The Experts below are selected from a list of 13338 Experts worldwide ranked by ideXlab platform
Lei Hou - One of the best experts on this subject based on the ideXlab platform.
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enhanced x band electromagnetic interference shielding performance of layer structured fabric supported polyaniline cobalt nickel coatings
ACS Applied Materials & Interfaces, 2017Co-Authors: Hang Zhao, Lei HouAbstract:Despite tremendous efforts, fabrication of lightweight conductive fabrics for high-performance X-band electromagnetic-interference (EMI) shielding remains a daunting technical challenge. We herein report an ingenious and efficient strategy to deposit polyaniline/cobalt–nickel (PANI/Co–Ni) coatings onto lyocell fabrics that involves consecutive steps of in situ polymerization and electroless Plating. The PANI–Co−Ni ternary-component system successfully induced a synergistic effect from EM wave-absorption and EM wave-reflection and, moreover, upgraded the match level between magnetic loss and dielectric loss. By the judicious control of polymerization cycles and Plating Time, low-weight fabric-supported PANI/Co–Ni composites (with PANI and Co–Ni loading of 2.86 and 3.99 mg·cm–2, respectively) were prepared, which displayed relatively high EMI shielding effectiveness (SE) (33.95–46.22 dB) when compared to their single peers (PANI-coated fabric and Co–Ni-coated fabric) or even the sum of them. Inspired by the...
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Enhanced X‑Band Electromagnetic-Interference Shielding Performance of Layer-Structured Fabric-Supported Polyaniline/Cobalt–Nickel Coatings
2017Co-Authors: Hang Zhao, Lei Hou, Siyi IAbstract:Despite tremendous efforts, fabrication of lightweight conductive fabrics for high-performance X-band electromagnetic-interference (EMI) shielding remains a daunting technical challenge. We herein report an ingenious and efficient strategy to deposit polyaniline/cobalt–nickel (PANI/Co–Ni) coatings onto lyocell fabrics that involves consecutive steps of in situ polymerization and electroless Plating. The PANI–Co−Ni ternary-component system successfully induced a synergistic effect from EM wave-absorption and EM wave-reflection and, moreover, upgraded the match level between magnetic loss and dielectric loss. By the judicious control of polymerization cycles and Plating Time, low-weight fabric-supported PANI/Co–Ni composites (with PANI and Co–Ni loading of 2.86 and 3.99 mg·cm–2, respectively) were prepared, which displayed relatively high EMI shielding effectiveness (SE) (33.95–46.22 dB) when compared to their single peers (PANI-coated fabric and Co–Ni-coated fabric) or even the sum of them. Inspired by the so-called “1 + 1 > 2” phenomenon, here we demonstrated that there was an EMI SE enhancement effect in this conductive polymer/metal system that may be associated with interphase chemical and/or physical interactions. Further analysis revealed that this EMI SE enhancement effect was evident under circumstances of relatively low metal content and became weak with the increase of metal content. The mechanisms involved were interpreted through a series of fundamental measurements, including Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), and vector network analysis (VNA). The linkage between PANI and Co–Ni coatings was in the form of Co–N/Ni–N, which mimics the atomic configuration occurring in cobalt porphyrins. The Co–N/Ni–N configuration strengthened the interphase adhesion and thus resulted in shielding fabrics with high durability for practical applications
S R Wenham - One of the best experts on this subject based on the ideXlab platform.
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uniform Plating of thin nickel layers for silicon solar cells
Energy Procedia, 2013Co-Authors: John Rodriguez, Alison Lennon, S R WenhamAbstract:Abstract This paper describes a galvanic deposition method for the formation of uniformly thin nickel seed layers for silicon solar cells. Unlike the previously-reported electroless and light-induced Plating methods, where the thickness of nickel seed layers can be vary significantly due to non-uniform nucleation of metal which can be exacerbated by variations in surface dopant concentrations and roughness, this method saturates resulting in Ni seed layers of uniform thicknesses in the range of 250-400 nm depending on the Plating Time and patterning process. The method was successfully used in the fabrication of nickel/copper plated homogeneous 100 Ω/□ emitter Si solar cells and laser-doped selective emitter (LDSE) cells, both with screen-printed, Al-alloyed back surface fields. Average cell efficiencies of 18.4% and 18.9% were achieved for the homogeneous emitter cells and LDSE cells, respectively, with the best LDSE cell having an efficiency of 19.2%.
Hang Zhao - One of the best experts on this subject based on the ideXlab platform.
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enhanced x band electromagnetic interference shielding performance of layer structured fabric supported polyaniline cobalt nickel coatings
ACS Applied Materials & Interfaces, 2017Co-Authors: Hang Zhao, Lei HouAbstract:Despite tremendous efforts, fabrication of lightweight conductive fabrics for high-performance X-band electromagnetic-interference (EMI) shielding remains a daunting technical challenge. We herein report an ingenious and efficient strategy to deposit polyaniline/cobalt–nickel (PANI/Co–Ni) coatings onto lyocell fabrics that involves consecutive steps of in situ polymerization and electroless Plating. The PANI–Co−Ni ternary-component system successfully induced a synergistic effect from EM wave-absorption and EM wave-reflection and, moreover, upgraded the match level between magnetic loss and dielectric loss. By the judicious control of polymerization cycles and Plating Time, low-weight fabric-supported PANI/Co–Ni composites (with PANI and Co–Ni loading of 2.86 and 3.99 mg·cm–2, respectively) were prepared, which displayed relatively high EMI shielding effectiveness (SE) (33.95–46.22 dB) when compared to their single peers (PANI-coated fabric and Co–Ni-coated fabric) or even the sum of them. Inspired by the...
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Enhanced X‑Band Electromagnetic-Interference Shielding Performance of Layer-Structured Fabric-Supported Polyaniline/Cobalt–Nickel Coatings
2017Co-Authors: Hang Zhao, Lei Hou, Siyi IAbstract:Despite tremendous efforts, fabrication of lightweight conductive fabrics for high-performance X-band electromagnetic-interference (EMI) shielding remains a daunting technical challenge. We herein report an ingenious and efficient strategy to deposit polyaniline/cobalt–nickel (PANI/Co–Ni) coatings onto lyocell fabrics that involves consecutive steps of in situ polymerization and electroless Plating. The PANI–Co−Ni ternary-component system successfully induced a synergistic effect from EM wave-absorption and EM wave-reflection and, moreover, upgraded the match level between magnetic loss and dielectric loss. By the judicious control of polymerization cycles and Plating Time, low-weight fabric-supported PANI/Co–Ni composites (with PANI and Co–Ni loading of 2.86 and 3.99 mg·cm–2, respectively) were prepared, which displayed relatively high EMI shielding effectiveness (SE) (33.95–46.22 dB) when compared to their single peers (PANI-coated fabric and Co–Ni-coated fabric) or even the sum of them. Inspired by the so-called “1 + 1 > 2” phenomenon, here we demonstrated that there was an EMI SE enhancement effect in this conductive polymer/metal system that may be associated with interphase chemical and/or physical interactions. Further analysis revealed that this EMI SE enhancement effect was evident under circumstances of relatively low metal content and became weak with the increase of metal content. The mechanisms involved were interpreted through a series of fundamental measurements, including Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), and vector network analysis (VNA). The linkage between PANI and Co–Ni coatings was in the form of Co–N/Ni–N, which mimics the atomic configuration occurring in cobalt porphyrins. The Co–N/Ni–N configuration strengthened the interphase adhesion and thus resulted in shielding fabrics with high durability for practical applications
K Balasubramanian - One of the best experts on this subject based on the ideXlab platform.
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electroless nickel phosphorus Plating on graphite powder
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2007Co-Authors: M Palaniappa, Veera G Babu, K BalasubramanianAbstract:Abstract Electroless deposition technique was used to coat Ni–P on graphite particles with high deposition rate and bath stability by activating the graphite powder in a furnace at 380 °C for 1 h. The effect of Plating Time, size of the powder and weight of the powder were studied. It was found that by a simple and controlled Plating method a uniform and continuous layer of nickel could be deposited on the surface of graphite particles. Scanning electron microscopy images and EDS spectra before and after electroless nickel Plating confirm that nickel is deposited on the surface of graphite particles. The rate of increase in weight percent nickel over graphite decreases with Time and reaches a plateau. Further increase in weight is attained by Plating the same powders in a fresh bath to obtain desired Ni–P alloy mass.
Yi Hua - One of the best experts on this subject based on the ideXlab platform.
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electroless pd and ag deposition kinetics of the composite pd and pd ag membranes synthesized from agitated Plating baths
Journal of Membrane Science, 2009Co-Authors: Engin M Ayturk, Yi HuaAbstract:Abstract The atomic absorption spectroscopy (AAS) has been successfully utilized for the measurement of the Pd and Ag ion concentrations in the Plating baths and to elucidate the effects of temperature, initial metal ion and reducing agent concentrations and agitation on the electroless Plating kinetics of Pd and Ag metals. The initial metal ion concentrations for Pd and Ag were varied over a range of 8.2–24.5 mM and 3.1–12.5 mM, respectively. The Plating reactions were conducted in a constant temperature electroless Plating bath over a temperature range of 20–60 °C and an initial hydrazine concentration range of 1.8–5.4 mM. It was found that the electroless Plating of both Pd and Ag were strongly affected by the external mass transfer in the absence of bath agitation. The external mass transfer limitations for both Pd and Ag deposition have been minimized at or above an agitation rate of 400 rpm, resulting in a maximum conversion of the Plating reaction at 60 °C and dramatically shortened Plating Times with the added advantage of uniform deposition morphology. The derivation of the differential rate laws and the estimation of the reaction orders and the activation energies for the electroless Pd and Ag kinetics were conducted via non-linear regression analysis based on the method of initial rates. For a constant-volume batch reactor, the integrated rate law was solved to calculate the conversion and the reactant concentrations as a function of Plating Time. The model fits were in good agreement with the experimental data. Furthermore, the bath agitation and the Plating conditions used in the kinetics study were adopted for the synthesis of 16–20 μm thick composite Pd/Ag membranes (10–12 wt% Ag) and a pure-Pd membrane with a hydrogen selective dense Pd layer as thin as 4.7 μm. While hydrogen permeance of the Pd/Ag membranes A and B at 450 °C were 28 and 32 m 3 /m 2 -h-atm 0.5 , the H 2 permeance for the 4.7 μm thick pure-Pd membrane at 400 °C was as high as 63 m 3 /m 2 -h-atm 0.5 . The long-term permeance testing of all the membranes synthesized from agitated Plating baths resulted in a relatively slow leak growth due primarily to the improved morphology obtained via the bath agitation and modified Plating conditions.