Phosphate ion sensor fabrication based on conductive polymer polypyrrole film coatings in doped phosphate using thick film technology

This study describes the development of chemical sensors to detect polypyrrole (PPy) based phosphate sensors in doped di-ammonium hydrogen phosphate (DAP) with thick film technology (TFT). Manufacturing screen-printed carbon electrode (SPCE) with thick film uses alumina substrate provided a more portable, miniature, inexpensive, and reduced use of samples and reagents. Polymer polypyrrole and di-ammonium hydrogen phosphate as sensitive membranes are electrodeposition on carbon electrodes. Characterization has been conducted to see the electrode morphology in scanning electron microscopy (SEM) test, which showed that sensitive material particles were distributed evenly on the surface of the sample and spherical. The energy dispersive spectroscopy (EDS) experiment results showed the atomic composition respectively carbon 86.95 %, nitrogen 6.94 %, oxygen 5.9 %, and phosphate 0.21 %, which were exposed to the electrode. The performance test of electrodes with a phosphate standard solution has proceeded at a concentration between 5 to 100 mg/l, which is measured using the galvanostatic method. The voltage range was from 0.252 to 0.957 V with R2 at approximately 90.265 %. The results of sensor performance were concluded that the electrode was able to detect phosphate ions.

Assessment and Evaluation of Blended Cement Using Bamboo Leaf Ash BLASH Against Corrosion

Concrete provides a high degree of protection against corrosion of embedded steel reinforcement. Owing to the harsh environmental conditions and the presence of aggressive elements from the marine environment, deteriorating corrosion affects the durability of reinforced concrete structures. This study evaluated the effectiveness of bamboo leaf ash BLASH as a supplementary cementing material or admixture with Portland cement to improve the durability of reinforced concrete structures. Specimens of 0, 10, 15, and 20% BLASH mixtures were prepared using 16, 20, and 25 mm steel reinforcements. A total of 100 cylindrical specimens were cast and used in this study. The specimens were accelerated by corrosion using impressed current techniques and a galvanostatic method in a simulated environment. The results show that specimens with a BLASH content of 10% exhibited superior performance and exhibited longer corrosion initiation and propagation times. It has a higher resistance to acid penetration and lower corrosion rates. The crack parameters of the specimen with BLASH admixtures, such as the crack width and crack frequency, were negligible. The use of BLASH as an admixture strengthens its durability and improves its residual strength and serviceability. Doi: 10.28991/cej-2021-03091707 Full Text: PDF

Electrodeposition of Bi-Se thin films involving ethylene glycol based electrolytes

The work is devoted to the electrochemical deposition of Bi-Se thin films from ethylene glycol-based electrolytes. The studies have been carried out by potentiodynamic and galvanostatic methods under various conditions, using Pt and Ni electrodes. By recording cyclic and linear polarization curves, the potential range of deposition of thin Bi-Se films on Pt (-0.75 to -1.2 V) and Ni (0.2 to -0.85 V) electrodes was determined. A comparison of the polarization curves of two electrodes showed that co-electrodeposition of Bi and Se occurs in approximately the same potential range. In order to find the optimal mode and composition of the electrolyte, the effect of various factors (concentration of initial components, temperature, etc.) on the process of co-electrodeposition of Bi with Se was studied. In addition, the samples of Bi-Se thin films obtained on Ni electrodes using the galvanostatic method were studied by scanning electron microscope (SEM) and X-ray phase analysis. The results of X-ray phase analysis confirmed the formation of thin Bi2Se3 films with and without additional heat treatment step. Elemental analysis of obtained films carried out by EDS shows that films contained 62.79 wt. % Bi and 37.21 wt. % Se.

Synthesis and Characterization of NiFeCo3O4 Ternary Thin Film Electrodes for Supercapacitors Applications by Galvanostatic Method

At this present task, an attempt done in order to synthesize NiFeCo3O4 ternary thin film electrode by Electrodeposition method. Microstructure of the films studied using X-ray diffraction, energy dispersive X-ray spectroscopy (EDAX) and Field emission (FESEM) scanning electron microscopy. Films Electrochemical property were studied and confirmed with the help of charge discharge techniques using cyclic voltammetry, which confirms that the prepared electrode has excellent electrochemical capacitive behaviour with 757 F g–1 specific capacitance value of at the density in current about 1 mA g–1.

Experimental Comparability Among Different Accelerated Reinforced Steel Concrete Corrosion Methods

The objective of this paper is to inspect the effect of changing the density of the impressed current and wetting-drying condition on accelerated corrosion of reinforced concrete specimens by a galvanostatic method. Small-scale reinforced concrete columns were prepared and then artificially corroded by different setups of accelerated corrosion under an impressed current and also under different wetting-drying cycles for comparison. The density of the impressed current ranged between 50 and 500 µA/cm2 with different wetting-drying cycles periods. Corrosion current, and cracking were monitored throughout the accelerated corrosion period to determine the level of damage caused by the development of expansive reinforcement steel corrosion products, appearance of the first crack, and pattern of cracking.The results indicated that the galvanostatic method with wetting-drying sequences can be utilized effectively to simulate the normal corrosion of steel reinforcement in the concrete structure. The usage of different intensities of the current has no influence on the crack pattern. Though, increasing the current level leads to a substantial increase in the crack width due to corrosion of the steel reinforcement in a shorter time.

Comparative Study of POA-PVS-DBS-GOD Electrode in Acetate and Phosphate Buffers for Determination of Glucose

In the present research work, the poly(o-anisidine)-polyvinyl sulphonic acid-dodecylbenzene sulphonic acidglucose oxidase (POA-PVS-DBS-GOD) electrode have been investigated. The silver electrode was used for the synthesis of poly(o-anisidine)-polyvinyl sulphonic acid-dodecylbenzene sulphonic acid (POA-PVS-DBS) composite film using galvanostatic method with 0.2 M o-anisidine, 0.4:0.1 M PVS:DBS, 1.0 pH and 1 mA/cm2 applied current density at room temperature. The synthesized film was characterized by using electrochemical technique, conductivity measurement, UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Glucose oxidase (GOD) was immobilized on synthesized POA-PVS-DBS composite film by cross-linking via glutaraldehyde in acetate buffer and phosphate buffer. The Michaelis-Menten constant (K′m) was determined for the immobilized enzyme. The POA-PVS-DBS-GOD electrode shows the maximum current response at pH 5.5 and potential 0.6 V. The sensitivity of POA-PVS-DBS-GOD electrode in acetate buffer and phosphate buffer has been recorded. The results of this investigation reveal that the phosphate buffer gives faster response as compared to acetate buffer in amperometric measurements.