Abstract:
Membranes casting was done by using non-woven polyester fabric as support material, Polyethersulfone and Polystyrene in varying concentrations were used as polymers while N-Methyl-2-pyrrolidone, Dimethylformamide and Tetrahydrofuran were used as solvents. Pore morphology in the membranes was produced by using Immersion by precipitation technique. Morphology and surface roughness of the membranes formed were observed through Scanning electron microscopy and Optical Profilometry. It was observed that when we used THF+NMP as solvent, flux was increased. The tensile strength of the membranes was higher when we used NMP as a solvent, on the other hands it was also slightly higher in MP-2 membrane (21 wt.% polymeric membrane using 70% PES and 30% polystyrene and NMP as solvent). The pure water flux of the membranes was also tested at various pressures. The results revealed the dependence of flux on the surface roughness and morphology of the membranes. These certain parameters used to prepare membranes played quite significant role in optimization of the prototype pilot scale plant.
The project also aims to explore the optimization conditions for casting membranes on the indigenously manufactured pilot-scale prototype plant for flat sheet polymer membranes. This plant can be used to make flat sheet membranes on pilot scale. The plant which is a semi-automated machine, can be operated by a single person. A mounted motor on the shaft is utilized to pull the support fabric. Precipitation time is a key factor for the formation of pores in the membrane. Controlled revolutions per minute of motor can provide enough time for precipitation of polymer in the bath tub. Rollers mounted on one another with calculated gap can ensure proper wetting of polymer on the support fabric. It occupies small space and can be used to make membranes on pilot scale.