelligent textiles with novel
functions;
– 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.
References
• Nano-technologies for Textile,
Clothing, and Footwear by Ian Holme,
• Textile Magazine 2005, Vol.32, No. 1,
p.7.