Realizing high thermoelectric performance in GeTe through decreasing the phase transition temperature via entropy engineering

2019 ◽  
Vol 7 (46) ◽  
pp. 26393-26401 ◽  
Author(s):  
Yuting Qiu ◽  
Yang Jin ◽  
Dongyang Wang ◽  
Mengjia Guan ◽  
Wenke He ◽  
...  
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Transition Temperature ◽  
Phase Transition Temperature ◽  
Thermoelectric Performance

Entropy engineering is one of the powerful approaches to suppress phase transitions.

scholarly journals The Effect of Selected Anions on Dipalmitoylphosphatidylcholine Phase Transitions

2002 ◽  
Vol 57 (7-8) ◽  
pp. 712-716 ◽  
Author(s):  
Adriana Przyczyna ◽  
Bożenna Różycka-Roszk ◽  
Marek Langner
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Transition Temperature ◽  
Phase Transition Temperature ◽  
Salt Concentration ◽  
Half Width ◽  
Main Phase ◽  
Interface Properties ◽  
Transition Enthalpy ◽  
Peak Half Width

The effect of three anions, Cl-, Br- and I-, on the phase transitions of dipalmitoylphosphatidylcholine (DPPC) was measured. Main phase transition was modestly affected by these anions in the salt concentration range 0.2 M. For Cl- and Br- the temperature of main phase transition was lower (by about 0.5 °C), its half-width modestly larger and enthalpy practically unchanged, all three parameters were altered to a much larger degree. Main phase transition temperature was 1.5 °C lower and the peak half-width significantly smaller. These changes were not accompanied by any alteration in main phase transition enthalpy. Iodide shifted the pretransition temperature toward lower values and increased its half-width to such an extent that at concentrations above 100 mm it was practically undetectable. Besides cations, the presence of anions also has a distinct effect on lipid bilayer interface properties.

scholarly journals Stabilization of model membranes during drying by compatible solutes involved in the stress tolerance of plants and microorganisms

2004 ◽  
Vol 383 (2) ◽  
pp. 277-283 ◽  
Author(s):  
Dirk K. HINCHA ◽  
Martin HAGEMANN
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Transition Temperature ◽  
Phase Transition Temperature ◽  
Membrane Lipids ◽  
Compatible Solutes ◽  
Stress Conditions ◽  
Lipid Phase ◽  
Cellular Protection ◽  
Solute Leakage

Many organisms accumulate compatible solutes under environmental stress conditions. Cyanobacteria accumulate compatible solutes in response to increased external salinity, with tolerance increasing from Suc (sucrose) or trehalose to 2-O-(α-D-glucopyranosyl)-glycerol and glycinebetaine accumulating species. It is not clear how these different solutes influence salt tolerance. One possible explanation may be a differential ability of these solutes to stabilize membranes under stress conditions. We therefore performed drying experiments with liposomes in the presence of compatible solutes. Suc, trehalose and sorbitol protected liposomes from leakage of a soluble marker and from membrane fusion during drying and rehydration. 2-O-(α-D-glucopyranosyl)-glycerol was less effective and glycinebetaine showed hardly any effect. In combination with Suc, the latter two solutes showed improved protection. Lipid-phase transitions are known to contribute to solute leakage from liposomes. We determined phase transitions in dry membranes in the absence or presence of the solutes, using Fourier-transform infrared spectroscopy. The ability of the solutes to decrease the phase transition temperature corresponded closely to their ability to protect the liposomes against solute leakage. All solutes interacted with the phosphate in the lipid headgroups. The magnitude of the shift in the asymmetric P=O stretching vibration correlated closely with the lipid-phase transition temperature. This indicates that the degree of membrane protection afforded by the solutes is mainly determined by their ability to interact with the membrane lipids. However, this is not a determinant of cellular protection against salt stress, as the solutes show a reverse order when ranked with regard to protection against these stresses.

POSS solid solutions exhibiting orientationally disordered phase transitions

2017 ◽  
Vol 53 (66) ◽  
pp. 9273-9276 ◽  
Author(s):  
Satoshi Morimoto ◽  
Hiroaki Imoto ◽  
Kensuke Naka
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Transition Temperature ◽  
Phase Transition Temperature ◽  
Solid Solutions ◽  
Single Phase ◽  
Disordered Phase

A mixture of two different monofunctionalized heptaisobutyl-substituted octasilsesquioxanes formed solid solutions showing a single phase-transition temperature, which exhibited orientationally disordered (OD) phases.

Phase transition metal–crown ether coordination compounds tuned by metal ions

2016 ◽  
Vol 45 (3) ◽  
pp. 1000-1006 ◽  
Author(s):  
Qiong Ye ◽  
Hui-Ting Wang ◽  
Lin Zhou ◽  
Li-Hui Kong ◽  
Heng-Yun Ye ◽  
...  
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Transition Temperature ◽  
Transition Metal ◽  
Crown Ether ◽  
Metal Ions ◽  
Phase Transition Temperature ◽  
Coordination Compounds ◽  
Room Temperature ◽  
Metal Center

(15-Crown-5)(BiCl3) and (15-crown-5)(SbCl3) are discovered to show phase transitions above room temperature, where the phase transition temperature relates to the metal center.

Kinetic condition driven phase and vacancy enhancing thermoelectric performance of low-cost and eco-friendly Cu2−xS

2019 ◽  
Vol 7 (18) ◽  
pp. 5366-5373 ◽  
Author(s):  
Wei-Di Liu ◽  
Xiao-Lei Shi ◽  
Han Gao ◽  
Raza Moshwan ◽  
Sheng-Duo Xu ◽  
...  
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Phase Transition Temperature ◽  
Hole Concentration ◽  
Low Cost ◽  
Thermoelectric Performance ◽  
Kinetic Condition

Cu2−xS pellets sintered from powders synthesized with different NaOH amounts have different phase compositions and average Cu vacancy levels. This has subsequently led to enhanced thermoelectric performance due to both enhanced hole concentration and reduced phase transition temperature.

scholarly journals DSC Investigations of the Phase Transitions of [M(NH3 )6](ClO4)2 and [M(NH3)6](BF4)2 , where M = Co and Cd

1999 ◽  
Vol 54 (10-11) ◽  
pp. 590-594 ◽  
Author(s):  
A. Migdał-Mikuli ◽  
E. Mikuli ◽  
S. Wróbel ◽  
Ł. Hetmańczyk
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Transition Temperature ◽  
Phase Transition Temperature ◽  
Lattice Parameter ◽  
Crystal Lattice Parameter ◽  
Two Phase ◽  
Enthalpy And Entropy Changes ◽  
Enthalpy And Entropy ◽  
Good Agreement

Solid polymorphism of four compounds of the type [M(NH3)6](XY4)2 , where M = Co2+ or Cd2+ , and XY4 = ClO4- or BF4- has been studied at 100 -300 K by DSC. One or two phase transitions of the investigated compounds have been found. For the compounds with M = Co the phase transitions have not yet been described in the literature. For the compounds with M = Cd the phase transition-temperature is in good agreement with the results obtained by NMR and EPR. Generally, for [M(NH3)6](BF4)2 compounds (M = Mg, Fe, Co, or Ni) the phase transition temperature TCl is lower than that for the corresponding [M(NH3)6](ClO4)2 , but for compounds with M = Cd it is higher. However, the enthalpy and entropy changes at the TCI phase transitions of [M(NH3)6](BF4)2 are always lower than those for [M(NH3)6](ClO4)2. Moreover, for the compounds of this type a correlation between the transition temperature TCl and the crystal lattice parameter a has been found.

The structure of membranes and membrane proteins embedded in amorphous ice

1992 ◽  
Vol 50 (1) ◽  
pp. 432-433
Author(s):  
Uwe Lücken ◽  
Joachim Jäger
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Membrane Proteins ◽  
Phase Transition Temperature ◽  
Lipid Vesicles ◽  
Freezing Stress ◽  
Amorphous Ice ◽  
Different Temperatures ◽  
Band Pass ◽  
Lipid Polymorphism

TEM imaging of frozen-hydrated lipid vesicles has been done by several groups Thermotrophic and lyotrophic polymorphism has been reported. By using image processing, computer simulation and tilt experiments, we tried to learn about the influence of freezing-stress and defocus artifacts on the lipid polymorphism and fine structure of the bilayer profile. We show integrated membrane proteins do modulate the bilayer structure and the morphology of the vesicles.Phase transitions of DMPC vesicles were visualized after freezing under equilibrium conditions at different temperatures in a controlled-environment vitrification system. Below the main phase transition temperature of 24°C (Fig. 1), vesicles show a facetted appearance due to the quasicrystalline areas. A gradual increase in temperature leads to melting processes with different morphology in the bilayer profile. Far above the phase transition temperature the bilayer profile is still present. In the band-pass-filtered images (Fig. 2) no significant change in the width of the bilayer profile is visible.

Molecular Ordering of a Nematogen at Phase Transition Temperature - A Theoretical Study

2002 ◽  
Vol 75 (4-5) ◽  
pp. 413-421
Author(s):  
Durga Prasad Ojha ◽  
Devesh Kumar ◽  
V.G.K.M. Pisipati
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Phase Transition Temperature ◽  
Theoretical Study ◽  
Molecular Ordering
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