The Use of Ionic Liquids in Refrigeration

2006 ◽  
Author(s):  
Mihir Sen ◽  
Samuel Paolucci
Keyword(s):  
Ionic Liquids ◽  
Room Temperature ◽  
High Heat ◽  
The Other ◽  
Refrigeration Cycle ◽  
Absorption Refrigeration ◽  
Transfer Coefficients ◽  
High Solubility ◽  
High Heat Capacity ◽  
Thermal And Chemical Stability

Ionic liquids are salts, usually with organic cations and inorganic anions, that are liquid at room temperature. There are a wide variety of ionic liquids that can be synthesized with different properties for different applications. They are generally non-volatile, non-toxic, and non-flammable with high heat capacity, high density, high thermal and chemical stability. We propose its use as an absorbent in an absorption refrigeration cycle. The refrigerant in this case would be a gas such as carbon dioxide. The present work deals with the desirable properties of ionic liquids for this application. For example, the absorbent must have a high solubility, and the heat and mass transfer coefficients of the absorbent-refrigerant solution must be large. The viscosity of the mixture, on the other hand, should not be so large as to make its pumping difficult.

Dynamic Modeling of an Absorption Refrigeration System Using Ionic Liquids

2007 ◽  
Author(s):  
Weihua Cai ◽  
Mihir Sen ◽  
Samuel Paolucci
Keyword(s):  
Ionic Liquids ◽  
High Heat ◽  
Cycle Performance ◽  
Refrigeration Cycle ◽  
Absorption Refrigeration ◽  
Refrigeration System ◽  
High Heat Capacity ◽  
Single Effect ◽  
Absorption Refrigeration System ◽  
Thermal And Chemical Stability

Ionic liquids are generally non-volatile, non-toxic, and nonflammable with high heat capacity, high density, and high thermal and chemical stability. This paper considers their use as absorbents in an absorption refrigeration cycle. A dynamic model of a single-effect absorption refrigeration cycle using ionic liquids as absorbent is developed. Modeling of the cycle performance requires thermodynamic properties which are obtained from an equation of state for the refrigerant-absorbent mixture (solution). The transient response of the cycle is investigated. Some design and operating parameters that affect the cycle performance are identified.

Positronium Formation in Room Temperature Ionic Liquids

2008 ◽  
Vol 607 ◽  
pp. 232-234 ◽  
Author(s):  
Tetsuya Hirade
Keyword(s):  
Ionic Liquids ◽  
Formation Process ◽  
Room Temperature ◽  
The Other ◽  
Room Temperature Ionic Liquids ◽  
Molecular Liquids ◽  
Free Electrons ◽  
Good Tool ◽  
Fast Reactions ◽  
Momentum Correlation

Positron annihilation age-momentum correlation measurements (AMOC) were performed for room temperature ionic liquids (IL) to investigate positronium (Ps) formation process. The solvation time of free electrons in IL is longer than in usual molecular liquids. And hence IL is very useful materials to investigate fast reactions such as Ps formation. On the other hand, Ps formation is a good tool to investigate the dry electrons. The para-Ps annihilation lifetime is about 125ps and then the effect of dry electrons should be seen on the S(t) parameters made by the age-momentum correlation measurements. The slow Ps formation was observed in the room temperature ionic liquids.

scholarly journals Synthesis and investigation of physico-chemical properties of dicationic ionic liquids

2018 ◽  
Vol 5 (12) ◽  
pp. 181230 ◽  
Author(s):  
Yi-Xin Sun ◽  
Ying-Ying Wang ◽  
Bing-Bing Shen ◽  
Bi-Xian Zhang ◽  
Xiao-Mei Hu
Keyword(s):  
Ionic Liquids ◽  
Heterogeneous System ◽  
Room Temperature ◽  
Chemical Properties ◽  
Homogeneous System ◽  
The Other ◽  
Melting Points ◽  
Good Solubility ◽  
Physico Chemical ◽  
Dicationic Ionic Liquids

A series of dicationic ionic liquids (ILs) including [C 4 (MIM) 2 ][PF 6 ] 2 , [C 5 (MIM) 2 ][PF 6 ] 2 , [C 6 (MIM) 2 ][PF 6 ] 2 and [C 4 (PYR) 2 ][PF 6 ] 2 were synthesized. Their thermal stability and melting points were analysed. It was found that dicationic ILs presented important implications in the design of homogeneous and heterogeneous system with water. A homogeneous system of dicationic ILs with water could be formed at a relatively high temperature and then a heterogeneous system was formed when the solution was cooled to a low temperature. The ILs recovered by altering the temperature were obtained in high percentage yields of [C 4 (MIM) 2 ][PF 6 ] 2 (97.6%), [C 5 (MIM) 2 ][PF 6 ] 2 (97.3%), [C 6 (MIM) 2 ][PF 6 ] 2 (98.0%) and [C 4 (PYR) 2 ][PF 6 ] 2 (94.2%). On the other hand, [C 4 (MIM) 2 ][PF 6 ] 2 and [C 5 (MIM) 2 ][PF 6 ] 2 exhibited good solubility in acetonitrile and acetone. A homogeneous system could be achieved with imidazolium-based ILs with a relatively low amount of water and acetonitrile at room temperature. All of the properties of dicationic ILs have a strong correlation with the nature of dications, the linkage chain and the symmetry of dications. Dicationic ILs may provide a new opportunity for some specific applications in order to enable the effective separation and isolation of products.

Green synthesis of methadone in eutectic solvent

2021 ◽  
pp. 1-12
Author(s):  
Robab Golzadeh ◽  
Mehrdad Mahkam ◽  
Ebrahim Rezaii ◽  
Leila Nazmi Miardan
Keyword(s):  
Hydrogen Bonding ◽  
Choline Chloride ◽  
The Other ◽  
Magnesium Bromide ◽  
Green Solvents ◽  
High Solubility ◽  
Partial Vapor Pressure ◽  
Ethyl Magnesium Bromide ◽  
New Generation ◽  
Thermal And Chemical Stability

Eutectic solvents (DES), have attracted much attention in the last decade. With the advantages of nonflammability, thermal and chemical stability, high solubility and partial vapor pressure, non-toxicity and reasonable prices, these solvents are suggested as useful solvents. On the other hand, the eutectic solvents developed by Abbott are the new generation of ionic liquids. The mixture of eutectics is from an ammonium salt and a hydrogen bonding compound such as urea, acid, amine, and non-toxic amines. Choline chloride and urea, are quite environmentally friendly and are known practically as green solvents. The purpose of the present research is to present the synthesis of diphenyl acetonitrile with 1-dimethylamino-2-chloropropane by a eutectic’s solvent. In addition, methadone is synthesized from the reaction of 2,2-Diphenyl-4-dimethylaminovaleronitrile with ethyl magnesium bromide in the presence of solvent eutectic, which is in optimal and environmentally compatible conditions and by principles of green chemistry.

Modification of the photophysics of 3-hydroxyflavone in aqueous solutions of imidazolium-based room temperature ionic liquids: a comparison between micelle-forming and non micelle-forming ionic liquids

RSC Advances ◽  
2015 ◽  
Vol 5 (61) ◽  
pp. 49054-49061 ◽  
Author(s):  
Saptarshi Ghosh ◽  
Nitin Chattopadhyay
Keyword(s):  
Ionic Liquids ◽  
Aqueous Solutions ◽  
Room Temperature ◽  
The Other ◽  
Room Temperature Ionic Liquids

Fluorometric techniques have been exploited to study the photophysical behaviour of an ESIPT probe, 3HF, in two imidazolium-based room temperature ionic liquids, one micelle-forming and the other non micelle-forming.

scholarly journals Dissolution of Chitin in Deep Eutectic Solvents Composed of Imidazolium Ionic Liquids and Thiourea

2019 ◽  
Vol 3 (4) ◽  
pp. 90 ◽  
Author(s):  
Satoshi Idenoue ◽  
Kazuya Yamamoto ◽  
Jun-ichi Kadokawa
Keyword(s):  
Hydrogen Bond ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Room Temperature ◽  
Ccd Camera ◽  
Deep Eutectic Solvents ◽  
The Other ◽  
Imidazolium Ionic Liquids ◽  
Eutectic Mixtures ◽  
Organic Resource

Chitin is an abundant organic resource but shows poor solubility, leading to difficulty in utilization as materials. We have already reported that an ionic liquid (IL), 1-allyl-3-methylimidazolium bromide, dissolves chitin at concentrations up to ca. 5 wt %. However, the color of the resulting solution is blackened, mainly owing to the presence of bromide. On the other hand, some deep eutectic solvents (DESs) have been already reported to dissolve chitin. In this study, we found that DESs composed of imidazolium ILs and thiourea dissolved chitin without obvious coloring. DESs are systems formed from eutectic mixtures of hydrogen bond accepters and donors. We first prepared DESs by heating mixtures of imidazolium ILs with thiourea at 100 °C for 30 min with stirring. Predetermined amounts of chitin were then added to the DESs, and for the dissolution, the mixtures were left standing at room temperature for 24 h, followed by heating at 100 °C for 24 h with stirring. The dissolution processes were evaluated by CCD camera views, which revealed in most cases the dissolution of chitin at 2–5 wt % concentrations with the present DESs.

Electron microscope studies of the plastic deformation of ternary alloys based on GaAs

1990 ◽  
Vol 48 (4) ◽  
pp. 1120-1120
Author(s):  
R. Haswell ◽  
U. Bangert ◽  
P. Charsley
Keyword(s):  
Plastic Deformation ◽  
Electron Microscope ◽  
Room Temperature ◽  
Stacking Faults ◽  
The Other ◽  
Ternary Alloys ◽  
Dislocation Mobility ◽  
Semiconducting Materials ◽  
Micro Indentation

A knowledge of the behaviour of dislocations in semiconducting materials is essential to the understanding of devices which use them . This work is concerned with dislocations in alloys related to the semiconductor GaAs . Previous work on GaAs has shown that microtwinning occurs on one of the <110> rosette arms after indentation in preference to the other . We have shown that the effect of replacing some of the Ga atoms by Al results in microtwinning in both of the rosette arms.In the work to be reported dislocations in specimens of different compositions of Gax Al(1-x) As and Gax In(1-x) As have been studied by using micro indentation on a (001) face at room temperature . A range of electron microscope techniques have been used to investigate the type of dislocations and stacking faults/microtwins in the rosette arms , which are parallel to the [110] and [10] , as a function of composition for both alloys . Under certain conditions microtwinning occurs in both directions . This will be discussed in terms of the dislocation mobility.

HAYNES STELLITE ALLOY No. 98M2

Alloy Digest ◽  
1960 ◽  
Vol 9 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
Compressive Strength ◽  
Physical Properties ◽  
Room Temperature ◽  
Base Alloy ◽  
Heat Treating ◽  
The Other ◽  
Stellite Alloy ◽  
Cobalt Base Alloy ◽  
Cobalt Base

Abstract HAYNES STELLITE 98M2 Alloy is a cobalt-base alloy having higher compressive strength and higher hardness than all the other cobalt-base alloys at room temperature and in the red heat range. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive strength as well as fracture toughness. It also includes information on heat treating, machining, and joining. Filing Code: Co-22. Producer or source: Haynes Stellite Company.

Modeling mass transfer and substrate utilization in the boundary layer of biofilm systems

1998 ◽  
Vol 37 (4-5) ◽  
pp. 139-147 ◽  
Author(s):  
Harald Horn ◽  
Dietmar C. Hempel
Keyword(s):  
Boundary Layer ◽  
Mass Transfer ◽  
Reynolds Number ◽  
Film Theory ◽  
Substrate Utilization ◽  
The Other ◽  
Concentration Profiles ◽  
Hydrodynamic Conditions ◽  
Time Axis ◽  
Transfer Coefficients

The use of microelectrodes in biofilm research allows a better understanding of intrinsic biofilm processes. Little is known about mass transfer and substrate utilization in the boundary layer of biofilm systems. One possible description of mass transfer can be obtained by mass transfer coefficients, both on the basis of the stagnant film theory or with the Sherwood number. This approach is rather formal and not quite correct when the heterogeneity of the biofilm surface structure is taken into account. It could be shown that substrate loading is a major factor in the description of the development of the density. On the other hand, the time axis is an important factor which has to be considered when concentration profiles in biofilm systems are discussed. Finally, hydrodynamic conditions become important for the development of the biofilm surface when the Reynolds number increases above the range of 3000-4000.

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