Self-enhancement of CO reversible absorption accompanied by phase transition in protic chlorocuprate ionic liquids for effective CO separation from N2

2019 ◽  
Vol 55 (23) ◽  
pp. 3390-3393 ◽  
Author(s):  
Zhuo-Heng Tu ◽  
Yi-Yang Zhang ◽  
You-Ting Wu ◽  
Xing-Bang Hu
Keyword(s):  
Phase Transition ◽  
Ionic Liquids ◽  
Phase Change ◽  
High Capacity ◽  
Efficient Strategy

An efficient strategy for the high-capacity capture of CO is reported, and a phase change in protic chlorocuprate ionic liquids (PCILs) from liquid to solid is found during CO absorption.

Influence of Metal Substitution on the Pressure-Induced Phase Change in Flexible Zeolitic Imidazolate Frameworks

2018 ◽  
Author(s):  
C. Michael McGuirk ◽  
Tomče Runčevski ◽  
Julia Oktawiec ◽  
Ari Turkiewicz ◽  
mercedes K. taylor ◽  
...  
Keyword(s):  
Phase Change ◽  
Single Crystal ◽  
Gas Adsorption ◽  
High Capacity ◽  
Phase Changes ◽  
Zeolitic Imidazolate Frameworks ◽  
Metal Substitution ◽  
Heat Management ◽  
Metal Organic ◽  
First Time

<p>Metal–organic frameworks that display step-shaped adsorption profiles arising from discrete pressure-induced phase changes are promising materials for applications in both high-capacity gas storage and energy-efficient gas separations. The thorough investigation of such materials through chemical diversification, gas adsorption measurements, and <i>in situ </i>structural characterization is therefore crucial for broadening their utility. We examine a series of isoreticular, flexible zeolitic imidazolate frameworks (ZIFs) of the type M(bim)<sub>2</sub> (SOD; M = Zn<sup> </sup>(ZIF-7), Co (ZIF-9), Cd (CdIF-13); bim<sup>–</sup> = benzimidazolate), and elucidate the effects of metal substitution on the pressure-responsive phase changes and the resulting CO<sub>2</sub> and CH<sub>4</sub> step positions, pre-step uptakes, and step capacities. Using ZIF-7 as a benchmark, we reexamine the poorly understood structural transition responsible for its adsorption steps and, through high-pressure adsorption measurements, verify that it displays a step in its CH<sub>4 </sub>adsorption isotherms. The ZIF-9 material is shown to undergo an analogous phase change, yielding adsorption steps for CO<sub>2</sub> and CH<sub>4</sub> with similar profiles and capacities to ZIF-7, but with shifted threshold pressures. Further, the Cd<sup>2+</sup> analogue CdIF-13 is reported here for the first time, and shown to display adsorption behavior distinct from both ZIF-7 and ZIF-9, with negligible pre-step adsorption, a ~50% increase in CO<sub>2</sub> and CH<sub>4</sub> capacity, and dramatically higher threshold adsorption pressures. Remarkably, a single-crystal-to-single-crystal phase change to a pore-gated phase is also achieved with CdIF-13, providing insight into the phase change that yields step-shaped adsorption in these flexible ZIFs. Finally, we show that the endothermic phase change of these frameworks provides intrinsic heat management during gas adsorption. </p>

Temperature Effect on the Two-Dimensional Phase Transition Kinetics of Adenine Adsorbed at the Hg Electrode/Aqueous Solution Interface

2003 ◽  
Vol 68 (8) ◽  
pp. 1407-1419 ◽  
Author(s):  
Claudio Fontanesi ◽  
Roberto Andreoli ◽  
Luca Benedetti ◽  
Roberto Giovanardi ◽  
Paolo Ferrarini
Keyword(s):  
Phase Transition ◽  
Aqueous Solution ◽  
Phase Change ◽  
Temperature Effect ◽  
Transition Rate ◽  
Effect Of Temperature ◽  
Two Dimensional ◽  
Solution Interface ◽  
Phase Transition Kinetics ◽  
Kinetics Of

The kinetics of the liquid-like → solid-like 2D phase transition of adenine adsorbed at the Hg/aqueous solution interface is studied. Attention is focused on the effect of temperature on the rate of phase change; an increase in temperature is found to cause a decrease of transition rate.

scholarly journals Combining Switchable Phase‐Change Materials and Phase‐Transition Materials for Thermally Regulated Smart Mid‐Infrared Modulators

2021 ◽  
pp. 2100417
Author(s):  
Xinrui Lyu ◽  
Andreas Heßler ◽  
Xiao Wang ◽  
Yunzhen Cao ◽  
Lixin Song ◽  
...  
Keyword(s):  
Phase Transition ◽  
Phase Change ◽  
Phase Change Materials ◽  
Mid Infrared

Sunlight-Activated Phase Change Materials for Controlled Heat Storage and Triggered Release

2021 ◽  
Author(s):  
Yuran Shi ◽  
Mihael Gerkman ◽  
Qianfeng Qiu ◽  
Shuren Zhang ◽  
Grace G. D. Han
Keyword(s):  
Phase Transition ◽  
Solar Radiation ◽  
Phase Change ◽  
Latent Heat ◽  
Photon Energy ◽  
Organic Phase ◽  
Phase Change Materials ◽  
Heat Storage ◽  
Triggered Release

We report the design of photo-responsive organic phase change materials that can absorb filtered solar radiation to store both latent heat and photon energy via simultaneous phase transition and photo-isomerization....

Preparation of PVA/PEG Phase Change Composite Nanofibers by Electrospinning

2011 ◽  
Vol 306-307 ◽  
pp. 37-40 ◽  
Author(s):  
Da Hui Sun ◽  
Tian Yu Xu ◽  
Yong Jia Liu ◽  
Mei Zhang
Keyword(s):  
Phase Transition ◽  
Phase Change ◽  
Composite Nanofibers ◽  
Diameter Distribution ◽  
Weight Percentage ◽  
Weight Content ◽  
Reversible Phase Transition ◽  
Change Characteristics ◽  
Micro Morphology ◽  
Reversible Phase

Phase change PVA / PEG composite nanofibers were prepared by electrospinning, micro-morphology of PVA / PEG fibers with different weight content were analyzed, the phase change characteristics were also analyzed. The result showed that well distributed composite nanofibers which composed by PVA/PEG blend solution can be obtained by electrospinning.PVA fibreforming were influenced because of the existence of PEG, including bond, irregular block, small rough, uneven diameter distribution in fibers. PVA/PEG blend solution of 4:6 weight content was well fibreforming compared with other different weight content.The continuity of spinneret flow in electrospinning would directly affected by polymer solution consentrition and viscosity. Further research about which and the influence in fibers diameter and morphology will be explored. Composite nanofibers possessed reversible phase transition characteristics,Tm Essentially unchanged ,Tcwere related to the weight percentage of PEG/PVA, at the same time, the enthalpy will increase along with the gradually increase in weight percentage of PEG.

Solidification of Ionic Liquids: Theory and Techniques

2010 ◽  
Vol 63 (4) ◽  
pp. 544 ◽  
Author(s):  
Anja-Verena Mudring
Keyword(s):  
Phase Transition ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Solid Phase ◽  
Soft Materials ◽  
Separation Science ◽  
Vast Number ◽  
Plastic Crystals ◽  
Thermal Fluids ◽  
Solid Phase Transition

Ionic liquids (ILs) have become an important class of solvents and soft materials over the past decades. Despite being salts built by discrete cations and anions, many of them are liquid at room temperature and below. They have been used in a wide variety of applications such as electrochemistry, separation science, chemical synthesis and catalysis, for breaking azeotropes, as thermal fluids, lubricants and additives, for gas storage, for cellulose processing, and photovoltaics. It has been realized that the true advantage of ILs is their modular character. Each specific cation–anion combination is characterized by a unique, characteristic set of chemical and physical properties. Although ILs have been known for roughly a century, they are still a novel class of compounds to exploit due to the vast number of possible ion combinations and one fundamental question remains still inadequately answered: why do certain salts like ILs have such a low melting point and do not crystallize readily? This Review aims to give an insight into the liquid–solid phase transition of ILs from the viewpoint of a solid-state chemist and hopes to contribute to a better understanding of this intriguing class of compounds. It will introduce the fundamental theories of liquid–solid-phase transition and crystallization from melt and solution. Aside form the formation of ideal crystals the development of solid phases with disorder and of lower order like plastic crystals and liquid crystals by ionic liquid compounds are addressed. The formation of ionic liquid glasses is discussed and finally practical techniques, strategies and methods for crystallization of ionic liquids are given.

Synthesis and Study of Microcapsules with Beeswax Core and Phenol-Formaldehyde Shell Using the Taguchi Method

2021 ◽  
Vol 7 (1) ◽  
pp. 1
Author(s):  
Tejashree Amberkar ◽  
Prakash Mahanwar
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Taguchi Method ◽  
Phase Change ◽  
Phase Change Material ◽  
Surfactant Concentration ◽  
Phenol Formaldehyde ◽  
Processing Parameters ◽  
Agitation Speed ◽  
Change Material

Phenol-formaldehyde shelled phase change material microcapsules (MPCMs) were fabricated and their processing parameters were analyzed with the Taguchi method. Core to shell ratio, surfactant concentration and speed of mixing are the parameters that were optimized in five levels. The optimized values for the surfactant concentration, core to shell ratio and agitation speed were 3%, 1:1 and 800 rpm, respectively. The obtained microcapsules were spherical in shape. The melting enthalpy of the MPCMs synthesized with optimized processing parameters was 148.93 J/g in 35–62 °C. The obtained temperature range of phase transition temperature can be used for storing different food articles such as chocolate and hot served foods.

scholarly journals The Effect of Channel Length on Phase Transition of Phase Change Memory

2018 ◽  
Vol 7 (3.11) ◽  
pp. 25
Author(s):  
M S. A.Aziz ◽  
F H. M.Fauzi ◽  
Z Mohamad ◽  
R I. Alip
Keyword(s):  
Phase Transition ◽  
Silicon Carbide ◽  
Phase Change ◽  
Pulse Width ◽  
Crystalline State ◽  
Phase Change Memory ◽  
Amorphous State ◽  
Channel Length ◽  
Change Memory

The phase transition of germanium antimony tellurium (GST) and the temperature of GST were investigated using COMSOL Multiphysic 5.0 software. Silicon carbide was using as a heater layer in the separate heater structure of PCM. These simulations have a different channel of SiC. The temperature of GST and the phase transition of GST can be obtained from the simulation. From the simulation, the 300 nm channel of SiC can change the GST from amorphous to crystalline state at 0.7V with 100 ns pulse width. The 800 nm channel of SiC can change the GST from amorphous to crystalline state at 1.1V with 100 ns pulse width. Results demonstrated that the channel of SIC can affecting the temperature of GST and the GST changes from amorphous state to crystalline state. As the channel of SiC decreased, the temperature of GST was increased and the GST was change to crystalline state quickly.  

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