Biopolymer aerogels were among the first produced aerogels, and despite the lack of early commercial opportunities, have never completely fallen off the radar of the research community. Current studies on biopolymer aerogels are motivated by the search for a 'stronger' replacement of brittle silica aerogels, and for more sustainable precursors compared to the oil-derived precursors of traditional polymer systems. In addition, biopolymers often have a high density of functional surface groups, for example, amino groups on chitosan or carboxyl groups on pectin or alginate, which opens up new applications and provides convenient anchoring points to add functionality. As an aerogel research team, we are working on the property optimization, fabrication technologies, pilot production and analytical tools for many aerogel systems, including silica, synthetic polymers and biopolymers. In the topic of biopolymer aerogels, we develop multiple polysaccharide aerogels, in particular cellulose, chitosan and pectin aerogels, and their silica hybrids. For instance, we developed NFC-silica, pectin-silica and chitosan-silica combining hybrid aerogels with highly improved mechanical property without penalizing thermal conductivity. For chitosan aerogels, in-depth SAXS investigations highlighted the role of solvents and sc-CO<sub>2</sub> drying on structure formation, and urea-modification enabled aerogel production through ambient pressure drying. Recently, we extended our know-how on silica aerogel additive manufacturing to successfully 3D print pure cellulose aerogel with anisotropic thermal and mechanical properties (ratio&gt;2). These 'green' biopolymer porous materials open up new perspectives for future applications of aerogels in filtration, oil-water separation, CO<sub>2</sub> capture, catalysis, and medicine, in addition to aerogel's well-established thermal management applications.

Biopolymer aerogels: synthesis, properties, processing and application development

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.