BOULDER — The University of Colorado Boulder has received a $1.8 million grant to develop a window coating that could improve buildings’ energy efficiency.
The grant came from the U.S. Department of Energy’s Advanced Research Projects Agency-Energy.
The CU team is using liquid crystals, widely known for their technological use in smartphones and flat-panel high-definition televisions, to create a transparent, solid film that is thermally insulating, soundproof and resists water condensation. Associate physics professor Ivan Smalyukh and mechanical engineering professor Ronggui Yang lead the team.
“Buildings consume about 40 percent of the energy expended annually in the United States,” said Yang in a prepared statement. “We think we can dramatically increase the energy efficiency of windows without compromising transparency and other functions.”
The liquid crystal-based aerogel — a synthetic, porous and ultralight material — can be created by using rodlike, cellulose nanoparticles, each with a diameter nearly a million times smaller than a grain of sand, said Smalyukh. Derived from food-industry waste or glucose with the help of a specific bacteria grown by the team, the rodlike nanoparticles spontaneously self-assemble into a liquid crystal, he said.
A key step in the process is to replace the water in the liquid crystal material with air, transforming it into flexible aerogel film.
“The material will be lightweight, insulating, mechanically stable, flexible and inexpensive,” said Smalyukh.
The cellulose-based liquid crystals are designed to self-organize and can be “pre-engineered” to assure transparency in the visible light range and high reflectivity in a selected part of the infrared spectrum that keeps the buildings cool or warm as needed. Dubbed “Air Film” by the team, the aerogel material is more than 99 percent air.
Graduate students and postdoctoral researchers will be involved in the effort, said Smalyukh, who also is a fellow at the Renewable and Sustainable Energy Institute, a joint institute of CU-Boulder and the National Renewable Energy Laboratory in Golden.
The grant is part of DOE’s Single-Pane Insulating Efficient Lucid Design, or SHIELD, program, which is expected to accelerate the development of materials that could halve the amount of heat lost through single-pane windows without replacing them, said Yang.
Air Film will have the ability to be laminated on the surface of existing windowpanes. The team aims to produce films that consumers can easily apply, which would decrease costs by eliminating professional installation labor expenses.
The CU-Boulder grant was one of 14 grants totaling $31 million for window-efficient technologies awarded by Energy Department officials. Experts estimate that retrofitting widows rather than replacing them could reduce heat loss and save roughly the amount of electricity needed to power 32 million U.S. homes each year.
In December, the DOE awarded another CU-Boulder research team $4 million over three years to develop an inexpensive, paintable coating to retrofit energy-inefficient windows. The infrared-reflective coating is expected to drastically reduce cooling costs for both residential and commercial structures, helping to reduce greenhouse gas emissions.