Fabrication of Ultrafiltration Polyacrylonitrile Membrane via Spraying Technique

Abstract

Spraying method produces a membrane with uniform thickness and defect free surface. However, most of the published research works focus on spray-coating rather than using spraying technique to produce membrane. Thus, the objective of this study is to fill the research gap by study the performance of membrane, which was fabricated via spraying technique. The effect of pressure on the physical properties and water flux performance of polyacrylonitrile (PAN) membranes was investigated. PAN membrane was fabricated by spraying the polymer solutions at different pressures, ranging from 10 psi to 35 psi on glass plates by using air-brush. It was followed by dry-wet phase inversion process. The membranes were characterized in terms of pure water permeation, molecular weight cut-off (MWCO), tensile property and membrane morphology. The results showed that spraying pattern governs the performance of membranes. Dripping spraying mode at 10 psi produced PAN ultrafiltration membrane with low hydrophilicity, where the contact angle was 77.74^o. The water flux of the membrane was low, which was 0.0044 L/(s.bar.m²) . At 25 psi, the desired cone-jet mode produced defect free membrane with high pure water flux (0.0161 L/(s.bar.m²)), good strength and good hydrophilicity property (53.15^o) . On the other hand, the pore size of membrane produced at 35 psi was small and thus reduced the flux performance 0.0119 L/(s.bar.m²). In conclusion, pressure contributed a great impact on the spraying pattern, which influences the performance of the membrane. The optimum operating pressure to produce ultrafiltration PAN membranes is identified at 25psi and this membrane can be used for ultrafiltration application in water treatment plant and food industry.