Multifunctional bacterial cellulose-based aerogel with tunable mechanical property for filtration and thermal...

Innovative materials for sustainable applications are of increasing interest in scientific research. The practicality of bacterial cellulose (BC) derived aerogels could be enhanced if they could fulfill the required mechanical property for applications. In this study, double-network aerogels composed of BC and cotton fibers (CF) were fabricated using the directional ice-templated method. The impact of different CF contents on the interfacial and structural properties of the BC/CF aerogels was investigated. With the introduction of CF, the mechanical properties of BC/CF aerogels were improved. With 33 % CF addition, the compressive strength of BC/CF aerogels reached a maximum value and achieved 34.2 kPa along the parallel ("a") direction, which is 110 % higher than that of pristine BC aerogel (16.2 kPa). With the introduction of methyl trimethoxy silane (MTMS), the mechanical properties and elasticity were further enhanced (97.2 kPa). Furthermore, the hybrid aerogels also demonstrated excellent thermal insulation and air filtration properties, A thermal conductivity of 26.0 mW/m·K along the perpendicular ("p") direction and a quality factor (QF) of 0.081 Pa^-1 were achieved. Notably, the hybrid aerogels exhibited excellent biodegradation performance in soil burial tests. These results open up new avenues for the development of BC derived aerogels, and position them as a sustainable alternative to filtration and thermal insulation materials.