Preparation of Polyvinylchloride Nanofiltration Membrane: Investigation of the Effect of Thickness, Prior Evaporation Time and Addition of Polyethylenglchol as Additive on Membrane Performance and Properties

In this work, polyvinylchloride (PVC) membrane was prepared via casting solution technique and phase inversion method. N, N dimethylacetamide (DMAC) was used as primary solvent and tetrahydrofuran (THF) was used as a co-solvent. The effects of parameters such as membrane thickness, evaporation time of casting film before immersion precipitation and addition of polyethylenglchol (PEG) on PVC membrane were studied in terms of deionized water flux (DIW), tensile strength, phase inversion time in non-solvent, water content, permeability flux, salt rejection and antifouling properties.The results revealed that DIW decreased with increasing of membrane thickness and prior evaporation time of casting film. The phase inversion time increased with increase of membrane thickness and prior evaporation time. Tensile strength of fabricated membranes increased sharply while evaporation time was increased. The results showed the reduction of water content percent with increase of casting film evaporation time. Addition of PEG from 1 to 4 % wt improved flux sharply from 1.04 to 13.62 (L/m2.h). Rejection results showed reducing trend of salt rejection for fabricated membrane with different concentrations of PEG, except at the concentration of 3 % wt PEG. The results clearly showed more stable permeation flux during filtration process for blend PVC/PEG membranes compared to PVC one.