Preparation and Oil-water Separation Properties of PAMAM-modified Chitosan/cellulose Sequential Interpenetrating Polymer Network Aerogels

The rapid development of industries has intensified the issue of oily wastewater pollution, necessitating sustainable solutions. Biomass aerogels, known for their environmental friendliness and biocompatibility, offer promising prospects for oil-water separation. This study fabricated a polyamidoamine (PAMAM)-modified chitosan/cellulose interpenetrating polymer network aerogel via sequential cross-linking and directional freeze-drying. This method endowed the aerogel with excellent mechanical properties, including good strength at a low density (0.06-0.11 g/cm), high anisotropy at 80 % strain, a high specific surface area (1.93-12.56 m/g), and hydrophobicity (WCA = 139.5°). The aerogel exhibited outstanding separation efficiencies for the carbon tetrachloride/water mixture (5501.85 L·m·h) and water-in-oil emulsions (4198.60 L·m·h, 96.67 %), as well as a removal rate of 61.24 % for the cationic dye RhB. A "demulsification-adsorption synergistic separation" mechanism involving dendritic PAMAM polymers and hydrophobic functional groups was proposed, with performance initially increasing and then decreasing as the PAMAM generation number increased. Despite certain limitations, such as sensitivity to environmental factors, the prepared all-biomass aerogel offered a green, efficient, and mechanically robust solution for the treatment of oily wastewater. This study provided a sustainable strategy for fabricating multifunctional hydrophobic aerogels, paving the way for advanced applications in environmental remediation.