98 results about "ORTHOSILICIC ACID" patented technology

The invention provides a method for synthesizing ordered mesopore nano-silica through pulverous coal. The pulverous coal is broken and ground through a planetary ball mill; the screened pulverous coal and a sodium hydroxide solution are mixed and react at a high temperature under high pressure, and a purified sodium silicate solution is obtained after separation, pH regulation and re-separation; a surfactant and the purified sodium silicate solution are placed in a high-temperature reaction kettle with the temperature being 80 DEG C, CO2 gas with the volume fraction ranging from 15 vol% to 30 vol% is injected in the high-temperature reaction kettle under the magnetic stirring condition, and a sodium carbonate solution and orthosilicic acid sediments are obtained after the mixture reacts for 3 h and is then separated; and orthosilicic acid is dried for 2 h at the temperature being 105 DEG C, calcined for 4 h to 8 h at the temperature being 550 DEG C to 600 DEG C and cooled to obtain an ordered mesopore nano-silica product. By means of the method, the resource utilization of the pulverous coal is achieved, the high-value ordered mesopore nano-silica and sodium carbonate by-products are synthesized, and the method is a sustainable chemical reaction route; and meanwhile, by means of the technology, the production cost is substantially reduced, the production efficiency is substantially improved, the product has a regular hexagonal porous structure, the specific area is larger than 1000 m<2> / g, and the average pore size ranges from 2.5 nm to 3.5 nm.

The invention relates to a method for preparing continuous SiO2 / nano-metal aerogel fibers with a catalysis performance through finally loading a nano-metal. The method comprises the following steps: processing silicate or silanol sol to prepare a spinning stock solution; adding an acidic solution to a coagulation tank to form a coagulation bath; and injecting the spinning stock solution to the coagulation bath, carrying out reaction wet spinning to obtain orthosilicic acid / silicate fibers, reeling the orthosilicic acid / silicate fibers, ageing the reeled orthosilicic acid / silicate fibers, washing the aged orthosilicic acid / silicate fibers with deionized water until neutrality, immersing the neutral orthosilicic acid / silicate fibers in a metal salt solution, taking out the immersed fibers, removing a solvent on the surface of the orthosilicic acid / silicate fibers, immersing the obtained fibers in a reducing agent, washing the obtained fibers with deionized water until the fibers are neutral, displacing the fibers with deionized water or ethanol, and drying the displaced fibers to obtain the continuous SiO2 / nano-metal aerogel fibers. The method has the advantages of cheap and easily available raw materials, simple reaction process and good spinnability, and the aerogel fibers obtained in the invention have the advantages of abundant holes, high specific surface area, high temperature resistance, chemical corrosion resistance, and adjustable specific surface area and nano-metal load capacity.

The invention relates to a method for preparing orthosilicic acid, the chemical formula of orthosilicic acid is H4SiO4. The method is characterized by the following steps: A, SiO2 and water are mixed according to the weight ratio of 10-20:100 and strongly stirred and NaOH or KOH solution is dropped until the pH value reaches 8-9 below the temperature of 15 DEG C; B, under strong stirring, the mixture is oil-bath heated until the temperature comes to 50-55 DEG C and reacts for 2-3 hours to obtain even solution; C, the solution is cooled to room temperature and under strong stirring, CO2 gas is fed into the even solution until the pH value is less than or equal to 4; D, choline chloride is added, wherein the weight ratio of choline chloride and the solution obtained from the step C is 20-45:100, then stirred for 10-20 minutes to obtain stable orthosilicic acid solution, wherein, the silicon content of the stable orthosilicic acid solution is 2-2.5 percent. The method of the invention has low cost to prepare orthosilicic acid, environmentally friendly preparation technique and no hazardous and noxious substances discharging during the preparation process; the orthosilicic acid solution obtained has the advantages of multifunction and long preservation time.

The invention provides a novel B type large-pore volume silica gel and a manufacture method of the novel B type large-pore volume silica gel. The manufacture method comprises the following steps of A, generating orthosilicic acid in a vortex type mixing reactor through sodium silicate solution and diluted mineral acid according to the conventional silica gel technology, and then standing and curing, and granulating twice; B, heating and curing, transferring the silica gel in an environment at 40 to 90 DEG C for being retained for 8 to 24 hours; C, surfacing the washed silica gel through inorganic salt and inorganic base, wherein for modifying the internal silanol on the internal surface of the silica gel hole, the alkaline can be sodium hydroxide, potassium hydroxide and lithium hydrate; and the inorganic salt can be ammonium chloride, sodium chloride, sodium carbonate, sodium bicarbonate and ammonium bicarbonate; and D, reinforcing the framework through the technology of dipping mineral acid and inorganic salt and thermally processing. According to the manufacture method, the silica gel is transferred into 0.01 to 10% of inorganic salt solution for being heated in water bath, and then is parched in a thermal environment at 100 to 200 DEG C, thus obtaining the silica gel provided by the invention. The manufacture method provided by the invention is simple, and easy to achieve mass production.

The invention provides a method for a layered silicate modified silica sol, wherein a dilute orthosilicic acid solution, an acidic activated orthosilicic acid solution, an alkaline orthosilicic acid solution, an active crystal seed sol, a first-stage growth silica sol and a first-stage growth silica sol / layered silicate suspension are prepared so as to finally obtain the layered silicate modified silica sol. According to the present invention, the cheap water glass is used as the raw material, and all the processes are carried out in the water phase without the organic solvents, such that the production cost is substantially reduced, the working environment is safe and health, and the method has advantages of simple process, low cost, and environment protection.

The invention relates to a preparation method of a ductile SiO2 aerogel fiber coated with PVP (polyvinylpyrrolidone). The preparation method comprises the following steps: a spinning solution is prepared from silicate or silanol sol; an acid solution is added to a coagulating basin to serve as a coagulating bath; the spinning solution is added to the coagulating bath for reaction wet spinning, an orthosilicic acid / silicate fiber is obtained and is subjected to winding, aging and washing to be neutral, and solvent exchange and drying performed; the dried fiber is soaked in a PVP aqueous solution, taken out and dried, and a product is obtained. The preparation method has the characteristics of cheap and available raw materials, simple reaction process and good spinnability; the prepared inorganic SiO2 aerogel fiber has rich pores, high specific surface area, high-temperature resistance and chemical corrosion resistance, meanwhile, the specific surface area of the fiber is adjustable, the fiber has certain toughness, the application range of the aerogel fiber can be expanded, and the aerogel fiber has higher practical value.

The invention relates to a method for preparing continuous hollow SiO2 porous fibers through coaxial spinning. The method comprises steps as follows: a spinning stock solution is prepared from silicate or silanol sol; one acid solution is added to a coagulating tank to be used as a coagulating bath, and the other identical acid solution is used as a coaxial spinning core spinning solution; the spinning stock solution and the coaxial spinning core spinning solution are injected into the coagulating bath through coaxial spinning needles at the same flow rate, reaction wet spinning is performed, hollow orthosilicic acid / silicate fibers are obtained, wound, aged and washed to be neutral with deionized water, solvent displacement is performed, and the continuous hollow SiO2 porous fibers are obtained through drying. The method has the characteristics that equipment is simple, raw materials are cheap and easy to obtain, the reaction process is simple and the spinnability is good. The hollow inorganic SiO2 porous fibers obtained with the method have rich pores and ultra-large specific surface area, are resistant to the high temperature and chemical corrosion, and have more advantages than common porous fibers in fields of catalysis, adsorption, filtration and the like.