Biomass derived antimicrobial cellulose aerogels as an alternative to fossil-based plastic materials and theoretical studies of gel structure formation

Abstract

Cellulose aerogels are biopolymer-based nanostructured porous solids gaining special interest due to their potential to be used as a sustainable thermal insulation and filter material. The fact that cellulose is the most abundant biopolymer on earth gives great potential to generate sustainable materials with exceptional physical properties. To benefit from the advantages of cellulose aerogels, the University of British Columbia (UBC) and the German Aerospace Center (DLR), alongside other partners, decided to cooperate in two different projects – GelSus and PISA. The aim of these projects is the exploitation of agricultural lignocellulosic residues to develop cellulose aerogels for several applications as an alternative to current fossil-based plastic materials. GelSus focuses on the production of cellulose aerogels with antimicrobial properties for sustainable food-packaging, filters and thermal insulation whereas PISA focuses on the pilot-scale production of cellulose aerogels to be used as a sustainable thermal insulation in buildings. The role of the DLR is the extraction of cellulose from the lignocellulosic biomass with an alkali-based process and the synthesis of cellulose aerogels, using the sodium hydroxide-urea approach to generate the cellulose solution. Additionally, multiscale models are developed to describe a digital twin of the aerogel at a material as well as the product level. Establishing successful correlations between the model parameters and those from synthesis, the models are to be further used to reverse engineer cellulose aerogels towards any targeted application. UBC enhances aerogels by incorporating antimicrobial agents, making them resistant to bacterial colonization and degradation, resulting in a longer service life and improved biocompatibility. The obtained results demonstrate the significant potential of cellulose aerogels as a novel and sustainable thermal insulator with good antimicrobial properties. Good agreement of experimental and numerical observations was proven, indicating clear potential of the developed numerical approach for virtual representation of the chosen biopolymer-based aerogel system.