Effect of microwave plasma treatment on membrane structure of polysulfone fabricated using phase inversion method

Abstract

Polysulfone is among the polymers known for excellent electrical resistivity, elongation capacity, transparency and thermal resistance. Polysulfone is being used in battery caps, oil pumps, oil control pistons, transmission parts, water treatment, etc. The focus of the presented work is to control the porosity level of polysulfone membranes through plasma treatment for water treatment application. Polysulfone membrane was fabricated using phase inversion method and treated with microwave plasma of oxygen under fixed plasma conditions. The membrane samples were plasma treated for 15 s to 30 s and analyzed for surface morphology, pore size distribution and functional groups. Presence of benzene rings, sulfonic groups and phenols groups in the samples were observed in a range of 855–1000 cm−1, 1290–1360 cm−1 and 3250–3420 cm−1, respectively. The blank sample had wider pore size distribution (3–18 µm) while plasma treated samples exhibited narrow pore size distribution. The pore size distribution after 15 s and 30 s of treatment ranged from 3 to 9 µm and 3 to 5 µm, respectively. Conclusively, uniform pore size distribution was possible after 30 s of plasma treatment.