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For the extraction of theophylline from a water phase, four hydrophobic ionic liquids (ILs) were designed and synthesized which included various amino acid ester cations and the same bis(trifluoromethyl)sulfonimide anion. After screening, L -phenylalanine ethyl ester bis(trifluoromethyl)sulfonimide ([PheC2][Tf2N]) showed the highest distribution coefficient and it was then applied to further investigations focused on the extraction conditions. It was also immobilized through a simple procedure and used for the adsorption of theophylline for comparison. The new sorbent was characterized via infrared spectroscopy (IR), scanning electron microscopy (SEM), elemental analysis, thermogravimetric analysis, and particle size analysis. In addition, thorough investigations into the adsorption conditions, kinetics, isotherms, and thermodynamics were carried out, together with selective separation studies. The post-treatment and reuse of the IL were also explored using the two separation approaches. A comprehensive comparison was made between these approaches and reported methods. [ABSTRACT FROM AUTHOR]

A new type of tropine-based ionic liquid (IL) gels were synthesized and characterized by Fourier transform infrared spectra (FT-IR), elemental analysis (EA), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and zeta potential measurements, and the swelling behavior of ionic liquid (IL) gels were further investigated. FT-IR, EA and XRD indicated the successful synthesis of IL gels, TGA analysis showed that the IL gels had good thermal stability, SEM showed that the introduction of ILs made the gel surface rough, and increased the specific surface area. The swelling values of IL gels were well correlated by the second-order kinetics equation with the correlation coefficients of at least 0.99. Furthermore, the IL gels were used as adsorbent to adsorb bovine albumin (BSA), the maximum adsorption capacity was up to 700 mg g−1. [ABSTRACT FROM AUTHOR]

Microemulsions with magnetic properties were formulated and optimized at 25 °C by using a series of pentaalkylguanidinium-based magnetic room-temperature ionic liquids (MRTILs) 1,1,3,3-tetramethyl-4-alkylguanidinium bromotrichloroferrate(iii) [CnTMG][FeCl3Br] (n = 2, 4, 6, and 8) as a polar phase, different aliphatic oils as a nonpolar phase, and an optimal mixture of nonionic surfactant Triton X-100 (TX-100) and different short-chain aliphatic alcohols as a cosurfactant. The phase behaviors of these microemulsions were investigated by a cloud titration method. The results revealed that cyclohexane (as the nonpolar phase) coupled with TX-100/1-pentanol (mole ratio of 1 : 3) showed the best ability to formulate MRTILs-based microemulsions and the range of monophasic region was expanded with an increase in the length of alkyl chain attached to the =NRH+ group of MRTILs cation. Based on conductivity measurements, the classical structural sequence of oil-in-MRTILs (O/MRTILs), bicontinuous sponge structure (BC), and inverse MRTILs-in-oil (MRTILs/O) microemulsions was observed with an increase of m(Oil)/m(MRTILs) ratio. Dynamic light scattering (DLS) and cryo-high resolution scanning electron microscopy (Cryo-SEM) measurements showed that microemulsion droplets with the size of about 3 to 7 nm were formed in the MRTILs/O subregions and the droplet size increased with an increase in the concentrations of MRTILs. Magnetic susceptibility and rheological measurements revealed that these MRTILs-based microemulsions had strong magnetic susceptibility and low viscosity over the entire optically clear range of composition. This comprehensive investigation provides useful information for formulating analogous MRTILs-based microemulsions and these magnetic microemulsions should have interesting potential applications by simply manipulating the external magnetic field. [ABSTRACT FROM AUTHOR]