8results about How to "Improve gas separation performance" patented technology

The invention discloses a polyimide hollow fiber gas separation membrane and a preparation method thereof, and the polyimide hollow fiber gas separation membrane is prepared by reasonably designing a precursor structure and accurately regulating spinning parameters. The prepared polyimide hollow fiber gas separation membrane is compact in surface, free of holes and defects and excellent in mechanical property, and has a high-flux and high-selectivity gas separation effect, especially for hydrogen. Wherein the hollow fiber spinning solution is obtained by mixing a polyimide polymer, a high-boiling-point solvent, a low-boiling-point solvent and a non-solvent, and the polyimide polymer is synthesized by carrying out condensation polymerization on a dianhydride monomer, a diamine monomer containing a benzimidazole group and other diamine monomers. The preparation method provided by the invention is simple, convenient and easy to operate, avoids tedious procedures and additional economic investment brought by subsequent processes (polydimethylsiloxane coating and crosslinking modification), and has a wide application prospect.

The application relates to a high-strength high-separation-performance carbon molecular sieve hollow fiber membrane and a preparation method and application thereof, and the preparation method comprises the following steps: (1) mixing cellulose acetate, cellulose, an organic solvent and an ionic liquid to prepare a casting solution, and stirring and heating the casting solution; (2) vacuumizing and defoaming the casting solution, and preparing a hollow fiber cellulose acetate membrane by using a dry-wet spinning method; and (3) drying the hollow fiber cellulose acetate membrane, and preparing the high-strength high-separation-performance carbon molecular sieve hollow fiber membrane by carbonizing under temperature rise in a protective atmosphere. Compared with the prior art, the carbon molecular sieve hollow fiber membrane has good gas separation performance and high strength. The carbon molecular sieve membrane is used for He / CH4 separation, has high He permeation performance and a high He / CH4 separation factor, has good gas separation performance under high pressure, and provides a new choice for natural gas helium extraction membrane materials.

The invention relates to the technical field of conjugated microporous polymer materials, and discloses a covalent triazine unit-based conjugated microporous polymer membrane with negative charges and a preparation method thereof. The method comprises the following steps: firstly, preparing a negatively charged cyanophenyl monomer through nucleophilic substitution reaction of a cyanophenyl-containing compound and 1, 4-butane sultone, then taking the monomer and biphenyl nitrile as comonomers, and carrying out step-by-step polymerization, heating film formation, shock cooling shaping and dual-solvent soaking post-treatment under the catalysis of trifluoromethanesulfonic acid to obtain the cyanophenyl-containing polymer film. And finally obtaining the covalent triazine unit-based conjugated microporous polymer membrane with negative charges. The preparation process is high in controllability, and the obtained film has high stability of a covalent triazine structure and the porous characteristic and negative charge function of conjugated micropores, and has wide application prospects in the fields of gas separation and the like through verification.

The invention discloses a preparation method of a benzoxazole-polyimide copolymer gas separation membrane, which comprises the following steps: a solvent and two aromatic diamines are added into a flask, one aromatic diamine is hydroxyl-containing aromatic diamine; adding dianhydride after dissolving, and reacting to generate a hydroxyl polyamide acid solution; filtering the hydroxyl polyamide acid solution in a filter, pouring on a tool plate, drying, performing thermal imidization in a drying oven, and cooling to obtain a hydroxyl polyimide-polyimide copolymer film; and placing the hydroxyl polyimide-polyimide copolymer film in a tubular furnace, and carrying out thermal rearrangement reaction in an argon atmosphere to generate the benzoxazole-polyimide copolymer film. According to the gas separation membrane obtained by the method, the gas permeability is remarkably improved, and the carbon dioxide separation capability is improved.

This application relates to the field of capacitor technology, specifically disclosing an environmentally friendly capacitor insulating oil and its preparation method. The environmentally friendly capacitor insulating oil comprises polyol esters and hydroxyl acrylates, wherein the molar ratio of hydroxyl groups in the polyol esters to those in the hydroxyl acrylates is 1–2:1–2. This application introduces small-molecule hydroxyl acrylates to reduce the intermolecular forces of the polyol esters, thereby improving the low-temperature fluidity of the insulating oil. Simultaneously, the small-molecule hydroxyl acrylates also provide free radical trapping sites, effectively improving the gas evolution performance, antioxidant stability, and electrical properties of the insulating oil under extreme low-temperature conditions. This solves the technical problem of existing insulating oils being unable to simultaneously achieve low-temperature fluidity, insulation, and environmental friendliness.

This invention belongs to the field of membrane material technology, and particularly relates to a six-membered ring polyimide copolymer separation membrane, its preparation method, and its applications. This invention utilizes naphthalene dianhydride copolymerized with rigid diamine monomers such as BAPF and TrMPD. The rigid structure of the naphthalene ring and fluorene ring on the main chain, with their high electron cloud density, improves the gas separation performance of the polymer membrane. The six-membered ring polyimide obtained through this method exhibits excellent gas separation performance for CO2. 2 / N 2 The separation effect of the mixed gas is better than the test results in the pure gas, indicating its broad application prospects in the field of exhaust gas treatment.

This invention discloses an anion-pillared ultraporous membrane, its preparation method, and its application in the separation of low-carbon hydrocarbons. The ultraporous membrane exhibits stable properties and excellent separation selectivity and permeation flux. Preparation method: A polymer with hydrogen-bonded groups is spin-coated onto a substrate, dried to form a film, the substrate is modified, and then an inorganic anion-pillared ultraporous material layer is grown in situ on the substrate surface to obtain the ultraporous membrane. The inorganic anion-pillared ultraporous material layer is formed by the self-assembly of metal ions, inorganic anions, and flexible ligands through coordination bonds; the metal ion is Cu. 2+ Zn 2+ At least one of the following; the inorganic anion is SiF6. 2‑ GeF6 2‑ At least one of the following; the flexible ligand is at least one of 4,4'-bipyridine sulfide and 4,4'-bipyridine sulfoxide.

The invention relates to the technical field of separation membranes, and particularly discloses a preparation process of a self-supporting gas separation membrane prepared from a polymer-assisted monolithic metal organic framework. Comprising the following specific steps: S1, uniformly mixing defective metal organic framework particles with a metal salt, a ligand and triethylamine, pressing the mixture into a wafer, and then putting the wafer into a reaction kettle for heating reaction to obtain MOFsp1; s2, uniformly mixing a metal salt, a ligand and triethylamine, re-pressing the mixture and the MOFsp1 prepared in the step 1 into a new wafer, and putting the new wafer into a reaction kettle for heating reaction to obtain MOFsp2; repeating the operation to prepare the self-supporting integral metal organic framework; s3, washing and drying the self-supporting monoblock metal organic framework prepared in the step 2 by using N, N-dimethylformamide and methanol respectively, then soaking the self-supporting monoblock metal organic framework in a polydimethylsiloxane solution, and drying the self-supporting monoblock metal organic framework to prepare the self-supporting gas separation membrane; the gas separation membrane prepared by the invention has relatively high gas separation performance.