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Boguslaw Pierozynski

The effect of thermal treatments on the mechanical and electrical properties of nickel-coated carbon fibre composites

Nickel-coated carbon fibre (NiCCF) composites may find technological applications within many industrial sectors, including: laptop computers, automotive and military industries. Typically, these applications require that NiCCF be subjected to extensive material processing; thus, optimization of mechanical (and electrical) properties for this material at the stage of its production is of significant importance. The present paper reports the application of specific, high-temperature heat treatments to laboratory-produced 12K50 NiCCF material, carried-out in order to improve the ductility and interfacial adhesion of electrodeposited Ni coating to the surface of carbon fibre substrate.

Open access

Boguslaw Pierozynski and Tomasz Mikolajczyk

Abstract

Electrochemical oxidation of ethanol becomes an important process of modern electrochemistry, due to its potential application into direct ethanol fuel cell technology. As rates of ethanol oxidation reaction (EOR) are significantly enhanced in alkaline media, employment of highly corrosion resistant under alkaline conditions, but non-noble metals becomes of superior practical importance. This communication article reports on the process of anodic dissolution of platinum, which is investigated on Pt activated, electrooxidized nickel foam electrodes, employed for ethanol oxidation reaction in 0.1 M sodium hydroxide solution. The above was revealed through the application of cyclic voltammetry and combined SEM/EDX (scanning electron microscopy and energy dispersive x-ray) spectroscopy examinations.

Open access

Tomasz Mikołajczyk, Marcin Turemko and Bogusław Pierożyński

Abstract

In this study, palladium-modified nickel foam substrate was applied to examine ethanol oxidation reaction (EOR) in 0.1 M NaOH supporting solution. An EOR catalyst was prepared by physical vapour deposition (PVD) of palladium onto Ni foam material. Temperature-dependent kinetics of the EOR were studied over the temperature range: 20-60°C by means of a.c. impedance spectroscopy and cyclic voltammetry techniques. Deposition of a noble metal additive was clearly exposed through scanning electron microscopy: SEM/EDX-supported analysis. Most importantly, this work investigated the effect of pre-deposited fullerene on nickel foam, on the catalytic (EOR) properties of such-produced Ni foam/Pd composite material.

Open access

Bogusław Pierożyński and Tomasz Mikołajczyk

Abstract

The electrochemical activity towards hydrogen evolution reaction (HER) was studied on commercially available (Toho-Tenax) and Ru-modified nickel-coated carbon fibre (NiCCF) materials. Quality and extent of Ru electrodeposition on NiCCF tows were examined by means of scanning electron microscopy (SEM). Kinetics of the hydrogen evolution reaction were investigated at room temperature, as well as over the temperature range: 20-50°C in 0.1 M NaOH solution for the cathodic overpotential range: -100 to -300 mV vs. RHE. Corresponding values of charge-transfer resistance, exchange current-density for the HER and other electrochemical parameters for the examined fibre tow composites were recorded.

Open access

Boguslaw Pierozynski and Henryk Bialy

Abstract

This communication reports on the concerns associated with possible generation of galvanic coupling effects for construction materials that are used to manufacture mounting assemblies for ground-mounted photovoltaic (PV) power stations. For this purpose, six macro-corrosion galvanic cells were assembled, including: hot-dip Zn/Magnelis®-coated steel/Al and stainless steel (SS)/Al cells. Corrosion experiments involved continuous, ca. three-month exposure of these couplings in 3 wt.% NaCl solution, conducted at room temperature for a stable pH value of around 8. All corrosion cells were subjected to regular assessment of galvanic current-density and potential parameters, where special consideration was given to compare the corrosion behaviour of Zn-coated steel samples with that of Magnelis®-coated electrodes. Characterization of surface condition and elemental composition for examined materials was carried-out by means of SEM and EDX spectroscopy techniques.

Open access

Grazyna Piotrowska and Boguslaw Pierozynski

Abstract

This work reports on the process of phenol electrooxidation, which is carried-out through continuous electrolysis of synthetic, sodium sulphate-based wastewater. Phenol electrodegradation is examined by means of a laboratory size (ca. 700 cm3 of working volume), poly (methyl methacrylate)-made electrolyser unit for various, carbon fibre and graphite-based anode configurations, and stainless steel cathodes, two different current-densities and concentrations of phenol in synthetically prepared wastewater solution. Proper monitoring of phenol degradation (including quantitative identification of reaction products and calculation of specific energy consumption) in wastewater is performed by means of instrumental, combined HPLC and MS technique in function of electrolysis time.

Open access

Bogusław Pierożyński, Grażyna Piotrowska and Tomasz Mikołajczyk

Abstract

This work reports on kinetics of phenol electrooxidation reaction (PhER), examined at polycrystalline Pt electrode in 0.5 M H2SO4 and 0.1 M NaOH supporting solutions. Important aspects of PhER kinetics were analysed based on potential-dependent, a.c. impedance-derived values of charge-transfer resistance and capacitance parameters. Special attention was also given to the influence of supporting electrolyte ions on the process of phenol oxidation (pH dependence of the PhER), in relation to an important role of anion adsorption on the Pt catalyst surface.

Open access

Lech Smoczyński, Kamilla Teresa Muńska, Bogusław Pierożyński and Marta Kosobucka

Electrocoagulation makes an alternative method to chemical coagulation. This paper presents the results obtained during the electrocoagulation of the model wastewater using aluminum electrodes. The wastewater was treated by means of chronopotentiometric electrocoagulation process in a static system, at the constant current I = 0.3 A; therefore higher doses of electrocoagulant required longer electrocoagulation time. Changes in zeta potential, pH, turbidity, chemical oxygen demand (COD), suspended solids and total phosphorus concentrations in the treated wastewater were determined. A new method for determining the optimal dosage of the aluminum electrocoagulant was proposed through application of the third degree polynomial function rather than the parabolic equation. An increase in the electrocoagulant dose raised the share of sweep fl occulation in the studied treatment process, resulting in the effective removal over 90% of phosphorus compounds from the system.

Open access

Lech Smoczyński, Kamilla Teresa Muńska, Marta Kosobucka, Bogusław Pierożyński, Regina Wardzyńska and Beata Załęska-Chróst

Abstract

This paper discusses the results of laboratory analyses of the coagulation and flocculation of model wastewater. The investigated wastewater was susceptible to treatment by chemical coagulation. The effectiveness of two commercial coagulants, PAC produced at the DEMPOL-ECO Chemical Plant and PIX manufactured by KEMIPOL, was compared. A mathematical model relying on a second-degree polynomial was used to describe and analyze experimental data. In each case, the parabola minimum point was a precisely determined coagulant dose, regarded as the optimal dose. The application of a coagulant dose higher than the optimal dose reduced the effectiveness of wastewater treatment by coagulation. A detailed analysis of turbidity, suspended solids, total phosphorus and pollutant removal measured by the COD test revealed that PAC was a more effective and a more efficient coagulant than PIX. The risk of coagulant overdosing was greater with the use of PAC than PIX.