Enhanced abrasion resistant PVDF/nanoclay hollow fibre composite membranes for water treatment

Seawater pretreatment with microfiltration and ultrafiltration is technically and economically feasible with advantages over conventional granular media filtration. Current membranes have short lifespans and wear irreversibly over time, especially in the presence of abrasive particles in seawater. Novel polyvinylidene fluoride (PVDF)/nanoclay hollow fibre membranes were fabricated by non-solvent induced phase separation (NIPS) to study the improvement of membrane physical endurance. Loss on ignition testing has shown high nanoclay retention was achieved at low initial nanoclay loading. Despite showing lower pure water permeability, the incorporation of nanoclay shifted the PVDF crystalline phase from α-phase to β-phase and improved the membrane structure as well as mechanical properties in terms of stiffness and flexibility. Tensile strength increased from 3.8 MPa to 4.3 MPa with 5.08 wt% Cloisite® 30B loading while break extension increased from 175% to 229% with 5.08 wt% Nanomer® I.44P nanoclay loading. An accelerated abrasion test revealed the membrane with an initial 5.08% loading of Nanomer® I.44P had improved abrasion resistance, lasting three times longer than the control membrane with no nanoclay addition. PVDF membranes containing commercial nanoparticles are therefore promising for improved abrasion resistance in water treatment applications.