I-Corps: Sustainable Nanocellulose-based Organic Aerogels for Thermal Insulation Applications

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

Inorganic aerogels such as silica, clay, and metal oxide have been extensively studied during the last 70 years. One major disadvantage of inorganic aerogels is that they are brittle. Organic aerogels generally are more flexible, but their mechanical moduli and strengths tend to be lower. The uniqueness of the team's nanofibrillated cellulose fiber (NFC)-based organic aerogels is that with optimized material formulations and processes, they can be both flexible and strong. The specific mechanical properties of the team's polyvinyl alcohol (PVA)-NFCgraphene oxide (GO) aerogels are favorable in comparison with the specific mechanical properties of other types of aerogels reported in the literature. Furthermore, NFCs are made from sustainable and abundant biomass, thus making it a more environmentally friendly material than petroleum-based products. In addition, these NFC-based aerogels are prepared using a freeze-drying process, which uses water instead of organic solvents. Freeze-drying has the potential to allow for easy scale-up. Aerogels have drawn significant attention due to their unusual and interesting material properties, including a high porosity (typically 90% to 99%), ultra-low density, high specific surface area, and very low thermal, acoustic, and electrical conductivities. The sustainable NFC-based aerogels the team fabricates using an environmentally friendly and scalable process in the lab have excellent flexibility and specific compressive strength, extremely low thermal conductivity and water absorption, and good thermal stability. As such, they can be used for a wide range of thermal insulation applications such as homes and buildings, industrial equipment, and clothing. This I-Corps project will help the team deepen their understanding of the aerogel density and material property relationship, which can provide a guideline, if successful, for material selections for various applications.