Magnetic Microemulsions Stabilized by Alkyltrimethylammonium-Based Magnetic Ionic Liquids Surfactants (MILSs)

Estimation of the Thermophysical Properties of Pentaalkylguanidinium-Based Magnetic Ionic Liquids with Unusual Thermal Expansion Coefficient

The thermal expansion coefficient (αexp. ), the molecular volume (Vm ), the entropy of surface formation (Sa ), and the Gibbs energy of surface formation (Ea ) of four pentaalkylguanidinium-based MILs [Cn TMG][FeCl3 Br] (n=2, 4, 6, 8) were calculated based on the density and surface tension data determined from 278.15 to 323.15 K. In terms of classical semiempirical methods, the standard molar entropy (S0 ), the lattice energy (UPOT ), the molar enthalpy of evaporation (Δ l g H m 0 ( T b ) ${{\rm{\Delta }}_{\rm{l}}^{\rm{g}} H_{\rm{m}}^0 (T_{\rm{b}} )}$ ,Δ l g H m 0 ${{\rm{\Delta }}_{\rm{l}}^{\rm{g}} H_{\rm{m}}^0 }$ (298 K)), and the thermal expansion coefficient (αest. ) of the MILs were further estimated. The estimation results indicate that the classical semiempirical methods are suitable for estimating the thermophysical properties of the MILs, except the unusual αexp. , which were extremely larger than those of representative non-magnetic ionic liquids (ILs). We further optimized the estimation methods and discussed the potential reasons for the unusual thermal expansion coefficient of the MILs.

Physico-Chemical Properties of Magnetic Dicationic Ionic Liquids with Tetrahaloferrate Anions

A series of imidazolium-based symmetrical and asymmetrical dicationic ionic liquids (DcILs) with alkyl spacers of different length and with [FeCl3 Br]- as counter ion have been synthesized. The synthesized DcILs are characterized by using FTIR and Raman spectroscopy as well as mass spectrometry, along with single-crystal XRD analysis. Physicochemical properties such as solubility, thermal stability and magnetic susceptibility are also measured. These compounds show low melting points, good solubility in water and organic solvents, thermal stability, and paramagnetism. The products of molar susceptibility and temperature (χmol ⋅T) for the synthesized DcILs have been found between 4.05 to 4.79 emu mol-1  K Oe-1 and effective magnetic moment values have also been determined to be compared to that expected from the spin-only approximation.