Summary The properties and quality of silicate glasses strongly depend on the amount of residual dissolved gases. Thus, the knowledge of the quantitative content of different volatile components is of great relevance within the technical production line. Several applications exist for the detection and quantification of a single gas in glass. Up to now no available technique provides simultaneous and quantitative information on different gases in a single run. We have developed a new technique to detect the most common volatiles (H2O, CO2, SO2, O2 and N2) simultaneously and quantitatively in silicate glasses with the help of a modified Netzsch TG/MS system. One characteristic feature of this new method is the direct coupling of a thermo balance and a mass spectrometer without the use of any capillary or skimmer system.
Authors:F. Branda, A. Costantini, G. Luciani, and G. Laudisio
In this paper Tg values of calcium (sodium) silicate glasses containing added with oxides of trivalent elements are reported. The plots of
Tg as a function of composition or vs. the ionic field strength prove to be useful in discussing the role of the oxides in the
glass structure. It is found that, at least in the studied composition range, Sc2O3, Y2O3, La2O3, and In2O3, behave as network modifier oxides.
In the compositional ranges studied, the hypothesis based on them well agree with the expectations based on the known criteria
reported in literature and on FTIR spectra.
Thermal reactions of model phospho-silicate gels of simple composition has been studied. The investigations demonstrate that
the kind of compounds introducing P2O5 into the gel silicate network, H3PO4, PO(OC2H5)3, POCl3 influence the course and temperature and the xerogel formation. The amount of interstitial water and xerogel porosity is
dependent on the cations, amorphous structure modifiers (Ca, Na) used. Thermal analysis curves appear the convenient carriers
of informations about the processes in gel pores and the formation of xerogel and glass.
The results of the StepScan
DSC obtained for 15Na2O⋅xMgO⋅(10–x)CaO⋅75SiO2 glasses were
described in the frame of the commonly accepted theory of the glass transition.
A new simplified model of the reversible part of StepScan DSC record
was developed on the basis of the Tool Narayanaswamy Moynihan relaxation theory.
Equivalence between the formal activation energy of enthalpy relaxation process
on one side, and the viscous flow activation enthalpy on the other side, was
of molybdenum high field strength, Mo 6+ cation has a limited solubility in silicateglasses and crystallization of alkali or alkaline-earth molybdates may occur during melt cooling or heat treatment of glasses [ 7 – 10 ].
Authors:A. Vértes, K. Burger, L. Takács, and I. Horváth
Liquids and solutions containing Mössbauer active isotopes when trapped in the capillaries of porous silicate glasses show the Mössbauer effect1 also at room temperature2,3. A model is given for the explanation of this phenomenon.
Mutual relation between thermal activity and biochemical activity of the phospho-silicate glasses which are used as controlled
rate release fertilisers and bioglasses for medical applications, has been observed. Analysis of the local atomic interactions
in the structure of glass is used to explain this relation.