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 ( Đ = 1.03–1.25) and a PHEMA content of 17–25 vol % as proven by size exclusion chromatography (SEC) and 1 H 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 20–60 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 sol–gel chemistry. For this purpose, titanium(IV) bis(ammonium lactato) dihydroxide solution (TiBALDH) is used followed by thermal treatment at 600 °C in a nitrogen atmosphere. Noteworthy, the pristine BCP porous membrane structure can be maintained having a titanium-functionalized open porous structure.