Poly(2-hydroxyethyl methacrylate)-Based Amphiphilic Block Copolymers for High Water Flux Membranes and Ceramic Templates

Microphase separation drives the structure formation in block copolymers (BCP), and it is a promising and convenient way for the preparation of well-defined hierarchically structured materials. In this work, we focus on the synthesis of amphiphilic block copolymers, i.e., polystyrene-block-poly(2-hydroxyethyl methacrylate) (PS-b-PHEMA), via sequential anionic polymerization. Molecular weights of the prepared BCPs were in the range of 103-308 kg mol(-1) with low polydispersity values (D = 1.03-1.25) and a PHEMA content of 17-25 vol % as proven by size exclusion chromatography (SEC) and H-1 NMR spectroscopy measurements. For the first time, the PS-b-PHEMA BCPs were subjected to the self-assembly and non-solvent-induced phase separation (SNIPS) process for the generation of integral asymmetric films on tailor-made porous paper substrates. After water immersion, the final BCP membranes reveal an isoporous open structure at the surface featuring adjustable pore diameters of 2060 nm. It is demonstrated that a high water flux of up to 2750 L m(-2) h(-1) bar(-1) in the fully swollen state of the membrane can be obtained. Additionally, the hydroxyl moieties of the porous BCP membranes and tailor-made paper support are further exploited for postmodification strategies by using solgel chemistry. For this purpose, titanium(IV) bis(ammonium lactato) dihydroxide solution (TiBALDH) is used followed by thermal treatment at 600 degrees C in a nitrogen atmosphere. Noteworthy, the pristine BCP porous membrane structure can be maintained having a titanium-functionalized open porous structure.