Influence of Colloidal Silica on Final Properties of no Cement Castables

2021 ◽  
Vol 321 ◽  
pp. 125-130
Author(s):  
David Zemánek ◽  
Lenka Nevřivová
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Bulk Density ◽  
Colloidal Silica ◽  
Sol Gel ◽  
Setting Times ◽  
Sol Gel Process ◽  
Initial Setting ◽  
Basic Parameters ◽  
Silica Sols

This paper deals with sol-gel process and application in no cement castables based on andalusite. The use of calcium free binder increases the refractory parameters of material and allows its faster drying. Six colloidal sols from CWK Bad Köstritz based on SiO2 were tested, which differed not only in concentration and particle size, but also in pH. The influence of silica sols on the consistency of fresh castable, initial setting and final setting times were investigated. Furthermore, basic parameters after firing, such as bulk density, apparent porosity, flexural and compressive strength, were tested.

UV Curable Organic-Inorganic Hybrid Materials

2000 ◽  
Vol 628 ◽  
Author(s):  
Guang-Way Jang ◽  
Ren-Jye Wu ◽  
Yuung-Ching Sheen ◽  
Ya-Hui Lin ◽  
Chi-Jung Chang
Keyword(s):  
Hybrid Materials ◽  
Colloidal Silica ◽  
Sol Gel ◽  
Solution Ph ◽  
Uv Curable ◽  
Inorganic Hybrid ◽  
Degradation Temperature ◽  
Sol Gel Process ◽  
The Stability ◽  
Thermal Degradation Temperature

This work successfully prepared an UV curable organic-inorganic hybrid material consisting of organic modified colloidal silica. Applications of UV curable organic-inorganic hybrid materials include abrasion resistant coatings, photo-patternable thin films and waveguides. Colloidal silica containing reactive functional groups were also prepared by reacting organic silane and tetraethyl orthosilicate (TEOS) using sol-gel process. In addition, the efficiency of grafting organic moiety onto silica nanoparticles was investigated by applying TGA and FTIR techniques. Experimental results indicated a strong interdependence between surface modification efficiency and solution pH. Acrylate-SiO2 hybrid formation could result in a shifting of thermal degradation temperature of organic component from about 200°C to near 400°C. In addition, the stability of organic modified colloidal silica in UV curable formula and the physical properties of resulting coatings were discussed. Furthermore, the morphology of organic modified colloidal silica was investigated by performing TEM and SEM studies‥

scholarly journals Synthesis of ZnO and CuO nanoparticles via Sol gel method and Its Characterization by using XRD and FT-IR Analysis

2022 ◽  
Author(s):  
Monika Patel ◽  
Sunita Mishra ◽  
Ruchi Verma ◽  
Deep Shikha
Keyword(s):  
Particle Size ◽  
Zno Nanoparticles ◽  
Sol Gel ◽  
Broad Band ◽  
Zinc Nitrate ◽  
Zno Nanoparticle ◽  
Absorption Bands ◽  
Characteristic Absorption ◽  
Sol Gel Process ◽  
Ft Ir

Abstract Nanotechnology is a completely unique branch of technology that offers with substances in a very small size between (1-100 nm) with various crystal shapes which include spherical nanoparticles, flower shaped, Nano rods, Nano ribbons, and Nano platelets. Metals have ability to produce large number of oxides. These metal oxides play an major role in many areas of chemistry, physics, material science and food science. In this research, Zinc Oxide (ZnO) and Copper (II) oxide nanoparticles were synthesized via sol-gel process using zinc nitrate and copper (II) nitrate as precursor respectively. The characterization of CuO and ZnO nanoparticles was done by using various techniques. X-ray Diffraction (XRD) indicates the crystallinity and crystal size of CuO and ZnO nanoparticle. Fourier transform infrared spectroscopy (FT-IR) was used to get the infrared spectrum of the sample indicating composition of the sample which contains various functional groups. XRD result shows the particle size of CuO at highest peak 29.40140 was 61.25 nm and the particle size of ZnO at highest peak 36.24760 was 21.82 nm. FT-IR spectra peak at 594.56 cm-1 indicated characteristic absorption bands of ZnO nanoparticles and the broad band peak at 3506.9 cm-1 can be attributed to the characteristic absorption of O-H group. The analysis of FT-IR spectrum of CuO shows peaks at 602.09, 678.39, and 730.19cm−1 which refer to the formation of CuO. A broad absorption peak noticed at 3308.2 cm−1 attributed to O–H stretching of the moisture content.

Crystallization of nanosized titania particles prepared by the sol-gel process

1994 ◽  
Vol 9 (8) ◽  
pp. 2102-2108 ◽  
Author(s):  
E. Haro-Poniatowski ◽  
R. Rodríguez-Talavera ◽  
Heredia M. de la Cruz ◽  
O. Cano-Corona ◽  
R. Arroyo-Murillo
Keyword(s):  
Particle Size ◽  
Steady State ◽  
Light Scattering ◽  
Sol Gel ◽  
X Ray ◽  
Constant Size ◽  
Size Profile ◽  
Nanosized Titania ◽  
Sol Gel Process ◽  
Kinetics Of

Sols of titania were obtained by the sol-gel method and their size profile was followed by dynamical light scattering. In the early stages of the reaction an unstable behavior was detected. After this unstable regime the particle size reaches a steady state where the sols have a constant size while increasing in number. Once the sol concentration reaches its overlap value, the gelation regime takes place. For samples prepared in this way Raman spectra and x-ray diffractometry were used to characterize the kinetics of crystallization of the material.

Preparation of SiO2 Antireflective Film by a Base/Acid Two-Step Catalyzed Sol-Gel Process

2013 ◽  
Vol 860-863 ◽  
pp. 845-848 ◽  
Author(s):  
De Yi Li ◽  
Kun Peng ◽  
Ling Ping Zhou ◽  
Jia Jun Zhu
Keyword(s):  
Raw Materials ◽  
Salt Spray ◽  
Sol Gel ◽  
Acid Base ◽  
Gel Method ◽  
Antireflective Film ◽  
Sol Gel Process ◽  
Acid Catalyzed ◽  
Antireflective Films ◽  
Silica Sols

SiO2 antireflective films were prepared by two-step catalyzed sol-gel method with TEOS as the raw materials, acid and ammonia as catalyst. Effects of the ratio of acid-catalyzed and base-catalyzed silica sols on the transmittance and stability of SiO2 film were investigated. The transmittance can be adjusted by change the ratio of base-catalyzed sols, and a higher transmittance can be obtained in the higher ratio of base-catalyzed coatings. A higher stability of SiO2 film in salt spray can be obtained in higher ratio of acid-catalyzed AR coatings. AR coatings with excellent transmittance and stability can be obtained by adjusting the ratio of acid/base catalyzed silica sols.

Study on the Preparation and Particle Size Control of Silica Sphere in a Sol-Gel Process

2013 ◽  
Vol 787 ◽  
pp. 52-57
Author(s):  
Ying Qiu ◽  
Shu Chun Hu ◽  
Jing Zhai ◽  
Zhi Jian Lin ◽  
Wen Feng Liu ◽  
...  
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Sol Gel ◽  
Size Control ◽  
Ammonia Concentration ◽  
Amorphous Structure ◽  
Silica Sphere ◽  
Sol Gel Process ◽  
Key Factor ◽  
Average Size

Silica sphere has wide applications not only in the field of physical chemistry dealing with dynamic behavior and stability of particulate systems, but also in industries including catalysts, ceramics, pigments, pharmacy, etc. However, the control on the particle size is a key factor in the preparation process of silica sphere. In this paper, silica sphere with uniform sphere morphology and amorphous structure was prepared by a sol-gel method, and the control of particle size was emphatically studied. The results showed that the particle size of the as-prepared silica sphere was obviously influenced by the raw materials concentration. The average size of the product increased from 0.66 μm to 0.90 μm when ethanol concentration increased from 7.14M to 9.55M, increased from 0.50 μm to 0.90 μm with the increase of ammonia concentration in the range of 1.88M to 2.36M, and increased from 0.47 to 0.90 μm while tetraethoxysilane concentration increased from 0.08M to 0.11M. Further study indicated that the silica particle size was also influenced by reaction temperature, it increased with the increase of temperature from 26°C to 28°C, and decreased with the further increase of temperature in the scope of 28°C to 32°C.

Comparative Studies of Multiferroic BiFeO3 Powders Prepared by Hydrothermal Method versus Sol-Gel Process

2014 ◽  
Vol 670-671 ◽  
pp. 113-116 ◽  
Author(s):  
Xiao Yan Zhang ◽  
Xi Wei Qi ◽  
Zhi Yuan Yang ◽  
Rui Xia Zhong
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Hydrothermal Method ◽  
Sol Gel ◽  
Distribution Analysis ◽  
Sem Images ◽  
Multiferroic Bifeo ◽  
Average Grain Size ◽  
Sol Gel Process

Multiferroic BiFeO3 powders were synthesized by two methods: sol-gel process and hydrothermal method. The synthesized powders were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (SEM) and particle size distribution analysis. The results obtained by XRD, which is consistent with 86-1518 JCPDS card, show that powders prepared by hydrothermal method are composed of the single phase with the trigonal structure (perovskite-type). It can be found by particle size distribution analysis that the particle size of the samples prepared by sol-gel process is finer and more uniform than that of the samples synthesized by the hydrothermal method. The SEM images of samples depicts that the synthesized BiFeO3 powders are united and the average grain size of hydrothermal processed samples is significantly large as compared to the sol-gel derived sample.

Some Comments on the Production of Medium Sized Spherical Particles by Anion and Water Extraction Variant of Sol-Gel Process

1994 ◽  
Vol 372 ◽  
Author(s):  
A. Deptula ◽  
W. Łstoke;ada ◽  
T. Olczak ◽  
A. Chmielewski
Keyword(s):  
Particle Size ◽  
Sol Gel ◽  
Ceramic Materials ◽  
Extraction Process ◽  
Spherical Particles ◽  
Drastic Reduction ◽  
Sol Gel Process ◽  
Emulsion Drops ◽  
Clustering Effect ◽  
Non Destructive

AbstractMedium sized spherical particles (with diameters below 100 μm) of ceramic materials (Al203 and Al203 +8%TiO2) were produced in the following steps: (1) preparation of concentrated hydroxide sols of cations by extraction of anions using Primene JMT, (2) formation of sol emulsion in 2-ethylhexanol-1 containing various amounts of surfactants (EH), (3) gelation of emulsion drops by extraction of water with partially dehydrated EH, (4) non-destructive thermal treatment. Principal properties of the sol depend on the temperature of the extraction process. For preparation of lowanionic sols a two step extraction process, separated by digestion of the aqueous phase at boiling point, was necessary. It was found that the parameters of emulsion formation as well as the properties of the sols significantly influence the particle size distribution. It was concluded that lowering of the sol- EH interracial tension by the surfactant does not influence the process. On the contrary the “anti-clustering” effect of surfactants is essential for preparation of perfect spherical powders. The thermal decomposition of gels to oxides is determinant for densities, specific surface area and carbon content. Medium sized spherical powders are free flowing. The compactibility and sinterability of those powders are poor. However drastic reduction of particle size by milling (connected with their transformation to irregular shape) significantly improves the sinterability.

Template-free synthesis of TiO2 microspheres with tunable particle size via a non-aqueous sol–gel process

CrystEngComm ◽  
2014 ◽  
Vol 16 (34) ◽  
pp. 7881-7884 ◽  
Author(s):  
Kay He ◽  
Gaoling Zhao ◽  
Gaorong Han
Keyword(s):  
Particle Size ◽  
Sol Gel ◽  
Sol Gel Process ◽  
Elimination Mechanism ◽  
Template Free ◽  
Tio2 Microspheres

TiO2 microspheres with tunable particle size were prepared in alcohols without a template via a facile non-aqueous sol–gel process, on the basis of an ester elimination mechanism.

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