Single-domain cobalt dot arrayswith high magnetic particle density, patterned over large areas (e.g., 10 cm diameter wafers) are fabricated by self-assembled block copolymer lithography, using a polystyrene–poly(ferrocenyldimethylsilane) as template. By varying the type and etching conditions properties can be tuned. The Figure shows typical array of Co dots with tungsten caps obtained via this procedure.

We present a visualization of the predicted instability in ionic conduction from binary electrolyte into charge selective solid. This develops when voltage greater than critical is applied to thin layer copper sulfate flanked by anode and cation membrane. The current-voltage dependence exhibits saturation at limiting current. With further increase voltage, current increases, marking transition overlimiting conductance. mediated appearing vortical flow that increases with voltage.

Dimensionally stable crosslinked poly(arylene piperidinium)-based AEMs were fabricated and used for alkaline water electrolysis. A high current density of 880 mA cm −2 at 2.2 V in 1 M KOH was achieved by using non-PMG catalysts.

The advancement of anion exchange membranes (AEMs) with superior ionic conductivity has been greatly hindered due to the inherent "trade-off" between membrane swelling and conductivity. To resolve this dilemma, macromolecular covalently cross-linked C-FPVBC-x AEMs were fabricated by combining partially functionalized ether-bond-free polystyrene (FPVBC) poly(arylene piperidinium). results from atomic force microscopy reveal that an increase in ratio FPVBC promotes fabrication microphase...

When placed on rough hydrophobic surfaces, water droplets of diameter larger than a few millimeters can easily form pearls, as they are in the Cassie-Baxter state with air pockets trapped underneath droplet. Intriguingly, natural evaporating process drive such Fakir drop into completely wetting (Wenzel) state. Our microscopic observations simultaneous side and bottom views upon transparent microstructures elucidate water-filling dynamics suggest mechanism this evaporation-triggered...

In electrodialysis desalination processes, the operating current density is limited by concentration polarization. contrast to other membrane processes such as ultrafiltration, in electrodialysis, transport above limiting possible. this work, origin of overlimiting at cation-exchange polymers investigated. We show that, under certain experimental conditions, electroconvection conductance. The theory concerning predicts a shortening plateau length membranes with increased conductive or...

Tailoring the hydrodynamic boundary condition is essential for both applied and fundamental aspects of drag reduction. Hydrodynamic friction on superhydrophobic substrates providing gas–liquid interfaces can potentially be optimized by controlling interface geometry. Therefore, establishing stable optimal crucial but rather challenging. Here we present unique microfluidic devices that allow presence controllable microbubbles at microchannels. We experimentally numerically examine effect...

In some cases water droplets can completely wet microstructured superhydrophobic surfaces. The dynamics of this rapid process is analyzed by ultrahigh-speed imaging. Depending on the scales microstructure, wetting fronts propagate smoothly and circularly or-more interestingly-in a stepwise manner, leading to growing square-shaped wetted area: entering new row perpendicular direction front propagation takes milliseconds, whereas once has happened, itself fills in microseconds ("zipping")....

We demonstrate that the equilibrium shape of composite interface between superhydrophobic surfaces and drops in Cassie state under electrowetting is determined by balance Maxwell stress Laplace pressure. Energy barriers due to pinning contact lines at edges hydrophobic pillars control transition from Wenzel state. Barriers narrow gap adjacent lateral propagation how reversible switching two wetting states can be achieved locally using suitable surface electrode geometries.

This review addresses the inconsistencies in interpreting measurements of intrinsic catalyst properties using lab-scale devices. Any experiment must be analyzed framework a model for which choice and assumptions regarding necessary parameters based on critical reasoning. Physical intuition about system is required both rigorous 3D computational simplified analytic descriptions. divergence between hypothesis characteristics systems affects investigation catalytic later industrial design where...

We discuss the formation of TiO2 thin films via DC reactive magnetron sputtering. The oxygen concentration during sputtering proved to be a crucial parameter with respect final film structure and properties. initial deposition provided amorphous that crystallise upon annealing anatase or rutile, depending on conditions. Substoichiometric (TiOx<2), obtained by at relatively low concentration, formed rutile in air, whereas stoichiometric anatase. This route therefore presents for lower...

The deposition of thin films inorganic nanoclusters as a route to one-step lithography has been achieved using block copolymers with inherent (Fe and Si) components. Nanodomains the organometallic part are resistant removal during subsequent O2 etch, which results in well-ordered separate domains iron silicon oxides, can be seen Figure.

Phase separation micromolding (PSmicroM) is a versatile microfabrication technique that can be used to structure very broad range of polymers, including block copolymers and biodegradable conductive polymers without the need for clean-room facilities. By incorporating subsequent process step, carbon, ceramic, metallic microstructures also fabricated from polymeric or hybrid precursor. The replication straightforward cost-effective. It relies on phase polymer solution while in contact with...

We employ micro-particle image velocimetry ($\mu$-PIV) to investigate laminar micro-flows in hydrophobic microstructured channels, particular the slip length. These microchannels consist of longitudinal micro-grooves, which can trap air and prompt a shear-free boundary condition thus slippage enhancement. Our measurements reveal an increase length when width micro-grooves is enlarged. The result smaller than analytical prediction by Philip et al. [1] for infinitely large textured channel...

We present a strategy to stabilize artificial protein hydrogels through covalent bond formation following physical association of terminal leucine zipper domains. Artificial proteins consisting two domains and random coil central domain form transient networks above certain concentration, but the dissolve when placed in excess buffer. Engineering cysteine residue into each allows disulfide bonds templated by aggregation. Circular dichroism spectra show that remain helical after residues are...

We investigate the coupled dynamics of local hydrodynamics and global electric response an electrodialysis system, which consists electrolyte solution adjacent to a charge selective membrane under forcing. Under dc current, counterions transport through charged while passage co-ions is restricted, thereby developing ion concentration polarization (ICP) or gradients. At sufficiently large currents, simultaneous measurements voltage drop flow field reveal several distinct dynamic regimes....

Electrodialysis (ED) and reverse electrodialysis (RED) are processes for the production of desalinated water power (RED). Temperature feed streams can strongly influence performance both processes. In this research, commercial membranes used investigation temperature gradients on ED RED We find that energy required be reduced by 9% if one is increased 20 °C, while maintaining charge-selectivity membranes. The direction gradient did not have a significant efficiency selectivity in Ohmic...

In order to investigate the relationship towards cationic structures and ion exchange membrane performance, three kinds of twisted poly(terphenylene)-based anion membranes (AEMs) with N-cyclic cations were prepared via facile Friedel-Crafts type polycondensation quaternization. The steric hindrance is gradually increased from small piperidinium sterically protected N-spirocyclic quaternary ammonium (QA). poly(terphenylene)s backbone promotes self-assembly polymer chain forms a microphase...

Nanofiltration (NF) is seen as a promising advanced treatment technology to deal with the increasing concentration of micropollutants (MPs) in water sources globally. To further improve successful implementation NF, an increased understanding membrane transport mechanisms important. One key aspect among these concerns influence solution composition on overall filtration performance. Although several studies report feed removal by NF membranes, underlying are often not fully understood. In...

Ion-exchange membranes (IEMs) are essential components of several electrochemical water technologies where they promote the transport certain ionic species over others. A characteristic property IEMs concerns their charge density (ICD) which is a key parameter for modeling ion transport. In literature, significant variations in ICD similar reported. We analyzed sources this and traced those back to content measurement. manuscript, we developed new technique measuring content, i.e., via...