• Journal of the Korean Chemical Society
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• v.50 no.3
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• pp.208-215
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• 2006

A simply prepared graphite, pencil-type working electrode was utilized to monitor fenitrothion concentrations, using the cyclic voltammetry (CV) and square-wave (SW) stripping voltammetry methods. The optimum conditions for analysis were sought. A very low detection limit was obtained compared to that obtained when other common voltammetry methods are used. The optimal parameters of the pencil-type electrode were found to be as follows: a pH of 3.7, a frequency of 500 Hz, an SW amplitude of 0.1 V, an increment potential of 0.005 V, an initial potential of -0.9V, and a deposition time of 500 sec. The analytical detection limit was determined to be 6.0 ngL-1 (2.16410-11 molL-1) fenitrothion at SW anodic and CV, and the relative standard deviation at the fenitrothion concentration of SW anodic 10 ugL-1 was 0.30% (n = 15) under the optimum conditions. Analysis was directly conducted through in-vivo real-time assay.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.2
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• pp.107-112
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• 2022

In this study, a silver paste capable of UV curing without using any solvent was developed. The viscosity and viscoelasticity of the silver paste developed as a solvent-free type were measured. And after printing the pattern by screen printing, an electrode coating film was formed by UV curing. Conductivity, pencil hardness, and adhesive force of the formed electrode coating film were evaluated. Finally, the curing characteristics of the electrode coating film were evaluated by TGA and FT-IR. Summarizing these results, in terms of conductivity, adhesion, and curing characteristics, it was found that Paste (4), that is, silver paste obtained by mixing 1.2 ㎛ spherical silver powder and 50 nm silver powder at 72:8% had the best physical properties.

• Journal of Electrochemical Science and Technology
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• v.11 no.3
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• pp.291-309
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• 2020

Chromium was electrodeposited from deep eutectic solvents-based Cr³⁺ electrolytes on HB-pencil graphite electrode. Factors influencing the electrochemical behavior and the processes of Cr nucleation and growth were explored using cyclic voltammetry and chronoamperometry techniques, respectively. Cr³⁺ reduction was found to occur through an irreversible diffusion-controlled step followed by another irreversible one of impure diffusional behaviour. The reduction behavior was found to be greatly affected by Cr³⁺ concentration, temperature, and type of hydrogen bond donor used in deep eutectic solvents (DESs) preparation. A more comprehensive model was suggested and successfully applied to extract a consistent data relevant to Cr nucleation kinetics from the experimental current density transients. The potential, the temperature, and the hydrogen bond donor type were estimated to be critical factors controlling Cr nucleation. The nucleation and growth processes of Cr from either choline chloride/ethylene glycol (EG-DES) or choline chloride/urea (U-DES) deep eutectic solvents were evaluated at 70℃ to be three-dimensional (3D) instantaneous and diffusion-controlled, respectively. However, the kinetics of Cr nucleation from EG-DES was found to be faster than that from U-DES. Cr nucleation was tending to be instantaneous at higher temperature, potential, and Cr³⁺ concentration. Cr nuclei electrodeposited from EG-DES were characterized at different conditions using scanning electron microscope (SEM). SEM images show that high number density of fine spherical nuclei of almost same sizes was nearly obtained at higher temperature and more negative potential. Energy dispersive spectroscopy (EDS) analysis confirms that Cr deposits were obtained.