Recent
advances in research on clay-polymer nanocomposites by Evangelos Manias,
assistant professor of materials science and engineering, has attracted
a flood of media coverage.
Manias’s
research focuses on the development of novel polymer-inorganic nanocomposites
materials, including polymer-clay and polymer-ceramic hybrids. His research,
dubbed “worth watching” by the Financial Times, and which “may revolutionize
the future of plastics” according to the MRS Bulletin, shows promise for
industrial applications.
Manias has found that adding clay to plastics could improve their qualities for specialized uses. Adding small amounts of natural clay to some plastic composites changes the physical qualities of the plastics, making them less permeable to liquids and gases. Polyethylene terephthalate (PET), the standard plastic used in soft drink bottling, allows a small amount of oxygen to permeate and reach the liquid inside. The lower permeability of the new clay-plastic composites would improve PET, making it a suitable material for bottling beer and wine.
The
nanocomposites contain only 1 to 5 percent clay. The added clay does not
alter the normal production and processing of the plastic, nor does it
affect the transparency of the plastic.
Manias’s
research also has environmental implications. Clay-polymer composites could
make a cleaner method of producing flame-retardant plastics. Most of today’s
flame-retardant plastics contain bromide, which produces poisonous gases
when burned. When the clay-polymer blends burn, the clay forms a char-layer
on the outside, insulating the material beneath.
“Using clay is a green alternative to current practices and reduces flammability in a wide range of plastics,” says Manias.
“Adding very small amounts of natural clays to plastics changes some of their physical properties. While we can tune the chemical interactions between the clays and some polymers, it is the general changes due to the nanometer fillers in all plastics that may be the most interesting,” says Manias.
Manias is also looking at polymer nanocomposites that contain platelets of metal and ceramic nanoparticles instead of clay. These fillers require different surfactants and offer more flexibility in property tailoring.
