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Y2O3 nanoparticles were used in a polyethersulfone (PES) as additives to increase the permeation properties of the polymeric membranes. Membranes were manufactured by diffusion-induced phase inversion in N-methyl-pyrrolidone (NMP) using a different concentration of nanoparticles. Y2O3 is used in polymeric membranes to enhance their functional properties, especially in wastewater treatment processes. Incorporating Y2O3 nanoparticles into the polymer matrix improves the membrane’s hydrophilicity, permeability, and mechanical strength. Additionally, Y2O3 provides better properties and reduces fouling. Recent studies highlight its potential as a modifying agent for advanced composite membranes. This paper investigated challenges in the synthesis of Y2O3-enhanced membranes and links synthesis with performance. It was observed that the composite membranes have better permeation properties by adding a small amount of Y2O3. For membranes at 21 wt.% PES permeability increase from 107 to 112 L/m2·h/bar. Fouling performance increases by adding nanoparticles, relative flux decreases by 30% for membranes without nanoparticles and by 10% for membranes with nanoparticles, both at a concentration of 25% PES. Rejection increases for membranes at 21%Pes from 21% for membranes without nanoparticles to 39% for membranes with nanoparticles. The influence of Y2O3 nanoparticles on the membranes’ performance was determined by filtration experiments to establish the permeability, fouling, retention, and the water flux; by contact angle to establish the surface hydrophilicity; and by SEM to investigate the membranes’ structures.

In this study Ni/nano-TiC functional composite coatings were produced by electro-codeposition of TiC nanoparticles (50 nm mean diameter) with nickel on 304L stainless steel support. Coatings were obtained from a Watts classical solution in which TiC nanoparticles were added. The surface morphology, chemical composition, structure, roughness and thickness, were evaluated in relation to the effect of TiC nanoparticles incorporation into Ni matrix. It was found that incorporation of TiC nanoparticles into the nickel matrix produces morphological changes in the deposit and increases the roughness. The fretting wear behavior in wet conditions of the obtained coatings was evaluated on a ball-on-plate configuration. To evaluate the wet fretting wear (tribocorrosion) behavior the open circuit potential was measured before, during and after the fretting tests at room temperature in the solution that simulates the primary water circuit of Pressurized Water Reactors. The results show that Ni/nano-TiC composite coatings exhibited a low friction coefficient, high nanohardness and fretting wear resistance in wet conditions compared with pure Ni coatings.

The aim of this work was to obtain hybrid Co/UHMWPE composite biocoatings reinforced by UHMWPE (ultra high molecular weight polyethylene) biopolymer microparticles in the cobalt matrix, by electro-codeposition technique, with possibilities to use them as biomaterials. UHMWPE was selected as surface modifier element, due to its high biocompatibility and low coefficient of friction being used in many biomedical applications. Cobalt is already used in biomedical implants as cobalt – chromium alloys. The obtained coatings were investigated in terms of surface morphology (scanning electron microscopy - SEM), chemical composition and inclusion percentage (energy dispersive X-ray spectroscopy - EDX), roughness and microtopography (atomic force microscopy - AFM), coating thickness and microhardness. The SEM morphologies of electrodeposited pure cobalt and Co/UHMWPE composite biocoatings, show differences due to UHMWPE biopolymer particles incorporation in the cobalt matrix. The inclusion of UHMWPE microparticles increases with increasing the UHMWPE concentration in the electrolyte as was demonstrated by EDX investigations. The addition of the UHMWPE biopolymer microparticles to the deposition bath led to an increase of the roughness of hybrid coatings comparatively with pure cobalt coating obtained under the same conditions. The coating thickness of the electroplated surfaces as were observed by cross sectional scanning electron micrographs confirm higher adhesion strength of the coatings on the stainless steel support.

Metallic biomaterial are the most suitable for replacing failed hard tissue up to now and for that is important to know the tribocorrosion resistance of these materials before use in biomedical applications. Surface engineering can play a significant role in extending the performance of medical implants made of titanium and its alloys. In this work was chosen electrodeposition of hydroxyapatite (HA) coatings into nanoporous titania layer formed by anodic oxidation as modified Ti-6Al-4V alloy surface. The comparative tribocorrosion behavior of untreated Ti-6Al-4V alloy surface, anodic nanoporous TiO2 surface and electrodeposited hydroxyapatite (HA) coatings into nanoporous TiO2 layers has been investigated in a bio-simulated fluid solution. The results of these investigations have shown that both surface treatments applied have improved the tribocorrosion resistance and friction coefficients as compared to the untreated Ti–6Al–4V alloy surface.

The life time of the metallic materials exposed to marine environment is influenced by their corrosion resistance. The marine environment is considered to be very aggressive to metallic materials used in the marine industry. In order to protect metallic substrates against corrosion process, important efforts have been made to develop corrosion resistance coatings, besides the cathodic protection systems. Thus, during the last years there were developed a series of organic protective coatings that have as principal component one or more polymers. This paper present a comparative investigation regarding the corrosion resistance of: i) uncoated naval steel EN32, ii) coated naval steel EN32 with a two-component polymeric primer and iii) coated naval steel EN32 with two-component polymeric primer followed by epoxy polyurethane paint coating. All the samples have been subjected to corrosion in seawater collected from the Black Sea (Mangalia sea port). In situ electrochemical measurements as: open circuit potential (OCP), polarization resistance (Rp), potentiodynamic polarization (PD) and cyclic voltammetry polarization (CV) were performed to monitor the corrosion process. The results showed an improved corrosion resistance of polymeric coatings in marine environment compared with uncoated naval steel EN32

In this paper, the results on the surface morphology, nanohardness and tribocorrosion properties of electrodeposited nanostructured Ni/TiC hybrid layers compared with pure Ni layers are presented. The Ni/nano-TiC hybrid layers were obtained by electro-codeposition of TiC nanoparticles (50 nm mean diameter) with nickel from a Watts type bath, on 316L stainless steel support. The combined fretting-corrosion performance was investigated using a reciprocating ball-on-disk tribometer coupled to an electrochemical cell in an electrolyte which simulates the primary water circuit of Pressurized Water Reactors (PWRs). Open circuit potential, as in situ electrochemical technique was performed before, during and after fretting tests in order to obtain information on the changes in surface conditions induced by fretting. The results clearly revealed enhanced nanohardness, improved tribocorrosion properties and reduced coefficients of friction for Ni/nano-TiC hybrid layers as compared to pure Ni layers. The much improved nanohardness and tribocorrosion behaviour can be attributed to the TiC nanoparticles reinforced into Ni matrix.

Vegetable extracts have become important as an environmentally acceptable, readily available and renewable source for wide range of inhibitors. They are the rich sources of ingredients which have very high inhibition efficiency. The aim of the present work is to study the corrosion inhibition characteristics of aqueous extract of USINHIB (the abbreviation attributed to garlic extract, derived from romanian language, which was used as vegetable inhibitor), which have been studied as an eco-friendly green inhibitor for corrosion control of carbon steel in 0.5 M hydrochloric acid. The inhibitive effect of naturally available vegetable extract USINHIB toward the corrosion of carbon steel in 0.5 M HCl solution has been investigated by electrochemical techniques. Open circuit potential, potentiodynamic polarization, electrochemical impedance spectroscopy and cyclic voltammetry in presence and absence of vegetable inhibitor were used to provide detailed information about the corrosion of steel surface which occurs in acidic environment. The three electrode electrolytic cell was used. The obtained results showed the increase in the inhibition efficiency.

The paper discusses the electrochemical interactions of Co-Cr alloy with different physiological solutions and organic substances, containing different ions and different pH values, which should play a key role in the materials lifetime. The physical and chemical reactions are numerous and the passivity of the Co-Cr alloy is submitted to the influence of the liquid environment. Some electrochemical investigations were carried out for understanding and predicting the passivity and the corrosion resistance of Co-Cr alloy in three types of simulated body fluids (SBF), namely Fusayama Meyer artificial saliva (pH=5), Hank’s solution (pH=7.4), Ringer's solution (pH=6.6) and citric acid as organic solution. The reason of using another type of environment (other than SBF), such as citric acid is that this medium is a powerful oxidant and has a lower pH value (pH=1.8). This acid environment can influence the state (the formation and growth) of the oxide layer on the surface of the alloy. Research has shown different behavior of the cobalt chromium alloy according to the pH, the chloride content and the oxidizing nature of the environment. Co-Cr alloy biomaterial, immersed in four aqueous media reveals that there are different levels of stabilization of the potential and different current densities depending on the pH value. The Co-Cr alloy biomaterial is very sensitive to localized corrosion (pitting) in Hank solution.

Y[sub.2]O[sub.3] nanoparticles were used in a polyethersulfone (PES) as additives to increase the permeation properties of the polymeric membranes. Membranes were manufactured by diffusion-induced phase inversion in N-methyl-pyrrolidone (NMP) using a different concentration of nanoparticles. Y[sub.2]O[sub.3] is used in polymeric membranes to enhance their functional properties, especially in wastewater treatment processes. Incorporating Y[sub.2]O[sub.3] nanoparticles into the polymer matrix improves the membrane’s hydrophilicity, permeability, and mechanical strength. Additionally, Y[sub.2]O[sub.3] provides better properties and reduces fouling. Recent studies highlight its potential as a modifying agent for advanced composite membranes. This paper investigated challenges in the synthesis of Y[sub.2]O[sub.3]-enhanced membranes and links synthesis with performance. It was observed that the composite membranes have better permeation properties by adding a small amount of Y[sub.2]O[sub.3]. For membranes at 21 wt.% PES permeability increase from 107 to 112 L/m[sup.2]·h/bar. Fouling performance increases by adding nanoparticles, relative flux decreases by 30% for membranes without nanoparticles and by 10% for membranes with nanoparticles, both at a concentration of 25% PES. Rejection increases for membranes at 21%Pes from 21% for membranes without nanoparticles to 39% for membranes with nanoparticles. The influence of Y[sub.2]O[sub.3] nanoparticles on the membranes’ performance was determined by filtration experiments to establish the permeability, fouling, retention, and the water flux; by contact angle to establish the surface hydrophilicity; and by SEM to investigate the membranes’ structures.

To determine the final quality of agricultural products it is essential a complex analysis of soil contamination with heavy metals in particular. Even if the sources of soil pollution are multiple, this study analyses the traffic influence on the degree of soil pollution. Soil samples were taken at different distances from public roads to determine the distance and spread mode of pollution. Following investigations, it appears that the road positioning from the wind direction has a very important role on the degree of pollution. Concentration of pollutants is increased in the first 3 meters from the road and decreases considerably with increasing distance.