Rational design of phase inversion membranes by tailoring thermodynamics and kinetics of casting solution using polymer additives

Recent Advances in Nanoporous Membranes for Water Purification

Nanoporous materials exhibit wide applications in the fields of electrocatalysis, nanodevice fabrication, energy, and environmental science, as well as analytical science. In this review, we present a summary of recent studies on nanoporous membranes for water purification application. The types and fabrication strategies of various nanoporous membranes are first introduced, and then the fabricated nanoporous membranes for removing various water pollutants, such as salt, metallic ions, anions, nanoparticles, organic chemicals, and biological substrates, are demonstrated and discussed. This work will be valuable for readers to understand the design and fabrication of various nanoporous membranes, and their potential purification mechanisms towards different water pollutants. In addition, it will be helpful for developing new nanoporous materials for quick, economic, and high-performance water purification.

Fabrication optimization of polyethersulfone (PES)/polyvinylpyrrolidone (PVP) nanofiltration membranes using Box–Behnken response surface method

Herein response surface methodology (RSM) is employed to optimize the fabrication of polyethersulfone (PES) nanofiltration (NF) membranes via phase inversion.

Free-standing thermo-responsive nanoporous membranes from high molecular weight PS-PNIPAM block copolymers synthesized via RAFT polymerization

Free-standing, fully reversible thermo-responsive nanoporous membranes were fabricated from PS-PNIPAM block copolymers.

Membrane properties and anti-bacterial/anti-biofouling activity of polysulfone-graphene oxide composite membranes phase inversed in graphene oxide non-solvent

PSF–GO composite membrane fabrication using a new and facile method where after casting, the polymer solution was phase inversed in di-water–GO non-solvent.

A new and facile method for the fabrication of polysulfone–graphene oxide composite membranes is reported, where after casting, phase inversion is carried out with graphene oxide flakes (GO) in a coagulation bath. The membranes were characterized and the morphology was analysed using scanning electron microscopy. A bacterial inhibition ratio of 74.5% was observed with membranes fabricated from a very low concentration of di-water–GO non-solvent (0.048% of GO). The membranes were successfully tested for permeate flux and fouling resistance using activated sludge filtration from an MBR system. The observed trend shows that GO can operate as a protective barrier for membrane pores against the bacterial community. To our knowledge this is the first time where the immersion precipitation mechanism was carried out in a coagulation bath with GO flakes under continuous stirring. Using this method, a very low concentration of GO is required to fabricate membranes with conventional GO composite membrane properties and better selectivity.

pH-Responsive nanofiltration membranes based on porphyrin supramolecular self-assembly by layer-by-layer technique

A novel pH-responsive nanofiltration membrane was fabricated by means of layer-by-layer technique based on porphyrin supramolecular self-assembly.

Improvements in permeation and fouling resistance of PVC ultrafiltration membranes via addition of Tetronic-1107 and Triton X-100 as two non-ionic and hydrophilic surfactants

Two non-ionic and hydrophilic surfactant additives, Tetronic-1107 and Triton X-100, were added to poly(vinyl chloride)/NMP polymeric solution to prepare ultrafiltration membranes via immersion precipitation. Surfactants at three different weight percentages up to 6 wt% were added, and the fabricated membranes were characterized and their performance for water treatment in the presence of bovine serum albumin (BSA) as a foulant was assessed. The scanning electron microscopy images indicated remarkable changes in morphology due to higher thermodynamic instability after surfactant addition. The membranes are more porous with more macro-voids in the sub-layer. Plus, the membranes become more hydrophilic. Water flux increases for the modified membranes by nearly two times and the ability of membranes for flux recovery increases from 66% to over 83%. BSA rejection reduces slightly with the addition of surfactants, however this parameter is still almost over 90% for the membranes with the highest amount of surfactants.

A WORM type polymer electrical memory based on polyethersulfone with carbazole derivatives

A series of high-performance polyethersulfone, which had pendent carbazole moieties (Cz-PES 1–3), have been designed and successfully synthesized for an application in a write-once read-many type memory device as the active polymer layer. The memory performance can be tuned by changing the substituent in the Cz derivatives units. Cz-PES 3 with excellent thermal properties ( Tg = 185°C and Td = 378°C) exhibits the best memory performance. For Cz-PES 3-based device indium tin oxide/Cz-PES 3/aluminum, the turn-on voltage is 2.5 V and the ON/OFF current ratio is higher than 106. Moreover, the data can be maintained for longer than 3 × 105 s once written and can be read for more than 450 cycles under a reading voltage of 1.0 V at ambient conditions. Thus Cz-PES 3 can serve as an excellent memory material in the data storage field of next generation.

Enhanced sequestration of large-sized dissolved organic micropollutants in polymeric membranes incorporated with mesoporous carbon

Hybrid polyvinylidene fluoride membrane incorporated with mesoporous carbon is fabricated for an enhanced sequestration of large-molecular-sized microcystin-LR and Rhodamine B (3.8 and 14.8 mg g⁻¹, respectively).

Fabrication of organic–inorganic hybrid membranes composed of poly(vinylidene fluoride) and silver cyanamide and their high photocatalytic activity under visible light irradiation

An active photocatalytic membrane composed of silver cyanamide and poly(vinylidene fluoride) showed high photocatalytic efficiency toward the degradation of Acid Blue 1 under visible light irradiation.