The expansion of membrane technology in emerging applications drives a constant demand for novel materials. In this work, it is presented and discussed the preparation of stable porous polymeric membranes for liquid separations in organic solvents that can operate in high temperature and/or acid or basic conditions. Polymeric membranes with the aforementioned properties could replace traditional and energy-intensive separation processes like thermal distillation. In particular, poly(oxindole) derivatives constitute a versatile new family of polymers, and they have been used to engineer porous flat-sheet membranes by non-solvent induced phase separation (NIPS). The prepared membranes were crosslinked using different strategies: (1) chemical crosslinking reacting with dibromides, (2) thermal crosslinking by the incorporation of propargyl as a side group, followed by immersion in hot glycerol, and (3) photo-induced crosslinking via thiol-yne click chemistry and (4) oxidative thermal oxidation. These membranes are used in organic solvents such as dimethyl sulfoxide (DMSO), N-methyl pyrrolidone (NMP), N,N-dimethylformamide (DMF) and others. The molecular weight cut-off of these membranes ranges from 1 kg mol-1to 20 kg mol-1and can be tuned by the casting conditions, with solvent permeance up to 68 L m-2h-1bar-1at 120 ˚C. The reported membranes show exceptional stability in common organic solvents, with minimum swelling and high degradation temperature, allowing them to be employed in organic solvent filtration and separation processes.

Bio: