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The use of colloidal silica as a binder for refractory castables has attracted great interest in recent years. Nevertheless, the resultant low green mechanical strength of colloidal silica-bonded ...
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 …
The main factors that influence the transferal of colloidal silica in liquefiable sand are the viscosity of the colloidal silica stabilizer, hydraulic gradient and the hydraulic conductivity of the liquefiable soil. ... Typical colloidal silica gel time curves for 5 wt% solutions at an ionic strength of 0.1 N [27]. However, it is difficult to ...
The present work addresses the effect of incorporation of colloidal Nano-Silica on the behavior of concrete containing recycled coarse aggregate. In this study, concrete mixes containing both natural and recycled aggregate are produced by replacing a fraction of Portland cement 0.75%, 1.5% and 3% of colloidal Nano-Silica …
Sodium silicate (Na 2 SO 4) containing 7.5–8.5 % NaO and 25.5–28.5 % SiO 2 and sulfuric acid (H 2 SO 4) were supplied by Aldrich Chemical Co. and were used as received.Sulfuric acid (1 M) was used as the gelation activator to control the pH value of the solution. Silica gels were prepared by a simple experimental procedure at ambient …
This paper investigates the effect of three different alkalis, namely ammonia (NH4OH), ethylenediamine (EDA), and tetrabutylammonium hydroxide (TBAOH) on the …
AbstractThe effect of mixing time on hardness, disintegration time and ejection force in tablettlng of magnesium stearate and lactose granules was studied. The hardness of the tablets decreased with an increase in mixing time of the blends, as previously reported. A semilogarithmic plot of the hardness versus mixing time gave a straight line having a …
Influence of mixing order and shear on tablet weight and powder flow. In all the cases, tablet weight decreased with an increase in flow index (worsening powder flow). (a) Mixing order was least effective for the blends mixed with Avicel PH200. Average tablet weight remained unchanged by changing the mixing order of flowing agents (CS and …
The purpose of this paper is to investigate and determine the effect of colloidal silica with a particle size of 10 nm (with 2%, 3%, and 4% replacement) on high-performance shotcrete from a rheological and mechanical perspective. In addition, to compare these indicators, silica fume is used with a 4% and 7% mixing rate.
The compressibility decreased only after 10 min of mixing for the blend having 1% colloidal silica loading (E1-10) and after 1000 of mixing for the blend having 5% colloidal silica loading (E5 – 1000) due to the de-aggregation of large colloidal silica aggregates in sufficient mixing time and better colloidal silica redistribution.
Due to the high surface area, adjustable surface and pore structures, and excellent biocompatibility, nano- and micro-sized silica have certainly attracted the attention of many researchers in the medical fields. This review focuses on the multifunctional roles of silica in different pharmaceutical formulations including solid preparations, liquid …
Therefore, colloidal silica may greatly influence the CAC cement hydration process and phases. Mostafa [ 1 ] found that the addition of silica fume to CAC cement prevented the strength loss of castables because the conversion reactions from CAH 10 to C 28 and C 36 were prevented, and Son [ 18 ] found similar results using nano …
This is caused by the absorption of silica colloidal particles with negative charge on the surface of alumina particles. Sol-dispersed alumina slurry shows a minimum in sedimentation volume and ...
The fresh samples were prepared to replicate 2009 sample conditions by mixing poorly graded concrete sand, colloidal silica (5%–9% concentration), and NaCl accelerator (0.3N–0.45N). Additionally, scanning electron microscopy tests were performed to support result interpretation and monitor microstructural changes over time.
Nano-silica is one of the most used nano-materials, and its use is rising 5.6 per cent per year to reach a projected 2.8 million metric tons in 2016.
DOI: 10.1016/J.CEMCONCOMP.2015.08.002 Corpus ID: 135684874; Influence of colloidal silica sol on fresh properties of cement paste as compared to nano-silica powder with agglomerates in micron-scale
Commercially available nano-silica powder (NS) and ammonium stabilized colloidal silica sol (SS) were used in the study. The specific surface area of NS measured through BET method was about 142.9 m 2 /g. The TEM photograph (Tecnai G2 F30 S-Twin) showed that the primary particles of NS are in nano-scale, but aggregate together, …
Nucleation seeding is a new approach to control the kinetics of cement hydration. It is known that nano-silica has an accelerating effect on cement hydration. It is assumed that the surface of these particles act as a nucleation site for C–S–H-seeds which then accelerate the cement hydration. In this case the acceleration should depend on …
AbstractThe effect of mixing time on hardness, disintegration time and ejection force in tablettlng of magnesium stearate and lactose granules was studied. The hardness of the …
DOI: 10.1016/0378-5173(79)90074-7 Corpus ID: 97417430; The influence of mixing time and colloidal silica on the lubricating properties of magnesium stearate …
Colloidal silica particles are measured on the nano-scale—billionths of a meter, sometimes as small as 5 nm. This gives them an enormous amount of surface area relative to their weight, and makes …
Colloidal silica, which refers to concentrated stable dispersions of sols made of discrete, dense particles of amorphous silica, 29 has excellent wear resistance. …
5.2.3. Use. Chrystalline Silica. Sand and gravel are used for road building and concrete construction ().In the United States, an estimated 44% of construction sand and gravel is used for concrete aggregates; the remainder is used for road base and coverings and road stabilization (25%), asphaltic concrete aggregates and other bituminous mixtures (13%), …
Colloidal silica with different dispersion states during silicon chemical mechanical polishing (CMP) are investigated in detail. As the dispersion of colloidal silica is improved, the roughness (R a) decreases gradually during polishing.The silicon surface has a minimum R a of 0.118 nm when the polydispersity index of particles is 0.078. …
Key takeaway: 'Short mixing time improves tablet strength and disintegration without reducing lubricating efficiency, while colloidal silica improves tablet strength but increases friction and does not improve disintegration.'
A synthetic method for the fabrication of colloidal mesoporous silica nanoparticles of a tunable mesopore size is presented. These nanoparticles form stable colloidal suspensions, have narrow particle size distributions in the 50–300 nm range and exhibit a framework-confined porosity made up of large mesopores with a diameter of up …
The gelation time (t gel) was determined from the rheological measurements at different frequencies of 0.1, 0.3 and 0.5 Hz. The results were analyzed using …
Key takeaway: 'Short mixing time improves tablet strength and disintegration without reducing lubricating efficiency, while colloidal silica improves tablet strength but …
The dissolved silica in the activating solutions was in two forms, as sodium silicate (SS) and in the form of colloidal nano-silica (NS). Colloidal nano-silica (NS) dispersed in water (Average particle size: 5–7 nm, pH: 10.30). The composition of the NS was 25% SiO 2 and 75% H 2 O.
In spite of the apparent simplicity of silica's composition and structure, scientists are still investigating fundamental questions regarding the formation, constitution, and behavior of colloidal silica systems. Colloidal Silica: Fundamentals and Applications introduces new information on colloid science related to silica chemistry as well
The purpose of this paper is to investigate and determine the effect of colloidal silica with a particle size of 10 nm (with 2%, 3%, and 4% replacement) on high …
Non-spherical colloidal silica particles are manufactured via a multi-step feeding method to compensate for the material removal rate of colloidal silica slurry, which is lower than that of fumed ...
Influence of colloidal silica sol (SS) consisting of mono-dispersed nano-silica on properties and microstructure of the hardened cement-based materials was investigated as compared to the nano ...
1. Introduction. The formation process of colloidal silica via sol-gel method is of interest due to the fact that colloidal silica can be used in various fields. The colloidal silica …