Effect Of Silica Addition Research Articles

Effect of Silica Addition on Ceramic Layer in Centrifugal-Thermit Reaction

Ceramic lined steel pipe is produced by a thermit process under a centrifugal force. A powdery mixture of ferric oxide and aluminum with silica is used. The addition of silica material has an important role for densification of the ceramic layer formed inside the pipe. It is found that the silicate materials of 2FeO·SiO 2 and 3Al 2 O 3 ·2SiO 2 in amorphous state significantly extend the liquid phase longer and improve the layer structure density as cooling proceeds. Additionally, it is proposed that a mechanism of solidification and densification progresses through four steps for the ceramic layer formation.

221 炭化ケイ素の水潤滑特性に及ぼすシリカ添加の影響(機素潤滑設計)

221 炭化ケイ素の水潤滑特性に及ぼすシリカ添加の影響(機素潤滑設計)

Effect of silica addition on crystallinity and photo-induced hydrophilicity of titania–silica mixed films prepared by sol–gel process

Effect of silicon dioxide (silica) addition into titanium oxide (titania) films on crystallinity and photo-induced hydrophilicity was investigated. Titania films and titania–silica mixed films with 20% or 50% silica were prepared by spin-coating deposition. For the titania films, photo-induced hydrophilicity is only observed in the films with anatase polycrystalline structure. For the titania–silica mixed films, however, despite these films showing no obvious anatase polycrystalline structure, very strong photo-induced hydrophilicity is observed. Particularly, even super-hydrophilicity where the contact angle shows 0° is easily observed for the titania–silica mixed films with 20% silica. The hydrophilicity of the titania films correlates closely with anatase crystalline structure. In the titania–silica mixed films, the synergistic effects of anatase polycrystalline structure of titania and water-trapping effect of silica are important for their strong photo-induced hydrophilicity.

The effect of SiO2 addition on porous silica composite strength

A porous silica composite was prepared by the resin-impregnated method with natural clay and silica as the starting materials. Its compressive strength is up to 1.59 MPa when the mass-blending ratio of silica and clay is 3/7. The effect of silica addition on product strength was significantly investigated.

The Effect of Silica Addition on the Properties of Poly((vinylidene fluoride)-co-hexafluoropropylene)-Based Polymer Electrolytes

The effect of fumed silica (SiO2) addition on the physical and electrochemical properties of poly((vinylidene fluoride)-co-hexafluoropropylene) based polymer electrolyte was investigated by various methods including morphology observation, thermal and crystallinity evaluations, impregnation test using an electrolyte solution, electrochemical stability analysis and impedance measurement. About 38 wt.-% of silica content proved to be the upper limit at which the silica could be no longer added to obtain a self-sustained polymer electrolyte film. As the silica content increased, a finer pore structure developed, a greater amount of electrolyte solution was absorbed, and thus higher ionic conductivity was shown. The electrochemical stability was preserved up to about 4.5 V for all the polymer electrolytes prepared. The interfacial resistance between the polymer electrolyte and the lithium electrode was reduced with the silica content and also showed a diminishing growth rate with time.

The Effect of Silica Addition on the Properties of Poly((vinylidene fluoride)-co-hexafluoropropylene)-Based Polymer Electrolytes

The effect of fumed silica(SiO 2 ) addition on the physical and electrochemical properties of poly((vinylidene fluoride)-co-hexafluoropropylene) based polymer electrolyte was investigated by various methods including morphology observation, thermal and crystallinity evaluations, impregnation test using an electrolyte solution, electrochemical stability analysis and impedance measurement. About 38 wt.-% of silica content proved to be the upper limit at which the silica could be no longer added to obtain a self-sustained polymer electrolyte film. As the silica content increased, a finer pore structure developed, a greater amount of electrolyte solution was absorbed, and thus higher ionic conductivity was shown. The electrochemical stability was preserved up to about 4.5 V for all the polymer electrolytes prepared. The interfacial resistance between the polymer electrolyte and the lithium electrode was reduced with the silica content and also showed a diminishing growth rate with time.

XPS studies of chemical interaction between modified phosphate coatings and iron

The effects of silica addition on properties of phosphate coatings deposited on iron surface are investigated. It has been observed that silica stabilizes phosphates and reduces the transport of iron towards the surface.

ChemInform Abstract: THE MECHANISM OF THERMAL REACTIONS IN APATITES‐SILICA‐WATER VAPOR SYSTEMS

AbstractDie Reaktionen zwischen Fluor‐, Hydroxyl‐ und Chlor‐Apatiten mit SiO2 in Gegenwart von Wasserdampf werden unter verschiedenen Bedingungen (verschiedene SiO2‐Mengen, Temperaturen, Glühzeiten und Wasserdampfdrücke) untersucht.

The Mechanism of Thermal Reactions in Apatites–Silica–Water Vapor Systems

Abstract The reactions of fluor-, hydroxy-, and chlorapatites with silica in the presence of water vapor have been studied under various conditions−i.e., various amounts of added silica, various temperatures (up to 1300°C), and various heating times and water-vapor pressures (0.6–760 mmHg). As the pressure increased, the decomposition rate of hydroxyapatite with silica decreased considerably. Fluorapatite and chlorapatite were found to be decomposed with silica after being partially defluorinated or dechlorinated. In the case of fluorapatite, no effect of silica addition was recognized under a low water-vapor pressure (0.6 mmHg). This effect was observed under a high water-vapor pressure (760 mmHg), accompanied by rapid increases in the fluorine volatility and the destruction rate of the apatite in their time-dependence plots. In the reaction using chlorapatite, a similar effect was found under both low and high pressures. The results for the defluorination and dechlorination could mostly be interpreted by assuming the following changes: (1) halogen-oxyapatite formation, (2) the substitution of hydroxyl ions for halogen ions, and (3) the decomposition of apatite with silica.

Effects of silica additives on sintering and stabilization characteristics of zirconium dioxide

It was found that the sintering of pure zirconium dioxide is inferior to that of the commercial brand. Even with additions of 10% MgO and at a firing temperature of 1700 C stabilization is incomplete.