| SM ISO690:2012|
SHARAGOV, Vasile; KURIKERU, G.. The study of the chemical interaction of container transparent colorless glass with hydrogen fluoride. In: Achievements and perspectives of modern chemistry. 9-11 octombrie 2019, Chişinău. Chisinau, Republic of Moldova: Tipografia Academiei de Ştiinţe a Moldovei, 2019, p. 142. ISBN 978-9975-62-428-2.
|Achievements and perspectives of modern chemistry 2019|
Conferința "International Conference "Achievements and perspectives of modern chemistry"" |
Chişinău, Moldova, 9-11 octombrie 2019
Thermochemical treatment of industrial glassware fordifferent purposes with fluorine– and chlorine–containing gaseous reagents increases their water resistance tenfold, while its mechanical strength is increased by 20-30 %, thermal resistanceand microhardness - by 10-15 % [1-2]. The aim of the undertaken experiments was to investigatethe nature of chemical interaction of container transparent colorless glass with hydrogen fluoride. Objects of investigation were bottles, jars and flasks made from transparent colorless glass. Different concentrations of hydrogen fluoride solutions were used for thermochemical treatment of glass samples. Thermochemical treatment of glass samples with hydrogen fluoride was held in laboratory and industrial conditions. The main regimes of thermochemical treatment of glass samples in laboratory experiments are the following: temperature – between 300 to 600oC; quantity of hydrogen fluoride introduced into the reacting vessel - between 0.01 and 0.10 mol; duration – between 1 s and 15 min. The regimes of treatment of glass containers on processing lines: temperature - between 500 and 600 oC , volume of hydrogen fluoride per one unit of glassware - between 0.05 and 5.00 mL, duration - between 1 and 5s. The thermochemical treatment ofsample surface and glassware with hydrogen fluoride resulted in the formation of reaction products of different intensity. A comprehensive analysis showed that the thermochemical treatment of container transparent colorless glass with hydrogen fluoride formed reaction products containing sodium, potassium and calcium fluorides. In laboratory experiments dealkalization of container transparent colorless glass with hydrogen fluoride increases its water and acid resistance several times, microhardness being increased by 10-15 %. In industrial conditions, the chemical resistance of glassware isimproved by dealkalizing its surface layers with hydrogen fluorideand modifying the glass structure without extraction of sodium, potassium and calcium cations. In the second case, it seems, there is a substitution on the glass surface of the OH– groups and part of the most active bridged oxygen anions by the F– anions, thus preventing the formation of the weakest =Si–OH bonds. The experiment helped to develop optimal regimes of thermochemical treatment of glass containers (bottles, jars and flasks) subjected to hydrogen fluoride in laboratory and industrial conditions.