Research On Hydroxyl Content And Form With“fragility”and Configuration Entropy Evolution Of Oxy-fuel Combustion Float Glass

As the second revolution in the history of the development of glass melting technology,oxy-fuel combustion technology has been receiving attention from various countries,and related research has been conducted on process optimization.Meanwhile,relevant research of performance of oxy-fuel combustion float glass has been carried out,however,the existed research has mainly stayed in macro-performance.For the micro structure of oxy-fuel combustion float glass,such as the influence of hydroxyl content on the "fragility" in glass,the research on the relationship between“fragility" and the configuration entropy with the internal structure of glass,has not been reported.In present work,the soda-calcium-silicon system oxy-combustion float glass as the research object,using infrared spectroscopy to determine the hydroxyl content in the glass,using dynamic thermal mechanical analyzer(DMA)to investigate the mechanism of structural relaxation in float glass by multi-Frequency—Strain(Temperature Ramp)mode and Stress Relaxation TTS mode.The Arrhenius equation was used to fit the activation energy of the float glass,based on analysis means of the configuration entropy loss law and Kohlrausch-Williams-Watts(KWW)equation to gain information of structural "fragility"and configuration entropy in oxy-fuel combustion soda-lime-silica glass.The relationship between different water content or hydroxyl combination mode with "fragility" and configuration entropy is obtained.Combining macroscopic properties of float glass to confirm the influence of hydroxyl content on "fragility" in oxy-fuel combustion float glass.The research observes that ?? relaxation appeared in the float glass above 550?and there was a linear logarithmic relationship between the height of a relaxation peak and the relaxation rate,satisfying ln(?)?-ln(v);?The apparent activation energy(obtained by fitting Arrhenius equation)values for 6 mm oxy-fuel combustion float glass,6 mm air-fuel combustion float glass,3 mm oxy-fuel combustion float glass,3 mm air-fuel combustion float glass are 4.95 eV,6.26 eV,8.42 eV and 8.97 eV,respectively;With water content increased(the ratio of H2O:CO2 atmosphere increased),the activation energy of the atmosphere glass decreases and its values are 4.18 eV(3:1),4.74 eV(2:1),5.82 eV(1:1),and 7.50 eV(air),respectively;?According to the configuration entropy loss law,more disordered internal structure of oxy-fuel combustion float glass compared to air-fuel combustion float glass.Increasing the glass forming time that will cause the internal structure of the glass become more disordered;as well as the disordering effect of the increasing water content in glass(increasing atmosphere ratio)onto the internal structure of glass;?Three stages during the structural relaxation process of float glass can be divided from the temperature dependent curve of non-exponential factor ?kww obtained by KWW equation fitting:(?)Flows units(FU)dominated region;(?)Hidden flow region;(?)Macroscopic flow region;?The glass produced under oxy-fuel combustion has lower water resistance,lower hardness and higher linear thermal expansion coefficient than air-fuel combustion float glass,Increasing the forming time of glass melt,resulting in a decrease in the hardness of the glass,the water resistance decreases and the linear thermal expansion coefficient becomes large;Increasing water content in glass(Increasing the ratio of atmosphere),the glass linear thermal expansion coefficient increases,hardness decreases and the water resistance decreases.