Flexible Conductive Polymer Membranes

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Unlike most manmade plastics that are insulator to electricity, conductive polymers can conduct electricity owning to their specific chemical structure called conjugation. Upon doping, i.e., addition of charged molecules, the originally localized charges in conjugated polymer chains become mobilized to carry electricity through the material. Examples include polypyrrole, polythiophene and polyaniline. However, it is also because of this conjugated molecular structure conductive polymers are mostly rigid, brittle and non-flexible. The lack of mechanical flexibility has greatly limited their applications in areas such as membrane and energy storage technologies. To overcome this drawback conductive polymers are often composed with other flexible polymers to gain mechanical performance, for example, coated on textiles or on flexible polymer membrane surface. Such coating has to be very thin otherwise it will compromise the mechanical property of the substrate. The coating also easily delaminates and often detaches from the substrate. In literature there has been no report on thick flexible membranes made of unmodified intrinsically conductive polymers. ***PI's group recently discovered a simple synthetic process to prepare large sized thick (up to 1 mm) nanoporous polypyrrole membranes with excellent membrane flexibility at room temperature and all way down to liquid nitrogen temperature that is -196 oC. This polypyrrole membrane has very high surface area, good electrical conductivity, and is extremely light. Scientifically this is the first discovery of flexible polypyrrole. Such membrane may have great potential in wide spectrum of applications such as energy storage, battery, antieletrostatic and field shielding, owing to its high surface area, electrical conductivity and ionic activity, lightness and low temperature performance. However, we still don't know the mechanism about how such structure is formed and why it has such flexibility even at -195 oC. ******This proposal is aiming at following objectives: 1. To investigate how such membrane is formed; 2. To study the structure-property relationship of the membrane. 3. To investigate the possibility of producing similar membrane with other types of conductive polymers. 4. To identify the potential application of such membranes, including the functionalization of the membranes during or after synthesis.******This project will train 2 highly qualified personnel, one with background in polymer chemistry and polymer engineering, to work on synthesis and membrane analysis. Another with background in material mechanics, to study the how the mechanical properties are related with nanostructures.