A method of manufacturing a porous film includes a decomposition step of introducing a porous film precursor which is formed by coagulating an undiluted film forming solution containing a hydrophilic polymer and a hydrophobic polymer, into a decomposition container; bringing a heated chemical containing an oxidizing agent into contact with the porous film precursor in the decomposition container; warming the porous film precursor in contact with the chemical; and decomposing the hydrophilic polymer remaining inside the porous film precursor using the oxidizing agent. An apparatus for manufacturing a porous film includes a decomposition device provided with the decomposition container.

A method for making a filter membrane includes: forming a polymer layer; applying a plurality of nanoparticles on the polymer layer, the nanoparticles being self-assembled to form a closed pack arrangement on the polymer layer; heating the nanoparticles such that a portion of the polymer layer contacting the nanoparticles is softened so that the nanoparticles are sunk into the polymer layer; and removing the nanoparticles from the polymer layer so that the polymer layer is formed with a plurality of pores penetrating the polymer layer and being arranged in a honeycomb pattern.

The present disclosure provides a porous hollow fiber membrane that exhibits blocking performance and water permeability performance suitable for filtration applications, as well as having excellent chemical resistance. In order to provide a solution to the above issue, the porous hollow fiber membrane of the present disclosure is made of a thermoplastic resin, wherein the crystallization onset temperature is 140 C. or lower, and the enthalpy of crystal fusion at and below the crystallization onset temperature is 10 J/g or less.

A porous membrane containing a hydrophobic polymer and a water-insoluble hydrophilic polymer, the porous membrane having a dense layer in the downstream portion of filtration in the membrane, having a gradient asymmetric structure in which the average pore diameter of fine pores increases from the downstream portion of filtration toward the upstream portion of filtration, and having a gradient index of the average pore diameter from the dense layer to the coarse layer of 0.5 to 12.0.

Methods of preparing a porous robust support to host an ultra-thin enzyme-assisted membrane, and a new membrane system that can be used for gas filtration purposes to remove/separate carbon dioxide or other gases from a gas mixture such as those from power production or enhanced oil recovery or fuel production or air and recycle/collect/utilize carbon dioxide are disclosed herein. A method may include protecting the surface with a blocking material and polishing the protected surface, coating a thin layer of silica nanospheres onto the polished surface, coating a silica sol-gel and surfactant solution onto the nanospheres, and then removing the surfactant and blocking material to generate a well-defined porous structure with nanochannels.