Room molten salt

In austempering the article is quenched to the desired temperature in the lower bainite region, usually in molten salt, and kept at this temperature until transformation is complete (Fig. 22). Usually, the piece is held twice as long as the period indicated by the isothermal transformation diagram. The article may then be quenched or air-cooled to room temperature after transformation is complete, and may be tempered to lower hardness if desired. 

As in die case of die diffusion properties, die viscous properties of die molten salts and slags, which play an important role in die movement of bulk phases, are also very stiiicture-seiisitive, and will be refeiTed to in specific examples. For example, die viscosity of liquid silicates are in die range 1-100 poise. The viscosities of molten metals are very similar from one metal to anodier, but die numerical value is usually in die range 1-10 centipoise. This range should be compared widi die familiar case of water at room temperature, which has a viscosity of one centipoise. An empirical relationship which has been proposed for die temperature dependence of die viscosity of liquids as an AiTlienius expression is... 

There are many synonyms used for ionic liquids, which can complicate a literature search. Molten salts is the most common and most broadly applied term for ionic compounds in the liquid state. Unfortunately, the term ionic liquid was also used to mean molten salt long before there was much literature on low-melting salts. It may seem that the difference between ionic liquids and molten salts is just a matter of degree (literally) however the practical differences are sufficient to justify a separately identified niche for the salts that are liquid around room temperature. That is, in practice the ionic liquids may usually be handled like ordinary solvents. There are also some fundamental features of ionic liquids, such as strong... 

What constitutes an ionic liquid, as distinct from a molten salt It is generally accepted that ionic liquids have relatively low melting points, ideally below ambient temperature [1, 2]. The distinction is arbitrarily based on the salt exhibiting liquidity at or below a given temperature, often conveniently taken to be 100 °C. However, it is clear from observation that the principle distinction between the materials of interest today as ionic liquids (and more as specifically room-temperature ionic liquids) and conventional molten salts is that ionic liquids contain organic cations rather than inorganic ones. This allows a convenient differentiation without concern that some molten salts may have lower melting points than some ionic liquids . 

The early history of ionic liquid research was dominated by their application as electrochemical solvents. One of the first recognized uses of ionic liquids was as a solvent system for the room-temperature electrodeposition of aluminium [1]. In addition, much of the initial development of ionic liquids was focused on their use as electrolytes for battery and capacitor applications. Electrochemical studies in the ionic liquids have until recently been dominated by work in the room-temperature haloaluminate molten salts. This work has been extensively reviewed [2-9]. Development of non-haloaluminate ionic liquids over the past ten years has resulted in an explosion of research in these systems. However, recent reviews have provided only a cursory look at the application of these new ionic liquids as electrochemical solvents [10, 11]. 

So far, there have been few published simulation studies of room-temperature ionic liquids, although a number of groups have started programs in this area. Simulations of molecular liquids have been common for thirty years and have proven important in clarifying our understanding of molecular motion, local stmcture and thermodynamics of neat liquids, solutions and more complex systems at the molecular level [1 ]. There have also been many simulations of molten salts with atomic ions [5]. Room-temperature ionic liquids have polyatomic ions and so combine properties of both molecular liquids and simple molten salts. 

Room-temperature molten salts are a relatively new subgroup of liquid nonaqueous electrolytes. They share their advantages and disadvantages. Unfortunately, until now, no useful room-temperature molten salt based on lithium cations has been available. 

Jeng EGS, Sun IW (1997) Electrochemistry of tellurium (IV) in the basic aluminum chloiide-l-methyl-3-ethylimidazolium chloride room temperature molten salt. J Electrochem Soc 144 2369-2374... 

Data on high-temperature melts are still limited. Conventional methods are difficult to apply because of the high values of thermal conductivity. Other difficulties in measuring molten salts are their corrosiveness, high electrical conductivities, and the necessity of careful preparation. Special care should be taken to exclude convection errors, which are usually the most serious source of errors, even at room temperature. 

Commonly is used a short term ionic liquid instead of room temperature ionic liquid or room temperature molten salt , which makes no distinction between salts liquid at room temperature and those liquid below 100°C. 

Hussey, C. L., The Electrochemistry of Room-Temperature Haloaluminate Molten Salts, in Chemistry of Nonaqueous Solutions, G. Mamantov and A. I. Popov, Editors. 1994, YCH Publishers New York. p. 227. 

Mitchell, J. A., The Electrodeposition of Cobalt, Iron, Antimony and Their Alloys from Acidic Aluminum Chloride 1 -methyl-3-ethylimidazolium Chloride Room-Temperature Molten Salts, Ph.D. Dissertation, 1997, University of Mississippi University, MS. 

Ionic liquids are also sometimes referred to as molten salts, nonaqueous ionic liquids (NAILs) or room temperature ionic liquids, and all of these names are entirely valid. The term molten salt is now used less frequently, and generally... 

Ionic liquids are, quite simply, liquids that are composed entirely of ions. Thus, molten sodium chloride is an ionic liquid a solution of sodium chloride in water (a molecular solvent) is an ionic solution. The term ionic liquids was selected with care, as it is our belief that the more commonly used phrase molten salts (or simply melts) is referential, and invokes a flawed image of these solvents as being high-temperature, corrosive, viscous media (cf. molten cryolite). The reality is that room-temperature ionic liquids can be liquid at temperatures as low as — 96°C, and are typically colorless, fluid, and easily handled. To use the term molten salts to describe these novel systems is as archaic as describing a car as a horseless carriage. Moreover, in the patent and recent academic literature, ionic... 

The term ionic liquid (IL) refers to a class of liquids that are composed solely of ions. It is a synonym of molten salt. Although molten salt imphcitly means a high-temperature hquid that is prepared by melting a crystalline salt, IL includes a new class of ionic compounds that are liquids at the ambient temperature [1]. Thus, IL in a narrow sense often stands for room-temperature ionic liquid (RIL). In the present chapter, IL is used in a broader sense and, if necessary, RIL is used to clarify that it is liquid at the ambient temperature. The history of ILs has aheady been reviewed [2]. 

Thapar R, Rajeshwar K (1983) Mott-Schottky analyses on n- and p-GaAs/room temperature chloroaluminate molten-salt interfaces. Electrochim Acta 28 195-198... 

An ionic liquid (IL) is a substance that is composed entirely of ions, and is a liquid at room temperature. Frequently the ionic liquid consists of organic cations and inorganic anions, although it is not limited to these combinations. While some people have said that the ionic liquid can have a high melting temperature such as in the case of the molten salt form of NaCl, the most commonly held understanding of this term is one that has a melting point of less than 100 °C, more preferably less than 50 °C. For example, many preferred ionic liquids are liquid at room temperature, or less. 

The electrochemistry of Cd(II) was investigated at different electrodes (GC, polycrystalline tungsten, Pt, Ni) in a basic l-ethyl-3-methylimidazolium chloride/tet-rafluoroborate, at room temperature molten salt [312], and in acidic zinc chloride-l-ethyl-3-methylimidazolium [284]. 

Formation of several successive layers of bulk intermetallic compounds has been shown. Also, Lee et al. [480] have detected, during Al UPD, the formation of two alloys on polycrystalline Au electrodes from acidic l-ethyl-3-methylimidazolium chloroaluminate that melt at room temperature. Moreover, in the Al UPD region, fast phase transition between these two intermetallic compounds has been evidenced. Later, the same group of researchers [481] has performed EQCM studies on Al deposition and alloy formation on Au(lll) in ambient temperature molten salts/benzene mixtures. 

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