Development of a New Polymer Membrane: Polyvinylidene fluoride/Polyetherimide Blend Membrane

Porous polyetherimide (PEI)/polyvinylidene fluoride (PVDF) coated flat sheet membranes with different compositions and polyethene glycol (PEG) pyrogenic additives have been prepared by non-solvent induced phase separation for the separation of metal salts and sucrose. By using non-solvent induction phase separation (NIPS), it has succeeded in preparing new members of mixed matrix PVDF membrane with (i) asymmetry pore structure, (ii) porosity 7.19%-18.93%, (iii) pore size 0.196 nm-0.453 nm and (iv) mechanical strength 4262.04-24472.57 N/m2, (vi) permeability respectively of 500.48 L/m2.h.bar for C12H22O11; 642.94 L/m2.h.bar for NaCl; 623.64 L/m2.h.bar for MgCl2; 1060.39 L/m2.h.bar for CaCl2; and 1292.85 L/m2.h.bar for CuSO4. Specifically, increasing PEI levels up to 2(wt.%) - 8 (wt.%) has reduced overall porosity and pore size, thus having a specific impact on mechanical strength, pure water permeability (PWF) and the permeability of the feed solution. The opposite phenomenon is observed when the PEI level reaches 10 (wt.%) - 14 (wt.%). Furthermore, compared to pure PEI membranes, PVDF/PEI composite membranes were observed to have a higher resistance to acids and lower to bases. This condition applies in contrast to pure PVDF membranes. Despite having moderate chemical resistance, PEI/PVDF membranes have excellent characteristics and separation performance compared to pure membranes. This demonstrates its promising potential for separation of soluble metal salts and sucrose produced by various industrial processes compared to PVDF and PEI membranes.