32results about How to "Raise the isoelectric point" patented technology

The invention discloses positively charged nano yttrium oxide and a preparation method thereof. The isoelectric point of nano Y2O3 with positive charges on the surface is 8-10, the Zeta potential of the surface is 20-30mV when the pH is 7, and the average size of the nano Y2O3 particles is 20-80nm. In the invention, an alcohol-water mixture is used as a reaction solvent, homogeneous nucleation of a yttrium-containing precursor is promoted by use of the solubility difference of the reactant in two solvents, and nano Y2O3 with relatively strong electropositivity and relatively high isoelectric point is obtained through high-temperature thermal decomposition. The method comprises the following specific steps: preparing an alcohol-water mixture according to a certain ratio as a solvent; separately adding a yttrium-containing compound and a precipitator; heating for reacting for homogeneous nucleation to obtain a yttrium-containing precursor; filtering the yttrium-containing precursor, washing and drying; and performing high-temperature thermal decomposition under the protection of a nitrogen atmosphere in a tube furnace to obtain surface positively-charged nano Y2O3. The invention is simple in technology, low in cost and suitable for industrial production.

The invention discloses an aminated modified sugar-based aldehyde tanning agent, which is prepared from the following raw materials in proportion by weight: 100 parts of sugar-based aldehyde tanning agent, 4-10 parts of amino compounds; the aminated modified sugar-based tanning agent provided by the invention In the preparation method of the sugar-based aldehyde tanning agent, after the first step of reaction, it can be directly filtered and separated to obtain high-concentration sugar-based aldehyde tanning agent and iodate precipitation, which simplifies the preparation process and significantly reduces the amount of amination modification. Preparation costs of sugar-based aldehyde tanning agents.

The invention discloses a vegetable oil derivative modified amphoteric polyurethane retanning agent and a preparation method thereof. Firstly, diisocyanate, polytetrahydrofuran diether alcohol and a catalyst are uniformly mixed for prepolymerization reaction, and anionic chain extenders 2 and 2 are successively added after heating up. ‑Dimethylolpropionic acid, cationic chain extender N ‑Methyldiethanolamine, then add ricinoleic acid into the system to react for a certain period of time, then cool down to neutralize, emulsify, and finally obtain ricinoleic acid modified amphoteric polyurethane retanning agent. The ricinoleic acid-modified amphoteric polyurethane retanning agent provided by the present invention contains both anion and cationic groups, which can effectively improve the absorption rate of chrome-free tanning, especially organic chrome-free tanned crust leather or fur, to leather chemicals, thereby improving Moisture and heat stability, handle, tear strength and other properties of chrome-free tanned leather and fur.

The invention relates to a guided tissue regeneration membrane and a preparation method thereof. The method comprises: a pretreatment step, i.e. collecting a mammalian peritoneum, conducting flowing water washing, hair removal and preliminary degreasing for standby use; an antigen removal treatment step, i.e. carrying out further degreasing on the standby peritoneum by means of an enzyme treatment process, an alkali treatment process, an acid treatment process and a hypertonic treatment process, and removing immunogenicity; a collagen fiber contraction treatment step, i.e. carrying out dehydration, non-hydrophilic substance removal and washing treatment on the peritoneum subjected to the antigen removal treatment so as to contract the collagen fibers of the peritoneum; and a drying step, spreading the contracted peritoneum on a culture dish surface to make the compact layer of the peritoneum contact the culture dish, rapidly transferring the peritoneum into a refrigerator at a temperature ranging from -60 to -80DEG C to undergo pre-freezing for 1-8h, then freeze-drying the peritoneums in a freeze dryer for 24-36h, thus obtaining a collagen membrane able to guide tissue regeneration. The guided membrane provided by the invention has a compact layer and a loose layer, also has good biocompatibility, hydrophilicity and bone induction ability, and has a long in-vivo degradation time.

The invention belongs to the field of liquid catalysis and industrial wastewater treatment, and relates to a supported noble metal catalyst with a coating structure, a preparation method thereof and application of the supported noble metal catalyst in Cr(VI) liquid catalytic reduction. The catalyst comprises a supported noble metal multi-wall carbon nano-tube, and the surface of the supported noble metal multi-wall carbon nano-tube is coated with a nitrogen doped carbon coating layer; the noble metal is Pd or Pt and is 0.5-5 percent of total mass of the supported noble metal multi-wall carbon nano-tube. The invention further provides a preparation method of the catalyst and application of the catalyst in Cr(VI) liquid catalytic reduction. The catalyst containing a nitrogen carbon coating layer shows remarkable stability in a liquid catalytic hydrogenation reduction reaction, and can be used for effectively prolonging the service life of the catalyst; and the synthesizing method is simple, and is easy to operate; and the synthesized material applied to Cr(VI) liquid catalytic reduction can be used for effectively removing or reducing toxin of Cr(VI).

The invention discloses a preparation method of titanium-doped birnessite capable of being used to efficiently treat antimony wastewater, and belongs to the technical direction of water treatment adsorption in the field of environmental protection. The method comprises the following specific steps: 1) placing a potassium permanganate solution into a conical flask, and carrying out stirring and heating to boiling by using an oil bath on a constant-temperature magnetic heating stirrer; 2) dropwise adding a mixed solution of hydrochloric acid and a certain amount of titanium sulfate by using a constant-flow pump; 3) continuing reacting for 30min after the dropwise addition is finished; 4) aging the product at 60-80 DEG C; and 5) washing and drying the aged mineral. The material prepared by the method has a high isoelectric point and a large specific surface area, and shows excellent performance of oxidizing and adsorbing Sb (V) and Sb (III), wherein the maximum adsorption amounts can reach 560 mg / g and 473 mg / g respectively. The method disclosed by the invention is simple and reliable, has low cost, and can be used for treating high-concentration mine wastewater or events that a waterbody is suddenly polluted by heavy metals.

The present invention proposes a high-temperature-resistant ferroelectric polymer-based dielectric energy storage composite film and its preparation method and application. Aiming at the easy seepage effect of SiC whiskers, the present invention prepares SiC@BaTiO by hydrolysis and hydrothermal method 3 The core-shell composite filler fully covers the SiC nanoparticles, which inhibits the formation of seepage channels; the high thermal conductivity of SiC (114W / m.K) enhances the thermal conductivity of the composite film and improves the thermal stability of the composite film; high dielectric Constant BaTiO 3 The interface polarization effect of the shell and core-shell particles enhances the dielectric constant of the composite film; at the same time, the core-shell filler with insulating properties and the surface modification of the core-shell filler promote the compatibility between the filler and the organic-inorganic interface of the substrate, maintaining The lower dielectric loss is achieved; finally, the composite film has higher energy storage density and breakdown strength under the test condition of 120 °C, and the working temperature range of the ferroelectric polymer is improved.