Please use this identifier to cite or link to this item:
Authors: Del Gaudio, P.* 
Behrens, H.* 
Deubener, J.* 
Title: Viscosity and glass transition temperature of hydrous float glass
Journal: Journal of Non-Crystalline Solids 
Publisher: Elsevier
Issue Date: 2006
DOI: 10.1016/j.jnoncrysol.2006.11.009
Keywords: Glass transition
Pressure effects
FTIR measurements
Alkali silicates
Water in glass
Subject Classification04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous 
Abstract: Viscosity of water-bearing float glass (0.03–4.87 wt% H2O) was measured in the temperature range of 573–1523 K and pressure range of 50–500 MPa using a parallel plate viscometer in the high viscosity range and the falling sphere method in the low viscosity range. Melt viscosity depends strongly on temperature and water content, but pressure up to 500 MPa has only minor influence. Consistent with previous studies on aluminosilicate compositions we found that the effect of dissolved water is most pronounced at low water content, but it is still noticeable at high water content. A new model for the calculation of the viscosities as a function of temperature and water content is proposed which describes the experimental data with a standard deviation of 0.22 log units. The depression of the glass tran- sition temperature Tg by dissolved water agrees reasonably well with the prediction by the model of Deubener [J. Deubener, R. Mu¨ ller, H. Behrens, G. Heide, J. Non-Cryst. Solids 330 (2003) 268]. Using water speciation measured by near-infrared spectroscopy we infer that although the effect of OH groups in reducing Tg is larger than that of H2O molecules, the difference in the contribution of both species is smaller than predicted by Deubener et al. (2003). Compared to alkalis and alkaline earth elements the effect of protons on glass fragility is small, mainly because of the relatively low concentration of OH groups (max. 1.5 wt% water dissolved as OH) in the glasses.
Appears in Collections:Article published / in press

Files in This Item:
File Description SizeFormat
1239.pdf644.79 kBAdobe PDFView/Open
Show full item record


checked on Feb 10, 2021

Page view(s) 50

checked on Mar 27, 2023

Download(s) 20

checked on Mar 27, 2023

Google ScholarTM