A New Phase for Polymer Synthesis Over the past fifty years polymer based materials, such as rubber, kevlar, and an assortment of plastics, have had a profound impact on the way we live – these materials are commonly used in nearly every tool, gadget, and piece of equipment available today. To support a research venture exploring novel methodologies and techniques for synthesizing these important macromolecules, Dr. M. Samy El-Shall, of the Department of Chemistry, has received awards from Philip Morris, Inc. and Chrysalis Technologies, Inc totaling $730,012 for fiscal year 2002.

The word polymer originates from the Greek polumeres – having many parts – and is the perfect term for describing these materials, which are composed of repeating units of small molecules joined head-to-tail to form very long chains. Furthermore, chemists have found that by changing the types and quantities of the small molecules used during polymer synthesis, they can tailor-make materials to fit a variety of functions. For example, small molecule subunits used to synthesize rubber, which is used in applications requiring an element of elasticity, are different from the components used to make styrofoam, which is comparatively more rigid.

Dr. El-Shall’s technique for synthesizing polymers is significantly different from traditional methods – in fact it takes place in a totally different state of matter. Currently, polymers are generated in liquid phase, and employ copious amounts of volatile, petroleum based organic solvents that are environmentally harmful and potentially carcinogenic. By comparison, Dr. El-Shall and his research team have come up with a gas phase method for generating polymers. During this process the chemical reaction is carried out using specialized equipment that initially vaporizes the small molecule building blocks, and then passes them over a catalytic surface, which initiates polymer formation. As the small molecules collide, they form macromolecular strands that are then received in a condensing chamber, where solidification occurs. An important implication for the success of these studies is the elimination of the need for potentially hazardous organic solvents during polymer synthesis. On an industrial scale, implementation of this technique would reduce the operating costs and energy consumption associated with solvent distillation and recovery, as well as polymer drying time.

An exciting result that has emerged from these studies is a new capability to generate polymers that incorporate a variety of nanosized metal particles. The technique involves coupling gas phase polymer formation with a state-of-the-art pulse laser, which is used to vaporize small amounts of metal catalysts including nickel, titanium, and iron. As the polymers form, the vaporized metal is incorporated into the growing macromolecular strands. The unique properties of such novel materials – which have both the flexibility and malleability of polymers and the electrical characteristics of metals – will make them interesting candidates for use as novel conducting, superconducting, and/or magnetic components in electronic and optical devices.