Abstract

The growing need for sustainable materials in the built environment has intensified interest in upcycling biomass waste into high-performance construction products. This study introduces a novel approach to valorize peanut husks, which is an abundant but underutilized agricultural residue, by extracting cellulose and converting it into multifunctional aerogels. Peanut husk-derived cellulose was combined with sodium alginate/CaCl<inf>2</inf> as a green gelation system, and aerogels with varying cellulose contents (2.5 %, 5 %, 7.5 %, and 10 %) were fabricated via freeze-drying. The samples were further surface-modified with methyltrichlorosilane (MTCS) using a chemical vapor deposition (CVD) method. The resulting aerogels exhibited low densities (0.047–0.130 g/cm³), excellent thermal insulation (0.017–0.029 W m⁻¹ K⁻¹), and high decomposition temperatures (∼336 °C). The MTCS-CVD treatment produced superhydrophobic surfaces (contact angle >150°) with high solvent adsorption capacity (up to 16 × their weight). These results demonstrate a technically feasible route for producing multifunctional cellulose aerogels from agricultural waste, emphasizing material design and process optimization for sustainable applications in energy-efficient and environmentally friendly building materials.