论文标题
解释玻璃过渡的明显激活能
Interpretation of the apparent activation energy of glass transition
论文作者
论文摘要
玻璃粘度的温度依赖性是玻璃研究领域的主要问题。与Arrhenius法的强烈偏差使对激活能量的解释变得难以解释。在本研究中，对明显的激活能的合理解释沿着与固态物理和化学中采用的相似的线条相似。与广泛认为的观点相反，玻璃中的相位过渡发生在参考温度$ t_ {0} $根据Vogel-Fulcher--Tammann公式，在目前的工作中，在玻璃转换温度$ t_ {g} $上观察到的过渡被认为是从液体到实心相的相变。玻璃的一个独特特征是，宽度$ΔT_{g} $的过渡范围内的能屏障显着变化。能量屏障的这种变化改变了表观激活能量构成Arrhenius形式的方式。对现有实验数据的分析表明，实际能屏障明显小于明显的激活能，重要的是，所获得的值在化学键期望的合理能量范围内。对明显激活能量的高估取决于$ t_ {g}/Δt_{g} $的比率，这解释了存在两种类型的玻璃杯的存在。从高温接近$ t_ {g} $时，脆弱性可以重新解释，以表明能量屏障的增加程度。由于在$ t_ {g} $以下没有观察到粘度的差异，因此不太可能在$ t_ {0} $处发生过渡。
The temperature dependence of the viscosity of glass is a major concern in the field of glass research. Strong deviations from the Arrhenius law make the interpretation of the activation energy difficult. In the present study, a reasonable interpretation of the apparent activation energy is demonstrated along similar lines as those adopted in solid-state physics and chemistry. In contrast to the widely held view that phase transition in glass occurs at the reference temperature $T_{0}$ according to the Vogel--Fulcher--Tammann formula, in the present work the transition observed at the glass-transition temperature $T_{g}$ is regarded as a phase transition from the liquid to solid phases. A distinct feature of glass is that the energy barrier significantly changes in the transition range with width $ΔT_{g}$. This change in the energy barrier alters the manner in which the apparent activation energy constitutes the Arrhenius form. Analysis of available experimental data showed that the actual energy barrier is significantly smaller than the apparent activation energy, and importantly, the values obtained were in the reasonable range of energy expected for chemical bonds. The overestimation of the apparent activation energy depends on the ratio $T_{g}/ΔT_{g}$, which explains the existence of two types of glasses strong and fragile glasses. The fragility can be re-interpreted as an indication of the degree of increase in the energy barrier when approaching $T_{g}$ from high temperatures. Since no divergence in viscosity was observed below $T_{g}$, it is unlikely that a transition occurs at $T_{0}$.
