1. Polymer-clay nanocomposites
Polymer-layered silicate nanocomposite have aroused much interest since Toyota’s first successful formulation of Nylon 6-clay nanocomposite. This kind of special materials took advantage of the unique characteristics of both materials to achieve an unusual synergic effect in properties. Polymer-clay nanocomposite technology is an exciting area since the combination of different polymer materials with clay in nanoscale offer vast possibilities of new special properties. Layered silicates are of special interest due to the high aspect ratio and unique structure. Researchers are formulating nanocomposite materials from various polymers and clay in order to obtain desired properties that the individual constituents cannot offer. Many polymer-clay nanocomposite systems, either intercalated or exfoliated (Figure 1), have shown enhanced thermal stability, fire retardant ability, and barrier properties. We are interested in formulating polymer-clay nanocomposites to achieve desired properties by manipulating their microstructure.
Figure 1 Structure of polymer-layered silicate nanocomposites
2. Conducting polymer for corrosion control
Conducting polymers are a class of special polymer materials due to their high electrical conductivity. Examples are polyaniline and polypyrrole. They exist in different oxidation states (Figure 2). Due to the special electrical and electronic properties of these polymers, they have been proposed for applications in electrochromic display, sensors, light-emitting diodes, capacitors, batteries, gas permeation membranes and corrosion protection coatings. However, the biggest disadvantages of conducting polymer that hinder their commercialization are their poor processability and stability. Incorporation of clay is a promising solution to these problems. The combination of conducting polymer and clay will offer tremendous possibilities in terms of both improving and generating new properties. It’s already been shown in our laboratory that formulating polyaniline-clay nanocomposite result in a significant improvement in thermal stability of polyaniline. We believe clay will play a major role in pushing conducting polymers into market. However, from out literature search, work in this area is extremely limited. Therefore, we are interested in formulating conducting polymer-clay nanocomposite aiming at overcoming the disadvantages of these materials and to produce new materials with exceptional physical, chemical, electrical, electronic and electrochemical properties.
Figure 2 Three major oxidation states of polyaniline (PANi) : Emeraldine (partially oxidized form), Leucoemeraldine (fully reduced form), Pernigraniline (Fully oxidized form)