36 results about "SILVER NITRATE CRYSTALS" patented technology

The invention discloses a method for in-situ preparing antibacterial supermolecule aquogel. The method comprises the following operation steps: silver nitrate crystal and polyethyleneglycol-polypropylene glycol-polyethyleneglycol triblock copolymer solution are mixed and stirred to obtain mixed solution; the steps of stirring the mixed solution for 15 minutes and ultrasonically dispersing the mixed solution for 5 minutes are alternatively carried out for 2-4 hours to obtain nano silver sol; and the nano silver sol and Alpha-cyclodextrin solution are mixed, stirred and stands at the room temperature to obtain hydrogel. The hydrogel can be used for preparing injectable drug carriers. The invention has the advantages of simple operation, adjustable gel strength and the gelation time, room temperature forming, no involvement of chemical cross linking reaction and the usage of organic solvent, favorable biocompatibility and antibacterial property of obtained gel, and the like and is prospective to be widely applied in the field of biomedical engineering materials.

The invention discloses a preparation method of antibacterial nanofibers, which comprises the following steps of: by mass, using 6 to 9 parts of acetone, 1 to 3 parts of dimethylacetamide and 0.5 to 2 parts of water as the raw materials, mixing the raw materials to prepare a solvent and adding cellulose acetate particles and silver nitrate crystals into the solvent to prepare cellulose acetate electrostatic spinning solution; carrying out electrostatic spinning on the cellulose acetate electrostatic spinning solution; carrying out drying treatment on the obtained electrostatic spinning fibers at a temperature of 60 DEG C and under the vacuum condition; and irradiating the dried electrostatic spinning fibers for 4 to 8 hours by ultraviolet light and reducing silver ions into silver nanoparticles so as to obtain the nanorfibers with an antibacterial function. The preparation method enables the electrostatic spinning solution to stably prepare the nano cellulose with the antibacterial function mainly by determining the optimal content of water and silver nitrate in the electrostatic spinning solution, is simple to operate and is low in cost.

The invention discloses a preparation method of a cellulose acetate electrostatic spinning solution. The preparation method comprises the following steps of taking 6-9 parts of acetone by mass, 1-3 parts of dimethylacetamide by mass and 0.5-2 parts of water by mass as raw materials to prepare solvent after mixing; adding cellulose acetate particles and silver nitrate crystals into the solvent, slowly heating to 60-80 DEG C at the heating speed of increasing by 2-5 DEG C at every minute and stirring for 60-120 minutes to fully dissolve the cellulose acetate particles so as to obtain a composite cellulose acetate solution containing 1 wt%-3wt% of silver nitrate; after the composite cellulose acetate solution is cooled, adding ammonium bicarbonate which is 1 wt%-3wt% of the mass of the composite cellulose acetate solution, placing in water bath at 40 DEG C, and mechanically stirring to carry out expansion treatment so as to obtain the cellulose acetate electrostatic spinning solution. According to the preparation method, nano-cellulose with an anti-bacterial function is stably prepared by the electrostatic spinning solution through determining the optimum contents of water and silver nitrate in the electrostatic spinning solution, and the preparation method has the advantages of simplicity in operation and low cost.

The invention discloses a method of preparing silver nanoparticles with a sugarcane extract. The method comprises the following steps: preparing the sugarcane extract; dissolving silver nitrate crystals into deionized water to prepare a silver nitrate solution with the concentration to be 0.005-0.02 mol/L; and adding an alkaline solution in the sugarcane extract, keeping a pH value of a reaction system to range from 8.5-10.5, then heating to boiling, adding the silver nitrate solution with the concentration to be 0.005-0.02 mol/L in the boiling state, reacting for 10-50 minutes, carrying out centrifugal separation on an obtained reaction solution after reaction is finished, and drying obtained precipitates to obtain the silver nanoparticles. The preparation method is simple, is easy to operate and cannot cause pollution to environment. The prepared silver nanoparticles are uniform, are good in dispersibility, do not have toxic chemical reagent residues on the surfaces, express obvious optical signals and can be widely applied to the field of biological medicines.

The invention discloses a production method of photography-level silver nitrate, comprising the following steps: (1) taking pure nitric acid and deionized water for standby; (2) adding a silver ingot the purity of which is more than 99.9% into a kettle, adding the pure nitric acid, heating to 60-65 DEG C, vacuumizing the kettle, and keeping excess silver, thus obtaining reactive fluid; (3) adding the reactive fluid into a diluting tank, diluting the reactive fluid with pure water until the specific gravity of solution is 1.4-1.5g/cm<3>, and standing for 24 hours; (4) adding decontamination agent (magnesium carbonate), and carrying out solid-liquid separation; (5) after separation, causing liquid phase to enter a condensed crystallization kettle, evenly stirring at the revolving speed of 25-30r/min to prepare silver nitrate crystal; and (6) filtering and drying the silver nitrate crystal, and drying the crystal, thus obtaining the photography-level silver nitrate. The silver nitrate produced by method provided by the invention has the advantages of high purity, good identity and good stability.

The invention provides a method for preparing silver nanoparticles with water-soluble starch. The method comprises the following steps that the water-soluble starch is dissolved in deionized water to prepare a water-soluble starch aqueous solution of which the concentration is 0.4-1.1 mol/L; silver nitrate crystals are dissolved in deionized water to prepare a silver nitrate solution of which the concentration is 0.006-0.014 mol/L; and the water-soluble starch aqueous solution is heated until boiled, the silver nitrate solution is added in the boiled water-soluble starch aqueous solution, the pH value of a reaction system is kept to 6.0-7.0, after being conducted for 15-35 min under the boiling condition, reaction is completed to obtain a reaction solution, the reaction solution is centrifugally separated to obtain a precipitate, and the precipitate is dried to obtain the silver nanoparticles. In the method, the adopted devices are simple and convenient to operate. The water-soluble starch is conveniently obtained, low in cost, and nontoxic. The prepared silver nanoparticles can be applied to the field of biological medicine.

The invention discloses a method for synthesizing flower-shaped silver micro-particles. The method comprises the following steps of respectively measuring ascorbic acid solid powder and silver nitrate crystal, and respectively dissolving the ascorbic acid solid powder and the silver nitrate crystal into deionized water for standby use; placing the prepared ascorbic acid solution into the silver nitrate solution, and ensuring the mol ratio of the ascorbic acid and the silver nitrate to be (0.8-1.2):1; immediately adding a cleaned stainless steel sheet into the mixed solution; magnetically stirring the reaction materials for 180min to 360min after the stainless steel sheet is added, and ending the reaction; taking out and centrifugally separating the stainless steel sheet in the material after the reaction is ended, and precipitating and washing the stainless steel sheet to obtain the flower-shaped silver micro-particles. By adopting the method, the shape of a product is controllable, simplicity in operation can be realized, the condition is moderate, and the repeatability is good.

The invention discloses a method for preparing and separating silver nanowires under normal pressure in a large scale. Firstly, a crystal type control agent is prepared into a solution, then the solution of the crystal type control agent, polyvinylpyrrolidone and polyhydric alcohol are taken and added into a reaction kettle to be stirred and subjected to temperature rise, and a first mixture is obtained, wherein with silver nitrate crystals as reference, the mass ratio of the crystal type control agent, the polyvinylpyrrolidone and the polyhydric alcohol in the reaction kettle is (5*10<-4>-2*10<-3>): (0.7-1.4): (50-100); the silver nitrate crystals are dispersed to obtain a silver nitrate/polyatomic alcohol solution which is added into the first mixture in three times, and after heat preserving, cooling is performed till normal temperature is achieved so that a second mixture can be obtained; and absolute ethyl alcohol with the volume being 3-6 times of the volume of the second mixture then is added in, after stirring, the second mixture and the absolute ethyl alcohol are transferred into a settling tank, by setting the height of the settling tank, standing separation is performed in a manner that both ends are broken off, and a material of the settling tank is not soluble with the silver nanowires. The preparation method is simple, and the obtained silver nanowires are good in dispersing performance and wide in application range.

The invention discloses a method for preparing high-purity superfine silver powder. The method comprises the following steps: a, purifying silver nitrate crystals; b, purifying sodium chloride crystals; c, preparing a silver chloride precipitate; d, putting the silver chloride precipitate obtained in the step c into a fourth container, further adding a water-ethanol solution of NH2OH*HCl into the fourth container, continuously stirring till the silver chloride precipitate is completely dissolved, wherein the reaction temperature is 20-25 DEG C, the stirring speed is 350-450r/minute, and suspended black solids are generated on the liquid surface; e, performing filtration and drying under a vacuum condition, and obtaining the high-purity superfine silver powder. The method has the beneficial effects that the silver powder can be prepared from reaction under a homogeneous condition, is small in granularity and uniform in granule, needs no addition of a dispersing agent, is easy to wash and high in silver powder purity; during the ionic reaction in the solution, the contact area is large and the reaction speed is high; the reaction is under normal pressure, the production process is simple and the cost is low; no pollutant is discharged.

The invention discloses a replacement reaction method for preparation of a silver dendritic super-hydrophobic surface. The method comprises the steps that 1, silver nitrate crystals are dissolved in distilled water and stirred to be even so as to obtain a solution A; 2, tetradecanoic acid is dissolved in absolute ethyl alcohol to obtain a solution B; 3, an oxide layer on the surface of a copper matrix is removed and then washed out sequentially through distilled water and absolute ethyl alcohol, and the copper matrix is dried for standby application; 4, the copper matrix is immersed in the solution A to be subjected to replacement reaction; and 5, the copper matrix obtained in the step 4 is washed out sequentially through distilled water and absolute ethyl alcohol, then the solution B is evenly smeared on the surface of the washed copper matrix, the surface of the copper matrix is aired and slightly wiped with a sponge, and then the silver dendritic super-hydrophobic surface is obtained. By the adoption of the method, the contact angle of the prepared super-hydrophobic surface on the copper matrix can reach more than 156 degrees, and the super-hydrophobic property keeps stable after the super-hydrophobic surface is put under the normal condition for one year.

The invention discloses a preparation method of silver powder for a low-temperature conductive adhesive. At first, silver nitrate crystals are dissolved in deionized water, and the metallic silver concentration of solutions is adjusted to 50g/L-300g/L; then alkali solutions are added and stirred evenly, the pH of the solutions is adjusted to be equal to 8-14, the temperature of the solutions is adjusted to 30-70 DEG C, excessive reductant solutions are slowly dripped, and stirring continues after dripping is finished to obtain superfine silver slurry; and the superfine silver slurry is stilled, the lower layer silver powder is washed, additives are added and fully dispersed for 10 minutes, drying is conducted until the constant weight is reached, and the silver powder for the low-temperature conductive adhesive is obtained. The process amplification is high, the process controllability is high, and the process is environment-friendly. The obtained superfine silver powder has stable indicators, appropriate particle size distribution and good disperstiveness. The preparation method is suitable for low-temperature curing conductive paste.

The invention discloses a preparing method of dendritic silver powder. The method includes the steps of dissolving silver nitrate crystals in deionized water to prepare a silver nitrate solution, dissolving ascorbic acid or glucose in deionized water to prepare a reducing agent solution, dropwise adding the silver nitrate solution to the reducing agent solution for chemical reduction reaction, stopping stirring when the silver nitrate solution is all dropwise added, performing solid-liquid separating on silver powder through suction filtration, and then performing drying to obtain the dendritic silver powder. No polymeric dispersants are added to the silver powder prepared through the method, washing and collecting are simple, waste liquid disposal cost is low, and the silver powder is friendly to the environment and suitable for industrial batch production; and by adjusting the content of a nucleation control agent to control the morphology of the silver powder, the prepared silver powder is dendritic silver powder with the trunk average length of 5-15 [mu]m and the single-branch average length of 0.5-3 [mu]m.

The invention provides a method for preparing silver nanoparticles through a caulis sargentodoxae extracting solution. The method comprises the steps of adding caulis sargentodoxae into deionized water, heating the deionized water containing the caulis sargentodoxae to be boiled and conducting centrifugal separation to obtain a supernatant, namely, the caulis sargentodoxae extracting solution; dissolving silver nitrate crystals into the deionized water to form a silver nitrate solution; heating the caulis sargentodoxae extracting solution to be boiled, adding the silver nitrate solution into the boiling caulis sargentodoxae extracting solution, keeping the pH of a reaction system within 5.3-6.3, conducting a reaction for 1-5 min in a boiling state, conducting centrifugal separation on an obtained reaction solution after completion of the reaction, and drying obtained precipitates to obtain silver nanoparticles. According to the preparation method, adopted equipment is simple, and operation is convenient. The caulis sargentodoxae extracting solution is convenient and easy to get and low in price and has no toxicity. The surfaces of the prepared silver nanoparticles cannot generate toxic chemical reagent residues and generate obvious optical signals. Thus, the synthetized silver nanoparticles can be applied to the biological medicine field.

The invention discloses a silver powder preparing technology for controlling the grain size through control over the adding amount of sodium hydroxide. The technology comprises the following steps that S100, silver nitrate crystals are taken to prepare a silver nitrate solution, sodium hydroxide crystals are taken to prepare a sodium hydroxide solution, and glucose crystals are taken to prepare a glucose solution; S200, in the stirring state, the silver nitrate solution is slowly added in the sodium hydroxide solution, and a solution A is obtained; S300, under the condition that the reaction temperature is 20-30 DEG C, the glucose solution is slowly added into the solution A and constantly stirred till the reaction is thorough, and a solution B is obtained; and S400, the solution B continues to be stirred for a period of time, then solid and liquid separation is carried out, a solid body is taken, washed and dried, and silver powder is obtained. The prepared silver powder is small in grain size distribution range and can be suitable for printing sizing agents of different application systems, toxic and harmful substances do not exist in waste liquid, the grain size of the silver powder can be controlled, and the preparing technology is simple.

The invention discloses a method for recycling silver nanowire waste, which comprises the following five construction procedures: pure water ultrasonic treatment of silver nanowires, drying, nitric acid dissolution, heating and vacuumizing, and purification and separation. The method comprises five steps. Silver-containing waste materials left after purification are recycled, an organic solvent is collected and washed, residual silver solids are dissolved through nitric acid and recrystallized, other impurities are not introduced in synthesis, and even chlorine and bromide ion-containing solids required by previous reaction are complexed, washed and dissolved in water by ammonia water, so that higher silver nitrate crystals can be obtained, namely, silver nanowire raw materials. By means of the repeated utilization, the rigorous treatment process, namely the treatment effect, is increased in the aspects of drying, heat preservation, vacuumizing and the like.

The invention relates to a biocolloid dispersant and a preparation method thereof. The preparation method comprises the following steps: adding silver nitrate crystals into pure water, and uniformly stirring, so that silver nitrate crystal solution is obtained; adding glycerol into the pure water, and uniformly stirring, so that dilute glycerol solution is obtained; adding menthol into the pure water, and uniformly stirring, so that menthol solution is obtained; uniformly stirring the glycerol solution with the menthol solution, so that mixed liquor is obtained; uniformly stirring the silver nitrate crystal solution with the mixed liquor, so that silver nitrate crystal solution mixed liquor is obtained; adding ternary acid into the silver nitrate crystal solution mixed liquor, and carrying out acidifying treatment, so that the silver nitrate crystal solution mixed solution is obtained; adding tartaric acid solution into the silver nitrate crystal solution mixed solution, and uniformly stirring, so that standby solution is obtained; adding sodium alginate into the pure water, heating, dissolving and stirring, then adding a penetrating agent, and stirring, so that a stabilizer is obtained; and adding the standby solution into a stirring container filled with the pure water, stirring, adding the stabilizer, continuously stirring, and sequentially standing, filtering and filling, so that the biocolloid dispersant finished product is obtained.