1737 results about "Dimethylacetamide" patented technology

The present invention provides a method for improving the performance of polyimide membranes as used in solvent-resistant nanofiltration. More specifically the method of the present invention allows to imrove the solvent stability of the polyimide membranes to solvents or solvent mixtures that would dissolve polyimide under the conditions applied during the filtration, such as dimethylforrnamide (DMF), N-methylpyrrolidinone (NMP), dimethylacetamide (DMAC), tetrahydrofuran (THF), y-butyrolacton (GBL), dimethylsulphoxide (DMSO) and chlorinated solvents.

The invention discloses a chemical separating method for an aluminum foil in a waste lithium ion battery positive plate. The method comprises the following steps of: (1) adding the waste lithium ion battery positive plate into a surfactant solution, performing ultrasonic oscillation treatment to loosen surface components of the positive plate, washing, drying, filtering and recovering the positive plate; (2) putting the positive plate treated in the step (1) into a mixed solution of N, N-dimethylacetamide and N-methylpyrrolidone, heating, taking the positive plate out, and washing with water; (3) putting positive plate treated in the step (2) into water, performing ultrasonic oscillation till the aluminum foil as well as active substances of an anode, a conducting agent and a bonding agent; and (4) filtering a solution obtained in step (3), washing to obtain a mixture containing the active substances, the conducting agent, the bonding agent and the aluminum foil, and screening to obtain a dissociative aluminum foil sheet. In the method, the aluminum foil sheet can be recovered directly; and compared with the conventional method for extracting an aluminum foil after dissolving with alkali, the chemical separating method has the advantages: the process is simplified, and cost is lowered.

The invention discloses a preparation method of an ultrathin Ni-Fe-MOF nanosheet. The preparation method comprises the following steps of dissolving an organic ligand in an organic solvent, dripping the obtained solution into a water solution with nickel and iron salts dissolved, mixing uniformly, then reacting for 3-6 hours at 140-160 DEG C, so as to obtain the ultrathin Ni-Fe-MOF nanosheet, wherein the organic ligand is p-phthalic acid and / or disodium terephthalate, and the organic solvent is N,N-dimethylacetamide and / or N,N-dimethylformamide. The invention further discloses the ultrathin Ni-Fe-MOF nanosheet and application thereof. The preparation method needs no surfactant, and can synthesize a large quantity of 2D ultrathin MOF material. The product has a clean surface and is easy toclean.

The invention discloses a high-performance flat plate type cellulose acetate / nano-titanium dioxide blended forward osmosis membrane, which is prepared by comprising the following steps: adding the following raw materials in percentage by weight: 7.0%-26.0% of cellulose acetate, 2.0%-16.0% of additives, 0.1%-5.0% of nano-titanium dioxide, 0.05%-0.1% of graphene, and a dimethylformamide or dimethylacetamide, N-methylpyrrolidine and acetone mixed solvent into a dissolving tank according to certain sequence, stirring and dissolving for 3-15h to be full and even at 25-90DEG C, thus obtaining blended forward osmosis membrane casting liquid; and preparing the high-performance flat plate type cellulose acetate / nano-titanium dioxide blended forward osmosis membrane on a supporting material by using a phase conversion method. According to the prepared forward osmosis membrane, 1M NaCl and deionized water are respectively taken as driving liquid and feed solution, the flux of pure water can reach more than 17.5L / m<2>.h during testing time of1h and the backward salt flux is less than 3.0g / m<2>.h.

The invention discloses a method for preparing a continuous carbon fiber-reinforced thermoplastic resin composite material, which comprises the following steps: mixing N,N-dimethylacetamide and acetone at the mass ratio of (1-5):1 to obtain mixed solvent; dissolving 1-5 parts by weight of polyether sulfone into 30-60 parts by weight of mixed solvent to be fully dissolved so as to obtain polyethersulfone solution; adding 0.5-2.5 parts by weight of indissolvable thermoplasticity powdered resin into the polyether sulfone solution by mechanical stirring or ultrasonic vibration to obtain suspension with stable performance, wherein the added thermoplasticity resin powder is evenly distributed; dipping the continuous carbon fiber into mixed thermoplasticity resin suspension at the temperature of 18-22DEG C to obtain prepreg; and carrying out hot pressing and shaping to the prepreg to obtain a product. The method for preparing the continuous carbon fiber-reinforced thermoplastic resin composite material has the advantages of low cost, simple technology and small solvent toxicity.

An improved process for preparing non-hygroscopic Azithromycin dihydrate wherein Azithromycin monhydrate can be converted to Azithromycin dihydrate with continous stirring / agitation in presence of a mixture of at least one solvent and water until non-hygroscopic crystals of Azithromycin dihydrate are obtained. The solvent used in the process can be selected from the group comprising dimethylformamide, dimethylacetamide, acetonitrile and iso-propanol.

The invention discloses a cellulose acetate / functionalized graphene mixed media hollow fiber positive osmotic membrane. 0.05-3.0% (w / w) of graphene is added into a solution composed of N-methyl-pyrrolidone or dimethylacetamide or dimethylformamide and 1,4-dioxane, 2.0-20.0% (w / w) of a polyethylene glycol or polyvinylpyrrolidone / lithium chloride composite additive with a volume ratio of 7:1 is added, stirring is carried out for 15-60min, then 10.0-35.0% (w / w) of cellulose acetate is added, stirring is carried out, the mixture is allowed to stand, and a casting film solution. The casting film solution is squeezed into an annular gap of a nozzle, goes through an air gap of 2-20cm, and goes into deionized water with a temperature of 20-60 DEG C, solidification is carried out, and a positive osmotic membrane is obtained after washing. When 1M of NaCl is employed as a drive liquid and deionized water is employed as a raw material liquid, the water flux is 18.3L / m2h, the reverse salt flux is less than 3.3g / m2h, and the contact angle is 57.5 degrees.

One example of a separation-material composition for a photo-resist according to the present invention comprises 5.0 weight % of sulfamic acid, 34.7 weight % of H2O, 0.3 weight % of ammonium 1-hydrogen difluoride, 30 weight % of N,N-dimethylacetamide and 30 weight % of diethylene glycol mono-n-buthyl ether. Another example of a separation-material composition for a photo-resist according to the present invention comprises 1-hydroxyethylidene-1, 3.0 weight % of 1-diphosphonic acid, 0.12 weight % of anmonium fluoride, 48.38 weight % of H2O and 48.5 weight % of diethylene glycol mono-n-buthl ether. The separation-material composition for the photo-resist is mainly used for a medicinal liquid washing liquid / scientific liquid in order to remove the photo-resist residuals and the by-product polymer after an ashing process of a photo-resist mask. It can propose a separation-material composition for a photo-resist such that the photo-resist residuals and the by-product polymer are easily removed after a dry etching process and at the same time the low dielectric-constant insulation film is avoided from erosion and oxidization.

The present invention provides a method for improving the performance of polyimide membranes as used in solvent-resistant nanofiltration. More specifically the method of the present invention allows to improve the solvent stability of the polyimide membranes to solvents or solvent mixtures that would dissolve polyimide under the conditions applied during the filtration, such as dimethylforrnamide (DMF), N-methylpyrrolidinone (NMP), dimethylacetamide (DMAC), tetrahydrofuran (THF), y-butyrolacton (GBL), dimethylsulphoxide (DMSO) and chlorinated solvents.