Papers by Keyword: Sodium Metasilicate

Abstract: The paper presents the results of studies of the effect of the concentration of binder components on the properties of cement alkaline stone. Formulations of clinker-free binders of alkaline activation with the level of filling the system of 20 and 40% have been developed, the properties of the cement paste of the binding binder "aspiration dust - mineral powder - liquid glass" have been studied, the dynamics of a set of strength indicators has been studied, both for bending and compressive forces. The received results allow to estimate uniqueness of properties of a binding binder "a mineral powder - Na₂SiO₃" and to create new materials on resource saving and energy saving technology. The results presented in this article were obtained within the framework of studies on the implementation of scientific project No. 05. 607.21.0320. "Development of technology for new building composites based on clinkerless cement of alkaline activation using substandard natural and secondary raw materials" supported by the Federal Target Program "Research and Development in Priority Areas of Development of the Scientific and Technological Complex of Russia for 2014-2020". The unique identifier for the agreement is RFMTFI60719X0320.

Abstract: Currently, construction volumes around the world are growing rapidly. Because of this fact the anthropogenic load on the natural resource potential of our planet is increasing, so special attention is paid to the development of less resource and energy-consuming technologies for building production, the development of new building composites based on the use of local secondary and substandard raw materials, the receipt of which high-temperature and expensive processing is not required. In this regard, the Grozny Scientific School of Energy and Resource Saving in the production of modern building materials has carried out the comprehensive studies to study the effectiveness of clinker-free alkaline binders as an alternative to traditional cement binders. The results presented in this article were obtained in the framework of the research on the implementation of scientific project No. 05. 607.21.0320. “Development of technology for new building composites on clinkerless alkaline binders using substandard natural and secondary raw materials” that received support from the federal target program “Research and Development in Priority Directions for the Development of the Russian Science and Technology Complex for 2014-2020”. Unique Agreement Identifier RFMTFI60719X0320

Abstract: The alkaline clinker-free binders formulations activation development based on fine powders of aluminosilicate nature will allow to obtain the effective building composites. The paper reveals the issues related to the theoretical foundations of the cement stone structure and strength formation based on the alkaline activator. The research results, in our opinion, are undoubtedly of practical importance for the construction industry, since the proposed recipes for clinker-free cements will replace the expensive and energy-consuming Portland cement, allowing to create strong and durable concrete and reinforced concrete structures. The results presented in this article have been obtained in the framework of research on the implementation of scientific project No. 05. 607.21.0320. “Development of technology for new building composites on clinker-free alkaline binders using substandard natural and secondary raw materials” which received support from the federal target program “Research and Development in Priority Directions for the Development of the Russian Science and Technology Complex for 2014-2020”. The unique identifier for the agreement is RFMTFI60719X0320.

Abstract: Laser-based resonant ultrasound spectroscopy (RUS) method was applied to measure elastic constants of a porous calcium titanate coating manufactured by water-stabilized plasma-spraying (WSP). To enhance the reflectivity of the polished surface of this material for the lasers applied at RUS measurements, a thin coating of sodium metasilicate (waterglass) was used. It is discussed how the metasilicate affects the acoustic properties of the underlying porous material and experimentally shown that such a surface treatment enables the characterization of the structural processes in these materials at elevated temperatures.

Abstract: It was shown, that using of sodium metasilicate (Na₂SiO₃) as stabilizing agent for CdS quantum dots or Ag nanoparticles in water leads to the formation of stable colloids of CdS/SiO₃^2- and Ag/SiO₃^2- particles. These colloids are active in the visible range of the spectrum. According to TEM and UV-visible spectroscopy data, an average size of the particles in colloids was ∼ 5 nm for CdS and 2-10 nm for Ag. Ag/SiO₃^2- water colloids showed an absorption band with a maximum at 380-410 nm. This band belonged to surface plasmon resonance. CdS/SiO₃^2- water dispersions were characterized by luminescence at the region of 500-800 nm. The luminescence intensity increased after addition of Ag⁺ into the colloids of CdS/SiO₃^2-.

Abstract: Exposed dentine with patent tubules allows the movement of tubule fluid leading to dentine sensitivity. Occlusion of patent dentinal tubules effectively reduces the state of dentine hypersensitivity. Strontium chloride (SrCl2) has been well known as a component of desensitizing dentifrice. Recently, new dentifrice containing sodium metasilicate was on the market for desensitizing dentifrice. The aim of this in vitro study was to compare the occlusion effect of dentinal tubule between the sodium metasilicate and the existing desensitizing dentifrices. Sixtyfour human dentine specimens were embedded into a Teflon mold and were grinded with the use of silicone carbide papers to expose the surface of dentin. The dentin surface was etched with 37% phosphoric acid for 60 seconds and was treated with ultrasonic washing for 1 hour. The dentifrices used in the study are classified into four groups: G1-dentifrice containing Sodium metasilicate, G2- dentifrice containing Strontium chloride, G3-dentifrice containing Hydroxyapatite and G4-BSI reference dentifrice (control group). Toothpaste slurries were prepared as 20 gram of toothpaste in 80 ml of distilled water. Thirty-two specimens were brushed with the toothpaste slurries using V8 Cross Brushing Machine. Tooth-brushing was performed 5,000 times using a back-and–forth stroke. The pictures of the sizes of dentinal tubules were taken by scanning electron microscopy (×3000) and changes of tubule sizes were analyzed by digital analysis. The results showed that the difference of tubule size in descending order: G1-3.30±1.80, G2-2.82±1.73, G3-1.49±1.14, G4- 1.04±0.94. The dentifrice containing Sodium metasilicate (22.5%) showed the highest dentinal tubule occlusion. Moreover, the dentifrice containing Sodium metasilicate statistically significantly increased occlusion of dentinal tubule as compared to BSI reference dentifrice (p<0.05). Thus, new desensitizing dentifrice containing sodium metasilicate was more effective than existing desensitizing dentifrice on occlusion of dentin tubules.

Abstract: This in vitro study compared the abrasivity of commercial desensitizing dentifrices with a sodium metasilicate (Na2SiO3) dentifrice using a Surface Profile Method. Dentin specimens were made from the root of extracted human molars. The cervical part of the teeth was sectioned with a diamond wheel disk. The teeth were embedded into an epoxy resin mold and the surface was gradually polished by silicone carbide paper. After grinding, the degree of surface roughness was tested within the range of 2 mm with tapping. The British Standard Institution reference dentifrice (BSI: CaCO3 40%) and experimental dentifrices (group 1: Na2SiO3 25%, CaCO3 10% and SiO2 10%, group 2: CaCO3 10% and SiO2 10%, group 3: CaCO3 10% and SrCl2 10%, group 4: Colloidal Silica 2-3% and Hydroxyapatite 10-20%) were evaluated. The dentifrice slurries were prepared by mixing 24 grams of the dentifrice in 12 ml distilled water. Each tooth specimen was brushed with the dentifrice slurries 1,000 times. The relative abrasivity of each dentifrice was evaluated from the ratio of the BSI standard dentifrice to each experiment. The results were analyzed by one-way ANOVA and Tukey’s multiple comparisons using Window SPSS (Statistical analysis system) 12.0. Groups 1 (71), 2 (74.2), 3 (38) and 4 (7.8) showed a lower abrasivity than the BSI dentifrice (100) (p<0.05). The relative abrasivity of groups 3 (38) and 4 (7.8) was the lowest compared with the BSI dentifrice (100). However, group 1 (71) containing Na2SiO3 showed a similar abrasivity to group 2 (74.2), which did not contain Na2SiO3 (p>0.05). Therefore, Na2SiO3 had no influence on the abrasivity of the dentifrice. In conclusion, the dentifrice containing Na2SiO3 had a lower abrasivity than the BSI reference dentifrice, but showed a significantly higher abrasivity than the existing commercial desensitizing dentifrices. Overall, the relatively high abrasivity of Na2SiO3 dentifrice is believed to be the result of other components in the abrasive system.