Products of Reaction between Barium Chloride and Sodium Hyrdosilicates: Examination of Composition
One of the promising directions of quality improvement of building materials (based on various binders) is to use hydrosilicates of calcium and barium. In particular, it is known that the application of calcium hydrosilicates can improve the compression strength in two or three times; the fracture toughness can be increased in two times and more. Prospects of using barium hydrosilicates in cement systems are due to the similarity of the chemical composition (with calcium hydrosilicates) and advantages of barium cements compared to traditional cements. It is advisable to synthesize the barium hydrosilicates by means of low-temperature technology. To investigate the influence of the curing agent (barium chloride) to the properties of the reaction products in the present study the IR spectroscopy and differential scanning calorimetry (DSC) are used. Analysis of the results allowed to state that the main reaction product is a crystalline silicate phase. Reducing the amount of curing agent leads to an increase of the content of silicic acid. DSC results show that dehydration of barium hydrosilicates takes place in two stages. It is typical for systems BaO•SiO2•6H2O. Increasing the content of silicic acid is accompanied by an endothermic effect in temperature range of 120...130 °C. Joint analysis of the results of IR spectroscopy and DSC leads to the conclusion that there is a reaction of barium carbonate and silicic acid. In general case, reduction of the amount of the curing agent contributes to increase of content of the silica acid and barium carbonate. Therefore, it is advisable to use compositions prepared with reduced amount of BaCl2 in systems capable of interacting with the silica acid and forming the insoluble products.
Anna Bogdan and Nikita Martyushev
A. N. Grishina et al., "Products of Reaction between Barium Chloride and Sodium Hyrdosilicates: Examination of Composition", Advanced Materials Research, Vol. 1040, pp. 347-350, 2014