Cincinnati -- Researchers in the department of materials science and engineering at the University of Cincinnati have developed a method for producing low-density nanoscale materials which can be used as environmentally safe super-insulators in refrigeration and other applications.
Gregory Beaucage, assistant professor in the UC College of Engineering, explained the method March 17 during the annual meeting of the American Physical Society (APS) in Los Angeles. Beaucage said acid-catalyzed, sol-gel chemistry is used to produce a silica xerogel ceramic modified with a polymer.
The polymer used in the UC process is a polysiloxane elastomer which helps prevent the ceramic's nano-sized pores from collapsing as the material dries. The result is a light, thin "super-insulator."
"You could make a thinner wall for your refrigerator," explained Beaucage. "and with nano-pores, you'll never lose your insulation. So, refrigerator life will increase and you'll have more space inside the refrigerator."
In contrast, chloro-fluorocarbons (CFCs) are being phased out of refrigeration systems because of their tendency to diffuse out of insulating systems and their detrimental impact on the environment.
During his presentation at the APS meeting, Beaucage described the growth of the materials and his proposed model to explain the changes seen moving from nanoscale to the microscopic and macroscopic level.
In a separate presentation, Beaucage discussed another project in his laboratory which adapts polymer theory to non-woven fibers at the micron to millimeter scale. A typical non-woven material, such as a tissue or sheet of paper, contains fibers about one- thousand times longer than a typical polymer molecule.
However, Beaucage and his graduate students have shown that you can use polymer theory to predict the physical properties and orientation for these fibers. They have even calculated the strength of a fiber network based on the fiber orientation.
The work has application in numerous commercial products which
use non-woven fibers. These include many styles of carpet, felt
mats and paper products.