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Complex aqueous emulsions represent a promising material platform for the encapsulation of cells, pharmaceuticals, or nutrients, for the fabrication of structured particles, as well as for mimicking the barrier-free compartmentalization of biomolecules found in living cells. Herein, we report a novel, simple, and scalable method of creating multicomponent aqueous droplets with highly uniform internal droplet morphologies that can be controllably altered after emulsification by making use of a thermal phase separation approach. Specifically, temperature-induced phase separation inside as-formed emulsion droplets comprising aqueous mixtures of two or more hydrophilic polymers allows for the generation of Janus and Cerberus emulsion droplets with adjustable internal morphologies that are solely controlled by a balance of interfacial tensions. We demonstrate our approach by applying both, microfluidic and scalable batch production, and present a detailed model study with predictive capabilities that enables fine-tuning and dynamically altering the droplet morphology as a function of types, molecular weights, and hydrophilicities of the polymers as well as the surfactant hydrophilic-lipophilic balance. The ability to rationally design complex aqueous emulsion droplets with previously unattainable dynamic control over their morphologies after emulsification entails the potential to design new responsive soft materials with implications for a variety of applications beyond encapsulation, including the design of complex adaptive and self-regulating materials, e.g. for chemical and biological sensing applications. [ABSTRACT FROM AUTHOR]

Abstract: The microwave absorption at frequencies between 10 MHz and 4 GHz is measured for aqueous brine droplets dispersed in a dielectric medium (). By varying the size of the droplets, ion type and ion concentration, it is found that the microwave absorption goes through a maximum which depends on the type of ions and their concentration. The absorption process is attributed to the polarization of the microdroplets through surface charges. Means to optimize microwave heating in emulsions is discussed. [Copyright &y& Elsevier]

[Display omitted] Developing materials for thermally driven adsorption chillers and adsorption heat pumps is a growing research field due to the potential of these technologies to address up to 50% of the world's total energy demand. These materials must be abundant, easy to synthesize, hydrophilic, and low in cost. Bare carbon materials are hydrophobic and therefore usually not considered for these applications. However, by introducing heteroatoms and tuning their porosity, the hydrophilicity of carbonaceous networks can be increased significantly. Herein, a series of highly nitrogen doped carbonaceous materials (CNs) have been synthesized by submitting uric acid to heat treatment at different temperatures in the presence of an inorganic salt mix as solvent and pore template. The effect of the thermal treatment on the materials composition, pore network, and water sorption capability has been studied. At 800 °C, a nitrogen depleted carbonaceous material with a maximal water uptake of 1.38 g H2O g−1 is obtained. Condensation at 750 °C creates an ultra-hydrophilic CN with a water uptake of 0.8 g H2O g−1 at already much lower partial pressures. While the maximum uptake is mainly ascribed to the mesopore volume of the material, the differences in hydrophilicity can be controlled by functionality. [ABSTRACT FROM AUTHOR]

• Surface acidic sites were imparted onto the carbon nitride photocatalysts. • The adsorption and activation of the intermediate aldehyde is significantly enhanced. • Tuning the surface acidic sites could greatly change the photocatalytic activity. • Excellent conversion of alcohols to esters with up to 99% selectivity was achieved. • A scalable continuous flow systemexhibits high efficiency and stability. Photocatalytic aerobic oxidation of alcohols for the direct synthesis of esters has received significant attention in recent years, but the relatively low efficiency and selectivity under visible light irradiation is the main challenge for their practical applications. Here, surface acidic sites were imparted onto metal-free heterogeneous photocatalysts by the protonation of carbon nitride (HMCN) to promote the activity for the esterification reaction through further adsorption and activation of the intermediate aldehyde. The activation of the substrate could be remarkably modulated through tuning the acidic sites on the surface of the photocatalyst, leading to a controllable reactivity of the catalytic reaction. The one-pot process for the direct aerobic oxidative esterification of alcohol exhibits high efficiency and selectivity under mild and additive-free conditions and the apparent quantum yield (AQY) of the photocatalytic esterification reaction is 0.41% at 420 nm. Moreover, a scalable photocatalytic process by the merging of a continuous flow system with the heterogeneous HMCN photocatalyst is demonstrated, combining high catalytic efficiency and stability at ambient temperatures and being promising for larger-scale applications. [ABSTRACT FROM AUTHOR]

• Photocatalytic organic reduction is conducted in new functional eutectic solvents. • Metal free potassium poly(heptazine imide) enables multielectron one-step reduction. • Components of the solvent stabilize long-lived radical anion of the catalyst. • Eutectic solvents are designed in way to control over the reaction products. • Ionic nature of the solvents enhance the catalyst activity and selectivity. In the past years organic semiconductor photocatalysis has made the remarkable advances in developing efficient synthetic chemical routes to well refined structures. Until now, most efforts were focused on optimizing of the semiconductor photocatalyst, while solvents were largely ignored. Herein, we design a series of functional deep eutectic solvents (DES) with adjustable physicochemical properties – density, viscosity, glass transition temperature, and chemical activity towards reductive formylation of nitroarenes. The DES are prepared from abundant, sustainable resources, which makes them an affordable alternative to the ionic liquids, even on larger industrial scales. By combining the ammonium formate-based DES with carbon nitride photocatalyst, we enable the simultaneous six-electron reduction of nitro-compounds to the corresponding N-substituted formamides and benzimidazoles in one pot. [ABSTRACT FROM AUTHOR]

Low-defect potassium poly(heptazine imide) (PHIK-BM) was engineered for application in photocatalytic oxidation of organic substrates. Mechanochemical pretreatment of a mixture of 5-aminotetrazole in LiCl/KCl eutectics using high-energy ball milling afforded a highly homogeneous mixture that, upon sequential thermolysis at 600 °C, gave nanosized particles of PHIK–BM. The photocatalytic activity of the free-standing PHIK–BM plates was assessed in the oxidation of benzyl alcohol to benzaldehyde under visible light irradiation using elemental sulfur as an electron acceptor. Both quantitative conversion (>99%) of benzyl alcohol and selectivity (>98%) with respect to benzaldehyde were achieved. The developed method was extended to aliphatic alcohol oxidation coupled with multicomponent Hantzsch 1,4-dihydropyridine synthesis. These 1,4-dihydropyridines were also photocatalytically oxidized by PHIK–BM to the corresponding substituted pyridines, with very good yields and under mild metal-free conditions. [ABSTRACT FROM AUTHOR]