“…A functionalized polysulfone containing quaternary ammonium side groups (PSFQ, Mn = 28,000 g/mol) was synthesized by substituting the chlorine atoms of a chloromethylated polysulfone (CMPSF, Mn = 29,000 g/mol, chlorine content, Cl = 7.42%) with ammonium groups using N,N-dimethylbutylamine tertiary amine, as described in previous studies [ 31 , 33 ]. Cellulose acetate phthalate (CAP, Mn = 2534 g/mol, high purity ≥99.5%, Sigma Aldrich, St. Louis, MO, USA) and polyvinylidene fluoride (PVDF, Mw = 180,000 g/mol) were obtained from Sigma-Aldrich (Sigma-Aldrich Chemie GmbH, Taufkirchen, Germany) and used as received without further purification ( Scheme 1 ).…”