Novel isochoric measurement of the onset of vapor–liquid phase transition using differential scanning calorimetry

2018 ◽  
Vol 20 (41) ◽  
pp. 26241-26248 ◽  
Author(s):  
Xingdong Qiu ◽  
Sugata P. Tan ◽  
Morteza Dejam ◽  
Hertanto Adidharma
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Liquid Phase ◽  
Dew Point ◽  
Gas Mixture ◽  
Scanning Calorimetry ◽  
Liquid Phase Transition ◽  
Dsc Method ◽  
Vapor Liquid

Dew point measurements of methane/ethane gas mixture using isochoric DSC method.

scholarly journals Voltammetric monitoring of a solid-liquid phase transition in N,N,N′,N′-tetraoctyl-2,6-diamino-9,10-anthraquinone (TODAQ)

2019 ◽  
Vol 24 (1) ◽  
pp. 11-16
Author(s):  
Sunyhik Ahn ◽  
Thomas R. Forder ◽  
Matthew D. Jones ◽  
Richard A. R. Blackburn ◽  
Paul S. Fordred ◽  
...  
Keyword(s):  
Phase Transition ◽  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Liquid Phase ◽  
Apparent Activation Energy ◽  
Electrode Surface ◽  
Scanning Calorimetry ◽  
Liquid Phase Transition ◽  
Midpoint Potential ◽  
Solid Liquid

AbstractExploratory experiments on effects from a phase transition are reported for a low-melting microcrystalline anthraquinone (N,N,N′,N′-tetraoctyl-2,6-diamino-9,10-anthraquinone or TODAQ). Data for the solid-liquid phase transition are obtained by differential scanning calorimetry and then compared to data obtained by voltammetry. In preliminary electrochemical measurements, microcrystal deposits on a basal plane pyrolytic graphite electrode are shown to undergo a solid-state 2-electron 2-proton reduction in contact to aqueous 0.1 M HClO4 with a midpoint potential Emid,solid = − 0.24 V vs. SCE. The reduction mechanism is proposed to be limited mainly by the triple phase boundary line and some transport of TODAQ molecules towards the electrode surface for both solid and melt. A change in the apparent activation energy for this reduction is observed at 69 °C, leading to an enhanced increase in reduction current with midpoint potential Emid,liquid = − 0.36 V vs. SCE. A change of TODAQ transport along the crystal surface for solid microcrystalline material (for the solid) to diffusion within molten microdroplets (for the liquid) is proposed. Upon cooling, a transition at 60 °C back to a higher apparent activation energy is seen consistent with re-solidification of the molten phase at the electrode surface. Differential scanning calorimetry data for solid TODAQ dry and for TODAQ in contact to aqueous 0.1 M HClO4 confirm these transitions.

Characterization of Main-Chain Liquid Crystal Elastomers by Using Differential Scanning Calorimetry (DSC) Method

2015 ◽  
Vol 1123 ◽  
pp. 69-72 ◽  
Author(s):  
Supardi ◽  
Y. Yusuf ◽  
Harsoyo
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Basic Principle ◽  
Main Chain ◽  
Scanning Calorimetry ◽  
Mechanical Effects ◽  
Liquid Crystal Elastomers ◽  
Dsc Method

We performed an experiment to characterize the four samples of main chain liquid crystal elastomers (MCLCEs) by using differential scanning calorimetry (DSC) method. Basic principle of this method is that difference in the amount of heat required to increase the temperature of the sample and reference is measured as a function of temperature. The temperature between the sample and reference is maintained nearly the same throughout the experiment. There were four samples with different concentrations of crosslinker we have taken, namely 8%, 12%, 14%, and 16%. The results showed that the phase transition from nematic to isotropic obtained by this method had correlation with their thermo-mechanical effects.

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