Concentration Of Water Glass Research Articles

Process Mapping of the Sol-Gel Transition in Acid-Initiated Sodium Silicate Solutions.

Fabricating large-scale porous bioactive glass bone scaffolds presents significant challenges. This study aims to develop formable, in situ setting scaffolds with a practical gelation time of about 10 min by mixing 45S5 bioactive glass with sodium silicate (waterglass) and an acid initiator. The effects of pH (2-11), waterglass concentration (15-50 wt.%), and acid initiator type (phosphoric or boric acid) were examined to optimize gelation kinetics and microstructure. A 10 min gelation time was achieved with boric acid and phosphoric acid at various pH levels by adjusting the waterglass concentration. Exponential and polynomial models were proposed to predict gelation times in basic and acidic environments, respectively. The optical properties of the gels were studied qualitatively and quantitatively, providing insights into gelation kinetics and structure. Acidic gels formed smaller particles in a dense network (pores < 550 nm) with higher light transmittance, while basic gels had larger aggregates (pores ~5 µm) and lower transmittance. As the waterglass concentration decreased, pore size and transmittance converged in both groups. The onset of gelation was detected around 8 min using the derivative of light transmittance. This work identifies the key factors controlling waterglass gelation and their impact on gel structure, enabling the tailored creation of formable, in situ setting bioactive glass bone scaffolds.

The process of optimizing the interfacial transition zone in ultra-high performance recycled aggregate concrete through immersion in a water glass solution

In this study, the use of water glass to immerse silicomanganese slag (SS) was investigated as a method for optimizing the interfacial transition zone (ITZ) in ultra-high performance concrete (UHPC). The length of the interfacial transition zone, microstructure of the composite, and mechanical performance of the UHPC were all analyzed. The results showed that the appropriate concentration of water glass can significantly improve the interfacial transition zone, leading to improved durability and strength of the UHPC.

Effects of the Silicate Modulus of Water Glass on the Hydration and Mechanical Properties of Alkali-Activated Blast Furnace Ferronickel Slag

Blast furnace ferronickel slag (BFNS), currently an underutilized metallurgical residue, was investigated for use as a precursor for alkaline activation. Water glass solutions with various moduli (0.5, 1.0, 1.5 and 2.0) were used at the same water glass concentration of 10% to investigate the influence of the modulus on hydration and mechanical properties. The results show that the modulus has a certain impact on the hydration and mechanical strength development of alkali-activated BFNS. Increasing the modulus of water glass does not change the type of hydration product and the activity of the Mg-containing phases, but it decreases the amount of C2AS, the Ca/Si and Al/Si ratios of the (N,C)-A(M)-S-H gel. In addition, a high silicate modulus deteriorates the pore structure, which has an adverse effect on the development of compressive strength and splitting tensile strength.

Flame Retardancy of Plywood Treated with Various Water Glass Concentration and Additives

The carbonized length and area of plywood by the various spreading concentration of water glass and the type of additives were measured in accordance with the 45° MecKel’s burner method of the fire protection performance standard of the Korean National Fire Agency. As a result of treating water glass with a concentration of 20 to 50 % on plywood, the flame retardancy tended to increase in proportion to the concentration of water glass. However, the optimum concentration of water glass was determined to be 30 % due to the efflorescence and sticky on the surface of plywood treated with high-concentration water glass of more than 30 %. As a result of the experiment by adding different proportions of additives to the water glass with concentration of 30 %, the standard of flame performance standard was satisfied under the conditions with the addition of 15% potassium hydroxide and 1-10% aluminum hydroxide, respectively. On the other hand, there were no significant difference in the flame retardancy by adding magnesium sulfate. These results about the flame retardancy of plywood by water glass and additives were expected to be basic data for improving flame-retardant treated wood.

Study on sodium water glass-based anti-reflective film and its application in dye-sensitized solar cells

In this paper, anti-reflective (AR) films are prepared from sodium water glass with a simple dip-coating method. The effects of SiO2/Na2O molar ratio, concentration of water glass, and withdrawal speed on the anti-reflection performance of the AR films are systematically studied. The optimized AR film is further applied in dye-sensitized solar cells (DSCs). The optical properties and surface morphology of AR films are analyzed by ultraviolet-visible spectrophotometer, scanning electron microscope, and atomic force microscope. Transmittance of the glass coated with sodium water glass-based AR film is increased by 3.2% when the SiO2/Na2O molar ratio, concentration, and withdrawal speed equal to 3.8, 5wt%, and 80mm/min, respectively. Under this condition, the thickness of the AR film is 127nm and the AR film has obvious porous structure. In addition, the power conversion efficiency of DSC coated by AR film is increased from 7.92% to 8.24%, compared with the DSC without AR film.

Preparation and Characterization of Calcium Sulfate Spherical Particles for Dentistry

In this article, calcium sulfate spherical particles were prepared to be used in alveolar bone defect repairing. We used α-calcium sulfate hemihydrate powder to prepare spherical particles of calcium sulfate with stir pelletizing method. The effect of powder addition, pelletizing time and concentration of water-glass on properties of the spherical particles were studied. It was indicated that with increasing of the powder addition, the particle size of the spherical particles was decreased. Prolonging the pelletizing time can improve the compression strength in certain conditions. With increasing of the concentration of water-glass used in preparation process, the shape of the spherical particles becomes non-circular, the granulous stem yield was decreased and the compression strength of the spherical particles was improved.

Production of nano-silica particles in liquid-liquid system by pulsed voltage application

Electrostatic atomization in liquid-in-liquid media has been performed to produce fine droplets with narrow size distribution. The droplet diameter was controlled from mm to mum with applying dc voltage. When ac superimposed on dc voltage was applied, uniformly-sized droplets were produced. The high frequency pulsed voltage was effective to disperse liquid into nm-sized droplets. Water glass aqueous solution was dispersed in alcohol solution, and then they were solidified into solid particles by dehydration. The diameter of the dispersed particles was measured with a laser scattering particle analyzer. Particle diameter was depended on the applied pulse frequency and voltage, flow rate of the water glass, and water glass concentration. With increasing applied pulse frequency, the particle diameter and size distribution were decreased. Particles with 200 nm average diameter were produced at 1 kHz and 5.3 kV of applied pulse.

분말 용가재판을 사용한 광폭 오버레이용 트윈토치 GMAW 공정개발

Generally, wear plate is steel plate having improved surface contact strength and impact strength by surface hardening which is welded using materials with good corrosion resistance, wear resistance and thermal resistance property. CFP GMAW(Compound Filler Plate Gas Metal Arc Welding) is the cladding method using GMAW with the CFP, which is bound with waterglass, on the substrate. It has advantages of reducing compound powder loss, uniform penetration, and preventing hardness decrease. To develope mass production technique of CFP GMAW process for production of high quality wear plate, the method for controling shallow penetration and increasing productivity is required. In this study, twin torch method applied to CFP GMAW process for increasing productivity. And the method was developed by controling penetration control, CFP dry time, gas formation flux and water glass concentration. As a result, applying twin torch method to CFP GMAW process was possible and high quality wide bead could be made without overlap joint.

Investigation of Portland slag cement activated by waterglass

The relatively poor reactivity of Indian BF slags results in lower strength of slag cement in comparison to OPC. In this investigation, a dosage of waterglass as an activator has been optimised. Percentage substitution of slag, concentration of waterglass, and their effects on properties of activated PSC have been studied. Up to 60% slag substitution and use of 1% waterglass as activator have yielded the best results. The activator has also acted as a grinding aid. Long-term storage of activated slag cement has been found to be detrimental.

電子ビーム合金化層の形成と耐食性評価

Surface alloys which have composition similar to stainless steel are produced on mild steel substrates by traversing the substrates under electron beam irradiation. Chromium and nickel powders are fixed onto the substrates with water glass. An electro-magnetic deflection system oscillates the beam as if its cross section at the substrate surface looks like a rectangle. A mathematical model is constructed which describes diffusion of alloying elements from powders on the surface into an alloyed layer. It is assumed that the alloying elements diffuse instantaneously into an alloyed layer. The calculated results on the concentration distribution show good agree-ment with experimental results. Anti-corrosion characteristics of the alloyed layers are evaluated by anodic polarization curves measured along Japanese Industrial Standard G 0579. The anodic polarization curves of the alloys were similar to the standard curve of a stainless steel, SUS 304, but show somewhat higher peak current density for passivation. The concentration of water glass in powders should be in the range of 0.8 to 2% to attain good and stable anodic polarization curves. The anodic polarization characteristics are better when the density of chromium and nickel is higher.

Pulp chemistry in calcite flotation. Modelling of oleate adsorption using theoretical equilibrium calculations

The usual method of obtaining calcite concentrates is reverse flotation, i.e. removal of impurities by flotation. This paper considers the conditions required for direct flotation of calcite. The reason is that calcite often occurs as an impurity in apatite and scheelite flotation, where it floats together with the principal mineral. In this context it is relevant to understand the mechanisms that control the flotation of calcite. Flotation experiments have been performed with oleate as the collector reagent and water glass as the dispersant and modifier. To be able to explain what happens in the flotation, solubility and adsorption experiments have been conducted parallel to, and under the same conditions as, the flotation experiments. Theoretical equilibrium calculations have been made with the help of data from the practical experiments for the purpose of modelling the adsorption experiments. The calculations point to the existence of a surface complex, CaOHO1, which is important at pH>10 and low oleate concentrations. Ca(O1) 2 is formed at lower pH. Water glass has a negative effect on oleate adsorption and if the water glass concentration is high enough, >200 g/t, calcite is totally depressed. With theoretical equilibrium calculations it is possible to predict that silicate ions will form complexes with calcium ions at the mineral surface.