Polymers and Nanoscience and Technology
Polymers and nanoscience & technology are very much
interrelated. One of the intrinsic length scales of polymers is the nanoscale
and therefore much of the design of polymeric materials is concerned with
control of structure and properties on that length scale. We have a number of
programmes which are overlay the current Governement led initiative in nano
science and technology.
Power
The Proton Exchange Membrane Fuel Cell is
now beginning to approach viability However, the costs associated with fuel cell
technology are still at least an order of magnitude too high for widespread
acceptance in the automotive field. The fuel cell component which currently
controls both cost and performance in this type of power source is the
membrane-electrode assembly, comprising a thin film of proton-conducting ionomer
laminated on each side to a layer of transition-metal catalyst and thence to a
porous gas-diffusion electrode. Current work at Reading is focused on the
development of new types of the essential membrane materials with a particular
focus on reducing costs.
Supercapacitors are essential for the effective
development of electric vehicles. They allow rapid charging and discharging to
take place and thus are effective in the power optimisation in electric vehicles
and in the use of hybrid power-trains. Currently, a number of small scale high
performance supercapacitors have become available commercially for use in
relatively low power electronic applications. However, it is difficult to
envisage how such existing devices can be economically scaled-up for
exploitation in large vehicles. Work at Reading has led to the development of a
new low cost approach to the production of nitrogen containing high surface area
carbon nano particles. When these are incorporated in to prototype
supercapacitors they exhibit power densities which are in excess of current
industry targets.
Smart materials
We have discovered how nano and micro conducting particles
can be dispersed in deformable media to yield materials whose electrical
conductivities remarkably increases rather decreases upon deformation. We are
exploring the potential for these novel materials as sensors and for use in
smart textiles.
The development of molecular sized wires has been a key
target in the field of molecular electronics and current work at Reading is
making considerable inroads towards realising this target. The approach taken is
to polymerise within a nanostructured tempate with very well defined porous
columns. The approach has considerable flexibility and a range of wires can be
prepared.
Nanocomposites
There is world-wide interest in the inclusion of nano-particles
in synthetic polymers to enhance existing and define new properties. We are
exploiting the expertise at Reading in time-resolving x-ray and neutron
scattering techniques to develop an understanding of how nano-particles such as
clays are mixed and exfoliated within a polymer matrix during flow.
We have discovered how small quantities of
a low molar mass compund can be dispersed in polymers including biodegradable
systems to provide a self-assembling nanoscale framework which directs the
subsequent crystallisation to yield high levels of crystal orientation. This
control can have a marked influence on the properties of the final material. We
are exploring this new approach in a variety of materials including those used
for preparing medical implants and scaffolds.
Optical
Photonic crystals provide the analogous properties for
light as semi-conductors provide for electrons. Self-assembly is seen as the key
in this materials demanding area. We are developing novel polymers for use in
self-assembling photonic crystals for exploitation in the visible and infra-red
regions spectrum
Security is a vital area in today's society and we have
initiated a major programme to develop novel security devices which use nano-structured
surfaces to define the optical properties of thin films. These are designed at
the outset to have the potential for volume manufacturing to facilitate use in
protecting documents, ID cards and high value goods.
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