Patent classifications
B01D2323/082
METHOD FOR ONE-STEP REGULATION OF A PORE STRUCTURE AND SURFACE PROPERTIES OF A SILICON CARBIDE (SIC) MEMBRANE
The present invention relates to a method for one-step regulation of a pore structure and surface properties of a silicon carbide (SiC) membrane. The method comprises: first, fully mixing SiC powder with a sintering aid, and then synergistically regulating a pore structure and surface wetting properties of a SiC membrane by controlling a molding pressure and a sintering condition. The amount of SiO.sub.2 generated by oxidation of SiC is controlled, and in situ reaction of SiO.sub.2 and the sintering aid is prompted to generate a neck connection, such that a sintering temperature of the SiC membrane can be reduced, and the strength and corrosion resistance properties of the SiC membrane can also be improved. The degree of sintering of the SiC membrane is effectively controlled by means of the regulation of the molding pressure and the sintering temperature. It is a simple method for one-step regulation of a pore structure and surface properties of a SiC membrane. The SiC membrane prepared has porosity adjustable in a range of 13% to 48% and a pore size adjustable in a range of 0.17 m to 1 m; and the SiC membrane has an initial dynamic water contact angle in a range of 12.01 to 66.8 and an underwater oil contact angle adjustable in a range of 120.3 to 155.1. The SiC membrane prepared has high bending strength and pure water permeation properties and show a broad application prospect in the field of oil-water separation and emulsion preparation.
POROUS MEMBRANES AND METHODS OF MAKING AND USING THEREOF
Polymeric porous membranes, filter containing, and methods of making the polymeric membranes the same are disclosed. The polymeric porous membrane has a first major membrane surface and a second major membrane surface opposite of the first major membrane surface, and a first layer proximate the first major membrane surface, the first layer including a first plurality of pores having a first average pore size. The membrane includes a second layer comprising a second plurality of pores having a second pore size. In some cases, the membrane includes a third layer comprising a third plurality of pores having a third pore size.
Methods for preparing ceramic fiber filter tubes with high air permeability
A method for preparing a ceramic fiber filter tube with high air permeability, including: using mullite short fibers as aggregates, adding glass fibers and silica sol as sintering aids, obtaining a ceramic fiber filter tube green body by using a filterer-pressing forming process, and obtaining the ceramic fiber filter tube with high air permeability by freeze-drying and heat treatment in turn. The combination of two sintering aids with different properties can effectively improve the performance of ceramic fiber filter tube prepared by a wet forming technology. At the same time, the freeze-drying treatment can block the migration path of nanoparticles in the silica sol to the surface of the ceramic fiber filter tube due to the capillary force, so that the properties of the prepared ceramic fiber filter tube are more uniform, providing a reference for the preparation of a ceramic fiber membrane with high flux.
Method for manufacturing ultra-thin polymer separation membrane by using low-temperature coating
The present disclosure relates to an ultra-thin polymer separation membrane including: a porous polymer support layer; a gutter layer formed on the porous polymer support layer; and a semi-crystalline polymer selection layer formed on the gutter layer, wherein the semi-crystalline polymer selection layer is coated with a nanometer-level thickness in a state in which the temperature of a semi-crystalline polymer solution is 0 C. to 50 C. Therefore, the crystallinity and orientation of the ultra-thin polymer separation membrane, essentially required for the scale-up of a separation membrane process and the actual application in the industry, can be controlled easily using a low-temperature coating method, in which the temperature of the polymer solution is lowered, during the coating of the selection layer. Furthermore, separation performance can be enhanced remarkably by using only polymers as raw materials, without additional additives that have been used in the manufacturing of conventional ultra-thin polymer separation membranes.
Methods for preparing microcapillary carbon molecular sieve membranes
A process for preparing a microcapillary carbon molecular sieve membrane may include extruding a polyvinylidene chloride polymer to a thickness from 10 m to 1,000 m to form an extruded polymeric microcapillary film, wherein the extruded polymeric microcapillary film comprises a first end, a second end, and one or more microcapillaries extending from the first end to the second end; pre-treating the extruded polymeric microcapillary film at a temperature from 100 C. to 200 C. for a time from 1 hour to 48 hours to form a pre-treated polymeric microcapillary film; and pyrolizing the pre-treated polymeric microcapillary film at a temperature from 200 C. to 1,500 C. for a time from 15 minutes to 5 hours to form the microcapillary carbon molecular sieve membrane.
SOLAR SEAWATER DESALINATION MEMBRANE, PREPARATION METHOD AND SEAWATER DESALINATION TREATMENT METHOD THEREOF
Disclosed are a solar seawater desalination membrane, a preparation method and a seawater desalination treatment method thereof. The preparation method includes: carrying out hydrophilic treatment on a first carbon cloth to obtain a second carbon cloth with hydrophilicity greater than that of the first carbon cloth; an average pore size of the second carbon cloth is of micron-scale; carrying out a coating treatment on the second carbon cloth based on a preset copper mesh to obtain a first cloth membrane; processing the first cloth membrane to obtain a second cloth membrane; the second cloth membrane includes a graphdiyne structure and the average pore size of the second cloth membrane is of nanometer-scale; processing the second cloth membrane to obtain the solar seawater desalination membrane. The solar seawater desalination membrane contains poly-dopamine particles, and the average pore size of the membrane is smaller than that of the second cloth membrane.
Large-scale fabrication technique for PIM-1 asymmetric membranes doped with low-molecular-weight polyethylene glycol for gas separation
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.
SEPARATION MEMBRANE AND MANUFACTURING METHOD THEREFOR
A degassing method of removing a dissolved gas from a liquid and a gas exchange method of exchanging a dissolved gas in a liquid and a gas component in a gas phase include a method using a separation membrane. To provide a separation membrane having solvent resistance while maintaining high gas permeability using poly(4-methyl-1-pentene) excellent in solvent resistance and gas permeability. To achieve the object, there is provided a separation membrane containing poly(4-methyl-1-pentene) as a main component and including a surface layer and an inner layer, at least one surface layer having lamellar crystals, wherein micropores are provided on the surface layer having the lamellar crystals, an opening ratio is 0.1% to 10% when a ratio of the micropores to a membrane surface is taken as the opening ratio and the membrane surface is 100%, and an average pore size of the micropores is 3 nm to 30 nm.
Method of Preparing Polyamide Membrane with Multi-Level Pore Structure Mediated by Protein Fiber Network
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.
Preparation method of Ti.SUB.3.C.SUB.2.T.SUB.X .MXene quantum dot (MQD)-modified polyamide (PA) reverse-osmosis (RO) membrane
The present disclosure belongs to the technical field of membrane separation, and discloses a preparation method of a Ti.sub.3C.sub.2T.sub.x MXene quantum dot (MQD)-modified polyamide (PA) reverse osmosis (RO) membrane. The preparation method includes the following steps: subjecting a Ti.sub.3C.sub.2T.sub.x MXene material to liquid nitrogen intercalation and interlayer expansion to obtain a Ti.sub.3C.sub.2T.sub.x MQD nanomaterial; preparing an aqueous phase solution with the Ti.sub.3C.sub.2T.sub.x MQD nanomaterial and an organic phase solution; soaking an ultrafiltration (UF) base membrane in the aqueous phase solution, and removing the aqueous phase solution on a surface of the UF base membrane through blow-drying; soaking the second UF base membrane in the organic phase solution to allow interfacial polymerization to form an active layer; and allowing a composite membrane obtained after the interfacial polymerization to stand, followed by a heat treatment to further promote the interfacial polymerization.