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Physical and chemical aspects of interaction of inorganic glasses with chemically active gases and electromagnetic fields


Author: Şaragov Vasilii
Degree:doctor habilitat of chemistry
Speciality: 02.00.04 - Physical chemistry
Year:2008
Scientific consultant: Gheorghe Duca
doctor habilitat, professor, Moldova State University
Institution:
Scientific council:

Status

The thesis was presented on the 1 February, 2008
Approved by NCAA on the 28 February, 2008

Abstract

Adobe PDF document0.45 Mb / in russian
Adobe PDF document0.41 Mb / in romanian

Thesis

CZU 666.1.053.65: 620.193

Adobe PDF document 8.83 Mb / in russian
272 pages


Keywords

glass, glassware, surface layer, structure, chemical resistance, mechanical strength, microhardness, thermostability, gaseous reagent, dealkalization, magnetic field, electric field, plasma of electrical discharge, section etching of HF solution, stratification

Summary

In the thesis the nature of chemical interaction of industrial and model inorganic glasses with fluorine– and chlorine-containing gases, hydrogen fluoride and chloride, sulphur, nitrogen and carbon oxides and mixtures of gases is studied. The main factors that determine the glass interaction character with gases are the temperature, the chemical composition of glass and the gas reagent. The mechanisms of interaction of industrial glasses with acid gases and with their mixtures are in generally analogical and can be reduced to dealkalization of the surface layer to the depth of 1.0 µm, at the degree of dealkalization 80%. In industrial conditions the treatment with fluoride- and chlorine-containing reagents of industrial glasses for different purposes improves its chemical resistance in 1-2 orders, while the mechanical strength of glass increases on 20-30%. The optimal regimes are determined and a technology of thermochemical glassware treatment by gaseous reagents is developed.

For the first time the nature of interaction of constant, alternating and impulse magnetic fields with industrial glasses for different purposes was investigated. The structural changes in glass depend on the temperature and the duration of magnetic treatment, on the characteristics of magnetic fields and the position of magnetic lines of force relatively to the plane samples. The optimal regimes are determined and a technology of thermomagnetic treatment of industrial glassware is designed. The electromagnetic treatment increases the mechanical strength on 20-40%, at the same time the microhardness increases on 10-20%, and thermostability on 5-10%.

For the first time the nature of interaction of the plasmas of corona and barrier discharges (alternating, positive and negative) with industrial glass was investigated.

For the first time groups, subgroups and separate factors that influence the exploitation of glass properties (mechanical strength, chemical resistance, thermostability, hardness and others), are established with the help of the system analysis. With the help of the system analysis the sources of systematical mistakes in the experiment are precisely and quickly detected. For the first time there was developed a classification of substance and material properties on the basis of the system analysis.