36results about How to "Good stability for repeated use" patented technology

The invention discloses a method for preparing nanoparticles of biomimetic silicon dioxide immobilized β-glucuronidase. The method comprises the steps of dissolving protamine sulfate in tris-hydrochloric acid buffer solution or deionized water to prepare a protamine sulfate solution, and dissolving β-glucuronidase in tris-hydroxymethylaminomethane - In hydrochloric acid buffer solution or deionized water, prepare β-glucuronidase solution, mix protamine sulfate solution with β-glucuronidase solution to obtain a mixed solution; dissolve sodium silicate in deionized water or in saline, and adjust the pH value to the sodium silicate solution; add the mixed solution to the sodium silicate solution, stand still, separate, remove the supernatant, wash, and freeze-dry to obtain biomimetic silicon dioxide immobilized β-glucuronic acid Glucosidase nanoparticles. The invention has the advantages of simple preparation process, high activity maintenance rate of the immobilized β-glucuronidase, and good repeated use stability.

The invention discloses a wollastonite-loaded strontium and lanthanum solid base catalyst and a preparation method and application thereof, and the solid base catalyst comprises a wollastonite carrierand strontium oxide and lanthanum oxide loaded on wollastonite. In the process of loading strontium oxide and lanthanum oxide on wollastonite, active sites can be uniformly distributed on the surfaceof the carrier, so that the agglomeration of active sites is effectively avoided, the effective contact between reactant molecules and the active sites is enhanced, the catalyst is ensured to have high catalytic activity, and the mechanical strength of the catalyst is enhanced due to the existence of the wollastonite carrier; the active site loss caused by the mechanical stress of the collision between the catalyst particles and other particles or the container wall is reduced, and the strontium oxide (SrO) and the wollastonite react to generate the new phase CaSrSiO4 so as to improve the immobilization rate of the active sites, such that the catalyst has good reuse stability.

The invention relates to a method for immobilizing beta-glucuronidase by alginic acid-calcium carbonate hybrid gel. Sodium carbonate solution and calcium chloride solution are mixed and stirred at room temperature to generate calcium carbonate powder precipitation, which is left to stand, washed with water and acetone, and dried to obtain micron-sized mesoporous calcium carbonate particles. Adsorb in aminomethane-hydrochloric acid (Tirs-HCl) buffer solution or aqueous solution, and centrifuge to obtain calcium carbonate particles adsorbing glucuronidase and mix them evenly with sodium alginate solution, then add dropwise to calcium chloride solution, Ageing. The preparation condition of the invention is mild, the preparation process is simple and easy, the obtained hybrid carrier has good immobilization ability for enzyme, the leakage rate of the immobilized β-glucuronidase is low, the swelling degree is low, and the repeated use stability is good.

The invention discloses a super-hydrophilic / underwater super-oleophobic co-deposition coating and a preparation method thereof. The method includes 1) adjusting the pH of a sodium chloroacetate solution to 7-8, and reacting the solution and a monomer at 40-80 DEG C for 3-10 h to obtain a mixture system A; 2) precipitating a product in the mixture system A and drying the product to obtain a zwitterionic monomer; 3) adding the zwitterionic monomer and dopamine into a Tris buffer solution having a pH value of 7-10 or a PBS buffer solution having a pH value of 7-10, and dissolving the added materials to obtain a mixture system B; 4) immersing a substrate into the mixture system B, and allowing co-deposition of polymerized dopamine and the polymerized monomer onto the substrate to form a composite A, taking the composite A out, and drying the composite A. Polydopamine microspheres with hydrophilic zwitterionic polymer are obtained on the surfaces of the co-deposition coating through a polymerization co-deposition technique and have a good super-hydrophilic / underwater super-oleophobic characteristic.

The invention discloses a preparation method of Beta- glucuronidase nanometer particle which is immobilized by bionic silicon dioxide. The process of the method comprises that the protamine sulfate isdissolved in the trishydroxymethylaminomethane-hydrochloride buffer or the deionized water for the preparation of protamine sulfate solution; the Beta- glucuronidase is dissolved in the trishydroxymethylaminomethane-hydrochloride buffer or the deionized water for the preparation of Beta- glucuronidase solution; the protamine sulfate solution is mixed with the Beta- glucuronidase solution to obtain the mixed solution; the sodium silicate is dissolved in the deionized water or the saline water and the pH value is adjusted to obtain the sodium silicate solution; the mixed solution is added intothe sodium silicate solution; through standing, separation, removal of the supernatant, washing and freeze drying, the Beta- glucuronidase nanometer particle which is immobilized by bionic silicon dioxide is obtained. The invention has the advantages that the preparation process is simple; the immobilized Beta- glucuronidase has a high activity maintenance rate and good stability for repeat use.

The invention relates to a method for immobilizing beta-glucosidase and hydrolyzing straw cellulose by cooperating the beta-glucosidase with cellulase, belonging to the technical field of biocatalysis. The method provided by the invention comprises the following steps of: (1) dissolving chitosan into a propionic acid solution to form a transparent and homogeneous colloid, mixing and stirring the colloid with Fe3O4 grains, dropwise adding a NaOH solution to obtain magnetic microspheres, and carrying out crosslinking on the magnetic microspheres in a glutaraldehyde solution to obtain an immobilized carrier; (2) adding the immobilized carrier into a beta-glucosidase solution for adsorption to obtain a magnetic immobilized beta-glucosidase, hydrolyzing a cellobiose substrate by using the magnetic immobilized beta-glucosidase, and measuring the enzyme activity of the magnetic immobilized beta-glucosidase; and (3) degrading maize straws by coordinating the magnetic immobilized beta-glucosidase with the cellulase. The immobilized beta-glucosidase prepared by the method has the characteristics of homogeneous shape, large specific surface area, high mechanical strength, high enzyme activity and easiness in recovery; and the immobilized beta-glucosidase can hydrolyze the straw cellulose by coordinating with the cellulase to increase the yield of hydrolyzed sugar, and the stability in repeated use is good, so that the cost for the enzymatic hydrolysis of the straw cellulose can be lowered.

A mesoporous supported composite catalyst is characterized in that: the catalyst is (Ni 0.13 mn 0.87 )(Ni 0.87 mn 1.13 )O 4 / SBA‑15 composite, double metal oxide (Ni 0.13 mn 0.87 )(Ni 0.87 mn 1.13 )O 4 The particles are evenly attached to the surface of SBA‑15 and inside the mesoporous orbitals, and are neatly arranged, (Ni 0.13 mn 0.87 )(Ni 0.87 mn 1.13 )O 4 The total load on the SBA‑15 is 20%. Prepared (Ni 0.13 mn 0.87 )(Ni 0.87 mn 1.13 )O 4 / SBA‑15 (Ni 0.13 mn 0.87 )(Ni 0.87 mn 1.13 )O 4 Small size, good loading uniformity on SBA-15, no agglomeration, high catalytic activity, up to 99.47%, short time required to degrade sulfapyridine, and excellent catalytic performance in a wide range of pH change environments , and the stability of the catalytic performance is good, and it can be reused. After repeated use for 10 times, its catalytic activity can still reach 94.6%.

The invention discloses a multi-enzyme system with immobilized polyethylenimine and metal coordination and a method for preparing the multi-enzyme system, and belongs to the technical field of immobilized enzymes. The method includes immobilizing glycerol dehydrogenase, coenzyme oxidase and glycerol dehydrogenase-coenzyme oxidase fusion enzymes by the aid of coordination of polyethylenimine and metal ions; forming netted polyethylenimine frameworks by polyethylenimine molecules under coordination effects of imine and the metal ions in immobilizing procedures; forming coordination bonds by the metal ions coordinated on the polyethylenimine, C-end histidine tags of the glycerol dehydrogenase and the coenzyme oxidase and C-end histidine tags of the glycerol dehydrogenase-coenzyme oxidase fusion enzymes so as to acquire the immobilized multi-enzyme system. Coordination crosslinking effects can be realized by the metal ions in the immobilizing procedures, and the catalysis efficiency of the multi-enzyme system can be improved. The multi-enzyme system and the method have the advantages that the multi-enzyme system is high in multi-enzyme coupling efficiency, preparation conditions are mild, and processes are simple and feasible; the immobilized enzymes are high in immobilizing rate and activity recovery rate and good in reuse stability, the temperature stability can be obviously improved, and the like.

The invention discloses a montmorillonite-based solid acid catalyst, which is prepared according to the following method: adding a metallocene compound and a montmorillonite into a mixed solvent of chloroform and ethanol, the metallocene compound being metallocene titanium, metallocene A mixture of one or two of metal zirconium and metallocene molybdenum, stirred and reacted at 30-80°C under the protection of argon, cooled to room temperature, added phosphoric acid or acetic acid aqueous solution, stirred evenly, let stand, filtered, filtered The cake is washed, dried, and calcined at 400-550° C. for 3-6 hours to obtain the montmorillonite-based solid acid catalyst. The catalyst provided by the invention can be used to catalyze the selective dehydration of glycerin in the gas phase to produce acrolein, the conversion rate of glycerin is 60-100%, the selectivity of acrolein is 74-95%, and it can run for up to 120 hours. The preparation process of the catalyst is simple and the catalytic performance is high. ,long life.

The invention relates to polyethylene imine-titanium oxide embedded with amine dehydrogenase and a preparation method of the polyethylene imine-titanium oxide, and belongs to the technical field of immobilized enzymes. A polyethylene imine (PEI)-titanium oxide immobilized particle embedded with the amine dehydrogenase has a grain size of 100-600 nm, wherein polyethylene imine has catalyzing and templating double effects in the immobilization process, namely the PEI promotes the formation of titanium oxide through an electrostatic and hydrogen bonding effect between an amino group in a molecule and a titanium precursor molecule; through a polyethylene imine structure, a template can also be induced, and the formation of a titanium oxide particle are regulated and controlled. The preparation method of the polyethylene imine-titanium oxide comprises the following steps: configuring the PEI (straight chain and branched chain) as well as mixed liquid containing the amine dehydrogenase; configuring a precursor II-dihydroxybis (2-hydroxypropanoato) titante diammonium (Ti-BALDH) solution of titanium; dropwise adding the precursor solution of the titanium into the PEI and the mixed liquid containing the amine dehydrogenase, stirring and generating the PEI-titanium oxide immobilized particle embedded with the amine dehydrogenase. The polyethylene imine-titanium oxide and the preparation method thereof have the advantages that the preparation conditions are mild, the process is simple and is easy to implement, the obtained immobilized particle embedded with the amine dehydrogenase has strong immobilization capacity and good reuse stability, and the temperature stability of the amine dehydrogenase can be obviously improved.

The invention discloses a bimetallic composite oxide catalyst, preparation method and application, which mainly solve the problems of low yield of methyl phenyl carbonate, difficulty in catalyst separation and recovery, etc. The catalyst uses MgO as the carrier and PbO as the active group wherein the mass percentage of PbO is 5% to 30%, the calcination temperature is 400 to 600°C, and is prepared by hydrothermal synthesis; the catalyst has a good catalytic effect on the synthesis of methyl phenyl carbonate by transesterification It has the advantages of high activity and high selectivity, easy separation and recovery from the reaction system, good stability for repeated use, no pollution to the environment, etc., and has potential industrial application value.