Showing papers on "Silicic acid published in 2006"

Review of methodologies for extracting plant-available and amorphous Si from soils and aquatic sediments

Abstract: There is a variety of methodologies used in the aquatic sciences and soil sciences for extracting different forms of Si from sediments and soils. However, a comparison of the published extraction techniques is lacking. Here we review the methodologies used to extract different Si fractions from soils and sediments. Methods were classified in those to assess plant-available Si and those to extract Si from amorphous silica and allophane. Plant-available Si is supposed to comprise silicic acid in soil solution and adsorbed to soil particles. Extraction techniques for plant-available Si include extractions with water, CaCl2, acetate, acetic acid, phosphate, H2SO3, H2SO4, and citrate. The extractants show different capabilites to desorb silicic acid, with H2SO3, H2SO4 and citrate having the greater extraction potential. The most common extractants to dissolve amorphous silica from soils and aquatic sediments are NaOH and Na2CO3, but both also dissolve crystalline silicates to varying degrees. In soils moreover Tiron is used to dissolve amorphous silica, while oxalate is used to dissolve allophanes and imogolite-type materials. Most techniques analyzing for biogenic silica in aquatic environments use a correction method to identify mineral derived Si. By contrast, in the soil sciences no correction methods are used although pedologists are well aware of the overestimation of amorphous silica by the NaOH extraction, which is most commonly used to extract silica from soils. It is recommended that soil scientists begin to use the techniques developed in the aquatic sciences, since it seems impossible to extract amorphous Si from soils completely without dissolving some of the crystalline silicates.

Biomimetic Synthesis of Titanium Dioxide Utilizing the R5 Peptide Derived from Cylindrotheca fusiformis

Abstract: Current approaches to the synthesis of metal oxides generally require harsh conditions. In contrast, many biological processes can produce intricate metal oxide nanostructures under ambient conditions. For example, the diatom Cylindrotheca fusiformis forms reproducible nanostructures from silicic acid using species specific peptides known as silaffins. Herein, we report that the R5 peptide a bioinspired analogue derived from the NatSil protein in C. fusiformis can form titanium dioxide (TiO2) in a concentration dependent manner from the non-natural substrate, titanium bis(ammonium lactato)dihydroxide. Additionally, the polypeptide poly(l-lysine) acts as a template for the biomimetic synthesis of TiO2. Subsequently, the nanoparticles were characterized using scanning electron microscopy, energy-dispersive X-ray spectrometry, and IR spectroscopy. A variable temperature X-ray diffraction study of the titanium dioxide phase transition from anatase to rutile was conducted. A delay in transition temperature was...

Mobilization of Arsenite by Competitive Interaction with Silicic Acid

Abstract: Due to the acute toxicity of As, mobilization of even a small fraction of As into surface and ground waters used as a source for drinking water represents a substantial risk to human health. Here we evaluate the mobilization of arsenite [As(III)] from the Fe-(hydr)oxide mineral goethite (a-FeOOH) through competitive displacement by silicic add, a naturally occurring and ubiquitous inorganic ligand. The adsorption behaviors of silicic add and As(III) on goethite were investigated at environmentally relevant pH (3-11). Single ion adsorption and zeta-potential data were collected at silica concentrations characteristic of natural waters (3-30 mg L - 1 ) and initial solution As(III) concentrations representative of high levels of contamination (3.75-7.5 mg L - 1 ). Competitive adsorption scenarios with either Si or As(III) sorbed first to the goethite surface, followed by equilibration with the other sorbate, were also examined. No competitive displacement of either oxyanion was observed at total sorbate concentrations less than reactive surface site density, regardless of pH or addition scenario. However, at total sorbate concentrations greater than reactive surface site density, As(UI) adsorption was reduced by 10 to 15% over the entire pH range regardless of addition scenario, resulting in aqueous concentrations well in excess of current (10 μg L - 1 ) drinking water maximum contaminant levels. Surface complexation modeling of single ion adsorption and zeta-potential data using the Charge Distribution Multisite Surface Complexation (CD-MUSIC) model was used to calculate an appropriate set of surface adsorption equilibrium constants for As(III) and silicic add adsorption, which was used to describe the competitive adsorption scenarios. Comparison of competitive adsorption data and CD-MUSIC model predictions, at total sorbate concentration greater than reactive surface site density of goethite, suggest that silica is competitively displaced by As(III).

Novel aspects of the physical chemistry of Co/SiO2 Fischer–Tropsch catalyst preparations: The chemistry of cobalt silicate formation during catalyst preparation or hydrogenation

Abstract: Co/SiO 2 catalysts were prepared by both impregnation and precipitation techniques and analyzed by IR, TPR, XRD, and BET methods at intermediate stages of their preparation to define the stage and mechanism of cobalt silicate formation. To prove that reducing conditions can lead to cobalt silicate, one part of a catalyst prepared by impregnation of silica with cobalt nitrate was calcined in air at 350 °C, and another part in H 2 –N 2 atmosphere at the same temperature. Infrared spectra revealed the presence of Co–O–Si absorption in the sample exposed to reducing atmosphere. Cobalt silicate formation is postulated to be a reaction between migrating silicic acid and hydrated cobalt hydroxide generated in the reduction process. Precipitation of cobalt nitrate solution at 80–90 °C with potassium hydroxide solution in the presence of Davison 952 silica resulted in amorphous cobalt silicate formation. Precipitation with sodium carbonate solution gave no IR-detectable quantities of cobalt silicate in the presence of Davison 952 silica, but cobalt silicate was detected when Cab-O-Sil HS-5 silica was used. Precipitations of Co and Mg nitrates (∼2:1 Co/Mg ratio) with sodium carbonate gave essentially quantitative yield of amorphous cobalt silicates whether the precipitation occurred in the presence of Davison 952 silica, or the silica was added after the precipitation. Cobalt silicate formation during precipitation either by KOH or Na 2 CO 3 solutions is a heretofore unrecognized facile reaction of hydrated cobalt hydroxide with silicic acid (dissolved silica). The mechanism which can explain Co(OH) 2 (H 2 O) x formation during Na 2 CO 3 precipitations is an acid–base reaction between hydrated Co ions and carbonate ions. This reaction also yields carbonic acid, which competes with silicic acid for Co(OH) 2 (H 2 O) x in secondary reactions.

Automated determination of silicon isotope natural abundance by the acid decomposition of cesium hexafluosilicate.

Abstract: A procedure for the automated determination of isotopic abundances of silicon from biogenic and lithogenic particulate matter and from dissolved silicon in fresh or saltwaters is reported. Samples are purified using proven procedures through the reaction of Si with acidified ammonium molybdate, followed by precipitation with triethylamine and combustion of the precipitate to yield silicon dioxide. The silicon dioxide is converted to cesium hexafluosilicate by dissolution in hydrogen fluoride and the addition of cesium chloride. Isotopic analysis is accomplished by decomposing the cesium hexafluosilicate with concentrated sulfuric acid to generate silicon tetrafluoride gas. Silicon tetrafluoride is purified cryogenically and analyzed on a gas source isotope ratio mass spectrometer. Yields of silicon tetrafluoride are >99.5%. The procedure can be automated by modifying commercial inlet systems designed for carbonate analysis. The procedure is free of memory effects and isotopic biases. Reproducibility is +/-0.03-0.10 per thousand for a variety of natural and synthetic materials.

Biomimetic approach to the formation of gold nanoparticle/silica core/shell structures and subsequent bioconjugation.

Abstract: The encapsulation of individual nanoparticles has gained great attention as a method for both stabilizing nanoparticles and tailoring their surface properties. In particular, the encapsulation of nanoparticles with silica shells is advantageous for bioconjugation and applications to (nano)biotechnology. Herein we report a method for constructing gold nanoparticle (AuNP)/silica core/shell hybrid structures by biomimetic silicification of silicic acids. The procedure consists of surface-initiated, atom transfer radical polymerization of 2-(dimethylamino)ethyl methacrylate (DMAEMA) from AuNPs and biomimetic polycondensation of silicic acids by using poly(DMAEMA) as a synthetic counterpart for silaffins that are found in diatoms. The resulting AuNP/silica hybrids were characterized by Fourier transform infrared spectroscopy, energy dispersive x-ray spectroscopy, UV-vis spectroscopy and transmission electron microscopy. In addition, the immobilization of biological ligands onto the hybrids was investigated for potential applications to biotechnology. As a model ligand, biotin was attached onto the AuNP/silica hybrids through substitution reaction and Michael addition reaction, and the attachment was confirmed by fluorescence microscopy after complexation with fluorescein-conjugated streptavidin.

The occurrence and distribution of various forms of silica and zeolites in soils developed from wastes of iron production

Abstract: Young soils developed in blast furnace slag, slag sand and ash are often alkaline. Under these conditions the solubility of silica increases greatly. In four soil profiles investigated (two in France and two in Germany) we found not only that dissolved silicic acid and amorphous silica occurred, but also that zeolites had developed. We identified several soil properties that may influence the formation of amorphous silica and zeolites. In the blast furnace slag, the formation of amorphous silica seemed to be enhanced by decreasing pH and increasing Mg content, while the amount of zeolites grew with increasing contents of water soluble Na and K and with decreasing content of CaCO 3 . In the slag sand, Mg also appeared to promote the formation of amorphous silica. In addition, there was a weaker correlation between rising CaCO 3 content and an increasing amount of amorphous silica. Furthermore, in the slag sand the Si o : Al o ratio decreased with increasing salinity, suggesting that the zeolites were Al enriched. Longer periods of water saturation of the soil, it is suggested, enhance the development of zeolites and inhibit the formation of amorphous silica.

Interaction of silicic acid with poly(1‐vinylimidazole)

Abstract: Poly(1-vinylimidazole) reacts with silicic acid and poly(silicic acid), giving rise to water-soluble complexes and insoluble composites because of hydrogen bond- ing. The composition, structure, and morphology of the obtained products have been studied with elemental analysis, Fourier transform infrared spectroscopy, and scan- ning electron microscopy. The main direction of the reaction depends not only on the initial ratio of the components, concentration, and pH but also on the sequence of the reagent mixing: the presence of poly(1-vinylimidazole) macromolecules during the for- mation of silicic acid stabilizes soluble complexes, which precipitate with an excess of H4SiO4 only. These soluble complexes may serve as a pattern of particles responsible for the transport of silicic acid in diatom algae and other organisms that assimilate

Fumed silica to colloidal silica conversion process

Abstract: A method of manufacturing a colloidal silica dispersion, by dissolving a fumed silica in an aqueous solvent having an alkali metal hydroxide to produce an alkaline silicate solution; removing the alkali metal via ion exchange to produce a silicic acid solution; adjusting the temperature, concentration and pH of the silicic acid solution to values sufficient to initiate nucleation and particle growth at elevated temperatures; and cooling the silicic acid solution at a rate sufficient to produce the colloidal silica dispersion. The colloidal silica particles in the colloidal silica dispersion have a mean particle size about 2 nm to about 100 nm. Also provided is a method of chemical mechanical polishing a surface of a substrate by contacting the substrate and a composition having a plurality of colloidal silica particles according to the present invention and a medium for suspending the particles. The contacting is carried out at a temperature and for a period of time sufficient to planarize the substrate.

Nutrient and phytoplankton dynamics during the stationary and declining phases of a phytoplankton bloom induced by iron-enrichment in the eastern subarctic Pacific

Abstract: This paper reports on the variations in nutrient concentrations and phytoplankton dynamics during the stationary and declining phases of a phytoplankton bloom induced by a mesoscale iron-enrichment conducted in the high-nutrient low-chlorophyll (HNLC) eastern subarctic Pacific. During the 26-d sampling period, the main pycnocline was located between 30 and 45 m with a shallow pycnocline developing at 10 m, 19 d after the first iron-enrichment. The iron-induced bloom dominated by diatoms peaked during days 15 and 18, a period of high chlorophyll a concentrations (ca. 5 mg m−3), and declined thereafter. Nitrogenous nutrients and phosphate were not depleted during the whole experiment. In contrast, silicic acid and iron concentrations became very low during the stationary phase of the diatom bloom (days 15–18) and Fv/Fm declined. These observations suggest that silicic acid and iron limitation probably prevented further development of the diatom bloom. The decline in chlorophyll a concentrations during days 19–24 was mostly due to the decrease in diatom abundance. On the other hand, cell abundances of pico- and nanophytoplankton exhibited little change until day 24. In the layer located between the main and the shallow pycnocline (10–30 m), ammonium and silicic acid concentration increased during days 19–26, suggesting recycling of these nutrients. The amount of silicic acid recycled during that period was estimated at 71.3–99.2 mmol m−2, while the dissolution rate of biogenic silica (BSi) was estimated to be 5.9–9.2% d−1 in the upper 50 m of the water column. These results show that the development of a shallow pycnocline during the experiment accelerated the iron and silicic acid depletion in the upper mixed layer and influenced the recycling of the organic matter assimilated during the iron-induced bloom in the ocean surface.

Manufacturing method of silica sol and obtained silica sol

Abstract: A process for preparing high-granularity Si sol includes such steps as heating the SiO2 dispersed water, stirring while adding alkaline catalyst and metallic Si powder, hydrolytic reaction at pH=7-14 to obtain active silicic acid micro-particles, and quickly adsorbing the micro-particles by SiO2 seed particles to become target sol. Its advantages are high speed and controllable and uniform granularity.

Formation mechanisms of colloidal silica via sodium silicate

Abstract: Colloidal silica is formed by titrating active silicic acid into a heated KOH with seed solution. The colloidal silica formation mechanisms are investigated by sampling the heated solution during titration. In the initial stage, the added seeds were dissolved. This might due to the dilution of seed concentration, the addition of potassium hydroxide (KOH) and the heating at 100°C. Homogenous nucleation and surface growth occur simultaneously in the second stage of colloidal silica formation. Homogenous nucleation is more important when the seed concentration is relatively low. On the other hand, surface growth plays an important role when the seed concentration is increased. In the middle seed concentration, the seed particles grow up and some new small particles are born by the homogenous nucleation process to form a bimodal size distribution product. As the titrating volume of active silicic acid exceeds a specific value in the last stage the particle size increases rapidly and the particle number decreases, which may be caused by the aggregation of particles. The intervals between each stage were varied with the seed concentration. Increasing the seed concentration led to the formation of uniform particle size colloidal silica.

Precipitated silica having a specific pore size distribution

Abstract: Preparation of precipitated silicic acid comprises (a) subjecting an aqueous solution of an alkali- and/or earth alkaline silicate and/or an organic or inorganic base; (b) simultaneously adding an alkali- and/or alkaline-earth silicate and an acidifying agent to increase the viscosity; (c) terminating the reaction after 35-85 minutes; (d) simultaneously adding an alkali- and/or alkaline-earth silicate and an acidifying agent to attain a solid content; (e) stirring the obtained suspension; (f) adjusting the pH by adding the acidifying agent; and (g) filtering and (h) drying. Preparation of precipitated silicic acid comprises: (a) subjecting an aqueous solution of an alkali- and/or earth alkaline silicate and/or an organic or inorganic base, where the subjected mixture exhibits the alkali number of 20-40; (b) simultaneously adding an alkali- and/or earth alkaline silicate under stirring at 55-85[deg]C and an acidification agent to increase the viscosity of the mixture; ( (c) terminating the reaction after the addition of mixture that takes place for 35-85 minutes, preferably after reacting the temperature of step (b); (d) simultaneously adding an alkali- and/or alkaline-earth silicate and an acidifying agent under agitation at 55-85[deg]C, to attain a solid content of 90-140 g/l; (e) stirring the obtained suspension for 1-120 minutes at 80-98[deg]C; (f) adjusting the pH of the solution to 2.5-5 by adding the acidifying agent; (g) filtering; and (h) drying. Independent claims are included for: (1) a precipitated silicic acid exhibiting physical-chemical parameters such as relative width (gamma ) of the pore size distribution of 4-10 (g nm)/ml, Brunauer, Emmett and Teller (BET)-surface 90-320 m 2>/g, cetylammonium bromide (CTAB) surface area of 100-200 m 2>/g, sears number (V2) of 25-40 ml/(5 g) and sears number (V2/CTAB) ratio of 0.18-0.28 ml/(5 m 2>); (2) a precipitated silicic acid, obtained by the above process; (3) a vulcanizable rubber mixtures and vulcanizate comprising the precipitated silicic acid as filler material; and (4) a tire, comprising at least a precipitated silicic acid.

Process for preparing stephanoporate powder doped silica aerogel heat-insulation material

Abstract: The invention discloses a process for preparing porous body powder doped silica aerogel thermal insulation material, which comprises preparing porous silicon dioxide through normal pressure drying, hydrolyzing 2-6 hours silicic acid ethyl acetate or silicic acid methyl ester as precursor under acidic condition at 50-80 deg. C, thus obtaining silicasol, then charging fiber, screening agent and porous silica flour into the hydrolyzed silicasol, charging ammonia to obtain wet gel, ageing the obtained wet gel in ethanol for 120-240 hours, exchanging 3-5 times with ethanol, finally drying in hypercritical solvent.

Oxidation polysilacidiron coagulant and preparation thereof

Abstract: An oxidized polysilicate iron coagulating agent and its production are disclosed. The process is carried out by mixing activating silicic acid with low-polymerization degree with acid ferrous sulfate solution, adding into oxidant, additive and stabilizer, aging to obtain liquefied product or curing to obtain product. Its advantages include short period, better stability, simple process and good coagulating effect.

Method for preparing polyimide/silicon dioxide nanometer hybridized film

Abstract: The invention relates to a producing process of the polyimide/silicon dioxide nm hybridization film. The method improves the existing sol-gel method; the positive silicate sol solution is added in before the forming of the polyamic acid to carry the hydrolytic condensation of the sol-gel and the macromolecule polyreaction of the polyamic acid synchronously; finally, it can be gained by the hot imine treatment of the composite composed by the polyamic and the positive silicic acid. Using the producing process of the polyimide/silicon dioxide nm hybridization film provided by the invention, the polyimide/silicon dioxide nm hybridization film stuff of separating evenly and having the physiofacies of which the size reached to the order of magnitude of 5nm-1um. Comparing with the existing technic, the method can avoid the problem of the silicon dioxide grain is difficult to be separated in the basal body because of the high solution viscosity of the polyamic acid; so it can improve the compatibility of the two phase; the ability of the mechanics and the optics of the hybirgization film is improved highly.

Modeling studies investigating the causes of preferential depletion of silicic acid relative to nitrate during SERIES, a mesoscale iron enrichment in the NE subarctic Pacific

Abstract: Numerical modeling experiments were conducted to examine the reasons for observed changes in the silicic acid ([Si(OH)4]) to nitrate ( [ NO 3 - ] ) drawdown ratio after the onset of algal iron stress during SERIES. During phytoplankton blooms and immediately after them, cells encounter a range of iron stress (between iron-replete and iron-deplete) and therefore show a range of growth rates. For these reasons, the potential influence of phytoplankton growth rate, under conditions of algal iron stress, on silicic acid and nitrate depletion were investigated in numerical experiments by altering the timing of a shift in the [Si(OH)4]: [ NO 3 - ] uptake ratio. These simulations suggested that the continued growth of iron-stressed phytoplankton at sub-maximum rates, with an elevated [Si(OH)4]: [ NO 3 - ] uptake ratio, induced depletion of silicic acid in the surface water and resulted in simultaneous limitation of growth by both iron and silicic-acid supply. Therefore, bottom-up control played an important role in terminating the phytoplankton bloom in SERIES. In the model simulations, the enhancement of diatom silicification due to increased rates of biomass-normalized silicic-acid uptake, led to increases in the export flux of opal after the onset of algal iron-stress and, consequently, it stimulated the silica pump. The regulation of both the [Si(OH)4]: [ NO 3 - ] uptake ratio and the growth rate of phytoplankton by iron supply are important factors that determine the relative consumption of silicic acid and nitrate upon iron stress, although the potential influence of a floristic shift in the diatom assemblage cannot be ruled out. These findings offer insights into the impact of iron fertilization, both artificial and natural, on the biogeochemical cycling of nutrients in high-nitrate, low-chlorophyll waters.

Complexation/speciation studies of Ni2+ion with ortho silicic acid in perchlorate media

Abstract: The complexation behavior of Ni2+with ortho-silicic acid (o-SA) has been studied as a function of ionic strength (I) from 0.20 to 1.00M (NaClO4) at pcH 4.55±0.05 and 25 °C by a solvent extraction technique with bis(2-ethylhexyl) phosphoric acid (HDEHP) as the extractant. The stoichiometry of the extracted species was determined to be Ni(DEHP)2(HDEHP)2. Ni2+forms a 1:1 complex, Ni(OSi(OH)3)+, as the predominant species withconcentrations of 1.00. 10-3to 1.00. 10-2M o-SA. The stability constant (logb1) values for Ni(OSi(OH)3)+complex formation decrease with increased ionic strength. These values have been fitted with the extended Debye-Huckel expression to obtain the value of logb1=6.34±0.03 at I=0.00M. The data allowed the calculation of speciation of the Ni2+- silicate system as a function of ionic strength.

Manufacturing method of modified wood

Abstract: PROBLEM TO BE SOLVED: To provide a manufacturing method of modified wood capable of simply obtaining the modified wood excellent in fire retardancy, flameproofness and smokeproofness. SOLUTION: The manufacturing method of the modified wood includes a silicic acid compound impregnation process for impregnating wood 1 with a silicic acid compound solution containing a silicic acid compound, a gelling process for gelling the silicic acid compound by an acid anhydride gas to form a silicic acid compound gel and a combustion inhibitor impregnation process for impregnating the wood after the gelling process with a combustion inhibitor solution containing at least one kind of a combustion inhibitor among a phosphorous type combustion inhibitor, a boron type combustion inhibitor and a halogen type combustion inhibitor. Further, a penetration pore forming process for forming penetration pores to wood can be provided before the silicic acid compound impregnation process. Furthermore, a drying process for drying wood before impregnating the wood with the silicic acid compound can be provided before the silicic acid compound impregnation process. The drying process can be provided after the gelling process but before the combustion inhibitor impregnation process. COPYRIGHT: (C)2007,JPO&INPIT

Organic silicic acids complex for therapeutic and cosmetic applications

Abstract: This invention describes materials containing organic silica, used in cosmetic for external uses (gel, cream or lotion) or for internal uses (microbeads/beads, tablets or solutions). These materials are vegetable extracts such as bamboo or algae which constitute richest sources in organic silica (more soluble and assimilable). After extraction in a basic medium, the organic silica extract can form a stable complex at acidic pH in presence of stabilizers such as gelatin, collagen, polyethylene glycol and/or chitosan, etc. These complexes can be used for cosmetic applications in gel, lotion and cream or as a matrix in order to immobilize various bioactive molecules. For internal uses, the soluble form of monomeric or oligomeic silicic acid is necessary to preserve its assimilability. In this context, the addition of stabilizers (gelatin and/or collagen) or the functionalization of silicic acid is possible to improve its solubility and biodisponibility.

Partially Hydrophobic Silicic Acid Aqueous Dispersions

Abstract: The invention relates to a silicic acid dispersion containing a partially hydrophobic silicic acid when the dispersion pH ranges from 5 to 12.

Method of manufacturing silica-based fine particle, coating material for film formation, and base material with film

Abstract: PROBLEM TO BE SOLVED: To provide a method of manufacturing a hollow spherical silica-based fine particle having void inside the shell to obtain the fine particle having a low refractive index. SOLUTION: When preparing a compound oxide fine particle dispersion by adding the aqueous solution of silicate and/or acidic silicic acid solution and that of an alkali-soluble inorganic compound into an alkali aqueous solution simultaneously, an electrolyte salt is added so that the ratio of the mole number (M E ) of the electrolyte salt to that (M S ) of SiO 2 is within 0.1-10 to grow the particle. Then, the silica-based fine particle is manufactured by adding further the electrolyte salt into the above fine particle dispersion if needed, removing at least a part of elements except silicon constituting the compound oxide fine particle, aging the obtained silica-based fine particle dispersion, and performing a hydrothermal treatment. COPYRIGHT: (C)2006,JPO&NCIPI

Solvents Effects on Physicochemical Properties of Nano-Porous Silica Aerogels Prepared by Ambient Pressure Drying Method

Abstract: Hydrophobic silica aerogels were synthesized by an ambient pressure drying method from silicic acid with a different pH value, which was prepared from sodium silicate solution (water glass). In this study we chose various hydrocarbon class solvents such as pentane, hexane, heptane, and toluene, and performed surface modification in TMCS (trimethylchlorosilane)/solvent solutions in order to improve reproducibility in aerogel production. Densities of the aerogels were about 0.1 ~ 0.3 g/cm3 , and apparent porosities were 88 ~ 96 %, depending on the processing conditions. Specific surface area was approximately 730 ~ 950 m2/g, and average pore size around 10 nm.

Method for producing a sorbent based on a methyl- silicic acid hydrogel

Abstract: The inventive method for producing a sorbent consists in adding a strong acid solution to a methylsiliconate sodium (or potassium) solution for obtaining a product, which after being stabilised, is ground and activated by adding a strong acid to the solution, is washed out by water until a neutral reaction is attained in such a way that a product, the pore space of which is equal to or greater that 0.8 cm3/g is obtained, wherein said product exhibits adsorption properties with respect to mean- and high-molecular agents and can contain chemical and/or biological additives. The thus obtained product has a general formula: {(CH3SiO1,5)⋅nH2O}[k1...Km], wherein ki is a mass ratio (mass%) for chemical additives (m≥2) or a qualitative characteristic for the content of biological additives; xerogel is produced at n=0; gel form is produced at n=30-46; past form is produced at n=54-62; suspension form is produced at n=63-495.

Method for manufacturing water-using home facility or equipment, and water-using home facility or equipment

Abstract: The present invention provides a method for manufacturing water-using household equipment of which hydrophilicity, surface hardness and appearances are good and the water-using household equipment. The water-using household equipment includes a coat including silicic acid, and a coat constituted by composition of 44 to 97% by mass of Si by SiO 2 conversion, 0.2 to 17% by mass of Li by Li 2 O conversion and 2.4 to 49% by mass of Na by Na 2 O conversion on the coat including the silicic acid on a surface of a substrate. The method for manufacturing water-using household equipment includes: a surface treatment step of treating at least a surface of the substrate contacting water or contacting a water vapor atmosphere with a coating agent including silicic acid and forming a surface treatment layer; and an application step of forming an application layer on the surface treatment layer by applying an aqueous solution including 1 to 20 mass portions of Si by SiO 2 conversion, 0.05 to 0.3 mass portion of Li by Li 2 O conversion and 0.5 to 1 mass portion of Na by Na 2 O conversion.