The present disclosure relates to hydrophilic microporous membranes comprising a modified surface. In addition, the present disclosure relates to a process for producing such hydrophilic membranes by modification of microporous membranes with fluorinated organosilane compounds and electron beam irradiation.

The present invention relates to ultrathin polymer nanofilm and its composite membrane, its method of preparation. Composite membranes are produced via interfacial polymerization of diamine (or polyamine) monomer (or polymer) and trimesoyl chloride. After IP, post-treatment of washing nascent nanofilm with sufficient volume of solvent and drying at room temperature for 10-30 s followed by annealing at 70-100° C. for 1-10 min is developed. This washing step removes remaining TMC in organic phase and stops further growth of polyamide nanofilm. Ultrathin nanofilm composite membrane gives high water permeance (up to 61.3 Lm.sup.−2h.sup.−1bar.sup.−1) with high rejection of Na.sub.2SO.sub.4 (up to 99.3%) by maintaining relatively low rejection of MgCl.sub.2 (up to 27.7%) and NaCl (up to 11.9%) tested under 5 bar pressure at 25 (±1) ° C. with 2 g/L feed solution.

The present invention relates to ultrathin polymer nanofilm and its composite membrane, its method of preparation. Composite membranes are produced via interfacial polymerization of diamine (or polyamine) monomer (or polymer) and trimesoyl chloride. After IP, post-treatment of washing nascent nanofilm with sufficient volume of solvent and drying at room temperature for 10-30 s followed by annealing at 70-100° C. for 1-10 min is developed. This washing step removes remaining TMC in organic phase and stops further growth of polyamide nanofilm. Ultrathin nanofilm composite membrane gives high water permeance (up to 61.3 Lm.sup.−2h.sup.−1bar.sup.−1) with high rejection of Na.sub.2SO.sub.4 (up to 99.3%) by maintaining relatively low rejection of MgCl.sub.2 (up to 27.7%) and NaCl (up to 11.9%) tested under 5 bar pressure at 25 (±1) ° C. with 2 g/L feed solution.

The present invention aims to improve the separation selectivity for light gases such as hydrogen and helium. The gas separation membrane according to the present invention includes a porous support layer and a separation functional layer containing a cross-linked polyamide and laid on the porous support layer, wherein: the separation functional layer has a protuberance structure containing a plurality of protrusions and recesses; randomly selected 20 of the protrusions on the surface of the separation functional layer indented under a load of 3 nN and observed in pure water at 25° C. by atomic force microscopy give an average deformation of 5.0 nm or more and 10.0 nm or less; and they give a standard deviation of the deformation of 5.0 nm or less.

The present invention aims to improve the separation selectivity for light gases such as hydrogen and helium. The gas separation membrane according to the present invention includes a porous support layer and a separation functional layer containing a cross-linked polyamide and laid on the porous support layer, wherein: the separation functional layer has a protuberance structure containing a plurality of protrusions and recesses; randomly selected 20 of the protrusions on the surface of the separation functional layer indented under a load of 3 nN and observed in pure water at 25° C. by atomic force microscopy give an average deformation of 5.0 nm or more and 10.0 nm or less; and they give a standard deviation of the deformation of 5.0 nm or less.

The present invention relates to the field of air filtration, in particular to a polytetrafluoroethylene composite filter material. The polytetrafluoroethylene composite filter material comprises a supporting layer and a polytetrafluoroethylene film layer, wherein the supporting layer is a silver-plated carbon nanomaterial-modified meltblown nonwoven fabric. The polytetrafluoroethylene composite filter material is prepared by fiberizing a resin material modified by silver-plated carbon nanomaterial on the surface of a polytetrafluoroethylene film by a melt-blowing method. The polytetrafluoroethylene composite filter material of the present invention combines filtering and sterilizing functions, has higher filtering efficiency and filtering precision, has the functions of sterilizing and killing viruses, has a good isolation effect, and greatly prolongs the service life of the filter material.

A continuous oil-water separation system includes a storage tank having an inlet and an outlet and storing an oil-water mixture, a filter housing including a storage space having a predetermined height and having an inlet connected to the outflow portion of the storage tank to allow the oil-water mixture to flow in therethrough, a water drain hole allowing water separated from the oil-water mixture to be discharged therethrough, and an outlet allowing a residual oil-water mixture to flow out therethrough, a super-hydrophilic oil-water separation filter positioned in the storage space of the filter housing to absorb water from the oil-water mixture and connected to the water drain hole to allow the absorbed water to be discharged therethrough, a pressure control valve installed on an outlet pipe extending from the outlet, and a hydrophobic membrane connected to a rear end of the pressure control valve on the outlet pipe.

A continuous oil-water separation system includes a storage tank having an inlet and an outlet and storing an oil-water mixture, a filter housing including a storage space having a predetermined height and having an inlet connected to the outflow portion of the storage tank to allow the oil-water mixture to flow in therethrough, a water drain hole allowing water separated from the oil-water mixture to be discharged therethrough, and an outlet allowing a residual oil-water mixture to flow out therethrough, a super-hydrophilic oil-water separation filter positioned in the storage space of the filter housing to absorb water from the oil-water mixture and connected to the water drain hole to allow the absorbed water to be discharged therethrough, a pressure control valve installed on an outlet pipe extending from the outlet, and a hydrophobic membrane connected to a rear end of the pressure control valve on the outlet pipe.

The disclosure relates to a method for separation and purification of N-acetyl-glucosamine, and belongs to the technical field of biological engineering. In the disclosure, a raw material solution containing N-acetyl-glucosamine is obtained by microbial fermentation or by hydrolyzing the chitin. The raw material solution is subjected to flocculation pretreatment, and continuous centrifugation or pressure filtration is performed to remove suspended solids such as microorganisms, proteins and polysaccharides to obtain clear liquid. Double-stage ion exchange chromatography is performed to remove impurities such as charged organic molecules and inorganic salts. Membrane concentration is performed to efficiently remove water to improve the concentration of the target product. Spray drying or further evaporation concentration and crystallization are performed. Finally drying is performed to obtain an N-acetyl-glucosamine crystal of which the purity is more than 99%.

The disclosure relates to a method for separation and purification of N-acetyl-glucosamine, and belongs to the technical field of biological engineering. In the disclosure, a raw material solution containing N-acetyl-glucosamine is obtained by microbial fermentation or by hydrolyzing the chitin. The raw material solution is subjected to flocculation pretreatment, and continuous centrifugation or pressure filtration is performed to remove suspended solids such as microorganisms, proteins and polysaccharides to obtain clear liquid. Double-stage ion exchange chromatography is performed to remove impurities such as charged organic molecules and inorganic salts. Membrane concentration is performed to efficiently remove water to improve the concentration of the target product. Spray drying or further evaporation concentration and crystallization are performed. Finally drying is performed to obtain an N-acetyl-glucosamine crystal of which the purity is more than 99%.