Scratching the Surface of Intelligent Materials: Characterisation Methods for Conducting Polymer Films

One essential aspect of an intelligent material is that it has some properties which are dynamic which can be utilised and controlled. It is well known that a number of polymeric materials are inherently dynamic. In order to utilise the full potential of polymers for use as intelligent materials it is imperative that processes occurring at the polymer interface are well understood. A large range of surface and other techniques are available to characterise this. At IPRL we has devel oped over a number of years intelligent material systems based on conducting polymers such as polypyrrole. This range of materials has been used as coated films, particles or stand-alone mem branes in systems designed either to sense/monitor the environment or to effect a separation. Poly pyrrole based systems are able to perform sophisticated functions because the polymer is a dynamic material which can change its chemical and physical properties by application of an electrical poten tial (thereby altering the oxidation state of the polymer). This change is accompanied by movement of ions in and out of the material. The paper presents results for a number of characterisation tech niques which elucidate what is happening at the polymer-solution interface such as cyclic voltametry and quartz crystal microbalance, together with other surface techniques such as scanning electron microscopy and the atomic force microscope which provide a microscopic picture of the polymer surface. It is shown that only by using a wide range of techniques is it possible to gain a full understanding of the unique properties of intelligent material such as polypyrrole. Only then can it be said that one is truly more than just scratching the surface.

[1]  Huijun Zhao,et al.  Transport across stand-alone conducting polypyrrole membranes containing dodecylsulfate counterions , 1994 .

[2]  G. Wallace,et al.  Effect of the counterion employed during synthesis on the properties of polypyrrole membranes , 1994 .

[3]  Huijun Zhao,et al.  Adaptive Membrane Systems Based on Conductive Electroactive Polymers , 1993 .

[4]  G. Wallace,et al.  Transport of copper(II) across stand-alone conducting polypyrrole membranes: the effect of applied potential waveforms , 1993 .

[5]  William E. Price,et al.  Electrochemically controlled transport across conducting polymer composites — Basis of smart membrane materials , 1993 .

[6]  Huijun Zhao,et al.  Electrochemically controlled transport of potassium chloride across a conducting electro-active polymer membrane , 1992 .

[7]  G. Mitchell,et al.  The role of the counter-ion in the preparation of polypyrrole films with enhanced properties using a pulsed electrochemical potential , 1992 .

[8]  G. Wallace,et al.  Development of a polymer-based electrode for selective detection of dichloramine , 1992 .

[9]  H. Block,et al.  Anisotropic films of polypyrrole formed electrochemically using a non-planar dopant , 1992 .

[10]  G. Wallace,et al.  High-performance liquid chromatography on polypyrrole-modified silica , 1991 .

[11]  G. Wallace,et al.  Characterisation of conductive, electroactive polymers using resistometry , 1991 .

[12]  William H. Smyrl,et al.  Quartz Crystal Microbalance Study: Ionic Motion Across Conducting Polymers , 1991 .

[13]  C. Zhong,et al.  Polypyrrole-based electrode coatings switchable electrochemically between the anion- and cation-exchanger states , 1990 .

[14]  N. Mermilliod,et al.  Capacitive Charge and Noncapacitive Charge in Conducting Polymer Electrodes , 1987 .

[15]  Stanley Bruckenstein,et al.  Experimental aspects of use of the quartz crystal microbalance in solution , 1985 .