Published: May 26, 2016
Associate Professor Ivan Smalyukh and Professor Ronggui Yang

A CU-Boulder research team thinks the same type of liquid crystals you see in the display panel of your smart phone may be the key component in a new window coating that could lower energy costs in buildings across the nation.

Thanks to a new $1.8 million grant from the Energy Department, the researcher team, led by Associate Professor Ivan Smalyukh and Professor Ronggui Yang, will use liquid crystals to create a transparent, solid film that is insulating, soundproof and water condensation-proof. The team includes graduate students and postdoctoral fellows.

“Buildings consume about 40 percent of the energy expended annually in the United States,” explains Yang of mechanical engineering, “We think we can dramatically increase the energy efficiency of windows without compromising transparency and other functions.”

The liquid crystal-based aerogel being developed by the team is a porous, ultralight material that can be created using cellulose nanoparticles nearly a million times smaller than a grain of sand, says Smalyukh. Derived from food industry waste, the nanoparticles that can spontaneously self-assemble into a liquid crystal.

A major step in the process is to replace the water in the liquid crystal material with air, transforming it into a lightweight, flexible and inexpensive film, says Smalyukh.

The new aerogel, which will be more than 99 percent air, has been dubbed AIR FILM. It will “pre-engineered” to assure transparency in the visible light range and high reflectivity in part of the infrared range to keep buildings cool or warm as needed.

Consumers will be able laminate AIR FILM on the surface of existing windowpanes. The team aims to produce films that can be easily applied, decreasing costs by eliminating professional installation labor expenses.

Smalyukh also a fellow at the Renewable and Sustainable Energy Institute (RASEI), a joint institute of CU-Boulder and the National Renewable Energy Laboratory headquartered in Golden. Yang is a RASEI affiliate.

The CU-Boulder grant is part of the ARPA-E’s Single-Pane Insulating Efficient Lucid Design (SHIELD) program. The SHIELD program is expected to accelerate the development of materials that could cut in half the amount of heat lost through single-pane windows without replacing them.

In December 2015, the Department of Energy 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.

RASEI Director Robert McGrath said the new project is a good example of the collaborative energy research happening on campus, including at the new Sustainable Energy and Environmental Complex (SEEC) on the East Campus.