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30 May 01:40

Microstructured gas-liquid-(solid) interfaces: A platform for sustainable synthesis of commodity chemicals | Science Advances

Abstract

Gas-liquid-solid catalytic reactions are widespread in nature and man-made technologies. Recently, the exceptional reactivity observed on (electro)sprayed microdroplets, in comparison to bulk gas-liquid systems, has attracted the attention of researchers. In this perspective, we compile possible strategies to engineer catalytically active gas-liquid-(solid) interfaces based on membrane contactors, microdroplets, micromarbles, microbubbles, and microfoams to produce commodity chemicals such as hydrogen peroxide, ammonia, and formic acid. In particular, particle-stabilized microfoams, with superior upscaling capacity, emerge as a promising and versatile platform to conceive high-performing (catalytic) gas-liquid-(solid) nanoreactors. Gas-liquid-(solid) nanoreactors could circumvent current limitations of state-of-the-art multiphase reactors (e.g., stirred tanks, trickle beds, and bubble columns) suffering from poor gas solubility and mass transfer resistances and access gas-liquid-(solid) reactors with lower cost and carbon footprint.
23 Dec 01:45

Mechanical intelligence simplifies control in terrestrial limbless locomotion | Science Robotics

A comparative biological and robotic study reveals principles of mechanical intelligence in terrestrial limbless locomotion.
22 Feb 01:31

Layer-by-layer design of nanostructured thermoelectrics: First-principles study of ZnO:organic superlattices fabricated by ALD/MLD

Publication date: April 2016
Source:Nano Energy, Volume 22
Author(s): Antti J. Karttunen, Tommi Tynell, Maarit Karppinen
Crystalline atomic/molecular layer deposited ZnO:organic superlattices form a fundamentally new exciting family of coherent multilayered thermoelectric materials. They retain the n-type electrical transport properties derived from the parent ZnO lattice, while the organic molecular layers reduce the thermal conductivity. The controlled nanostructuring opens up the possibility of improving the thermoelectric characteristics of the parent oxide. Here we employ quantum chemical methods to rationalize our experimental results on the ZnO:organic superlattices and determine the thermoelectric structure–property relationships arising from the nanoscale layer-by-layer engineering of ZnO. Our results reveal the importance of systematic tailoring of the organic superlattice component and provide us with atomic-level guidelines for the rational design of novel hybrid inorganic–organic thermoelectrics.

Graphical abstract

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14 Jan 12:09

Pressure-Tuned Structure and Property of Optically Active Nanocrystals

by Feng Bai, Binsong Li, Kaifu Bian, Raid Haddad, Huimeng Wu, Zhongwu Wang, Hongyou Fan
Zion

I like

Thumbnail image of graphical abstract

Investigations through high-pressure X-ray scattering and spectroscopy in combination with theoretical computations shows that high-pressure compression can systematically tune the optical properties and mechanical stability of the molecular nanocrystals.

14 Jan 12:09

Enhancement of Magnetic Resonance Imaging with Metasurfaces

by Alexey P. Slobozhanyuk, Alexander N. Poddubny, Alexander J. E. Raaijmakers, Cornelis A. T. van den Berg, Alexander V. Kozachenko, Irina A. Dubrovina, Irina V. Melchakova, Yuri S. Kivshar, Pavel A. Belov
Zion

good job

Thumbnail image of graphical abstract

It is revealed that the unique properties of ultrathin metasurface resonators can improve magnetic resonance imaging dramatically. A metasurface formed when an array of metallic wires is placed inside a scanner under the studied object and a substantial enhancement of the radio­frequency magnetic field is achieved by means of subwavelength manipulation with the metasurface, also allowing improved image resolution.

19 Nov 03:17

Thin-finger growth and droplet pinch-off in miscible and immiscible displacements in a periodic network of microfluidic channels

by Agnieszka Budek, Piotr Garstecki, Adam Samborski and Piotr Szymczak

We report the results of experimental and numerical studies of two-phase flow in a periodic, rectangular network of microfluidic channels. This geometry promotes the formation of anisotropic, dendrite-like structures during viscous fingering experiments. The dendrites then compete with each other for the available flow, which leads to the appearance of hierarchical growth pattern. Combining experiments and numerical simulations, we analyze different growth regimes in such a system, depending on the network geometry and fluid properties. For immiscible fluids, a high degree of screening is present which results in a power-law distribution of finger lengths. Contrastingly, for miscible fluids, strong lateral currents of displaced fluid lead to the detachment of the heads of the longest fingers from their roots, thus preventing their further growth.