scholarly journals Effect of reaction time on formation of silica core/shell particles

2015 ◽  
Vol 9 (4) ◽  
pp. 209-214 ◽  
Author(s):  
Milan Nikolic ◽  
Radoslav Filipovic ◽  
Slobodanka Stanojevic-Nikolic
Keyword(s):  
Reaction Time ◽  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Sodium Silicate ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Core Shell ◽  
Silica Core ◽  
Shell Particles ◽  
Core Particles

The silica core/shell nanostructures were prepared by a wet-chemical process. Silica core particles were prepared by hydrolysis and condensation of tetraethylorthosilicate. The obtained particles (average size ~0.4 ?m) were used as templates for assembling of silica nanoparticles generated from highly basic sodium silicate solution. The silica core particles were functionalized with 3-aminopropyltriethoxysilane (APTES) to allow electrostatic assembling of silica nanoparticles on the surface of silica core particles. In order to find the optimal conditions for synthesis of silica core/shell particles with mesoporous shells, the effect of reaction time on formation of silica nanoparticles was investigated. The effect of process parameters on generation and aggregation of silica nanoparticles prepared from highly basic sodium silicate solution was also investigated. It was shown that the size of silica nanoparticles and tendency towards aggregation increase with increasing the reaction time and temperature. These behaviours were reflected on the formation of mesoporous silica shell around silica core particles. Thin and uniform mesoporous silica layers were obtained if reaction times were kept short. When the reaction time was prolonged, the thicker and non-uniform shells were obtained.

scholarly journals Synthesis and characterization of mesoporous silica core-shell particles

2010 ◽  
Vol 4 (2) ◽  
pp. 81-85 ◽  
Author(s):  
Milan Nikolic ◽  
Konstantinos Giannakopoulos ◽  
Vladimir Srdic
Keyword(s):  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Silica Particles ◽  
Core Shell ◽  
Functionalized Silica ◽  
Silica Core ◽  
Shell Particles ◽  
Average Size ◽  
Core Particles

Core-shell particles were formed by deposition of primary silica particles synthesized from sodium silicate solution on functionalized silica core particles (having size of ~0.5 ?m) prepared by hydrolysis and condensation of tetraethylortosilicate. The obtained mesoporous shell has thickness of about 60 nm and consists of primary silica particles with average size of ~21 nm. Scanning electron microscopy and zeta potential measurements showed that continuous silica shell exists around functionalized core particles which was additionally proved by FTIR and TEM results.

scholarly journals Oil absorption in mesoporous silica particles

2010 ◽  
Vol 4 (4) ◽  
pp. 265-269 ◽  
Author(s):  
Radislav Filipovic ◽  
Dragica Lazic ◽  
Mitar Perusic ◽  
Ivan Stijepovic
Keyword(s):  
Mesoporous Silica ◽  
Sodium Silicate ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Processing Parameters ◽  
Synthesis Temperature ◽  
Silica Particles ◽  
Clear Correlation ◽  
Oil Absorption ◽  
Different Temperatures

Mesoporous silica particles were prepared from highly basic sodium silicate solutions, having different silica modulus and SiO2 concentrations, by adding sulphuric acid at different temperatures. Pore structure of prepared silica particles (aggregates) is strongly influenced by processing conditions and easy controllable in broad range of the specific surface area, pore size, pore volume and size distribution. It is shown that there is a clear correlation between volume of absorbed oil and processing parameters used in preparation of silica aggregates. Thus, oil absorption is higher in the samples prepared from sodium silicate solution with higher SiO2 concentration and at higher synthesis temperature.

Facile Synthesis Silica Nanoparticles from Indonesia Silica Sand and their Physico-Chemical Properties

2020 ◽  
Vol 862 ◽  
pp. 35-39
Author(s):  
Agus Ismail ◽  
Ariffinisa Lintang Widyaningtyas ◽  
Bambang Heru Susanto ◽  
Mohammad Nasikin
Keyword(s):  
Silica Nanoparticles ◽  
Sodium Silicate ◽  
Sol Gel ◽  
Chemical Properties ◽  
Spherical Shape ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Silica Sand ◽  
Easy Method ◽  
Simple Method

Silica nanoparticles are a very promising functional material when purified from silica sand for wide application. In addition, a low cost and easy method to obtain the material will be increasing the value of silica sand. To synthesize of nanoparticles using an easily scalable, cheap and simple method, we suggest a sodium silicate solution as a precursor that silica sand was diluted on the NaOH. After that, the sodium silicate solution under various alcohols (methanol and ethanol) in the acid medium was conducted by sol gel method to obtain silica nanoparticles. The synthesized of silica nanoparticles was observed to the non-agglomerate, homogeneous and spherical shape with an average size about 200 nm. We also noted the existence of NaNO3 by side product of reaction on the system, which may be the amorphous silica unidentified on the XRD results.

Effect of surface functionalization on synthesis of mesoporous silica core/shell particles

2012 ◽  
Vol 155 ◽  
pp. 8-13 ◽  
Author(s):  
Milan P. Nikolić ◽  
Konstantinos P. Giannakopoulos ◽  
Miloš Bokorov ◽  
Vladimir V. Srdić
Keyword(s):  
Mesoporous Silica ◽  
Surface Functionalization ◽  
Core Shell ◽  
Silica Core ◽  
Shell Particles ◽  
Effect Of Surface

The Effect of Milling Time on the Size of Silica Particles from Silica Sand

2018 ◽  
Vol 917 ◽  
pp. 162-166 ◽  
Author(s):  
Agus Ismail ◽  
Insan Akbar Alamsyah ◽  
Muhammad Kholil ◽  
Bambang Heru Susanto ◽  
Mohamad Nasikin
Keyword(s):  
Silica Nanoparticles ◽  
Sodium Silicate ◽  
Milling Time ◽  
Sol Gel ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
High Energy ◽  
Silica Sand ◽  
X Ray Diffraction ◽  
Sol Gel Process

We report a method to adjust the size of silica nanoparticles from silica sand. In this study, synthesized silica nanoparticles by sol gel process from silica sand were conducted, with previously was controlled the size of silica sand by mechanical milling. Silica sand was milled by High Energy Milling in order to reduce the size into powder form. Effect of milling time shown the content of sodium and silicon is increased in sodium silicate solution obtained from various times of silica sand milling (30, 60 and 90 minutes, respectively) which is reacted with sodium hydroxide 8 M. The result of silica nanoparticles from sol gel process of sodium silicate solution were characterized using atomic absorption spectroscopy, scanning electron microscopy and X-ray diffraction techniques. It was found that the size of silica nanoparticles could be tailored with the change of milling time.

scholarly journals Printability and Setting Time of CSA Cement with Na2SiO3 and Gypsum for Binder Jetting 3D Printing

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2811
Author(s):  
Okpin Na ◽  
Kangmin Kim ◽  
Hyunjoo Lee ◽  
Hyunseung Lee
Keyword(s):  
3D Printing ◽  
Sodium Silicate ◽  
Setting Time ◽  
Sodium Silicate Solution ◽  
Preliminary Test ◽  
Silicate Solution ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate ◽  
Parametric Studies ◽  
Binder Jetting

The purpose of this study is to optimize the composition of CSA (calcium sulfoaluminate) cement with sodium silicate (Na2SiO3) and gypsum for binder jetting 3D printing. The preliminary test was carried out with an applicator to decide the proper thickness of one layer before using the 3D printer. A liquid binder was then selected to maintain the shape of the particles. Based on the results, the optimal mixture of dry materials and a liquid activator was derived through various parametric studies. For dry materials, the optimum composition of CSA cement, gypsum, and sand was suggested, and the liquid activator made with sodium silicate solution and VMA (viscosity modified agent) were selected. The setting time with gypsum and sodium silicate was controlled within 30 s. In case of the delayed setting time and the rapid setting mixture, the jetting line was printed thicker or thinner and the accuracy of the printout was degraded. In order to adjust the viscosity of the liquid activator, 10% of the VMA was used in 35% of sodium silicate solution and the viscosity of 200–400 cP was suitable to be sprayed from the nozzle. With this optimal mixture, a prototype of atypical decorative wall was printed, and the compressive strength was measured at about 7 MPa.

scholarly journals Silica extraction from bauxite reaction residue and synthesis water glass

2021 ◽  
Vol 10 (1) ◽  
pp. 268-283
Author(s):  
Yunlong Zhao ◽  
Yajie Zheng ◽  
Hanbing He ◽  
Zhaoming Sun ◽  
An Li
Keyword(s):  
Sodium Silicate ◽  
Water Glass ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Hydrated Calcium Silicate ◽  
Precipitated Silica ◽  
Alumina Gel ◽  
Silica Alumina ◽  
Element Removal ◽  
Hydrated Calcium

Abstract Bauxite reaction residue (BRR) produced from the poly-aluminum chloride (PAC) coagulant industry is a solid acidic waste that is harmful to environment. A low temperature synthesis route to convert the waste into water glass was reported. Silica dissolution process was systematically studied, including the thermodynamic analysis and the influence of calcium and aluminum on the leaching of amorphous silica. Simulation studies have shown that calcium and aluminum combine with silicon to form hydrated calcium silicate, silica–alumina gel, and zeolite, respectively, thereby hindering the leaching of silica. Maximizing the removal of calcium, aluminum, and chlorine can effectively improve the leaching of silicon in the subsequent process, and corresponding element removal rates are 42.81%, 44.15%, and 96.94%, respectively. The removed material is not randomly discarded and is reused to prepare PAC. The silica extraction rate reached 81.45% under optimal conditions (NaOH; 3 mol L−1, L S−1; 5/1, 75°C, 2 h), and sodium silicate modulus (nSiO2:nNa2O) is 1.11. The results indicated that a large amount of silica was existed in amorphous form. Precipitated silica was obtained by acidifying sodium silicate solution at optimal pH 7.0. Moreover, sodium silicate (1.11) further synthesizes sodium silicate (modulus 3.27) by adding precipitated silica at 75°C.

A Study on a Green Route to Preparation of Silica Powders with Rice Husk Ash

2014 ◽  
Vol 1010-1012 ◽  
pp. 1015-1019
Author(s):  
Ze Xin Yang ◽  
Lin Dong ◽  
Meng Wang ◽  
Huan Li
Keyword(s):  
Sodium Bicarbonate ◽  
Sodium Silicate ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Sodium Hydroxide Solution ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Raw Material ◽  
Transmission Electron ◽  
Thermal Analyzer

The main purpose of this article is to develop an environmentally friendly and economically effective process to produce silica from rice husk ash. Sodium silicate solution was prepared by the reaction of rice husk ash and sodium hydroxide solution, and then the sodium silicate solution was used as the raw material for the preparation of silica with sodium bicarbonate. During the reaction, the by-product can be passed into CO2 to prepare sodium bicarbonate what can be reutilized. Experimental route achieved resource recycling and environment-friendly, low energy consumption, zero emissions and so on. Meanwhile the microstructures of the silica powders were characterized by Transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Thermo gravimetric/Differential thermal analyzer (TG-DTA).The purity of silicon was up to 99.43% and the particle size was 200-300nm.

Fabrication and dual imaging properties of quantum dot/silica core-shell particles immobilized with gold nanoparticles

2018 ◽  
Vol 33 (11) ◽  
pp. 737-747
Author(s):  
Ting-ting Li ◽  
Tomoya Inose ◽  
Takahiro Oikawa ◽  
Masayuki Tokunaga ◽  
Keiichiro Hatoyama ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Quantum Dot ◽  
Core Shell ◽  
Silica Core ◽  
Dual Imaging ◽  
Shell Particles ◽  
Imaging Properties
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