Ionic Liquids as Advantageous Reaction Media for Free Radical Polymerization

Rapid polymerization of polyhedral oligomeric siloxane-based zwitterionic sulfoalkylbetaine monolithic column in ionic liquid for hydrophilic interaction capillary electrochromatography

A novel polyhedral oligomeric siloxane (POSS)-based zwitterionic monolithic capillary column was prepared via one-pot polymerization in ionic liquid porogen, using N,N-dimethyl-N-methacryloxyethyl-N-(3-sulfopropyl)ammonium betaine (DMMSA) and methacrylic ethyl trimethylammonium chloride (META) as binary functional monomers, and methacryl substituted POSS as cross-linker. The pore structure, permeability and homogeneity were well tuned by optimizing the polymerization conditions. The resultant monolith was characterized by scanning electron microscopy, nitrogen adsorption/desorption isotherm and Fourier transform infrared spectroscopy. The incorporation of zwitterionic ligand (DMMSA), quaternary amine group (META) and rigid POSS skeleton endows the hybrid organic-silica monolith with high hydrophilicity, electrostatic interaction and good mechanical stability, as well as a tunable electroosmotic flow over wide pH range. A close investigation of capillary electrochromatographic separations of different types of polar compounds such as bases, nucleosides and benzoic acids on such stationary phase exhibited a retention independent column efficiency up to 118,000 plates/m (thiourea), as well as a mixed-mode hydrophilic interaction chromatography (HILIC) retention mechanism including weak electrostatic interaction, hydrophobic interaction and anion exchange.

Synthesis and characterization of nitrogen-based ionic liquids bearing allyl groups and examples of their application

The synthesis and characterization of a series of allyl-functionalized ionic liquids and examples of their application in catalysts and surface-functionalizing compound formation.

Is it possible to control kinetic rates of radical polymerisation in ionic liquids?

Experimental studies have noted the often surprising and unpredictable effect of ionic liquids as solvents on reaction kinetics for radical polymerisation. We theoretically investigate the energetic and structural effects of ionic liquids, both protic and aprotic, on radical stability, presenting stabilisation of the radical by the ionic liquid by up to -78.0 kJ mol-1. Kinetic data relating to propagating systems for several industrially viable monomers indicate that propagation rates can be increased or decreased (by up to 6 orders of magnitude) depending on the monomer and ionic liquid combination. The interplay of activation entropy and activation enthalpy, much of which depends on hydrogen bonding between the solvent and reactants, play a crucial role in controlling reaction kinetics. It is concluded that the use of cheaper protic ionic liquids as solvents may be viable for improved kinetic control over radical reactions.