Starch as an eco-friendly and sustainable option for separation membranes: A review of current status and future directions

The increasing global demand for sustainable materials has intensified research into starch-based biopolymers for membrane applications. Starch, a renewable and biodegradable polysaccharide, offers advantages such as hydrophilicity, biocompatibility, and ease of chemical modification, making it an attractive candidate for environmentally friendly membranes. Starch films have been widely used in the food packaging and medical industries; however, the application of starch in separation membranes has been less investigated. This review examines developments in separation starch-derived membranes over the past decade, focusing on their structure, extraction, fabrication techniques, and broad applications. Starch-based membranes have demonstrated efficacy in micro-, ultra-, and nanofiltration for contaminant removal, along with gas separation, pollutant adsorption, pervaporation, and proton exchange membrane fuel cells. Challenges inherent to native starch, particularly water sensitivity and limited mechanical strength, have been addressed by chemical modification, polymer blending, nanoparticle incorporation, and crosslinking, all of which improve membrane stability and selectivity. Advanced fabrication methods, including phase inversion, interfacial polymerization, and electrospinning, have also enhanced membrane performance. Future research should prioritize advanced modification strategies, the development of composite systems with emerging nanomaterials, green and scalable manufacturing, and rigorous life cycle assessments. Real-world validation and cost competitiveness with petrochemical-based membranes are essential for broader implementation.