Mary Carroll, Union College – Aerogels

On Union College Week:  How do we make buildings more energy-efficient?

Mary Carroll, professor of chemistry, looks into this question.

Mary K. Carroll is the Dwane W. Crichton Professor of Chemistry at Union College. She co-directs the College’s Aerogel Lab with Dr. Ann M. Anderson, the Agnes S. MacDonald Professor of Mechanical Engineering. They have developed a rapid supercritical extraction method for preparing aerogels and involved 150 undergraduate STEM majors, several high-school students and faculty colleagues from Union and other institutions in research in the fabrication, characterization and applications of aerogel materials. Their work has resulted in three patents, 26 papers in refereed scientific journals, several conference publications and book chapters, and more than 100 presentations at regional, national and international conferences. In addition to the work in aerogel-based windows for sustainable buildings described here, their group is actively developing catalytic aerogel materials for automotive pollution mitigation.

Aerogels

Aerogels are materials with remarkable properties, including high surface area and low density. Fabrication of these intriguing materials, which were first described in the 1930s, has traditionally been difficult.

Our Aerogel Research Lab is co-directed by Ann Anderson, the Agnes S. MacDonald Professor of Mechanical Engineering, and myself. As an engineer and a chemist we bring complementary backgrounds to research in aerogel materials. Working with undergraduate students, we have invented, developed and patented a novel, rapid approach to making these materials and have used this method to prepare aerogels for a variety of applications from sensing to pollution mitigation to sculpture.

Silica aerogels, which have a chemical composition similar to glass, are highly translucent and have superior insulation properties. There is considerable interest in energy-efficient building materials. Recently, we have focused on the use of aerogels for window applications in sustainable buildings.

In collaboration with Professor Cinzia Buratti and her group at the University of Perugia in Italy, we have studied the thermal, acoustic and optical properties of silica aerogel monoliths. Our work has shown that window prototypes prepared with monolithic silica aerogel are two to three times more thermally insulating than conventional windows. If implemented in buildings, these windows could also yield significant improvement in noise insulation. Although silica monoliths are not as transparent as glass, they have solar transmittance levels of 70% with high color rendering index and minimal visual distortion.

Scaling up the aerogel window fabrication process for widespread commercial application remains challenging and is a focus of our ongoing research.