Marine mussel inspired polydopamine (PDA) has received increased attention due to its good thermal and chemical stability as well as strong adhesion on most materials. In this work, high-performance nanofiltration membranes based on interpenetrating polymer networks (IPN) incorporating PDA and polybenzimidazole (PBI) were developed for organic solvent nanofiltration (OSN). Generally, in order to obtain solvent stability, polymers need to be covalently cross-linked under harsh conditions, which inevitably leads to losses in permeability and mechanical flexibility. Surprisingly, by in situ polymerization of dopamine within a PBI support, excellent solvent resistance and permeance of polar aprotic solvents were obtained without covalent cross-linking of the PBI backbone due to the formation of an IPN. The molecular weight cutoff and permeance of the membranes can be fine-tuned by changing the polymerization time. Robust membrane performance was achieved in conventional and emerging green polar aprotic solvents (PAS) in a wide temperature range covering −10 °C to +100 °C. It was successfully demonstrated that the in situ polymerization of PDAcreating an IPNcan provide a simple and green alternative to covalent cross-linking of membranes. To elucidate the nature of the solvent stability, a detailed analysis was performed that revealed that physical entanglement along with strong secondary interaction synergistically enable solvent resistance with as low as 1–3% PDA content.

Covalent organic frameworks (COFs) have attracted considerable interest owing to their structural predesign ability, con-trollable chemistry, long-range periodicity, and pore interior functionalization ability. The most widely adopted sol-vothermal synthesis of...

Robust, ion-stabilized membranes from polybenzimidazole (PBI) and its blends with polymer of intrinsic microporosity (PIM-1) were fabricated for organic solvent nanofiltration in polar aprotic solvents (PAS). Flat sheet membranes comprised of polybenzimidazole and 4–12 wt % PIM-1 were fabricated via conventional phase inversion followed by the reduction of nitrile PIM-1 to amine PIM-1. Stabilization of the membranes was achieved via ion formation (chloride salt) under acidic conditions. Such simple ion-stabilization methodology could replace cumbersome cross-linking. The aging of the membranes and the their performance at room and elevated temperatures, in a wide range of pH, in the presence of organic bases, in six conventional and two green PAS, were investigated. The PIM-1 content enabled fine-tuning of the molecular weight cutoff (MWCO) of the membranes between 190 and 650 g mol–1.

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Microalgal cultivation in photobioreactors and membrane separations are both considered sustainable processes. Here we explore their synergistic combination to extract and concentrate a heterologous sesquiterpenoid produced by engineered green algal...