In another study, Wang and co-workers demonstrated the requirement of optimum NH 3 concentration for the synthesis for monodisperse colloidal silica spheres [56]. They reported the coagulation of silica spheres at higher concentration of ammonia, whereas longer reaction time or even absence of silica particles were observed at lower …
The effect of the use of colloidal silica on the workability and compressive strength of M20 grade concrete was studied in the present study. Colloidal silica (CS-TX & CS-FX) of two types were replaced in different percentages by the weight of cement. Conplast SP-430 is added as a superplasticizer.
The process used for making colloidal silica from sodium silicate using sol-gel method included ion-exchanging method [16]. This method can easily control the particle size and distribution in colloidal silica. Control of silica size in colloidal precursor was important due to it would influenced the bulk
Figure 4 illustrates a typical silica polymerisation path proposed by Iler—increasing dissolved silica concentration well above solubility limit in the CP layer …
The aim of this work is to see the effect of aging at industrially reasonable timescales, i.e. up to 24 h, on the TEOS based silica gel structure and their ability to withstand ambient pressure drying. We systematically investigate the influence of different aging times (from 2 to 24 h) and temperatures (55, 65 & 75 °C) on the physico-chemical ...
The influence of mixing time and colloidal silica on the lubricating properties of magnesium stearate was studied using an instrumented single-punch machine. The lubricant was mixed with sodium chloride, anhydrous lactose, calcium citrate granulate and sodium chloride-colloidal silica-mixtures. Short mixing time decreased …
Non-agglomeration and dispersion of silica nanoparticles in polymers and their interfacial interactions to polymer matrix are the most important factors that influence nanocomposites performance.
The influence of synthesis conditions including solution composition and temperature on the formation of silica nanoparticles were systematically investigated. ... Despite the fact that colloidal silica as investigation object was studied for many years, the interest towards this system does not only weaken but on the contrary becomes stronger ...
Colloidal silica is the result of the silico-oxygen acid polymerisation process . Colloidal silica can form in bulk solution or RO feed when dissolved silica solubility exceeds the silica solubility limit. In CSG waters, silica exists as either colloids or as un-dissociated (ortho-) silicic acid (H 4 SiO 4) when the pH is between 8.5 and 9.2.
The influence of mixing time and colloidal silica on the lubricating properties of magnesium stearate was studied using an instrumented single-punch machine. The lubricant was mixed with sodium chloride, anhydrous lactose, calcium citrate …
The formation process of stable colloidal silica solution was discussed in this article. The affecting parameter including pH, zeta potential, and colloidal …
In this study, nanosilica particles were prepared from self-made silica gel under the protection of citric acid in situ complexation and ethyl acetate as the latent acid reagent. The effects of ethyl acetate, citric acid, reaction temperature, and reaction time on the particle size of nanosilica were studied. The optimum process parameters were …
The results showed that the process parameters such as the titration rate, the KOH concentration and the formation temperature have influences on the mean particle …
The colloidal silica mixing ratio was selected as 0, 2, 3, and 4% for this study. Colloidal silica is incorporated with different percentages of the high-performing AE water-reducing agent to secure the target slump. For cement hydration, the optimum mixing ratio of silica fume for calcium hydroxide and the pozzolanic reaction is 7%.
Pan et al. [111] mixed colloidal silica and fumed silica in a certain ratio to prepare hybrid gel. This hybrid gel showed a longer time for gelation and a better cross-linking structure in ...
The glass marbles were used to assist in making gel time and viscosity observations. Glass marbles were selected so they would not react with the colloidal s ilica and ... Table 6-2 Colloidal Silica Samples for Gel Time Curves Type of Ludox Silica Concentration (weight %) NaCl Concentration (N) pH Range SM 5 0, 0.01, 0.03, 0.10 5 - 9
In contrast with the image of 1% colloidal silica – MCC mixture (Fig. 11 c), it is seen that by the longest time of mixing, there is still enough colloidal silica present on the surface to work as a glidant in mixture of 5% of colloidal silica and MCC (Fig. 11 e).
The silica dust is generated during the grinding, cutting or abrading of rocks containing quartz crystals and the exposure of workers to the breathable particles during those activities, or the manipulation of the silica powder, leads not only to silicosis, but also to other respiratory and systemic diseases. 33,44 Conversely, the exposition to ...
The wet weights of the silica dispersion, natural latex, and water are shown in Table 3, and they were mixed in a mixing tank (Lim Karn Chang Ltd., Songkhla, Thailand) with an impeller speed of 250 rpm and a mixing time of 5 min. After good mixing was achieved, the silica and natural latex mixture was coagulated by adding 10% w/w acetic …
The results of the study demonstrate that torque viscosity decreases and flow resistance increases with the increase in the percentage of colloidal silica. Similarly, …
The rheometer was used to test the rheology of cement paste with and without nano-silica, and the fluidity and free water content were tested, the isothermal calorimetry of cement and C 3 S was tested and hydration products were monitored using Raman spectroscopy. A modified Bingham model was used to describe the rheological …
The above mentioned benefits of nano-silica have been demonstrated previously, based on normal strength cement mortar or concrete with water-to-binder ( w/b) ratio between 0.35 and 0.50. Use of nano-silica in high performance cement composites (HPCC) or ultra-high cement composite (UHPC) is still limited so far.
The effect of aging time, silica to alumina ratio is studied and the results show well defined crystalline structure with nano particle size (70 and 81nm) with surface area of 499m 2 /gm ...
This study focuses on investigating the possible effects of graphene and fumed silica nanoparticle fillers on polymer processing and product properties. ... Mixing time (minutes) Low: 50: 180: 3% (Low), 5% (Medium), 8% (high) 10: ... Preparation and thermal properties of epoxy-silica nanocomposites from nanoscale colloidal silica. …
Colloidal silica is used in many applications including catalysis, pharmaceuticals, and coatings. Although naturally formed silica materials are widely …
Mesoporous silica materials refer to a subset of colloidal silicas, wherein soluble silica precursors are assembled into liquid-crystalline mesophases using amphiphilic surfactants or block ...
aging test. The stability of colloidal silica is very important in its application. The accelerated aging test can be taken by decreasing the slurry pH value and increasing the store temperature. The sodium ions were removed from the products and pH value from 9.5-10 to 2-3 by mixing colloidal silica with action exchange resin
The main objective of the current research is to study the dynamic behaviour of colloidal silica treated grout. The treatment of foundation soil with colloidal silica improves the cyclic strength of the soil, which has the potential to reduce damages in buildings during earthquakes. Cyclic triaxial tests were conducted at various double …
Colloidal assembly of silica (nano)particles is a powerful method to design functional materials across multiple length scales. Although this method has enabled the fabrication of a wide range of silica-based materials, attempts to design and synthesize porous materials with a high level of tuneability and control over pore dimensions have …
The effect of silica particle morphology is first investigated as shown in Figure 4. Two different sizes of colloidal silica, 20 nm and 40 nm, were used as a base material in this study. The CS20 and CS40 had comparable λ values with NB (0.0476 W/m·K), whereas minute effects are observed for σ 50% and H, yet comparable to NB.