A better blend

There is a lot of excitement about incorporating nano particles into polymers because of the ability to improve various properties with only a small percent of the particles. "You can improve the barrier to gases, such as hydrogen, carbon dioxide, and oxygen. You can increase material strength with little increase in weight," said Don Baird, professor of chemical engineering at

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But there are problems. "While one percent by weight of nano particles will change a material's properties dramatically, two or three percent provides hardly any additional enhancement," he said. "The particles just clump together, and thereby reduce the advantages associated with the surface area of single particles."

Another problem is that the incorporation of nano particles changes a polymer's flow properties leading to potential processing problems.

Baird's research group at Virginia Tech has developed a method for improving the dispersion, or exfoliation, of individual nano particles into polymers. He will present his research at the 230th American Chemical Society National Meeting, held in Washington, D.C. "The paper will present how we are dispersing nano particles and how we are using flow properties to monitor dispersion," he said.