434 results match your criteria good insulating

Improved Breakdown Strength of Polypropylene Film by Polycyclic Compounds Addition for Power Capacitors.

Materials (Basel) 2021 Mar 3;14(5). Epub 2021 Mar 3.

Key Laboratory of Smart Grid of Education Ministry, School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, China.

In this paper, an improved method for the electric performance of polypropylene (PP) film was proposed to promote the safety and stability of power capacitors. Modified PP films containing three different polycyclic compounds were prepared, which showed good thermal properties and decreased DC conductivity. The DC breakdown strength of the modified PP films under both positive and negative voltage is increased compared with that of the original film. Read More

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Size-Controlled Polarization Retention and Wall Current in Lithium Niobate Single-Crystal Memories.

ACS Appl Mater Interfaces 2021 Apr 1;13(14):16641-16649. Epub 2021 Apr 1.

Stare Key Laboratory of ASIC & System, School of Microelectronics, Fudan University, Shanghai 200433, China.

Highly conductive domain walls in insulating ferroelectric LiNbO (LNO) single-crystal thin films with atomic smoothness are attractive for use in high-density integration of the ferroelectric domain wall random access memory (DWRAM) because of their excellent reliability and high read currents. However, downscaling of the memory size to the nanoscale could cause poor polarization retention. Understanding the size-dependent electrical performance of a memory cell is therefore crucial. Read More

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Functionalized CNTs with DOPO and Silicon Containing Agents: Effective Reinforcer for Thermal and Flame Retardant Properties of Polystyrene Nanocomposites.

Front Chem 2020 10;8:627642. Epub 2021 Feb 10.

Beijing Key Lab of MFPTS, China Academy of Safety Science and Technology, Beijing, China.

DOPO and silicon containing agents modified multiwalled carbon nanotubes (MCNTs) were synthesized through sol-gel process and MCNTs are introduced into polystyrene (PS) through polymerization. TEM observations and FTIR results of MCNTs demonstrated that the MCNT nanofillers were coated with the organic/inorganic flame retardant compound. Moreover, the TEM results of the composites indicate that MCNTs dispersed in polystyrene PS matrix uniformly due to the modification. Read More

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February 2021

Strategic Customization of Polymeric Nanocomposites Modified by 2D Titanium Oxide Nanosheet for High-k and Flexible Gate Dielectrics.

Small 2021 Mar 14:e2007213. Epub 2021 Mar 14.

Thin Film Materials Research Center, Korea Research Institute of Chemical Technology (KRICT), 141 Gajeong-ro, Yuseong-gu, Daejeon, 34114, Republic of Korea.

Organic polymer-based dielectrics with intrinsic mechanical flexibility and good processability are excellent candidates for the dielectric layer of flexible electronics. These polymer films can become even more rigid and electrically robust when modified through cross-linking processes. Moreover, the composites formed by dispersing nanoscale inorganic fillers in a polymer matrix can exhibit further improved polarization property. Read More

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Highly Thermal Conductive and Electrical Insulating Epoxy Composites with a Three-Dimensional Filler Network by Sintering Silver Nanowires on Aluminum Nitride Surface.

Polymers (Basel) 2021 Feb 25;13(5). Epub 2021 Feb 25.

School of Chemical Engineering & Materials Science, Chung-Ang University, Seoul 156-756, Korea.

In this study, a new fabrication technique for three-dimensional (3D) filler networks was employed for the first time to prepare thermally conductive composites. A silver nanowire (AgNW)- aluminum nitride (AlN) (AA) filler was produced by a polyol method and hot-pressed in mold to connect the adjacent fillers by sintering AgNWs on the AlN surface. The sintered AA filler formed a 3D network, which was subsequently impregnated with epoxy (EP) resin. Read More

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February 2021

Controlling Native Oxidation of HfS for 2D Materials Based Flash Memory and Artificial Synapse.

ACS Appl Mater Interfaces 2021 Mar 19;13(8):10639-10649. Epub 2021 Feb 19.

Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou 350207, P. R. China.

Two-dimensional (2D) materials based artificial synapses are important building blocks for the brain-inspired computing systems that are promising in handling large amounts of informational data with high energy-efficiency in the future. However, 2D devices usually rely on deposited or transferred insulators as the dielectric layer, resulting in various challenges in device compatibility and fabrication complexity. Here, we demonstrate a controllable and reliable oxidation process to turn 2D semiconductor HfS into native oxide, HfO, which shows good insulating property and clean interface with HfS. Read More

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On-site and quantitative SERS detection of trace 1, 2, 3-benzotriazole in transformer oil with colloidal lignin particles-based green pretreatment reagents.

Spectrochim Acta A Mol Biomol Spectrosc 2021 May 15;252:119469. Epub 2021 Jan 15.

College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China. Electronic address:

Since 1, 2, 3-Benzotriazole (BTA) is one of the most commonly used metal passivators in transformer oil, on-site and quantitative detection of BTA plays a significant role in fast evaluation of the performance of the insulating oil. Herein, we proposed a cycle-growth synthetic protocol for yielding two-dimensional (2D) plane-based surface-enhanced Raman scattering (SERS) substrates with tunable optical property and controllable interparticle distance, and an extraction material, so called colloidal lignin particles (CLPs), for the fast separation of BTA from oil matrix. After BTA from transformer oil were adsorbed by hydrophilic CLPs, highly reproducible SERS signal of BTA can be obtained by dropping on the substrate. Read More

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Epitaxial Growth of Two-Dimensional Insulator Monolayer Honeycomb BeO.

ACS Nano 2021 Feb 22;15(2):2497-2505. Epub 2021 Jan 22.

Department of Physics, The University of Texas at Austin, Austin, Texas 78712, United States.

The emergence of two-dimensional (2D) materials launched a fascinating frontier of flatland electronics. Most crystalline atomic layer materials are based on layered van der Waals materials with weak interlayer bonding, which naturally leads to thermodynamically stable monolayers. We report the synthesis of a 2D insulator composed of a single atomic sheet of honeycomb structure BeO (h-BeO), although its bulk counterpart has a wurtzite structure. Read More

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February 2021

Microstructure, Thermal Conductivity, and Flame Retardancy of Konjac Glucomannan Based Aerogels.

Polymers (Basel) 2021 Jan 14;13(2). Epub 2021 Jan 14.

Glyn O. Phillips Hydrocolloid Research Centre at HBUT, School of Food and Biological Engineering, Hubei University of Technology, Wuhan 430068, China.

With abundant renewable resources and good biodegradability, bio-based aerogels are considered as promising insulating materials for replacing the conventional petroleum-based foam. In this study, konjac glucomannan (KGM)-based aerogels were prepared as thermal insulation materials via a convenient sol-gel and freeze-drying progress with different content of plant polysaccharides, proteins, and wheat straw. The morphology, thermal conductivity, and flame retardancy of KGM-based aerogels were determined. Read More

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January 2021

Highly Sensitive Strain Sensors Based on Molecules-Gold Nanoparticles Networks for High-Resolution Human Pulse Analysis.

Small 2021 Feb 19;17(8):e2007593. Epub 2021 Jan 19.

University of Strasbourg, CNRS, ISIS UMR 7006, 8 Alleé Gaspard Monge, Strasbourg, F-67000, France.

High-performance flexible strain sensors are key components for the next generation of wearable health monitoring devices. Here, the authors have fabricated a novel strain sensor based on gold nanoparticles (AuNPs) interconnected by flexible and responsive molecular linkers. The combination of conductive AuNPs (25 nm in diameter) with tetra(ethylene glycol) dithiol (SH-TEG-SH) linkers yields a covalent 3D network which can be directly deposited onto prepatterned flexible supports exposing interdigitated Au electrodes. Read More

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February 2021

Low-temperature plasma polymerized fluorocarbon coating promotes surface charge dissipation in polystyrene.

Nanotechnology 2021 Mar;32(12):125703

Beijing International S&T Cooperation Base for Plasma Science and Energy Conversion, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, People's Republic of China. School of Electrical Engineering, Chongqing University, Chongqing 400030, People's Republic of China.

Polystyrene (PS) is a common insulating material in pulsed power devices, which has excellent and reliable insulation properties. However, the charge accumulation on the insulator surface seriously threatens its surface insulation property. Surface modification has been verified as an effective way for inhibiting surface charge accumulation. Read More

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Common clothing area factor estimation equations are inaccurate for highly insulating (I>2 clo) and non-western loose-fitting clothing ensembles.

Ind Health 2021 Mar 22;59(2):107-116. Epub 2020 Dec 22.

Energy Institute, Brno University of Technology, Czech Republic.

The aim of this study was to evaluate the equations for calculating the clothing area factor (f) used in the standards based on data sets of clothing ensembles, that are meant to provide thermal comfort over a wide range of climatic conditions from hot summer days to extremely cold winter. Over 10 equations for f calculations were selected from the international standards and the literature. At first a theoretical comparison based on a range of insulation values was performed. Read More

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Gibbs ensemble Monte Carlo simulations of the liquid-vapor equilibrium and the critical point of sodium.

Phys Chem Chem Phys 2021 Jan;23(1):311-319

CNRS, École Normale Supérieure de Lyon, Laboratoire de Géologie de Lyon LGLTPE UMR 5276, 46 allée d'Italie, Lyon 69364, France. and The Centre for Earth Evolution and Dynamics (CEED), University of Oslo, Postbox 1028 Blindern, N-0315 Oslo, Norway.

The ab initio (ai) Gibbs ensemble (GE) Monte Carlo (MC) method coupled with Kohn-Sham density functional theory is successful in predicting the liquid-vapour equilibrium of insulating systems. Here we show that the aiGEMC method can be used to study also metallic systems, where the excited electronic states play an important role and cannot be neglected. For this we include the electronic free energy in the formulation of the effective energy of the system to be used in the acceptance criteria for the MC moves. Read More

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January 2021

InPbSbS: A Stable Quaternary Chalcogenide with Low Thermal Conductivity.

Inorg Chem 2021 Jan 11;60(1):325-333. Epub 2020 Dec 11.

Center for High Pressure Science and Technology Advanced Research (HPSTAR), Beijing 100094, China.

Transition-metal-based chalcogenides are a series of intriguing semiconductors with applications spanning various fields because of their rich structure and numerous functionalities. This paper reports the crystal structure and basic physical properties of a new quaternary chalcogenide InPbSbS. The crystal structure of InPbSbS was determined by both powder and single-crystal X-ray diffraction techniques. Read More

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January 2021

Rigid Polyurethane Foams Reinforced with POSS-Impregnated Sugar Beet Pulp Filler.

Materials (Basel) 2020 Dec 2;13(23). Epub 2020 Dec 2.

Laboratory of Thermal Insulating Materials and Acoustics, Institute of Building Materials, Faculty of Civil Engineering, Vilnius Gediminas Technical University, Linkmenu st. 28, LT-08217 Vilnius, Lithuania.

Rigid polyurethane (PUR) foams were reinforced with sugar beet pulp (BP) impregnated with Aminopropylisobutyl-polyhedral oligomeric silsesquioxanes (APIB-POSS). BP filler was incorporated into PUR at different percentages-1, 2, and 5 wt.%. Read More

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December 2020

Physical and thermal insulation properties of the composites based on seawater-neutralised bauxite residue.

J Hazard Mater 2021 Feb 19;403:123723. Epub 2020 Aug 19.

Chemical & Petroleum Engineering Department, UAE University, P.O. Box 15551, Al Ain, United Arab Emirates.

The objective of this study is to evaluate the possibility of using bauxite residue (BR), which is a highly hazardous waste, as a filler in thermoset polymer matrices for applications in insulating construction materials to minimise heat loss in buildings. Unsaturated polyester resin (UPR) blended with the seawater-neutralised BR in a ratio of 0-60 vol.% was transformed into a solid via a crosslinking process at room temperature. Read More

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February 2021

A Capacitive Sweat Rate Sensor for Continuous and Real-Time Monitoring of Sweat Loss.

ACS Sens 2020 12 2;5(12):3821-3826. Epub 2020 Dec 2.

Institute for Nanobiotechnology, John Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States.

Individualized measurement of sweat loss under heat stress is important in assessing physical performance and preventing heat-related illness for athletes or individuals working in extreme environments. The objective of this work was to develop a low-cost and easy-to-fabricate wearable sensor that enables accurate real-time measurement of sweat rate. A capacitive-type sensor was fabricated from two conducting parallel plates, plastic insulating layers, and a central microfluidic channel formed by laser cutting a plastic film. Read More

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December 2020

In Vitro Infrared Thermographic Assessment of Temperature Change in the Pulp Chamber during Provisionalization: Effect of Remaining Dentin Thickness.

J Healthc Eng 2020 10;2020:8838329. Epub 2020 Nov 10.

Department of Conservative Dentistry and Endodontics, Pomeranian Medical University, Szczecin, Poland.

Interim crowns and partial fixed dental prosthesis materials generate exothermic heat during polymerization. The amount of heat transmitted to the pulp chamber can be a function of several factors, including the thickness and quality of the remaining dentin after crown preparation. The aim of this in vitro study was to measure with infrared thermography the temperature changes on the adjacent surface of the chamber roof of premolar teeth extracted from young and old patients (having different thicknesses of remaining dentin after crown preparation) during fabrication of provisional resinous restorations. Read More

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November 2020

Hybrid Solid Electrolyte Interphases Enabled Ultralong Life Ca-Metal Batteries Working at Room Temperature.

Adv Mater 2021 Jan 20;33(2):e2006141. Epub 2020 Nov 20.

State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials Science and Engineering, Sun Yat-Sen (Zhongshan) University, Guangzhou, 510275, P. R. China.

Currently, the application of calcium metal anodes is challenged by rapidly degenerated plating/stripping electrochemistry without suitable solid electrolyte interphases (SEIs) capable of fast Ca transport kinetics and superior ability to resist anion oxidation. Here, through in situ evolved Na/Ca hybrid SEIs, symmetrical Ca//Ca batteries readily remain stable for more than 1000 h deposition-dissolution cycles (versus less than 60 h for those with pure Ca SEIs under the same condition). Coupled with a specially designed freestanding lattice-expanded graphitic carbon fiber membrane and tailored operation voltages, the proof-of-concept Ca-metal batteries reversibly run for almost 1900 cycles with ≈83% capacity retention and a high average discharge voltage of 3. Read More

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January 2021

Immobilizing a π-Conjugated Catecholato Framework on Surfaces of SiO Insulator Films via a One-Atom Anchor of a Platinum Metal Center to Modulate Organic Transistor Performance.

Inorg Chem 2020 Dec 10;59(24):17945-17957. Epub 2020 Nov 10.

Graduate School of Material Science, University of Hyogo, 3-2-1, Kouto, Kamigori, Ako, Hyogo 6781297, Japan.

Chemical modification of insulating material surfaces is an important methodology to improve the performance of organic field-effect transistors (OFETs). However, few redox-active self-assembled monolayers (SAMs) have been constructed on gate insulator film surfaces, in contrast to the numerous SAMs formed on many types of conducting electrodes. In this study, we report a new approach to introduce a π-conjugated organic fragment in close proximity to an insulating material surface via a transition metal center acting as a one-atom anchor. Read More

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December 2020

Enhanced Thermal Conductivity and Dielectric Properties of h-BN/LDPE Composites.

Materials (Basel) 2020 Oct 23;13(21). Epub 2020 Oct 23.

Tianjin Jinhang Technical Physics Institute, No. 58 Zhong Huan Xi Road, Tianjin Airport Economic Zone, Tianjin 300308, China.

Low-density polyethylene (LDPE), as an excellent dielectric insulating material, is widely used in electrical equipment insulation, whereas its low thermal conductivity limits its further development and application. Hexagonal boron nitride (h-BN) filler was introduced into LDPE to tailor the properties of LDPE to make it more suitable for high-voltage direct current (HVDC) cable insulation application. We employed melt blending to prepare h-BN/LDPE thermally conductive composite insulation materials with different contents. Read More

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October 2020

Proposal of new spinel oxides semiconductors ZnGaO, [ZnGaO]:Mn and Rh: ab-initio calculations and prospects for thermophysical and optoelectronic applications.

J Mol Graph Model 2020 12 10;101:107750. Epub 2020 Sep 10.

Department of Basic Sciences, Military College of Engineering, National University of Science and Technology (NUST), Islamabad, Pakistan.

Transparent conducting oxides (TCOs) of semiconductor family gained significant attention due to increasing trends in the optoelectronic and thermo-physical applications. In current work, we reported electronic, optical, transport and thermodynamical properties of spinel oxides ZnGaO, [ZnGaO]:Mn and [ZnGaO]:Rh compounds. Based on DFT, we employed first-principles calculations implemented in Wien 2k using the modified-Becke-Johnson (mBJ) on parent spinel and generalized-gradient-approximation plus Hubbard potential U (GGA + U) on doped materials, respectively. Read More

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December 2020

Effect of AlO with Different Nanostructures on the Insulating Properties of Epoxy-Based Composites.

Materials (Basel) 2020 Sep 23;13(19). Epub 2020 Sep 23.

Key Laboratory for Robot Intelligent Technology of Shandong Province, Shandong University of Science and Technology, Qingdao 266590, China.

High thermal conductivity insulating dielectrics with good electrical properties have received widespread attention due to the continuous development of power systems and power electronic technologies. In this paper, the effects of differently structured nano alumina fillers on the thermal conductivity and insulating properties of polymer-based composites were studied. It was found that all three types of AlO nano-fillers enhanced the thermal conductivity of the composites, and the thermal conductivity increased more dramatically with increasing filler particle size. Read More

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September 2020

The Research of Conductivity and Dielectric Properties of ZnO/LDPE Composites with Different Particles Size.

Materials (Basel) 2020 Sep 17;13(18). Epub 2020 Sep 17.

Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Harbin University of Science and Technology, Harbin 150080, China.

Nanocomposites exhibit a high dielectric strength, whereas microcomposites exhibit a high thermal conductivity. In this study, good insulating materials were developed on the basis of the synergetic effect of micro- and nanoparticles, which were used as inorganic fillers. With a double-melting blend, nano-ZnO/low density polyethylene (LDPE), micro-ZnO/LDPE, and micro-nano-ZnO/LDPE composites were prepared, according to the scanning electron microscope test, polarization microscope test, conductivity test, breakdown test, and dielectric spectrum test, the dielectric property of micro-nano-ZnO/LDPE was explored. Read More

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September 2020

Joule heating-enabled electrothermal enrichment of nanoparticles in insulator-based dielectrophoretic microdevices.

Electrophoresis 2021 Mar 28;42(5):626-634. Epub 2020 Sep 28.

Department of Mechanical Engineering, Clemson University, Clemson, SC, USA.

Insulator-based dielectrophoresis (iDEP) exploits the electric field gradients formed around insulating structures to manipulate particles for diverse microfluidic applications. Compared to the traditional electrode-based dielectrophoresis, iDEP microdevices have the advantages of easy fabrication, free of water electrolysis, and robust structure, etc. However, the presence of in-channel insulators may cause thermal effects because of the locally amplified Joule heating of the fluid. Read More

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The Effects of the Dynamic Thermophysical Properties of Clothing and the Walking Speed Input Parameter on the Heat Strain of a Human Body Predicted by the PHS Model.

Int J Environ Res Public Health 2020 09 5;17(18). Epub 2020 Sep 5.

College of Fashion and Design, Donghua University, Shanghai 200051, China.

The prediction accuracy of the Predicted Heat Strain (PHS) model is affected by the correction approaches of static thermophysical properties of clothing considering the pumping effects of wind and body movement. In this study, a comparison of different correction algorithms for three types of clothing and their influence on the heat strain predicted by the PHS model was carried out with experimental data obtained from the literature. Results show that the dynamic insulation values calculated by ISO 9920 corrections are larger than those obtained by ISO 7933 when the static insulation values are higher than 0. Read More

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September 2020

A single-electron tunneling model: a theoretical analysis of a metal nanoparticle-doped epoxy resin to suppress surface charge accumulation on insulators subjected to DC voltages.

Nanotechnology 2020 Nov;31(47):475707

Department of Electrical Engineering, Tsinghua University, Beijing 100084, People's Republic of China.

In high-voltage direct current transmission systems, charges accumulate at the gas-solid interface, distorting the local field strength, causing a reduction in the flashover voltage, and threatening the safe and reliable operation of the power system. The latest research has found that doping metal nanoparticles into an epoxy resin effectively suppresses the surface charge accumulation on insulators and improves their flashover voltage. This paper further analyzes the microscopic mechanism of this phenomenon, establishes a single-electron tunneling mode, and draws two conclusions: when there is no agglomeration of the doped nanoparticles, a higher doping concentration can be achieved, which provides a better insulative performance. Read More

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November 2020

Mechanical Strength, Thermal Conductivity and Electrical Breakdown of Kenaf Core Fiber/Lignin/Polypropylene Biocomposite.

Polymers (Basel) 2020 Aug 15;12(8). Epub 2020 Aug 15.

Institute of Tropical Forestry and Forest Products (INTROP), Universiti Putra Malaysia, UPM Serdang, Selangor 43400, Malaysia.

Mechanical strength, thermal conductivity and electrical breakdown of polypropylene/lignin/kenaf core fiber (PP/L/KCF) composite were studied. PP/L, PP/KCF and PP/L/KCF composites with different fiber and lignin loading was prepared using a compounding process. Pure PP was served as control. Read More

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Dynamic Changes in Charge Transfer Resistances during Cycling of Aprotic Li-O Batteries.

ACS Appl Mater Interfaces 2020 Sep 9;12(38):42803-42810. Epub 2020 Sep 9.

Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan.

Various electrolyte components have been investigated with the aim of improving the cycle life of lithium-oxygen (Li-O) batteries. A tetraglyme-based electrolyte containing dual anions of Br and NO is a promising electrolyte system in which the cell voltage during charging is reduced because of the redox-mediator function of the Br/Br and NO/NO couples, while the Li-metal anode is protected by LiO formed via the reaction between Li metal and NO. To maximize the potential of this system, the fundamental factors that limit the cycle life should be clarified. Read More

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September 2020

Electrokinetic biased deterministic lateral displacement: scaling analysis and simulations.

J Chromatogr A 2020 Jul 12;1623:461151. Epub 2020 May 12.

School of Electronics and Computer Science, University of Southampton, Southampton SO17 1BJ United Kingdom.. Electronic address:

Deterministic Lateral Displacement (DLD) is a microfluidic technique where arrays of micropillars within a microchannel deflect particles leading to size-based segregation. We recently demonstrated that applying AC electric fields orthogonal to the fluid flow increases the separation capabilities of these devices with a deflection angle that depends on the electric field magnitude and frequency. Particle deviation occurs in two distinct regimes depending on frequency. Read More

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