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In this paper, hydrothermal method was used to provide stable colloidal suspension of spherical carbon nanoparticles (CNPs) with good uniformity of size and shape. XRD analyses showed the formation of crystalline structure of carbon material. CNPs Raman spectrum indicates the high quality with a low content of structural defects and high graphitic degree. The formation of CNPs is confirmed by an absorption peak at 264 nm. XPS technique showed well a significant decrease of oxygen-containing functional groups, indicating a low degree of graphite oxidation. The active surface area of CNPs was measured by BET technique. TEM images show that CNPs are nearly spherical in shape and the diameters varying between 50 and 120 nm. The CV behaviors showed that CNPs exhibit the higher specific capacitance values, and is greatly improved over that of previously reported carbon nanomaterials.

BACKGROUND: Titanium nitride (TiN), titanium carbide (TiC) and titanium carbonitride (TiNC) thin films show promising practical applications due to their photoelectric properties and corrosion behaviour. OBJECTIVE: In this work, we investigated the factors which may affect the optical properties and the corrosion behaviour of these coatings. METHODS: The titanium coatings were carried out by sputtering using the target of Ti6Al4V (purity 99.96%) with different N2, CH4 and Ar partial pressures. XRD, FTIR, Raman and SEM with EDX studies show the formation of titanium nitride, titanium carbide coatings. Uv-vis spectroscopy was carried out to estimate the optical properties using the numerical Swanepoel method. Potentiodynamic polarization studies in Hank’s solution show that the corrosion resistance is found to be in the order of C-TiN(2) > C-TiN(1) > TiN > TiC. RESULTS: A high protective efficiency was determined (60%) when comparing TiNC(2) and TiC corrosion current densities, which confirms the lower corrosion velocity and the higher passivation stability of the coatings composed with TiN and TiC phases. Electrochemical impedance spectroscopy studies show that the Rct increases in the following order: TiC < TiN < C-TiN(1) < C-TiN(2), highlighting the fact that C-TiN(2) coating has the higher corrosion resistance.

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A variety of chemical and physical procedures could be used for synthesis of silver nanoparticles. However, these methods are confronted with many problems including use of toxic solvents. A green method for silver nanoparticles synthesis using dittrichia viscosa leaves extract is proposed. This plant is available in abundance on the coastal Mediterranean countries can replace polyvinylpyrrolidone conventionally used in the synthesis of silver nanoparticles. Polyol method (reflux heating) was used for silver nanoparticles synthesis. The nanoparticles obtained were characterised using X-ray diffraction, ultraviolet-visible spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy and transmission electron microscopy. Compared with silver nanoparticles prepared by polyvinylpyrrolidone and ethanol 96%, the bactericidal effect of silver nanoparticles synthesised by dittrichia viscosa is more efficient against bacteria. No toxic solvents were used in the present work; therefore, it is an environmentally safe method with potential for biomedical applications.

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