Mechanically Robust, Thermally Stable, and Crosslinked Bacterial Cellulose Aerogels for Superior Oil Absorption

Abstract

ABSTRACT Frequent oil spills and industrial oily wastewater discharges necessitate the development of high‐performance, recyclable oil‐absorbing materials, as traditional options suffer from low adsorption capacity and poor reusability. To address these limitations, this study developed crosslinked bacterial cellulose (BC) aerogels using 1,2,3,4‐butanetetracarboxylic acid (BTCA) and sodium hypophosphite (SHP) as crosslinking agents. The aerogels were fabricated via freeze‐drying and brief thermal esterification. By systematically optimizing BTCA content, the 10% BTCA formulation achieved a dense 3D network without crystalline precipitation, exhibiting high porosity (99.8%), minimal shrinkage (5.9%), and reduced pore size (2.2 nm). Crosslinking preserved the cellulose I structure but reduced crystallinity, as confirmed by FTIR and XRD. Thermal stability improved significantly, with residual mass at 600°C increasing from 21.8% to 39.0%. The aerogel demonstrated superior compressive resilience and structural stability in water, with oil absorption capacities of 115.4 g/g for paraffin oil, 98 g/g for engine oil, and 96 g/g for edible oil. Recyclability tests showed 84% retention after 20 ethanol cycles. This work provides a scalable, eco‐friendly strategy for robust aerogels with multifunctional oil‐absorption capabilities.