Biopolymers for a sustainable future: advanced nanoarchitectonics and multifunctional applications

Abstract Growing global concern over plastic pollution, fossil-resource dependency, and the demand for sustainable separation materials has intensified research on natural biopolymers and bio-based polymers for purification technologies. However, despite extensive research activity, the field lacks an integrated framework that systematically links polymer origin, fabrication strategy, and structure–performance relationships. This review consolidates recent advances in natural biopolymers such as cellulose, chitosan, and alginate, along with bio-based polymers including PLA and PHAs, emphasizing their use in membranes, cryogels, and advanced porous architectures for water treatment and multifunctional application. The discussion underlines the fact that porosity, hydrophilicity, surface charge, and network morphology, which are directly related to fabrication routes- electrospinning, solvent casting, 3D printing, thermal gelation, lyophilization, and surface modification, determine the flux, solute rejection, fouling resistance, adsorption capacity, and mechanical durability. This review also highlights current challenges related to mechanical robustness, scalability, and long-term performance are critically discussed, and a materials-selection roadmap linking polymer chemistry, processing strategies, and performance targets is proposed to support future industrial translation.