Papers by Keyword: Chemical Deposition

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Authors: Shi Lei
Abstract: It introduces a kind of technique method that recycling waste liquid in the sulfate copper plating technological experiment in the laboratory, involving the fields in electroplating and comprehensive utilization of waste liquid. This process includes the following steps: first filter the waste liquid to remove impurities in it, and then using electrolytical method to recycle copper in the waste liquid. Add NaOH, NaHSO3 into the solution, through chemical deposition remove heavy metal ions in the waste liquid, and carry on the harmlessization handle to sediments, finally deal with the waste liquid through a semipermeable membrane to get pure water. This process provides a kind of simple, easy to operate, low cost method for the treatment with waste liquid of electroplating produced in the laboratory, which is toxic and pollute the environment.
Authors: Bárbara Ramos Ferreira, Andrea Santos Liu, Liu Yao Cho
Abstract: Pyrrole was successfully polymerized on copper surface in ethanol solution using hydrogen peroxide as catalyst to generate an adherent and homogeneous polypyrrole (PPy) coating. The PPy was formed of clusters composed of small spherical grains. The layer has remained stable when immersed in 0.1mol L-1 NaCl for 7 days, which indicated that the copper-PPy arrangement is stable in corrosive environment. The polarisation curves showed that the PPy layer can promote a positive displacement in the corrosion potential compared to the value of the uncoated copper. It also was observed that the corrosion current density decreases sharply in the presence of the lauric acid as dopant. These results indicate that PPy-lauric acid can act as a protective layer on copper and improve the overall corrosion performance.
Authors: Ramin Rohanizadeh, W.A. Al-Fraih, M. Harsono, Racquel Z. LeGeros
Authors: Anatoly V. Chzhan, Semen Y. Kiparisov, Gennagy S. Patrin
Abstract: Coercivity of amorphous Co-P single-layer and trilayer films fabricated by chemical deposition has been investigated. It has been established that the thickness dependences of the coercivity for isotropic and anisotropic films are different. Data on the coercivity variation with a nonmagnetic spacer thickness and a number of magnetic layers in the trilayer films are reported. The results obtained are analyzed with regard to the features of the induced anisotropy in amorphous ferromagnetic films and the magnetic coupling between magnetic layers in sandwich structures.
Authors: Jin Han Jeon, Il Kwon Oh, Jae Hung Han, Sun Woo Lee
Abstract: The ionic-polymer-metal-composite actuators can easily actualize the bio-mimetic fish-like locomotion owing to their best merit for large deformation. And novel fabrication methods of IPMC patterned with multiple electrodes were developed to apply the different driving waves to the multiple electrodes. Generally, the IPMC actuator has been fabricated in electroless plating technique, while it is high time-consuming process, showing poor repeatability in the actuation performance due to the variables in the process of fabrication. Therefore the several fabricating methods was newly investigated by combining electroless plating, photolithography, physical sputtering and electroplating techniques capable of precisely patterning and actuating of the multiple electrodes. On the whole, four different methods were compared and analyzed in similar thickness level of Platinum electrodes. Consequently, the mixing the electroless chemical reduction and electroplating can be a promising candidate for the low time-consuming method and the better bending performance.
Authors: Mónica Araceli Vidales-Hurtado, Arturo Mendoza-Galván
Abstract: Nickel hydroxide nanoporous electrochromic thin films were obtained by chemical bath deposition method using nickel nitrate in two different formulations. In one case, ammonium hydroxide controlled the precipitation of the β-Ni (OH)2 phase through the formation of coordination compounds. In the second case, the decomposition of urea yielded the α-Ni (OH)2 phase. After thermal annealing in air in between 250 and 300 °C, the electrochromic behavior of the films was examined by cyclic voltammetry and single wavelength transmittance. The optical contrast and structural transformations between colored and bleached states of the samples were studied by ex-situ optical transmittance, X-ray diffraction, as well as Raman and infrared reflectance spectroscopies. The α-Ni (OH)2 films showed higher optical contrast and reversibility, properties associated with their porous morphology which is revealed by scanning electron microscopy studies.
Authors: Anatoly V. Chzhan, V.A. Seredkin, Gennady S. Patrin, Vladimir N. Zabluda, Yan V. Zubavichus, Yu.L. Mikhlin, R.Yu. Rudenko
Abstract: Amorphous Со-Р and Co-Ni-P films fabricated by chemical deposition under the same conditions are investigated. It is demonstrated that the phosphorous content in the Co-Ni-P exceeds that in the Со-Р films by 1.5−2%. The atomic force microscopy analysis of the surface morphology shows that incorporation of Ni atoms in the Со−Р alloy leads to coarsening of grains due to the higher rate of deposition of Ni atoms as compared with the rate of deposition of Со atoms. The reduction of the dispersion of the polar Kerr effect saturation field in the Со-Ni-P films is attributed to ordering of Сo-Ni atomic pairs.
Authors: Lida Mahmoudi, Farzad Mahboubi, Moreteza Saghafi Yazdi
Abstract: Nickel oxide/carbon nanotubes (NiO/CNTs) composite materials for supercapacitor are prepared by chemically depositing of nickel hydroxide onto CNTs pretreated by ultrasonication and followed by thermal annealing at 200-300°C. A series of NiO/CNTs composites with different weight ratios of CNTs and different annealing temperature are synthesized via the same route. The scanning electron microscope (SEM) images show that the nucleation of the nickel hydroxide formed on the outer walls of CNTs due to ultrasonic cavitations, and then nickel oxide coated uniformly on the outer surface of the individual CNTs after thermal annealing. The NiO/CNTs electrode presents a maximum specific capacitance of 254 F/g as well as a good cycle life in 2 M KOH electrolyte. The good electrochemical characteristics of NiO/CNTs composite can be attributed to the three-dimensionally interconnected nanotubular structure with a thin film of electroactive materials.
Authors: Ramin Rohanizadeh, Racquel Z. LeGeros
Abstract: The aim of this study was to deposit an adherent apatite coating on titanium substrate using a two-step chemical deposition method. First, titanium substrates were immersed in an acidic solution containing calcium and phosphate ions, resulting in the deposition of a monetite (CaHPO4) coating. Second, the monetite crystals were converted to apatite by hydrolysis in NaOH solution. Composition and morphology of the initial and final coatings were identified using X-ray diffraction (XRD), Scanning Electron Microscopy, and Energy Dispersive Spectroscopy (EDS). The final coating was porous and the apatite crystals were agglomerated and followed the outline of the large monetite crystals. The average tensile bond of the coating was 5.2 MPa and cohesion failures were observed more frequently than adhesion failures. The coating adhesion measured using scratch test was 13.1N. In conclusion, this study showed the potential of a two-step chemical deposition method for depositing an adherent coating of apatite at low temperatures.
Authors: Jing Wu Zheng, Zhi Liang Wang, Liang Qiao, Wei Cai, Li Qiang Jiang, Yao Ying, Sheng Lei Che
Abstract: Abstract. This article reports the chemical deposition of silver shells on the surface of micro- carbon spheres. The structure, morphology and composition were characterized by scanning electron microscopy and X-ray diffraction. These result show that: concentrated nitric acid can transform the hydrophily of carbon surface; the application of promoting tin-or silver-containing agents that enhance metallic shell deposition by vigorous redox reaction between Sn2+or Ag+, is important to the site-selective deposition of silver. The resulting thickness of uniform silver shells on the surface of carbon and the crystal size of silver is 24.8nm. Amount of Ag-C core-shell structure composite can be systematically controlled through adding PVP and modest pH value
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