Superhydrophobic, recyclable bacterial cellulose/graphene oxide composite aerogels with enhanced mechanical and thermal stability for efficient oil-water separation

The oil pollution in aquatic ecosystems poses a serious threat to public health and ecological balance. In addressing this challenge, this investigation employed bacterial cellulose (BC) as the matrix material, through strategic incorporation of chemical cross-linking agents (Butane tetracarboxylic acid and graphene oxide) combined with freeze-drying technology and chemical vapor deposition (CVD) method to fabricate cross-linked BC (CBC) aerogels. Subsequent hydrophobic modification via chemical vapor deposition was implemented to optimize surface properties. Key findings revealed that the cross-linked composite aerogel demonstrated a homogeneous 3D lamellar architecture with negligible crystal precipitation, manifesting remarkable structural stability (linear shrinkage rate 5.88%) and ultrahigh porosity (99.9%) accompanied by minimal average pore diameter (1.9 nm). Enhanced thermal stability was evidenced by increased mass residual rate from 15.9% to 41.5% at 600 °C. The material maintained superior compression resilience through 10 compression cycles at 50% strain, preserving structural integrity in aqueous environments. Optimal hydrophobicity (contact angle 152°) was achieved after 3.5 h of vapor deposition, while remarkable adsorption capacities for various oils were recorded (45–204 g/g). Notably, the composite exhibited outstanding reusability, retaining 85.2% of ethanol adsorption capacity after 20 extraction cycles, and preserving 76.7% of paraffin oil adsorption capacity. These results collectively demonstrate the broad application prospects of this bio-based oil-absorbing material in oil-water separation technologies.