Contact: Ellen Sterner
SMU News & Media Relations
(214) 768-7650

August 24, 2001


DALLAS (SMU) -- Two chemistry professors from Southern Methodist University have recently received grants totaling more than $600,000 from the National Science Foundation. Both grants will be used to find new and innovative uses for inorganic polymers.

Inorganic polymers have traditionally not been used as much as carbon-based organic polymers because they are more difficult and more expensive to make. SMU researchers, however, hope to find new ways to inexpensively combine the best features of both inorganic and organic polymers.

Patty Wisian-Neilson, a professor of chemistry at SMU, focuses her research on phosphazene polymers, which have a backbone made of phosphorus and nitrogen. She recently received a three-year, $348,000 grant from the National Science Foundation, which she will use to study different ways to combine phosphazenes and the resulting properties of these compounds such as gas permeability and flammability.

Until now, the main market for phosphazene polymers has been the military, which has used them for applications such as insulation because they do not make toxic gases when they burn. However, the emerging field of nanotechnology has revived interest in phosphazenes because such applications would require much smaller quantities of the compounds.

"Cost would not be a factor in small-scale applications such as biomedical applications," Wisian-Neilson said.

Still, Wisian-Neilson hopes to keep costs down by combining phosphazenes with organic polymers.

"We want to take the best of both systems," Wisian-Neilson said. "To date, no one has systematically looked at ways to combine phosphazenes and organic polymers. With a little chemistry, it is possible to completely change the properties of these polymers."

Already, Wisian-Neilson has found that polyphosphazenes can help organize gold nanoparticles -- a discovery that could have implications for the continued miniaturization of electronic and biomedical devices. She now wants to find out which combination of polyphosphazenes will best help organize gold nanoparticles. Her research could lead to improved membranes for fuel cells or new types of flame-retardant materials.

SMU Chemistry Professor David Son has received a three-year, $309,500 grant from the National Science Foundation to study inorganic polymers that contain silicon and nitrogen. Son focuses his work on hyperbranched inorganic polymers, which have a tree-like structure instead of a linear shape. This tree-like structure can enhance the strength of these polymers.

"No one has really looked at changing the structure of these (silicon and nitrogen) polymers to see how their properties are different," Son said.

Highly branched inorganic polymers such as Son is studying could theoretically be used for drug delivery systems because they have a ball-like structure that protects what is put in them. This structure could then be broken down upon demand by injecting chemicals.

Son also plans to combine metal atoms with his inorganic polymers to create a polymer-metal composite. He believes such a composite could make a good catalyst or could have good structural integrity.

"Materials scientists want compounds with better properties," Son said. "These better properties are going to come if you incorporate inorganic elements. Pure organic polymers are weak and don't have the resistance to heat and oxidation that inorganic polymers do."

Ed Biehl, chair of the chemistry department at SMU, said these grants demonstrate that national funding agencies recognize the caliber of chemistry research at SMU.

"Even though SMU does not have a Ph.D. program in chemistry we have a faculty that is doing very high-caliber research," Biehl said.