Direct Observation of Self‐Organized Water‐Containing Structures in the Liquid Phase and Their Influence on 5‐(Hydroxymethyl)furfural Formation in Ionic Liquids

Abstract

Water-containing organic solutions are widespread reaction media in organic synthesis and catalysis. This type of multicomponent liquid system has a number of unique properties because of the tendency for water to self-organize in mixtures with other liquids. The characterization of these water domains is a challenging task because of their soft and dynamic nature. In the present study, the morphology and dynamics of micrometer- and nanometer-scale water-containing compartments in ionic liquids were directly observed by electron microscopy. A variety of morphologies, including isolated droplets, dense structures, aggregates, and 2D meshworks, have been experimentally detected and studied. Using the developed method, the impact of water on the acid-catalyzed biomass conversion reaction was studied at the microscopic level. The process that produced nanostructured domains in solution led to better yields and higher selectivities compared with reactions involving the bulk system.

Sustainable Utilization of Biomass Refinery Wastes for Accessing Activated Carbons and Supercapacitor Electrode Materials

“…[4,5] Cellulose and various C 6 carbohydrates constitute approximately 75 %o fb iomass. One of the most rapidly developing strategies applied to biomass conversion involves catalytic conversion of carbohydratesi nto 5-hydroxymethylfurfural (HMF) and/orl evulinic acid (LA) and formic acid [1,[5][6][7][8] (Scheme 1). One of the most rapidly developing strategies applied to biomass conversion involves catalytic conversion of carbohydratesi nto 5-hydroxymethylfurfural (HMF) and/orl evulinic acid (LA) and formic acid [1,[5][6][7][8] (Scheme 1).…”

“…[5] The high oxygen content, low solubility,a nd polymericn ature of cellulose disallow the straightforward use of biomass in the majority of industrial processes.M uch effort of academic and industrial research is currentlyf ocusedo nt he development of processes for effec-tive transformationo fc arbohydrates into substances of higher carbon content, suitable for processing with established technologies. One of the most rapidly developing strategies applied to biomass conversion involves catalytic conversion of carbohydratesi nto 5-hydroxymethylfurfural (HMF) and/orl evulinic acid (LA) and formic acid [1,[5][6][7][8] (Scheme 1). HMF and LA are regarded as top value-added chemicals obtained from carbohydrates;t hey are considered as "platform chemicals" for the synthesis of various polymers, pharmaceuticals, solvents, and fuels.…”

Microscopic rigidity and heterogeneity of ionic liquids probed by stochastic molecular librations of the dissolved nitroxides

“…Methods such as X-ray diffraction/scattering, [16][17][18]22 neutron diffraction, 26 quasi-elastic neutron scattering 27 were intensively used. Recently, magnetic resonance methods 20,28,29 and electron microscopy 21 were also involved in the study of heterogeneities and nanostructuring in ILs. However, still the number of experimental approaches to detect and characterize the heterogeneities formed in ILs is relatively small.…”

Effect of Water Content on Properties of Homogeneous [bmim]Fe(III)Cl4–H2O Mixtures and Their Application in Oxidative Absorption of H2S

“…The homogeneous liquids at x(H 2 O) ≥ 80% are brownish yellow. Since there wasn't the presence of structured water in the hydrophobic ionic liquid phase [19], it is very easy to separate water from [bmim]Fe(III)Cl 4 in the two-phase mixtures without affecting the oxidative absorption of hydrogen sulphide. However, it is difficult to separate water from the homogeneous [bmim]Fe(III)Cl 4 -H 2 O mixtures without evaporation method [11,12].…”