Salt synthesis ionic conductivity

A chemical cross-hnking of MEEP was obtained by Shriver [606] by using polyethylene glycol (PEG) dialkoxide, which also forms polymer salt complexes. The cross-linked polymers were prepared by substituting a part (1 and 10 mole%) of the methoxyethoxyethoxy ethanol by PEG in the synthesis of MEEP. Contrary to the MEEP, the amorphous polymers obtained do not flow and are stable even at 140 °C. The maximum ionic conductivity at 30 °C, obtained after complexation with liSOjCFj, are 4.1x10" S cm for MEEP/PEG 1% complexed with 6.4 wt% salt and 3x10" S cm for MEEP/PEG 10% com-plexed with 8.9 wt% salt. These values are comparable with those obtained with the parent hnear polyphosphazenes. 

Although the use of these molten salts is hampered by their instability in air and water, and this instability may also be reflected in the resultant polymer films, it is important to note that much of this earlier work clearly identifies a number of the potential benefits of using ionic liquids for the synthesis of conducting polymers. 

Yoshizawa M. Ohno H. (2001). Synthesis of molten salt-typ)e polymer brush and effect of brush structure on the ionic conductivity, Electrochimka Acta, vol.46, n°10-ll, pp.1723-1728, (March 2001), ISSN 0013-4686... 

Harris and coworkers reported the synthesis of the monomer 4,4 -(l,4-phenylene)bis(2,6-diphenyl-pyrybum tetrafluoroborate) 41 and a novel class of high molecular weight poly(pyridinium tetrafluoroborate)s 42 salts (PPS) (Scheme 16). These phenylated heterocycUc polymers are well known for their excellent solubility in otganic solvents, film-forming abibty, thermal stability, ionic conductivity, ion-exchange membrane formation, and chemical stability. 

Measurement of Ionic Conductivity. The synthesis of solvent-free metal salt complexes of polyethylene oxides prompted detailed electrical measurements with the thought that these materials might prove to be useful electrolytes, in a hydrous environment, for high energy density batteries (13-15). Many fundamental properties of these polymer electrolytes have been examined and a large literature on the subject is available (16-17). We prepared a disk of one of our polyether complexes and measured its conductivity by impedance methods. 

Higashiya S, Devarajan TS, Rane-Fondacaro MV, Dangler C, Snyder J, Haidar P (2009) Synthesis of oxygen-containing spirobipyrrolidinium salts for high conductivity room temperature ionic liquids. Helv Chim Acta 92(8) 1600-1609... 

The further study on sol-gel preparation of MEEP-silicate composite materials involved the synthesis of a polyphosphazene precursor via the covalent linkage of MEEP with an organometallic alkoxide (triethoxysilane group) [63]. The following hydrolysis and condensation produced a covalently interconnected hybrid material with controlled morphologies and physical properties. A maximum ionic conductivity of 7.69 X10 S cm was achieved for the composite materials complexed with LiTFSI salt. 

Research on spin-charge separation in distonic ion-radicals has been carried out in recent years with an emphasis on theoretical calculations. Experiments were performed to prove their existence and observe their behavior in a mass spectrometer chamber. The next step is likely to emphasize the synthesis of the distonic ion-radical salts, which could be stable under common conditions. Applications of the salts would be possible in creating magnetic, conductible media and other materials possess practically useful properties. The attractive strength of distonic ion-radicals is that they can enter ionic reactions at the charged site and radical reactions at the radical site. Success in this direction can open a new window in terms of organic reactivity. 

Abbott et al. [98-103] reported the synthesis and characterization of new moisture-stable, Lewis acidic ionic liquids made from metal chlorides and commercially available quaternary ammonium salts (see Chapter 2.3). They showed that mixtures of choline chloride (2-hydroxyethyltrimethylammonium chloride, [Me3NC2H40H]Cl and MCU (M=Zn, Sn) give conducting and viscous liquids at or around room temperature. These deep eutectic solvents/ionic liquids are easy to prepare, are water-and air-stable, and their low cost enables their use in large-scale applications. Furthermore, they reported [104] that a dark green, viscous liquid can be formed by mixing choline chloride with chromium(III) chloride hexahydrate and that the... 

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