Using Polymerization‐Induced Self Assembly ( PISA ) Nanoparticles as Additives for the Fabrication of Functionalized PVDF Membranes

ABSTRACT Polymerization‐induced self‐assembly (PISA) facilitates the rapid and‐ scalable preparation of well‐defined block copolymer nanoparticles. However, their utilization as functional additives in solid materials—particularly for separation membranes—remains a significant challenge. To address this, we incorporate PISA‐synthesized poly(dimethylaminoethyl methacrylate)‐ b ‐poly(tert‐butylstyrene) (PDMAEMA‐ b ‐PtBS) nanoparticles into poly(vinylidene fluoride) (PVDF) membranes via non‐solvent‐induced phase separation (NIPS). The resulting core–shell nanoparticles form stable colloidal dispersions in polar solvents such as N,N‐dimethylformamide (DMF), owing to the soluble PDMAEMA corona, while the insoluble PtBS core provides structural integrity. During membrane formation, these nanoparticles serve a dual function: as effective pore‐forming agents that increase membrane porosity to above 90%, and as pH‐responsive modifiers due to the tertiary amine groups in the PDMAEMA block. This unique design enables reversible tuning of pure water permeability by up to a factor of 2 through simple acid–base treatment cycles. Our work thereby demonstrates a viable strategy for fabricating smart polymeric membranes using structurally intact, stimuli‐responsive PISA nanoparticles, bridging the gap between nanoparticle synthesis and functional material design.