کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
674253 1459552 2012 4 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Structural and vibrational relaxations at spontaneous aging in glass
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
پیش نمایش صفحه اول مقاله
Structural and vibrational relaxations at spontaneous aging in glass
چکیده انگلیسی

The entropy change of intermediate-range orders (IROs) through the glass transition is discussed on the basis of the theories developed by Adam–Gibbs and Prigogine. It is estimated that the time dependence of the configurational entropy of glass is zero, but that of its vibrational entropy shows a constant decrease with the smallest change, while maintaining a constant fictive temperature and an isostructural state. It is shown that the spontaneous aging of well annealed glass shows a vibrational relaxation with a long relaxation time, while the annealing and physical aging of glass show a structural relaxation with a short relaxation time. The results indicate that the volume of glass decreases at a constant time rate through spontaneous aging at a constant temperature. It is emphasized that the existence of the constant configurational entropy below the glass transition temperature is the basic feature of glass forming. The nanoorder-size of the IROs in glass determines the residual entropy. The time symmetry in glass is spontaneously violated. The glass transition is a nano-emergence through the abrupt decrease in the fluctuations in the supercooled liquid state.


► The glass transition is a self-organization of intermediate-range orders.
► The glass transition is a nano-emergence through the decrease of fluctuations.
► Glass is the 4th state after gas, liquid and crystal.
► The time symmetry in glass is spontaneously violated.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Thermochimica Acta - Volume 532, 20 March 2012, Pages 172–175
نویسندگان
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