The present invention relates to a method for producing a porous membrane, the method being characterized in that a solvent system comprising 2-pyrrolidone and N-alkyl-2-pyrrolidone is used, wherein the content ratio of 2-pyrrolidone to N-alkyl-2-pyrrolidone in the solvent system is from 90%:10% to 10%:90%, based on mass %, and wherein N-alkyl-2-pyrrolidone is N-propyl-2-pyrrolidone and/or N-butyl-2-pyrrolidone. Furthermore, the present invention relates to a porous membrane obtainable by said method. Moreover, the present invention relates to the use of a specific solvent system for the production of a porous membrane.

This invention provides a polymeric separation membrane that has excellent durable antibacterial effect and stain resistance, and a preparation method thereof. The polymeric separation membrane can be widely applied for water treatment, which belongs to the field of water treatment and membrane separation science and technology. The polymeric separation membrane containing quaternary ammonium salt is prepared by the immersion precipitation phase inversion method, using quaternary ammonium salt mixed with polymer and additives. This modification method effectively improves the antibacterial and antifouling ability of the polymeric separation membrane prolongs the service life of membranes and significantly inhibits the reproduction of bacterial and microbial. The preparation method has the advantages of simple process, easy operation, easy for promotion, and also avoids expensive equipment. The polymeric separation membrane has great antibacterial ability and stain resistance, therefore, it has potential application in the field of water treatment.

A large-scale fabrication technique for PIM-1 asymmetric membranes doped with low-molecular-weight polyethylene glycol for gas separation. Based on the membrane fabrication technique of dry/wet phase inversion, firstly, the coagulation process of casting solution is regulated by low-molecular-weight polyethylene glycol to thin the dense functional layer, to improve the hydrophilicity of the membrane structure, and to form mass transfer channels for the diffusion of polyethylene glycol into the dense functional layer. Then, directional migration and enrichment of polyethylene glycol are realized through capillary action induced by directional water evaporation for large-scale fabrication of PIM-1 asymmetric membranes doped with low-molecular-weight polyethylene glycol in the dense functional layer for gas separation, and thereafter high permeation ability and high selectivity are achieved simultaneously.

A method for preparing a homogeneous braid-reinforced (HMR) PPTA hollow fiber membrane combines PPTA hollow tubular braids with PPTA surface separation layer. The method includes following steps of: (1) preparing the PPTA hollow tubular braids, wherein the PPTA hollow tubular braids which are made from PPTA filament yarns are woven by a two-dimensional braided method, the outer diameter of the PPTA tubular braids is 1-2 mm; (2) preparing the PPTA casting solution as the surface separation layer, wherein the 1-3 wt % PPTA resin, 0-2 wt % inorganic particles and 10-20 wt % pore-forming agents are mixed into 75-89% inorganic acid solvent, stirred for 1-3 hours at 70 C.-90 C. to form homogeneous and transparent casting solution; and (3) preparing reinforced PPTA hollow fiber membrane, wherein the casting solution as the surface separation layer is evenly coated on the surfaces of the PPTA hollow tubular braids through spinneret, and they are immersed in a coagulation bath for solidified formation.

A separation mechanism comprises a top plate; a base parallel the top plate; a membrane between the top plate and the base; a channel formed by the top plate and the base; and a low-bind coating at a surface of at least one of the top plate or the membrane along which a sample stream in a flow path flows through the channel to reduce or prevent analyte particles of the sample stream from sticking to the top plate.

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.