Room temperature ionic liquids as emerging solvents for the pretreatment of lignocellulosic biomass.

Room temperature ionic liquids (RTILs) are emerging as attractive and green solvents for lignocellulosic biomass pretreatment. The unique solvating properties of RTILs foster the disruption of the 3D network structure of lignin, cellulose, and hemicellulose, which allows high yields of fermentable sugars to be produced in subsequent enzymatic hydrolysis. In the current review, we summarize the physicochemical properties of RTILs that make them effective solvents for lignocellulose pretreatment including mechanisms of interaction between lignocellulosic biomass subcomponents and RTILs. We also highlight several recent strategies that exploit RTILs and generate high yields of fermentable sugars suitable for downstream biofuel production, and address new opportunities for use of lignocellulosic components, including lignin. Finally, we address some of the challenges that remain before large-scale use of RTILs may be achieved.

Aggregation and coarsening of ligand-stabilized gold nanoparticles in poly(methyl methacrylate) thin films.

Dodecanethiol-stabilized gold nanoparticles (5 nm diameter) are shown to self-organize to form a two-dimensional hexagonal structure in poly(methyl methacrylate) films upon spin-casting from solution onto a substrate, using high-angle annular dark-field scanning transmission electron microscopy. Through use of the distribution functions describing particle distributions, we show that the particle coarsening dynamics is self-similar, characterized by two distinct growth stages. During the initial stage, coarsening occurs via simultaneous Ostwald ripening and coalescence mechanisms, whereas during the second stage, the dominant coarsening mechanism is coalescence.