Thermoreversible Polymer Gels in DMF Formed from Charge- and Crystallization-Induced Assembly

Polymer organogels formed through dynamic interactions are interesting for various applications. The fabrication of polymer organogels in polar solvents through ionic interaction is rare, although such organogels in non-polar organic solvents have been well studied. Herein, polymer organogels in a polar solvent N,N-dimethyl formamide (DMF) were fabricated from a triblock copolymer, poly(4-vinyl pyridine)-block-poly(ethylene glycol)-block-poly(4-vinyl pyridine) (4VPm-EGn-4VPm), and a fluorinated surfactant, perfluorooctanoic acid (PFOA), and their microphase separation and properties were studied. Ordered microphase separation and the crystalline structures were revealed by small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS), respectively. All the 4VPm-EGn-4VPm/PFOA organogels are sensitive to temperature, and the ratio of PFOA to pyridine groups reversibly. The polymer organogels are also responsive to triethylamine and triethylammonium acetate.

Structural Features of Triethylammonium Acetate through Molecular Dynamics

I have explored the structural features and the dynamics of triethylammonium acetate by means of semi-empirical (density functional tight binding, DFTB) molecular dynamics. I find that the results from the present simulations agree with recent experimental determinations with only few minor differences in the structural interpretation. A mixture of triethylamine and acetic acid does not form an ionic liquid, but gives rise to a very complex system where ionization is only a partial process affecting only few molecules (1 over 4 experimentally). I have also found that the few ionic couples are stable and remain mainly embedded inside the AcOH neutral moiety.

Efficient synthesis of some new antiproliferative N-fused indoles and isoquinolines via 1,3-dipolar cycloaddition reaction in an ionic liquid

Triethylammonium acetate (TEAA) as a new, recyclable and environmentally friendly reaction medium for the intramolecular[3+2] cycloaddition reaction.

SOLVENT INDUCED CHANGES IN THE CONFORMATIONAL STATE OF β-LACTOGLOBULIN AND THE INFLUENCE OF PROTIC IONIC LIQUIDS

The protic ionic liquids (pILs), triethylammonium acetate, triethylammonium trifluoroacetate, triethylammonium mesylate and trimethylammonium sulfate were used to induce various native and non-native conformational states of the protein β-lactoglobulin (βLG). Changes in the secondary structure of βLG were observed on moving from a high water content to a high pIL content. We examined the stability of various pIL induced states via thermal unfolding and refolding, where it was found that at a given pIL concentration a highly stable non-native conformation was formed. The βLG non-native conformation was characterized by a high α-helical content. Additionally, pIL conditions that promoted amyloid fibril formation were identified and characterized by CD, a Thioflavin T binding assay and transmission electron microscopy (TEM). This work highlights the use of pILs as solvents in the study of protein folding using βLG as a model system.