In recent years, the development of sustainable membrane manufacturing processes by the use of environmentally friendly solvents has become a considerable challenge. In this work, poly(ether sulfone) (PES) hollow fiber membranes were manufactured by the nonsolvent‐induced phase separation (NIPS) using the green solvent Agnique® AMD 3 L (N,N‐dimethyl lactamide; AMD) andN‐ethyl‐2‐pyrrolidone (NEP) as a conventional solvent. The effect of the solvent on the dope solution and membrane properties was investigated. The morphology, mechanical characteristics, barrier pore sizes as well as gas and water permeances of the hollow fibers prepared with AMD were evaluated and compared to membranes that were similarly prepared using NEP as solvent. Membranes prepared with AMD as polymer solvent and NEP as bore liquid exhibit the largest barrier pore size among all variations. Thus, highest water permeance of 406.9 ± 37.4 kg m⁻² h⁻¹ bar⁻¹was obtained with this combination. Whereas AMD as sole solvent in membrane preparation decreases membrane permeances caused by a denser membrane structure. Nevertheless, AMD is a promising solvent for a sustainable membrane fabrication providing membrane properties that are competitive with membranes manufactured using the conventional solvent NEP.

In this study, a triblock copolymer was used as additive to fabricate new dual layer hollow fiber membranes with a hydrophilic active inner surface in order to improve their fouling resistance. The polymeric components of the solutions for membrane fabrication were poly(ether sulfone), poly(N-vinyl pyrrolidone), and the triblock copolymer. The additive consists of three blocks: a middle hydrophobic poly(ether sulfone) block and two outer hydrophilic alkyl poly(ethylene glycol) blocks. By varying the additive concentration in the solutions, it was possible to fabricate dual layer hollow fiber membranes that are characterized by a hydrophilic inner layer, a pure water permeance of over 1800 L/(m² bar h) and a molecular weight cut-off of 100 kDa similar to commercial membranes. Contact angle and composition determination by XPS measurements revealed the hydrophilic character of the membranes, which improved with increasing additive concentration. Rheological, dynamic light scattering, transmission, and cloud point experiments elucidated the molecular interaction, precipitation, and spinning behavior of the solutions. The low-molecular weight additive reduces the solution viscosity and thus the average relaxation time. On the contrary, slow processes appear with increasing additive concentration in the scattering data. Furthermore, phase separation occurred at a lower non-solvent concentration and the precipitation time increased with increasing additive content. These effects revealed a coupling mechanism of the triblock copolymer with poly(N-vinyl pyrrolidone) in solution. The chosen process parameters as well as the additive solutions provide an easy and inexpensive way to create an antifouling protection layer in situ with established recipes of poly(ether sulfone) hollow fiber membranes. Therefore, the membranes are promising candidates for fast integration in the membrane industry.

In this study, we focus on membranes of polyethersulfone and poly( N ‐vinyl pyrrolidone) and elucidate the influence of composition on the rheological, diffusion and precipitation properties of solutions which are used for membrane preparation via a non‐solvent‐induced phase separation process. The low‐molar‐mass component of the solution is a mixture of the solvent N ‐methyl‐2‐pyrrolidone and the non‐solvent glycerol. Cloud point, viscosity and diffusion measurements as well as precipitation experiments were performed in order to achieve a comprehensive understanding of the time dependence of the precipitation process. The addition of glycerol yields an increase of viscosity and a stronger tendency for demixing. The enhanced tendency for demixing causes a more rapid precipitation process. The average relaxation time of the solution as a function of glycerol concentration follows a similar trend to its viscosity. The increase of viscosity is associated with the increase of the monomeric friction coefficient. Two diffusive processes with clearly separated time scales appear in dynamic light scattering experiments in the presence of glycerol. This phenomenon is discussed taking into account the phase behaviour of the solution and the quality of the solvent. The addition of glycerol yields a lower pure water permeance whereas the molecular weight cut‐off is not altered in the ultrafiltration range. © 2020 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

This article describes the synthesis and characterization of a novel crosslinked polymer with tricyanuric acid core bearing tetrasulfide bridges as a novel redox polymerization electrode material for rechargeable lithium–sulfur batteries. The new material was synthesized by reaction of stoichiometric sulfur monochloride amounts with trithiocyanuric acid and the structure of the redox polymer proven by the means of elementary analysis, infrared spectroscopy and Raman spectroscopy. Electrochemical evaluation of the polymer as electroactive cathode component showed cycling stability up to 140 cycles after initial capacity of 650 mAhg–1 with 73% utilization of the theoretical specific capacity (893 mAhg–1) regarding the electroactive tetrasulfide moieties. Cell operation with excess amounts of electrolyte did not accelerate the cell degradation, indicating that the reduced sulfur species such as lower polysulfides (Li2S, Li2S2) and tris lithium salt of trithiocyanuric acid are efficiently immobilized on the cathode side.