The structure of the electrical double layer at interface planar electrodes and aqueous solutions is investigated. Electrical impedance spectroscopy used to measure sodium chloride two different surfactants over a wide range concentrations. electrode capacitance directly inferred from admittance spectra as well by regression an equivalent circuit. It found that remains on same order magnitude entire investigated This contradictive predictions Gouy-Chapman-Stern theory which predicts that,...

We demonstrate a simple noncovalent functionalization technique, which involves graphite exfoliation and subsequent coating of the resulting graphene nanoplatelets (GNPs) with trimellitic anhydride (TMA), using thermomechanical process. TMA adsorbs on surface GNPs, in reduction specific area to 312 ± 9 m2/g compared 410 12 for unmodified GNPs. Detailed imaging, thermogravimetric, X-ray diffraction analysis showed that modified GNPs (TMA-GNPs) maintain similar structure The presence...

In the present work, high-concentration aqueous dispersions of graphene nanoplatelets, stabilized by small amounts oxide, are investigated as hydrogel precursors. Experiments with varying synthesis parameters performed to determine their influence on specific surface area and dynamic shear modulus. Correlations generated which allow for formulation an "optimized" hydrogel. The optimized hydrogels characterized in terms material electrochemical properties. A volumetric capacitance 14.4 F cm−3...

Abstract A novel flexible hybrid battery–supercapacitor device is proposed consisting of high specific surface area electrodes paired with an electrolyte, which contains a redox species that can exist in more than two oxidation states. The initially equal half‐cells the consist reduced graphene oxide hydrogel encapsulates vanadium ions, synthesized single‐step method. During charge, state ions changes, resulting different potentials considerably increases energy density. achieved maximum...

The addition of surfactants can considerably impact the electrical characteristics an interface, and zeta potential measurement is standard method for its characterization. In this article, a comprehensive study poly(methyl methacrylate) (PMMA) in contact with aqueous solutions containing anionic, cationic, or zwitterionic surfactant at different pH ionic strength values conducted. Electrophoretic mobilities are inferred from electrophoretic light scattering measurements particulate PMMA....

Many unit operations required in microfluidics can be realised by electrokinetic phenomena. Electrokinetic phenomena are related to the presence of electrical surface charges microfluidic substrates contact with a liquid. As cannot directly measured, zeta potential is considered as relevant parameter instead. PMMA an attractive substrate since micron-sized features manufactured at low costs. However, existence not well understood and data found literature show significant disagreement. In...

Download This Paper Open PDF in Browser Add to My Library Share: Permalink Using these links will ensure access this page indefinitely Copy URL High-Performance Symmetric Battery-Supercapacitor Hybrid Three Oxidation States of Tempo 20 Pages Posted: 10 Jan 2025 See all articles by Joshua ChamberlandJoshua Chamberlandaffiliation not provided SSRNScott Parentaffiliation SSRNDominik Barzaffiliation SSRN Abstract Here, we develop a novel ionic liquid-based battery-supercapacitor hybrid that uses...

We investigate the electrokinetic flow and transport within a micro-electrophoresis device. A mathematical model is set up, which allows to perform two-dimensional, time-dependent finite-element simulations. The reflects dominant features of system, namely electroosmosis, electrophoresis, externally-applied electrical potentials, equilibrium chemistry. For solution equations we rely on numerical simulations core region, while immediate wall region treated analytically at leading order. This...

This paper presents a new method to determine the zeta potential of porous substrates in contact with liquid. Electroosmosis, arising near solid/liquid boundaries within fully saturated substrate, pumps against capillary pressure from surface tension droplet placed series pump. The is based on measuring liquid/gas interface deflection due imposed electric difference. distinguishing features our technique are accuracy, speed, and reliability, accomplished straightforward cost-effective setup....

This work is concerned with the investigation of concentration fields in an electrokinetic micromixer and its optimization order to achieve high mixing rates. The concept based on combination alternating electrical excitation applied a pressure-driven base flow meandering microchannel geometry. induces secondary velocity component, which results complex field within meander bends. A mathematical model describing physicochemical phenomena present implemented in-house finite-element-method...

Here we study the nature and extent of free electrical charges in nonpolar liquids, using a recently introduced technique observing droplet deflection generated by electrokinetic flow porous substrate. In presence dispersed water, surfactant molecules agglomerate inverted micelles are which may act as charge carriers. present work, conductivities solutions liquid with several concentrations dissolved measured transients. The induced current densities proportional to applied voltage,...

We investigate the flow field in an electrokinetic micromixer. The concept of micromixer is based on combination alternating electrical applied to a pressure-driven base meander–channel geometry. presence leads additional electro-osmotic velocity contribution, which results complex within meander bends. fields are measured by means microparticle-image velocimetry method. Furthermore, we introduce mathematical model, describing and fluid-mechanical phenomena present device, perform...

Electrokinetic phenomena play an important role in the electrical characterization of surfaces. In terms planar or porous substrates, streaming potential and/or current measurements can be used to determine zeta substrates contact with aqueous electrolytes. this work, we perform impedance spectroscopy infer resistance a microchannel same conditions as for experiment. Novel correlations are derived relate and Reynolds number channel flow. Our results not only quantify influence surface...