Thermochemical treatment of glassware with gaseous reagents is the simplest method to improve the surface properties of glass. The main disadvantage of this method of treatment is the low depth of dealkalization layer (about 1 m in the case of industrial glassware), so it has a smaller effect in comparison to other strengthening methods i.e. ion exchange, etching in hydrofluoric acid and tempering [1]. Due to the same reason, during the operation of glassware their modified layers are rapidly destroyed and there is a degradation of glass strength. Hence, the wide use of this method is due to the increased thickness of dealkalized layer. It is known that electric, magnetic and acoustic fields significantly affect the chemical processes [2]. The effect of physical fields on chemical interaction between acid gases and glass has not been described in literature. The aim of the undertaken experiments was to investigate the influence of electric fields on the process of dealkalization of industrial glassware with gaseous reagents. The subjects of investigation were various types of industrial glassware: sheet glass samples, containers (bottles, jars and flasks) of colorless glass, bottles of green glass, ampoules made from medical glass, illuminating glassware made from transparent colorless and milk glasses, laboratory and assorted glassware. SO2, NO2, HCl, CF2Cl2, CHF2Cl and mixtures of these gaseous reagents (CF2Cl2 + SO2, CHF2Cl + NO2, SO2 + HCl etc.) were used as gaseous reagents. The samples of glass were exposed to thermochemical treatment with gaseous reagents in the electric fields both in laboratory and industrial conditions. The main regimes of thermochemical treatment of glass are the following: temperature - between 300 and 600 oС, duration - between 1 s and 2 h, quantity of gas reagent introduced into the reacting vessel - between 0.01 and 1.00 mol, voltage value - up to 5 kV. The intensity of glass dealkalization by acid gases was estimated using the extraction rate of alkaline cations [3]. During the first stage of investigation we determined the rate of dealkalization of industrial glasses with different gaseous reagents based on the optimal regime of thermochemical treatment in laboratory conditions. In the following experiments the thermochemical treatment was repeated, but under the influence of electric fields (constant and alternating). We have established that the rate of dealkalization of industrial glasses with gaseous reagents under the impact of electric fields has increased by 2-3 times. The results achieved may be explained by the voltage value, shape, material and size of the electrodes, the distance between the electrodes etc. Similar results have been obtained for industrial experiments. References: [1] Бутаев, А. М. Прочность стекла. Махачкала: Дагестанский государственный университет, 1997, 253 с. [2] Poller, S. Chemie auf dem Wege ins dritte Jahrtausend. Leipzig – Jena – Berlin: Urania – Verlag, 1979, 400 p. [3] Sharagov, V., Duca, Gh. Increasing physical and chemical properties of annealed hollow glassware as well as of those stored and used. Romanian Journal of Materials. 2013, nr. 43 (2), 218-222.
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