Polymeric membranes are widely used across various industrial sectors, ranging from separation processes to energy storage systems. However, conventional membranes are typically fabricated from fossil-derived polymers and involve the use of toxic, hazardous solvents. Due to increasing environmental concerns and more stringent regulations, significant research is directed towards the development of sustainable polymeric membranes. In this context, cellulose acetate (CA) represents a highly promising bio-based alternative owing to its renewable origin, biodegradable nature, and excellent film-forming properties. This thesis focuses on the preparation and characterisation of sustainable CA membranes, as well as their evaluation in different technological applications. The membranes were synthesised via the phase inversion method, specifically non-solvent induced phase separation (NIPS).