Spin columns that include a poly(acid) membrane separation matrix are provided. Also provided are kits that include the subject devices, as well as methods of using the devices, e.g., in sample preparation (such as protein purification) protocols.

Spin columns that include a poly(acid) membrane separation matrix are provided. Also provided are kits that include the subject devices, as well as methods of using the devices, e.g., in sample preparation (such as protein purification) protocols.

The purpose of the present invention is to provide a composite semipermeable membrane whose water permeability is hard to decline even when exposed to high temperature environment for a long period of time, a spiral wound separation membrane element using the composite semipermeable membrane, and a method for producing the same. Another purpose of the invention is to provide a method for evaluating water permeation performance of a composite semipermeable membrane, which method evaluates whether the water permeability of a composite semipermeable membrane is likely to decline due to heat, by a simple evaluation method. The composite semipermeable membrane having a skin layer that includes a polyamide resin, the skin layer being placed on a porous support and having an elastic modulus of 100 MPa or more, calculated by AFM force curve measurement in water.

The purpose of the present invention is to provide a composite semipermeable membrane whose water permeability is hard to decline even when exposed to high temperature environment for a long period of time, a spiral wound separation membrane element using the composite semipermeable membrane, and a method for producing the same. Another purpose of the invention is to provide a method for evaluating water permeation performance of a composite semipermeable membrane, which method evaluates whether the water permeability of a composite semipermeable membrane is likely to decline due to heat, by a simple evaluation method. The composite semipermeable membrane having a skin layer that includes a polyamide resin, the skin layer being placed on a porous support and having an elastic modulus of 100 MPa or more, calculated by AFM force curve measurement in water.

The present invention relates to a thin film composite forward osmosis membrane with a polyethylene porous support, and a thin film composite forward osmosis membrane which is low cost, has excellent durability and chemical resistance, and outstanding performance (water flux and specific salt flux) may be provided in the present invention.

The present invention relates to a composite semipermeable membrane including: a support membrane including a base and a porous support layer; and a separation functional layer disposed on the porous support layer and including a crosslinked aromatic polyamide, in which the separation functional layer contains sulfo groups in an amount of 7.0×10.sup.−5 to 5.0×10.sup.−2 g/m.sup.2 and includes a structure represented by the formula 1.

The present invention relates to a composite semipermeable membrane including: a support membrane including a base and a porous support layer; and a separation functional layer disposed on the porous support layer and including a crosslinked aromatic polyamide, in which the separation functional layer contains sulfo groups in an amount of 7.0×10.sup.−5 to 5.0×10.sup.−2 g/m.sup.2 and includes a structure represented by the formula 1.

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.

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.

A flexible electrocatalytic membrane for removing nitrate from water, a preparation method and use thereof are provided. The method of the present invention includes dropwise adding an aramid fiber solution into deionized water to prepare an aramid nanofiber sol, then reacting an ethanol solution containing 3,4-ethylenedioxythiophene and ferric nitrate with the aramid nanofiber sol to prepare a conductive aramid nanofiber sol, and finally dropwise adding MXene nanosheets ultrasonically pretreated by a tetramethylammonium hydroxide solution into the conductive aramid nanofiber sol to prepare the flexible electrocatalytic membrane. The prepared flexible electrocatalytic membrane possesses good mechanical strength and flexibility, and can not only effectively remove nitrate but also avoid failure of electrocatalytic materials due to surface fouling in the process of electrocatalytic reduction of nitrate, and thus has a long service life.