Amine-Functionalized Amyloid Aerogels for CO2 Capture

Abstract

Climate change caused by excessive CO₂ emissions constitutes an increasingly dire threat to human life. Reducing CO₂ emissions alone may not be sufficient to address this issue, so that the development of emerging adsorbents for the direct capture of CO₂ from the air becomes essential. Here, we apply amyloid fibrils derived from different food proteins as the solid adsorbent support and develop aminosilane-modified amyloid fibril-templated aerogels for CO₂ capture applications. The results indicate that the CO₂ sorption properties of the aerogels depend on the mixing ratio of aminosilane featuring different amine groups and the type of amyloid fibril used. Notably, amine-functionalized β-lactoglobulin (BLG) fibril-templated aerogels show the highest CO₂ adsorption capacity of 51.52 mg (1.17 mmol) CO₂ /g at 1 bar CO₂ and 25.5 mg (0.58 mmol) CO₂ /g at 400 ppm; similarly, the CO₂ adsorption capacity of chitosan-BLG fibril hybrid aerogels is superior to that of pure chitosan. This study provides a proof-of-concept design for an amyloid fibril-templated hybrid material facilitating applications of protein-based adsorbents for CO₂ capture, including direct air capture.

Keywords: Amyloid fibrils; CO2 capture; Microporous materials; aerogel; biomass.