76results about How to "Stable particle size distribution" patented technology

The invention discloses a cross-linked sodium hyaluronate biomembrane and a preparation method thereof. The cross-linked sodium hyaluronate biomembrane is prepared by: conducting freeze drying on a prepared gel with a crosslinking degree up to 60%-80%, and then pressing the freeze-dried gel into a membrane. The preparation method of the gel includes: acquiring cross-linked sodium hyaluronate dry powder, then washing the collected sieved powder by dimethyl sulfoxide (DMSO); washing the DMSO washed powder by ethanol; then conducting vacuum drying to obtain cross-linked sodium hyaluronate powder; fully swelling the powder, performing purification for 6-10h at a room temperature of 15-35DEG C, then carrying out homogenization micronization treatment in a high-speed dispersion machine, and then collecting the uniform gel particles, thus obtaining the cross-linked sodium hyaluronate gel used for biomembrane preparation. The cross-linked sodium hyaluronate biomembrane prepared by the method provided by the invention has is pyrogen-free, sterile, free of residual crosslinking agent, and has low cytotoxicity. With long residence time in vivo, the biomembrane has good anti-adhesion effect, good biocompatibility and tissue repair performance.

The invention discloses a preparation method of a nano silver chloride/chitosan fiber anti-bacterial dressing. The method includes following steps: (1) pretreatment of a surface of a chitosan fiber nonwoven cloth: spraying an acid solution onto the surface of the chitosan fiber to enable the acid solution to infiltrate into the surface of the nonwoven cloth, treating the nonwoven cloth for 1-5 min and then washing the nonwoven cloth with deionized water; (2) soaking the pre-treated nonwoven cloth in a silver nitrate solution with a concentration of 0.0048-0.036 mmol/mL with a normal-temperature shaking operation for 30 min; (3) draining the nonwoven cloth and air-drying the nonwoven cloth until the water content is 30-40%; (4) uniformly spraying a 0.036-0.27 mmol/mL sodium chloride solution having an equal saturate water absorption amount onto the surface of the nonwoven cloth, wherein molar number of the sodium chloride is 1.2-1.5 times than that of adsorbed silver, and carrying out a reaction for 5-10 min; and (5) spraying deionized water and quickly washing the nonwoven cloth, draining the nonwoven cloth and vacuum-drying the nonwoven cloth at 50-60 DEG C. The preparation method is high in silver recycle ratio. A nano silver chloride anti-bacterial material is stable in physical and chemical performances, is excellent in anti-bacterial performance or bacteria-inhibiting peroformance, is good in fixation performance of silver chloride particles to the chitosan fiber, and can be used as a medical wound dressing.

The liquid is supplied to an emitter electrode which is provided at a tip of a liquid carrier, receives a high voltage, is electrical-charged, and discharged as a mist of charged minute water particles of nanometer order from the emitter electrode. The emitter electrode discharges the mist of the charged minute water particles of micron order at the same time by a pressure which is applied to the liquid which is supplied to the tip of the emitter electrode. An electrostatically atomizing device supplies liquid to an emitter electrode of a tip of a liquid carrier, applies the high voltage to the liquid, electrically-charges the liquid, and causes the emitter electrode to discharge a mist of charged minute water particles of nanometer order. In addition, the electrostatically atomizing device applies a pressure to the emitter electrode and causes the emitter electrode to discharge a mist of the charged minute water particles of micron order. The electrostatically atomizing device is able to humidify a space by the mist of the charged minute water particles of micron order as well as is able to decompose harmful substances in the space, is able to sterilize and deodorize the substances in the space by radicals which is included by the mist of the charged minute water particles of nanometer order.

The invention relates to a method for preparing a phosphate series lithium ion battery anode material, comprising the following steps: preparing one or more of divalent manganese source compound, ferrum source compound, nickel source compound or cobalt source compound into a mixed solution; adding oxalic acid or oxalate, acid and urea, and slowly hydrolyzing the urea by controlling the reaction temperature and time; causing the pH value of the system to rise to reach the condition of homogeneous precipitation; after the reaction, filtering, washing and drying to obtain a precursor; evenly mixing and carrying out ball milling on the precursor, a lithium source and a phosphorous source; and calcining the mixture under the non-oxidability atmosphere to prepare the unitary or multielement phosphate series lithium ion battery anode material. The precursor prepared with the method has the advantages of stable ingredient proportion, even granularity distribution, good consistency and simple synthetic technology, does not need to consider the influence of flow rate and agitation and is suitable for industrial production. The synthesized battery anode material is the phosphate compound with an olivine structure, the average grain size of the primary particle is 100-500nm, and the battery anode material has good electrochemistry property.

The invention relates to medicinal low-release micro particles and in particular relates to triptorelin slow-release micro particles and a preparation method thereof. The triptorelin slow-release micro particles comprise the following components in percentage by weight: 0.5-20% of triptorelin, 79-99% of PLGA and 0.1-1% of poloxamer. The preparation method of the triptorelin slow-release micro particles comprises the steps of mixing all the components, then putting the mixture into a hot melt extruder, and performing heating melting, extrusion and low-temperature crushing in the hot melt extruder. The triptorelin slow-release micro particles provided by the invention are good in shape, high in entrapment efficiency, good in drug loading capacity and stable in releasing. Moreover, the triptorelin slow-release micro particles are simple in synthetic process, are harmless, generate nontoxic products after degradation, and are stable in quality.

The invention discloses a method for preparing a nanoscale anionic laminar material continuously, which mainly comprises the steps of reacting, filtering, washing and drying. Compared with the conventional method for preparing the anionic laminar material in China, the method has the following advantages: (1) a helix channel rotating bed high gravity reactor is adopted to enable nucleus formation to be formed in a uniform micro hybrid environment quickly with a narrowed particle size distribution, the reaction solution in the reactor is kept under a stable high pH value condition by condensing NH3 so as to avoid generating an impurity phase, the reaction time is short and the operation is simple; (2) crystal seeds are added during reaction to greatly reduce the induction period of nucleus formation and accelerate nucleus formation, the crystallinity is high, the particle size distribution is more uniform, the size and distribution of newly generated particles can be controlled according to the particle size of the added crystal seeds, and thus, the particle size is controllable; (3) a crystallization process is not required for product post processing; and (4), the process is quick and allows for continuous production, and the average particle size of the prepared anionic laminar material is 30 to 90 nanometers.

The invention relates to a preparation method of a compound phosphate-series positive electrode material for a lithium-ion battery. The method comprises the following steps: preparing a solution from a soluble bivalent iron salt and a soluble transition metal nickel salt, cobalt salt or manganese salt, and then adding an acid and urea to prepare a mixed solution; adding a precipitant to the mixed solution for reaction and preparing a mixed oxalate precursor; and carrying out ball-mill mixing on the precursor, a lithium source and a phosphorus source evenly and preparing the compound phosphate-series positive electrode material for the lithium-ion battery in an inert or weak reductive atmosphere. The used aqueous urea solution is slowly hydrolyzed under the acid, alkali and urease catalysis or heating conditions. The urea hydrolysis rate is low and the hydrolysis product is simple and easy to volatilize, so that the aqueous urea solution can be applied to homogeneous precipitation of elements and ions. The first charge and discharge specific capacity of the obtained product at a room temperature and 0.1C rate can reach about 160mAh/g; and the compound phosphate-series positive electrode material is good in cycle performance and charge and discharge performance.

The invention relates to low-cost lead-free soldering flux alloy powder for an LED (light emitting diode) and a preparation method of the alloy powder, and belongs to the field of soft soldering fluxes and application. The alloy powder consists of the following components in percentage by weight: 6.5-9.5 percent of Zn, 1.0-3.0 percent of Bi, 0.5-1.0 percent of Cu and the balance being Sn. The preparation method comprises the steps of putting the raw materials into an induction furnace crucible after burdening according to the weight percentage; pre-vacuumizing a smelting chamber and an atomization chamber, and filling the chambers with inert protection gas; performing heating smelting on the raw materials by an induction coil; feeding high-pressure atomized gas into a nozzle, wherein the high-pressure atomized gas crushes alloy liquid flow which is in a smelted state after falling into the atomization chamber from the bottom of the crucible, and highly atomized liquid drops are formed, fall off and are cooled into alloy powder in an atomization tank; grading the alloy powder which is cooled through screening, and performing vacuumizing nitrogen-filled packaging. The soldering flux alloy powder prepared by the method disclosed by the invention is spherical and is high in oxidization resistance and corrosion resistance and excellent in mechanical property.

The invention relates to a lipid targeted ultrasound contrast agent and a preparation method thereof. The preparation method of the contrast agent comprises the following steps: adding synthetic phospholipids and poloxamer to deionized double distilled water and uniformly mixing the mixed liquid to prepare a mixed suspension A; adding palmitic acid which combines probe polypeptide to absolute alcohol which is an organic solvent to dissolve the palmitic acid so as to prepare a solution B; ultrasonically treating the mixed suspension A, meanwhile, dropping the solution B into the mixed suspension A, and uniformly mixing the mixed suspension A and the solution B to obtain a settled solution C; adding PEG-4000 to the settled solution C to dissolve the PEG-4000; introducing perfluoropropane gasinto the settled solution C, and at the same time of sufficient saturation, applying high-speed mechanical shearing equipment to process the settled solution C to form a microvesicle mixed suspensionwith an average grain diameter of 1-4 micrometers. Prepared ultrasound microvesicles have proper size, uniform and stable grain diameter distribution, proper concentration and high targeted probe binding rate; and reagent materials used for connecting ligands except preparation raw materials of the contrast agent do not need to be added. The invention has simple preparation method, small interference to the characteristics of the microvesicles and is beneficial to purify the targeted contrast agent.

The invention relates to a preparation method of polydopamine gelatin microspheres. The preparation method is characterized by comprising the following steps: placing prepared gelatin microspheres into a prepared Tris/HCI buffer solution of which the pH is equal to 8.5; then, adding 2mg/mL of dopamine solution; stirring at the temperature of 37 DEG C for 12 to 24 hours; centrifuging and washing with deionized water three times; drying in the air to obtain the polydopamine-coated gelatin microspheres. The gelatin microspheres are covered well with polydopamine, so that the chemical multifunctionality of the surfaces of the polydopamine gelatin microspheres is enhanced, and Vc can be loaded successfully. The polydopamine gelatin microspheres have a potential value on the aspect of drug sustained release.

The present invention relates to a particulate carbon material that can be produced from renewable raw materials, in particular from biomass containing lignin, comprising: a 14C content that corresponds to that of the renewable raw materials, said content being preferably greater than 0.20 Bq/g carbon, especially preferably greater than 0.23 Bq/g carbon, but preferably less than 0.45 Bq/g carbon in each case; a carbon content in relation to the ash-free dry substance of between 60 ma.% and 80 ma. %; an STSA surface area of the primary particles of at least 5 m2/g and at most 200 m2/g; and an oil absorption value (OAN) of between 50 ml/100g and 150ml/100g. The present invention also relates to a method for producing said carbon material and to the use thereof.

The invention discloses a quantum dot composite material having a dual-component substrate and a preparation method thereof. The quantum dot composite material comprises a transmittance base material, a microcapsule layer and a quantum dot layer, the microcapsule layer is positioned on the transmittance base material, the quantum dot layer is positioned on the microcapsule layer, the microcapsule layer is formed by the microcapsules through self assembly, the quantum dot layer is formed by quantum dots through self assembly, the microcapsule comprises a shell layer and a core, the shell layer contains polystyrene and silica, and the core is paraffin. The quantum dot composite material can keep excellent properties of high luminescence efficiency and photochemical stability of common quantum dots, the illumination intensity also has a specific temperature sensitive value, and thus the quantum dot composite material can be used for associating and monitoring the specific temperature. The quantum dot composite material also has good reuse performance and no shedding of the quantum dots.

The invention discloses a chitosan nano particle which comprises the following raw materials in percentage by weight: 0.5-5% of chitosan, 1-10% of cosolvent, 0-5% of antifreezing agent, 0.1-1% of surfactant, 0.1-0.5% of emulsifier, 40-60% of buffer solution and the balance of water. The invention also provides a biological pesticide preparation for controlling tobacco caterpillars and a preparation method thereof. The biological pesticide preparation mainly comprises the following components in percentage by weight: (A) 0.05-15% of active component: a siRNA (small interfering ribonucleic acid) is designed and synthesized in accordance with a tobacco caterpillar high-efficiency killing target gene and is a 15-50nt double-chain RNA; (B) 19.95-55% of solvent; and (C) 30-80% of chitosan nano particle. The chitosan nano particle ensures that the stability and the control effect of the biological pesticide preparation are better.

A preparation method of a ternary positive electrode material NCA precursor comprises the following steps: (1) mixing an Ni water-soluble salt, a Co water-soluble salt and an Al water-soluble salt toprepare an aqueous solution, to obtain a mixed ion solution; (2) making the flow rate of the NaOH and NH3.H2O mixed solution constant at 300-600 L/h, continuously adding the mixed ion solution of thestep (1) into a reactor, carrying out equimolar synthetic reaction, constantly adjusting the flow rate to stabilize the pH value of the reaction, and then heating and stirring to obtain a mixed alkalisolution; and (3) carrying out solid-liquid separation of the mixed alkali solution of the step (2), and washing and drying the obtained solid to obtain the ternary positive electrode material NCA precursor.