A fabrication technique for PIM-1 asymmetric membranes doped with polyethylene glycol for gas separation includes the following steps. Firstly, the coagulation process of casting solution is regulated by polyethylene glycol to thin the dense layer, to improve the hydrophilicity of the membrane structure, and to form mass transfer channels for the diffusion of polyethylene glycol into the dense layer. Then, directional migration and enrichment of polyethylene glycol are realized through capillary action induced by directional water evaporation for fabrication of PIM-1 asymmetric membranes doped with polyethylene glycol in the dense layer for gas separation.

Embodiments of the present disclosure describe a mixed-matrix membrane (MMM), and methods of fabricating a MMM, that includes a filler and a seamless polymer matrix forming a first zone and a second zone. The density of the filler is asymmetric with a greater density of filler within the polymer matrix forming the second zone. A MMM of the present disclosure may be an integrally skinned asymmetric (ISA) MMM or a dense MMM. MMMs of the present disclosure may be utilized in numerous industries. e.g., in the field of organic solvent nanofiltration membranes (OSN), gas separation, fuel cell, battery, catalysis, sensors, pharmaceutical, food and beverages, cosmetics, and composite materials, among others.

Hollow fiber membranes, membrane contactors, and related production and use methods. The asymmetric hollow fiber membranes include a porous substrate having a multiplicity of pores and including at least one semi-crystalline thermoplastic polyolefin (co)polymer. A skin layer including at least one polydiorganosiloxane polyoxamide copolymer overlays the porous substrate. The skin layer is less porous than the porous substrate and forms an outer surface of the asymmetric hollow fiber membrane, while the porous substrate forms an inner surface of the hollow fiber membrane. The skin layer is preferably nonporous.

A separation membrane has high strength and low leakage property while maintaining high gas permeability using poly(4-methyl-1-pentene) excellent in chemical resistance and gas permeability. The separation membrane contains poly(4-methyl-1-pentene) as a main component, in which a ratio RA of a rigid amorphous of poly(4-methyl-1-pentene) in the separation membrane is 43% or more and 60% or less, a porosity is 30% or more and 70% or less, and a dense layer is provided on at least one surface.

Asymmetric hollow fiber membranes comprising a porous substrate layer and a skin layer are described. The skin layer is a copolymer of polymethyl pentene and polypropylene. Gas separation articles made using such hollow fiber membranes, as well as methods of making and using such hollow fiber membranes and gas separation articles are also described.

Methods for the manufacture of a polyelectrolyte coacervate membrane are provided. In an aspect, the method includes providing a polyelectrolyte coacervate phase. The polyelectrolyte coacervate phase includes a polyanion, a polycation, water, and a salt. The polyelectrolyte coacervate phase is coated onto a substrate, and the coated substrate is immersed in a coagulation bath to provide a polyelectrolyte coacervate membrane. The polyelectrolyte coacervate membrane can be annealed. Polyelectrolyte coacervate membranes made by the method are also described.