11 results about "Asymmetric membranes" patented technology

The application relates to a preparation method of a high-porosity high-flux asymmetric membrane, and belongs to the field of membrane separation technology. The preparation method of the high-porosity high-flux asymmetric membrane comprises the following steps: uniformly dissolving a polymer and a hydrophilic additive in an organic solvent to prepare a homogeneous casting solution; preparing a nascent membrane from the casting solution; then, performing atomization pretreatment on the nascent membrane; rapidly cooling the nascent membrane after the pretreatment; then, immersing the nascent membrane in a gel bath to form an asymmetric membrane; and performing multiple flushing and soaking on the asymmetric membrane in normal-temperature deionized water to obtain the high-porosity high-flux asymmetric membrane. The asymmetric membrane adopts a non-solvent atomization technology combined with cooling-induced crystallization, the non-solvent atomization is introduced into the surface of the nascent membrane, the solution is rapidly saturated by accurate temperature control, the crystal formation is triggered, the macroporous pores are formed, and the membrane porosity and flux are improved. The obtained asymmetric membrane has a macroporous network on the surface layer and a finger-shaped pore on the support layer, the porosity is 75% to 85%, the pure water flux is greatly improved, and the high-efficiency separation requirement is met.

The application discloses an asymmetric two-dimensional metal organic framework film and a preparation method and separation application thereof. By controllable adjustment of an organic ligand, different functional groups are introduced to improve the separation performance of hydrogen / carbon dioxide and ethanol dehydration. The preparation method comprises the following steps: synthesizing precursor nanosheets by a solvothermal method, obtaining a two-dimensional nanosheet dispersion liquid by delamination, assembling the nanosheets on the surface of a porous carrier, and microwave-assisted secondary growth to form a film. The two-dimensional metal organic framework micro-area asymmetric film prepared by the functional group gradient regulation strategy has excellent gas screening and liquid phase separation performance, and has a wide application prospect.

The application belongs to the field of membrane separation, and particularly relates to an asymmetric membrane for separating miscible organic solvent mixtures, and a main step of a preparation method thereof is as follows: (1) a fabric membrane with strong affinity to weakly polar solvents is prepared by treating a cotton fabric with a modifier by an immersion method; (2) a nano material is oxidized with a strong oxidant in a concentrated acid, and then the nano material is deposited on a surface of a base membrane to obtain a nano material membrane with strong affinity to strongly polar solvents; and (3) the two membranes are combined to build a separation system, and the asymmetric membrane for separating miscible organic solvent mixtures is obtained. The asymmetric membrane separates miscible organic solvents by the different interactions of the upper and lower filter membranes to organic solvents with different polarities.

The invention discloses an asymmetric two-dimensional metal organic framework membrane as well as a preparation method and separation application thereof. The organic ligand is controllably modulated, and different functional groups are introduced, so that the separation performance of hydrogen / carbon dioxide and ethanol dehydration is improved. The preparation method comprises the following steps: synthesizing precursor nanosheets by a solvothermal method, peeling to obtain a two-dimensional nanosheet dispersion liquid, assembling the nanosheets on the surface of a porous carrier, and carrying out microwave-assisted secondary growth to form the film. The two-dimensional metal organic framework microcell asymmetric membrane prepared through a functional group gradient regulation strategy has excellent gas screening and liquid phase separation performance and has a wide application prospect.

The invention relates to a preparation method of a high-porosity and high-flux asymmetric membrane, and belongs to the technical field of membrane separation. A preparation method of a high-porosity and high-flux asymmetric membrane comprises the following steps: uniformly dissolving a polymer and a hydrophilic additive in an organic solvent to prepare a homogeneous membrane casting solution; preparing a primary membrane from the membrane casting solution, then carrying out atomization pretreatment on the primary membrane, rapidly cooling after treatment, then immersing the primary membrane in a gel bath to form an asymmetric membrane, and washing and soaking the asymmetric membrane in normal-temperature deionized water for multiple times to obtain the high-porosity and high-flux asymmetric membrane. According to the asymmetric membrane, a non-solvent atomization technology is combined with cooling induced crystallization, non-solvent atomization is introduced into the surface of a primary membrane, the temperature is accurately controlled, so that a solution is rapidly saturated, crystal formation is triggered, large-aperture pores are formed, and the porosity and flux of the membrane are improved. The surface layer of the obtained asymmetric membrane is provided with a large-aperture network, the supporting layer is finger-shaped holes, the porosity is 75%-85%, the pure water flux is greatly improved, and the efficient separation requirement is met.

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.

A process of preparing a crosslinked asymmetric membrane for solvent nanofiltration, comprising: (1) dissolving an aromatic polymer and one or more aromatic polyamine(s) in an organic solvent system to form a casting solution: (ii) casting the solution onto a support: (iii) creating an asymmetric membrane by phase inversion; (iv) placing the resulting asymmetric membrane in an aqueous nitrite solution in an acidic environment; and (v) recovering a crosslinked asymmetric membrane.

The application discloses an asymmetric PTFE porous membrane and a preparation method and application thereof, the porous membrane comprises a main body, one side of the main body is a first outer surface, and the other side is a second outer surface, the first outer surface comprises strip-shaped nodes and strip-shaped fibers, the strip-shaped fibers are distributed in a fishbone shape along the length direction of the strip-shaped nodes, the second outer surface comprises dot-shaped nodes and trapped fibers, and the trapped fibers are distributed in a radial shape along the circumferential direction of the dot-shaped nodes; the PTFE porous membrane is integrally formed; the PMI average pore diameter of the PTFE porous membrane is 0.5-20 mu m, and the thickness is 5-100 mu m; the PTFE porous membrane is an asymmetric membrane and is integrally formed, has high trapping efficiency, is relatively fast in flow rate, is suitable for filtering fluid in a short time, has good mechanical strength, has a wide application range, and is particularly suitable for being applied to the filtration of stripping liquid and etching liquid in a semiconductor process and being used as a waterproof and breathable membrane in electronic equipment and medical equipment; in addition, the application further provides a preparation method of the porous membrane, and the method is simple in operation.

The present invention relates to a process for purifying an electrolyte solution, the process comprising application of an alternating electric field between a first electrode and a second electrode, resulting in solvent transport and solute filtration through an asymmetric membrane, and to a system for purifying an electrolyte solution using such a process.

The invention belongs to the field of membrane separation, and particularly relates to an asymmetric membrane for separating a miscible organic solvent mixture, and a preparation method of the asymmetric membrane mainly comprises the following steps: (1) treating a cotton fabric with a modifier by adopting an impregnation method to prepare a fabric membrane with strong affinity to a weak polar solvent; (2) oxidizing a nano-material in concentrated acid by using a strong oxidant, and depositing the nano-material on the surface of the basement membrane to obtain a nano-material membrane with strong affinity to a strong polar solvent; and (3) combining the two membranes, and constructing a separation system to obtain the asymmetric membrane for separating the mixed and dissolved organic solvent mixture. According to the asymmetric membrane disclosed by the invention, the separation of miscible organic solvents is realized through the interaction of the upper and lower filter membranes on the difference of the organic solvents with different polarities.

The present invention relates to a method of purifying an electrolyte solution, the method comprising applying an alternating electric field between a first electrode and a second electrode, thereby enabling solvent transfer and solute filtration through an asymmetric membrane. The invention also relates to a system for purifying the electrolyte solution by adopting the method.