Provided is a high permeance nanofiltration membrane with nanoring-like structure and preparation method thereof. The membrane includes a base film and a polyamide layer having nanoring-like structure morphology on its surface. The method includes: (1) formulating a piperazine nanoemulsion containing a surfactant, vegetable oil, piperazine and water; and (2) infiltrating a base film with the piperazine nanoemulsion, and removing excess droplets from the surface of the base film to obtain a treated base film; covering the surface of the treated base film with a solution of trimesoyl chloride in n-hexane to perform interfacial polymerization; and drying the resulting membrane. Introduction of nano-oil droplets into aqueous phase as templates to construct nanoring-like structure morphology on the surface of the polyamide layer significantly increases the specific surface area and free volume of the polyamide layer without losing the salt rejection rate of the membrane, thereby greatly improving its water permeance.

The present invention relates to a monolithic bipolar membrane with a low transmembrane voltage and a preparation method thereof. The preparation method includes the following steps: preparing a membrane liquid with styrene and divinylbenzene; heating the membrane liquid, and then impregnating a polyolefin thin membrane; polymerizing an impregnated thin membrane and preparing a basement membrane; producing the basement membrane into a semi-anion membrane; additionally partially sulfonating and additionally quaternizing one side of the semi-anion membrane; then, soaking the bipolar membrane in a FeCl.sub.2 solution, transforming the bipolar membrane in an alkaline solution, and preparing the bipolar membrane. The present invention effectively reduces the transmembrane voltage, thereby being beneficial to reducing energy consumption.

The present invention relates, in general terms, to a composite membrane for use in filtration. The present invention also relates to a method of fabricating the composite membrane, and a method of filtrating using the composite membrane as disclosed herein. The method of fabricating a composite membrane comprising contacting a perfluorinated polymer solution with a surface of a polymer layer and drying the perfluorinated polymer solution at a relative humidity of less than 20% to form a perfluorinated polymer layer physisorbed on the surface of the polymer layer.

One aspect of the present invention provides a polymer electrolyte membrane including: a porous substrate including a first part including a first polyolefin modified with a halogen-based compound, and a second part including a second polyolefin; and a halogen-based polymer electrolyte impregnated in pores of the porous substrate, wherein in the porous substrate, the first part and the second part constitute a discontinuous phase and a continuous phase, respectively, and a content of the halogen-based compound in the porous substrate is 0.5 to 10 wt %, and a method of manufacturing the same.

Nanoporous selective sol-gel ceramic membranes, selective-membrane structures, and related methods are described. Representative ceramic selective membranes include ion-conductive membranes (e.g., proton-conducting membranes) and gas selective membranes. Representative uses for the membranes include incorporation into fuel cells and redox flow batteries (RFB) as ion-conducting membranes.

A composite that includes an expanded polytetrafluoroethylene (ePTFE) membrane having a porous microstructure. The porous microstructure of the ePTFE membrane is impregnated with a stiffening polymer. An acoustic device assembly that includes the composite and an acoustic device is also described. The composite and the acoustic device assembly can exhibit an insertion loss of less than 7 dB at 1 kHz when measured by the Acoustic Response Measurement (ARM) Test.

The present invention relates to a method for producing a composite membrane, the method comprising impregnating a surface of a porous membrane substrate with an aqueous suspension comprising a mixture of at least one polyamine and at least one phospholipid; and contacting the impregnated surface with an organic phase containing a monomer to thereby deposit a polyamide layer on the impregnated surface. The present invention also relates to a composite membrane comprising at least one porous membrane substrate having nano-sized or micro-sized pores; and at least a polyamide layer disposed on a surface of the porous membrane substrate, the polyamide layer comprising at least one phospholipid dispersed therein, and wherein the polyamide layer is an interfacial polymerization product.

A composite membrane comprising: a) a first layer comprising a first porous support and a first ionic polymer present in the pores of the first porous support; b) a second layer comprising a second porous support and a second ionic polymer present in the pores of the second porous support; c) a third layer comprising a third porous support, a third ionic polymer and a fourth ionic polymer, wherein the third ionic polymer is present in the pores of the third porous support; wherein: (i) one of the first ionic polymer and the second ionic polymer is a cationic polymer and the other is an anionic polymer; (ii) the third layer c) is interposed between the first layer a) and the second layer b); (iii) the third ionic polymer comprises a network of pores and the fourth ionic polymer is present within the pores of the third ionic polymer; and (iv) one of the third ionic polymer and the fourth ionic polymer is a cationic polymer and the other is an anionic polymer.

The present invention relates to a method for producing a composite membrane, the method comprising impregnating a surface of a porous membrane substrate with an aqueous suspension comprising a mixture of at least one polyamine and at least one phospholipid; and contacting the impregnated surface with an organic phase containing a monomer to thereby deposit a polyamide layer on the impregnated surface. The present invention also relates to a composite membrane comprising at least one porous membrane substrate having nano-sized or micro-sized pores; and at least a polyamide layer disposed on a surface of the porous membrane substrate, the polyamide layer comprising at least one phospholipid dispersed therein, and wherein the polyamide layer is an interfacial polymerization product.

A method of preparing a polyamide membrane with multi-level pore structure mediated by protein fiber network includes the steps of: preparing protein fiber; quenching and carrying out dialysis; loading protein fiber network on ultrafiltration membrane; preparing aqueous and organic phase solutions; and carrying out interfacial polymerization, which can solve the problems of the integrity and separation performance of the polyamide layer being affected by low porosity of the base membrane and uneven distribution of amine monomers. The polyamide membrane prepared by the method of the present invention greatly improves the water flux while ensuring a high salt rejection rate. At the same time, the introduction of the protein fiber network also enhances the mechanical strength and anti-pollution ability of the membrane.