Making a better nonstick frying pan

Friday, December 9, 2005

Cooking pans, cars and trucks, and children's toys are all forms of polymers, which have made living more convenient and affordable.

Polymeric materials, commonly known as plastics, are in the products that help Texans grow older with ease and keep their children safe. Polymers are in furniture and clothes. They help keep food safe and the world connected.

In just a few decades, scientists have come to consider the extraordinary properties of plastics as nothing out of the ordinary.

At the University of North Texas, Witold Brostow, Regents Professor of materials sciences, leads an international team -- faculty members, visiting professors, postdoctoral researchers and students -- in continuing the polymeric evolution. Scientists from universities in Argentina, France, Germany, Indian, Mexico, Poland and the Ukraine have worked in the UNT Laboratory of Advanced Polymers and Optimized Materials, or LAPOM, which Brostow directs in the UNT College of Engineering.

Under his direction, researchers work to discover new properties and uses for plastics. The laboratory's primary function is to find ways to improve the properties of existing materials or to create new ones that are scratch-resistant, have low friction, survive high temperatures and can sustain great impacts. As more metal car and airplane parts are being replaced by plastics, the demand for such materials is growing.

UNT's lab is one of the leading polymer science and engineering laboratories in the world. And each January, as chair of the POLYCHAR (Polymer Characterization) Scientific Committee, Brostow organizes a POLYCHAR World Forum at UNT with participants from 40 or more nations.

Some of the lab's current research focuses on improving polymer coatings -- including those used on cookware.

"Many people use Teflon-covered frying pans because foods don't stick," Brostow says. "Yet, the surface is so easily scratched, the pans have to be handled with extreme care."

The researchers hope to create a material that will simultaneously have low friction (no stick) and high scratch resistance. And although more work is needed, Brostow believes the results so far are quite promising.

If the new coating is successful, cooks could use trusty metal spatulas to flip pancakes without destroying the surface of the polymer-coated frying pan, while also having the pancakes slide right out onto the plate once they're finished cooking.

And while most cooks would laud such an advance in morning fry-up technology, for the scientists it is a fairly complex task.

"The two properties are almost exclusive of each other, which means we have to develop one product that is essentially two," Brostow says.

The team members look for the best molecular structure for the materials they want to create to meet their requirements. Sometimes they create them by chemical modification, while other times they create them by blending commercial epoxies with other materials.

But before they do either, they use a program of unique 3-D computer simulations of molecular structures. The program allows the researchers to specify the properties they want -- such as flexibility and hardness -- and then see what the structure for such a material might be.

The program then tests the computer-generated material, applying forces to determine the amount of stress it can withstand before breaking down -- and allowing the researchers to see how the material failed.

Once a material with a defined composition has been selected, a number of experimental tests determine its usability. One such test -- the scratch test -- employs a diamond blade hooked up to sensors that monitor its force and the material's behavior.

Developing materials with high healing capabilities is important not only for the improved cookware coating, but also for the surface protection of materials such as ceramics and metals.

Other research at the lab investigates polymeric materials for automotive, telecommunication, biotechnology, medical, chemical and agricultural applications. The work has been funded by Volvo, Ford, Texas Instruments, Dow Chemical, Alcon, the National Science Foundation, NASA and NATO.

The research conducted at LAPOM occurs in an atmosphere of teamwork and shared expertise. Brostow, who was recently reelected as the president of the International Council on Materials Education, calls the laboratory "not only a place for research, but also a classroom."

Brostow says the best part of his work is shaping students as researchers. These include students in the Texas Academy of Mathematics and Science, a two-year residential program at UNT that allows high school juniors and seniors to finish high school while completing their first two years of college.

Several of the TAMS students working in LAPOM have received national honors, including Barry M. Goldwater Scholarships , considered to be among the most prestigious national scholarships given to students planning careers in mathematics, science and engineering.

The students' projects have ranged from developing better ways to attach prosthetics to muscle tissue to creating intra-ocular lenses to improve vision.

All of the students working in LAPOM are learning from the best. The international visiting professors, who usually work in the lab for one- or two-year stints, are among the world's finest polymer scientists.

Brostow himself is a fellow of the Royal Society of Chemistry in London, winner of the Fred A. Schwab International Award of the Society of Plastics Engineers, and a member of the National Academy of Sciences of Mexico and of the Union for Polymer Research in Berlin. In 1999, Brostow received an honorary doctorate from the Lvivska Politechnika National University in Ukraine, only the second awarded by the school since World War II.

As president of the International Council of Materials Education, a position to which he was first elected to in 1998, Brostow directs an organization that addresses all aspects of materials education and engineering for students in elementary and secondary schools, as well as for students in colleges and universities, for professionals and for the general public.

He's eager to share his knowledge of materials science with all who visit or work in his laboratory.

"Some people believe research and teaching are opposing ideas, but this does not need to be the case. Students working on research are learning how to solve problems and are acquiring the tools of the trade. When they finish, they are able to apply those tools on their own," he says. "I realize that not every student in my lab will go into materials science research, so it's important for me as a teacher to provide skills that will serve them also in other areas."

UNT News Service Phone Number: (940) 565-2108