Specific heat anomaly at the glass transition

2002 ◽  
Vol 117 (22) ◽  
pp. 10151-10155 ◽  
Author(s):  
Takashi Odagaki ◽  
Takashi Yoshidome ◽  
Toshiaki Tao ◽  
Akira Yoshimori
Keyword(s):  
Glass Transition ◽  
Specific Heat

Effect of Ag andγ-ray irradiation on the specific heat of glass transition of Se78Te20Sn2glassy alloy

2019 ◽  
Vol 6 (9) ◽  
pp. 095201 ◽  
Author(s):  
Ankita Srivastava ◽  
Neeraj Mehta ◽  
John C MacDonald ◽  
Dipti Sharma
Keyword(s):  
Glass Transition ◽  
Specific Heat

Enthalpy Relaxation Near the Glass Transition of a Supercooled Liquid [Ca(NO 3) 2]0.4[KNO3]0.6

1995 ◽  
Vol 407 ◽  
Author(s):  
I. K. Moon ◽  
Yoon-Hee Jeong
Keyword(s):  
Relaxation Time ◽  
Glass Transition ◽  
Specific Heat ◽  
Transition Region ◽  
Exponential Function ◽  
Supercooled Liquid ◽  
Frequency Range ◽  
Slow Dynamics ◽  
Glass Transition Region ◽  
Equilibrium Dynamics

ABSTRACTWe have investigated the slow dynamics in the glass transition region of a supercooled liquid [Ca(NO3)2]0.4[KN3]0.6 by measuring the dynamic specific heat in the frequency range from 0.01 Hz to 5 kHz. The equilibrium dynamics of the system in this range is well described by the stretched exponential function, exp[-(t/τ)β], and the Vogel-Fulcher type relaxation time, τ = τ0exp[Δ/(T − T0)].

Thermal Properties of PVP Cryoprotectants With Nanoparticles

2011 ◽  
Vol 2 (2) ◽  
Author(s):  
Baotong Hao ◽  
Baolin Liu
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Aqueous Solutions ◽  
Specific Heat ◽  
Warming Rate ◽  
The Difference ◽  
Transfer Properties

Vitrification is an effective way for the cryopreservation of cells and tissues. The critical cooling rates for vitrification solution are relatively high. It is reported that nanoparticles can improve the heat transfer properties of solutions. To increase the heat transfer coefficient of aqueous cryoprotectant solutions, Hydroxyapatite (HA) nanoparticles were added into Polyvinylpyrrolidone (PVP) solutions (50%, 55%, and 60%, w/w). The glass-transition temperature, devitrification temperature, and specific heat of PVP aqueous solutions with/without HA nanoparticles (0.1%, 0.5%, and 1%, w/w) were measured by a differential scanning calorimeter at a cooling rate of 20°C/min and a warming rate of 10°C/min. The change in density of the above solutions with temperature was determined by using a straw that can reveal the volume change of solutions. The thermal conductivity was calculated based on the experimental data. A device that can be used to measure the thermal conductivity of vitrification solutions with/without nanoparticles was developed in this study. The results showed that the glass-transition temperature, devitrification temperature, and specific heat of PVP aqueous solutions with HA nanoparticles are larger than those without HA nanoparticles. The thermal conductivity of solutions with HA nanoparticles is larger than those without HA nanoparticles at a specific temperature. The lower the temperature, the smaller the difference in thermal conductivity between the solutions with and without HA nanoparticles. The calculated thermal conductivity meets the measured data well.

Specific-Heat Spectroscopy of the Glass Transition

1985 ◽  
Vol 54 (25) ◽  
pp. 2674-2677 ◽  
Author(s):  
Norman O. Birge ◽  
Sidney R. Nagel
Keyword(s):  
Glass Transition ◽  
Specific Heat ◽  
Specific Heat Spectroscopy

Thermal Properties of PVP Cryoprotectants With Nanoparticles

2009 ◽  
Author(s):  
Baotong Hao ◽  
Baolin Liu ◽  
Senjie Rong ◽  
Yan Zhou ◽  
Zhixin Gao
Keyword(s):  
Thermal Conductivity ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Aqueous Solutions ◽  
Specific Heat ◽  
Warming Rate ◽  
Specific Temperature ◽  
The Difference ◽  
The Heat Transfer Coefficient

Vitrification is an effective way for the cryopreservation of cells and tissues. The critical cooling rates for vitrification solution are relatively high. It is reported that nanoparticles can improve the heat tranfer properties of solutions. To increase the heat transfer coefficient of aqueous cryoprotectant solutions, HA nanoparticles were added into PVP solutions (50%, 55%, 60%, w/w). The glass transition temperature, devitrification temperature and specific heat of PVP aqueous solutions with/without HA nanoparticles (0.1%, 0.5% and 1%, w/w) were measured by differential scanning calorimeter (DSC) at the cooling rate of 20°C/min and warming rate of 10°C/min. The change of density of above solutions with temperature was determined by using a straw that can reveal the volume change of solutions. The thermal conductivity was calculated based on the experimental data. A device that can be used to measure the thermal conductivity of vitrification solutions with/without nanoparticles was developed in this study. The results showed that the glass transition temperature, devitrification temperature and specific heat of PVP aqueous solutions with HA nanoparticles are larger than that without HA nanoparticles. The thermal conductivity of solutions with HA nanoparticles is larger than that without HA nanoparticles at a specific temperature. The lower the temperature, the smaller the difference of thermal conductivity between solutions with and without HA nanoparticles. The calculated thermal conductivity meets the measured data well.

Specific heat peculiarities at the glass transition of binary polymeric systems

1994 ◽  
Vol 15 (11) ◽  
pp. 887-892 ◽  
Author(s):  
Maria Cristina Righetti ◽  
Giuseppe Ajroldi ◽  
Giovanni Pezzin
Keyword(s):  
Glass Transition ◽  
Specific Heat ◽  
Polymeric Systems

Some Properties of the Glass Transition in the Amorphous Sb-As-S-Se-I System

2007 ◽  
Vol 555 ◽  
pp. 165-170
Author(s):  
F. Skuban ◽  
S.R. Lukić ◽  
D.M. Petrović ◽  
Mirjana Šiljegović
Keyword(s):  
Activation Energy ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Specific Heat ◽  
Heating Rate ◽  
Glass Composition ◽  
Transition Process ◽  
Abrupt Increase ◽  
Pseudobinary System

Transformations of glasses from the multicomponent pseudobinary system (As2Se3)100−x(SbSI)x were analyzed from the aspect of determining the glass transition temperature Tg, activation energy of the process Et, and characteristic changes of the specific heat. The established dependence of Tg on glass composition and heating rate served as the basis for determining the activation energy of glass transition process Et. An abrupt increase in the specific heat cp at the glass transition temperature was analyzed with the aim of classifying the materials according to the criterion of the so-called 'fragility'. It was found that the investigated glasses, i.e. their melts, belong to the group of thermodynamically 'strong' melts.

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