Faculty and students attribute their recent success in the aerogel lab to a combination of hard work and an inventory problem at a local auto parts store.
“We have tried to be systematic but our latest breakthrough was more serendipitous than anything else,” said Prof. Ann Anderson of mechanical engineering about the discovery that using a thicker rubber gasket yields a quality aerogel in five hours. The old way took about 12 hours.
It turns out the thicker gasket was more compliant, Anderson said. It more evenly distributes the pressure and forms a better seal, making a higher quality aerogel in is less time.
Anderson joins her colleague, Richard Wilk and chemists Mary Carroll and Michael Hagerman, and a team of students on a project that is supported by a grant of $250,000 from the National Science Foundation. The faculty members are assisted by mechanical engineering seniors Smitesh Bakrania and Matthew King, and chemistry senior Rebecca Wolfe. Bakrania and Wolfe are making aerogels the subject of their senior theses.
The team is producing aerogels in a hydraulic, heated press where they combine a mixture tetramethylorthosilicate, a catalyst, methanol and water. The mixture gels and the “wet” gel is then brought to a “supercritical” phase in which there is no surface tension between the liquids and solids. At that point, the wet gel can be dried without degrading the solid matrix inherent in that form of aerogel.
Aerogels are ultra-light matrix materials that are excellent insulators. The challenge for the researchers is to devise a manufacturing method that will make production of the material more cost effective. Current applications are limited mostly to the space program, where aerogels have been used as an insulator on the Mars rover and to collect comet dust.
The aerogel manufacturing lab had its beginning last year when Anderson and a former student, Ben Gauthier '02 (now at Stanford), began experimenting with the process. Before long, they were consulting with faculty in chemistry for help understanding the chemical processes involved.
The aerogel team meets weekly to discuss their progress. They are also finalizing plans for a new lab made possible by the NSF grant. They expect it to be fully operational in December, Anderson said.
The research is proceeding in two phases, the first focusing on finding improvements in the manufacturing process. The second phase – and the subject of Bakrania's and Wolfe's theses – will be characterizing the properties of the aerogels produced.
The team has applied for a patent on a process they call a “Fast Supercritical Extraction Technique for Simplified Aerogel Fabrication.”