Preparation of thermoresponsive PVDF/SiO2-PNIPAM mixed matrix membrane for saline oil emulsion separation and its cleaning efficiency

• Published in: Desalination 2017-04, Vol.408, p.1-12
• Main Authors: Ngang, H.P., Ahmad, A.L., Low, S.C., Ooi, B.S.
• Format: Article
• Language: English
• Subjects: Actuation force; Fouling; Mixed matrix membrane; Oil emulsion; Thermoresponsive, poly (N-isopropylacrylamide)
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/j.desal.2017.01.005

Thermoresponsive polyvinylidene fluoride/silica-poly (N-isopropylacrylamide) (PVDF/SiO2-PNIPAM) mixed matrix membranes were synthesized using diffusion induced phase separation techniques via direct blending method. The effects of SiO2-PNIPAM particle concentrations and surface cavity size on membrane physicochemical properties were investigated through oil emulsion separation using cross-flow ultrafiltration. Compared with pristine PVDF membrane, the PVDF/SiO2-PNIPAM membrane showed higher alternated thermal cleaning ratios (N=2.04) especially at higher SiO2-PNIPAM particle concentrations. Proper control of cavity size allows better particles actuation and minimized the surface roughness that would induce fouling phenomenon. The flux recovery ratio of 69.91% can be achieved by preparing the membrane using dope solution at 25°C, coagulation bath temperature at 40°C at particle dosage of 1.0wt.% (M25-40/1.0). It was found that the actuation force as a result of temperature swing is responsible for loosening the irreversible fouling layer (gel layer) on the membrane surface. •Thermoresponsive SiO2/PNIPAM particles were direct blended into the membrane matrix.•Various membranes forming temperature for proper control of cavity size•The shrinking-swelling actuation motion will loosen the fouling layer by alternate thermal cleaning method.•Improving the cleaning efficiency by controlling the free gaps for particles actuation