scholarly journals Stochastic theory for the glassy state. 1. Influence of formation history on the glass transition temperature and equation of state

1992 ◽  
Vol 25 (25) ◽  
pp. 6921-6928 ◽  
Author(s):  
S. Vleeshouwers ◽  
E. Nies
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Equation Of State ◽  
Glassy State ◽  
Stochastic Theory ◽  
Formation History ◽  
State 1

scholarly journals Physical Aging Behavior of a Glassy Polyether

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 954
Author(s):  
Xavier Monnier ◽  
Sara Marina ◽  
Xabier Lopez de Pariza ◽  
Haritz Sardón ◽  
Jaime Martin ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Physical Aging ◽  
Glassy State ◽  
Aging Behavior ◽  
Scanning Calorimetry ◽  
Narrow Temperature Range ◽  
Glass Forming ◽  
Fast Scanning Calorimetry

The present work aims to provide insights on recent findings indicating the presence of multiple equilibration mechanisms in physical aging of glasses. To this aim, we have investigated a glass forming polyether, poly(1-4 cyclohexane di-methanol) (PCDM), by following the evolution of the enthalpic state during physical aging by fast scanning calorimetry (FSC). The main results of our study indicate that physical aging persists at temperatures way below the glass transition temperature and, in a narrow temperature range, is characterized by a two steps evolution of the enthalpic state. Altogether, our results indicate that the simple old-standing view of physical aging as triggered by the α relaxation does not hold true when aging is carried out deep in the glassy state.

Tilted Microlens Fabrication Using Nano-Magnetic Particles

2015 ◽  
Vol 1105 ◽  
pp. 259-263
Author(s):  
Shih Yu Hung ◽  
Yu Ting Hung ◽  
Ming Ho Shen
Keyword(s):  
Magnetic Field ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Magnetic Particles ◽  
Lower Layer ◽  
Glassy State ◽  
Reflow Process ◽  
Photoresist Layer ◽  
Thermal Reflow

Double-layer heterogeneous photoresist method will be used firstly to obtain the round photoresist column with two layers of different photoresists. Since both photoresists are the positive-type, the exposure is only required once. During the thermal reflow processing, the upper photoresist layer (AZ-4620 and nanomagnetic powder mixture) reaches the glass transition temperature, which is transformed from a glassy state into a rubbery state. Since the glass transition temperature of the lower photoresist layer (AZ-5214E) is higher than the temperature of thermal reflow, the lower photoresist layer is still able to maintain its solid state. The lower layer creates a round base during the thermal reflow process, and then subjected to an appropriate magnetic field. The base can not only restrict the bottom shape of the liquid photoresist to a round shape but also prevent the sliding of liquid photoresist during the thermal reflow process, so the tilted microlens array can be obtained. We can vary the strength of magnetic field to control the oblique angle of the tilted microlens.

scholarly journals Oбобщенный кинетический критерий перехода жидкость--стекло

2020 ◽  
Vol 62 (10) ◽  
pp. 1706
Author(s):  
Д.С. Сандитов ◽  
В.В. Мантатов ◽  
С.Ш. Сангадиев
Keyword(s):  
Relaxation Time ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Cooling Rate ◽  
Glassy State ◽  
Fluctuation Volume ◽  
Dimensionless Constant ◽  
Transition Criterion

Using the model of delocalized atoms, a substantiation and generalization of the Schmelzer glass transition criterion is proposed. In contrast to the Bartenev and Volkenstein - Ptitsyn approaches, in the generalized kinetic glass transition criterion, along with the relaxation time and the cooling rate of the melt, the glass transition temperature and an almost universal dimensionless constant appear, which is determined by the fraction of the fluctuation volume frozen at the glass transition temperature. The idea is developed that the liquid goes into a glassy state when its cooling rate q reaches a certain fraction of C_g of the characteristic cooling rate q_g=(T_g/taug), which is closely related to the relaxation time of the structure tau_g at the glass transition temperature T_g.

Glassy State in Plant Cuticles during Growth

1994 ◽  
Vol 49 (3-4) ◽  
pp. 273-275 ◽  
Author(s):  
Patricia Luque ◽  
Antonio Heredia
Keyword(s):  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Tomato Fruit ◽  
Glassy State ◽  
Fruit Growth ◽  
Scanning Calorimetry ◽  
Plant Cuticles ◽  
Second Order Transition

The existence of a glassy state in isolated tomato fruit cuticles was investigated using differential scanning calorimetry. Tomato fruit cuticular membranes showed a glass transition temperature at -30 °C and an additional second order transition temperature near 30 °C. Changes in these temperatures during fruit growth were also studied

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