3 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 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.