Self-cleaning loose nanofiltration membranes for selective separation

Overview

This solution offers loose nanofiltration (NF) membranes engineered for selective separation of organics and inorganic salts, combined with self-cleaning functionality. The membranes are built by embedding iron aminoclay (Fe-AC) nanofillers into a piperazine-trimesoyl chloride derived polyamide (PA) selective layer supported on a polyacrylonitrile (PAN) ultrafiltration base. The iron content enables photo-Fenton catalytic activity, allowing the membrane surface to degrade organic foulants under light exposure, while the aminoclay sheets create two-dimensional nano-channels that tune selectivity for target molecules. The technology targets applications such as coconut water clarification and concentration, dye/salt separation in textile effluents, and broader industrial water treatment where fouling resistance and selective molecular separation are critical.

Technical specifications

Key features:

• Selective layer composition: Piperazine-based polyamide thin film embedded with Fe-AC nanofillers, producing two-dimensional nano-channels for finely tuned molecular separation
• Self-cleaning mechanism: Iron aminoclay induces photo-Fenton activity that degrades organic foulants on the membrane surface under light exposure, reducing cleaning frequency and downtime
• Support structure: PAN-based ultrafiltration membrane providing mechanical strength and a suitable platform for the polyamide layer
• Separation performance: Designed for loose NF selectivity, enabling separation of small organics from monovalent and divalent salts rather than tight rejection of all solutes
• Analytical characterization: Validated using HPLC, ICP-MS, AAS, and complementary advanced instrumentation for feed and permeate analysis
• Module format: Lab-scale flat-sheet membranes with planned scale-up to spiral-wound modules for industrial deployment
• Synergies: Complementary to recent work on aminoclay-graphene oxide nanocomposite fillers in thin film composite membranes

Technology readiness level

The technology is at an early-to-mid stage of development. Aminoclay synthesis and polyamide layer fabrication are feasible at laboratory scale using existing in-house chemicals and equipment. A pre-filtration skid is already operational for producing clarified coconut water feed, supporting initial proof-of-concept work. The proposed plan targets initial lab-scale testing and proof-of-concept within six months, followed by membrane scale-up and spiral-wound module fabrication over the subsequent twelve months. Scale-up equipment and key personnel hiring require additional funding. Strong collaboration with IIT Madras provides access to advanced fabrication and characterization facilities. Validation to date has been limited to bench-scale feasibility, with pilot and field-scale demonstration representing the next milestones.