Mixture Of Copper Research Articles

ZnO-CuO nanocomposites: synthesis, characterization and antibacterial activity

Nanotechnology deals with the study of manipulation of the materials on molecular or an atomic scale. Nanomaterials and nanocomposites possess unique characteristics such as miniature particle sizes with a close particle size distribution properties and pose as a highly dispersed and non-agglomerative mass. The typical blend and diverse characteristics of these particles prove to be of added advantage in typical applications such as medical and pharmaceutical treatments for bacterial infections. This paper describes the detailed process of synthesizing nanocomposite oxide mixtures of copper and zinc through the sol-gel formulation route technique. The particle size distribution is assessed using Brunauer-Emmett-Teller and Scanning Electron Microscopy analysis. The mineralogical analysis of the nano-composite is carried out using X-Ray Fluorescence and X-Ray Diffraction techniques. The synthesized ZnO-CuO particles possess antibacterial properties against both gram-(positive/negative) bacteria and hence, they exhibited good results on E.coli, Staphylococcus aureus and Pseudomonas aeruginosa.

Composition tuning in copper - oxide decorated reduced graphene oxide yields efficient photo- and reduction catalysts

A direct low-cost chemical reduction method is presented for the synthesis of the ternary Cu-Cu2O-CuO system. In the presence of graphene oxide, the chemical reduction results in nanostructured copper and copper oxide decorated reduced graphene oxide structures. The presence of graphene oxide limits the conversion of copper to copper oxide and help the formation of the ternary system without the need for any controlled atmosphere. The composition of the ternary system could be changed by varying the amount of copper precursor used. X-ray diffraction studies and XPS analysis confirms the compositional variation in the synthesized nanocomposites. The dominant metallic phase converts to a mixture of metallic copper and Cu2O dominant composition and then to a CuO dominant composition as the copper content increases in the sample. C1s peak shift in the XPS spectra indicates a strong interaction between graphene sheets and copper in copper rich compositions which has not been reported before. The composite nanostructures possess promising catalytic efficiency towards the visible light photodegradation as well as the hydride reduction reactions. The reduced graphene oxide-copper nanocomposites show improved photocatalytic activity with a rate constant value of 0.012 min-1 compared to pure CuO which is having a rate constant value of 0.002 min-1. The enhanced visible light assisted photodegradation is found to be due to the reduced graphene oxide assisted charge transfer and effective plasmonic coupling of the thermal and photonic energies over Cu2O nanostructures. The electronic nature of the enhancement in photocatalytic activity was also confirmed by the quantitative assessment of hydroxyl radical formation using coumarin as a fluorescent probe during the visible light illumination reactions. The highest efficiency for the hydride reduction of para nitroaniline was exhibited by a different catalyst, CuRGO2 with a rate constant value of 0.269 min-1. The Cu2O-Cu-CuO ternary composition of CuRGO2 is instrumental in the high catalytic activity observed for this composite in the hydride reduction reaction. Thus, a rational design of heterostructured nanocatalyst for the visible light assisted degradation as well as the hydride reduction of organic pollutants can be achieved using the presented direct reduction synthesis.

Terephthalic acid‐directed supramolecular Cu(II)‐metallogel for photosensitive semiconducting Schottky diode with promising electronic charge transportation

SummaryTerephthalic acid‐based supramolecular metallogel of Cu(II) (ie, Cu‐TA) is developed by sonicating the mixture of copper(II) acetate monohydrate and terephthalic acid in N,N‐dimethyl formamide solvent. The rheological study is performed to expose the mechanical property of metallogel. The flake‐like morphological patterns are found through FESEM microstructural investigations. The formation strategy, crystalline nature, and thermal behavior of the Cu‐TA metallogel are also studied. The optical and electrical properties of Cu‐TA metallogel are exhaustively scrutinized, and the measured data show that Cu‐TA metallogel is semiconducting in nature. The electrical analysis indicates that the conductivity of Cu‐TA metallogel increased up to ~four times under illumination (7.49 × 10−5 S m−1) rather than the nonirradiation condition (1.83 × 10−5 S m−1). The measured I‐V characteristics of Cu‐TA metallogel‐based thin‐film metal‐semiconductor (MS) junction devices under irradiation and nonirradiation conditions show a nonlinear rectifying behavior, typical of a Schottky diode (SD).

Long-term effect of heavy metals Cr(III), Zn(II), Cd(II), Cu(II), Ni(II), Pb(II) on the anammox process performance

The process of the anaerobic ammonia oxidation (anammox) has been successfully used to remove nitrogen from reject water after dewatering of the digested sewage sludge. However, it is also used on other types of wastewater, including industrial wastewater, which may contain substances that inhibit this process. Examples of such substances include heavy metals which may be found in tanning wastewater, landfill leachate, or coke oven wastewater. The study presented shows the influence of two different mixtures of heavy metals on the anammox process in a long-term test. In SBR1, a mixture of nickel (Ni2+), copper (Cu2+), and zinc (Zn2+) was tested, while in SBR3 a mixture of chromium (Cr3+), cadmium (Cd2+), and lead (Pb2+) was checked, whereas the SBR2 reactor was a control reactor. The study demonstrated that even the highest levels of chromium, cadmium, and lead tested did not inhibit the process. However, in the case of the second metal mixture, strong inhibition of the nitrogen removal efficiency was observed. It was shown that zinc is the metal that was predominantly responsible for the inhibition, and its elimination from the incoming sewage allowed to restore the initial efficiency of the process.

Organically functionalized bentonite for the removal of perfluorooctane sulfonate, phenanthrene and copper mixtures from wastewater

The co-occurrence of a wide range of hydrophobic and hydrophilic contaminants with contrasting physicochemical properties in wastewaters makes practical remediation a challenge. Applications of ion exchangers such as clays are an environmentally friendly option in a cleanup strategy. However, clays often require chemical functionalization to adsorb non-polar contaminants. In this study, the most readily available low-cost Iranian bentonite was modified with Arquad® 2HT-75 (IBA) and further tailored with palmitic acid (IBAP) in order to prepare effective adsorbents. They were used for the removal of perfluorooctane sulfonate (PFOS), phenanthrene (PHE) and copper ions (Cu2+) both in single (S) and binary (B) contaminant conditions in simulated and real wastewater. The IB showed a large affinity for Cu2+ in both single (qmax: 43.43 mg/L) and binary (qmax: 43.95 mg/L) systems. Adsorption of PFOS and PHE was dramatically enhanced by the functionalized clays IBA (KF (PFOS): 11.1 and KF (PHE): 9.65 mg (1-n) Ln g−1) and IBAP (KF (PFOS): 10.2 and KF (PHE): 16.68 mg (1-n) Ln g−1). The co-occurrence of PFOS or PHE with Cu2+ enhanced their adsorption onto clays indicating that Cu2+ can form bridges between clays and PFOS or PHE in different mechanism to increase adsorption of PFOS or PHE in binary solutions. The surface-tailored organoclay IBAP showed great potential for the complete removal of PFOS, PHE and 86.6% of Cu2+ from real wastewater, which is usually considered challenging.

Physiological and genetic effects of cadmium and copper mixtures on carrot under greenhouse cultivation

The exposure to combinations of heavy metals can affect the genes of vegetables and heavy metals would accumulate in vegetables and thereby indirectly affecting human health. Exploring the links between genetic changes and phenotypic changes of carrot under the combined pollution of Cd and Cu is of great significance for studying the mechanism of heavy metal pollution. Therefore, this study examined the effects of mixtures of cadmium (Cd) and copper (Cu) on physiological measures (malondialdehyde (MDA), proline, and antioxidant enzyme) and expression of growth-related genes (gibberellin gene, carotene gene, and glycogene) in carrot under greenhouse cultivation. The results showed in the additions with mixtures of Cd and Cu at higher concentration, the MDA content increased significantly (p < 0.05), whereas the proline content was not significantly different from those in the control. In the mixed treatments with high Cd concentrations, the activity of superoxide dismutase (SOD) was significantly lower than that in the control (p < 0.05); whereas the activity of peroxidase (POD) increased to different degrees compared to the control. In the additions with mixtures of Cd and Cu, compared with the control, the expression of the gibberellin gene was downregulated from 1.97 to 20.35 times (not including the 0.2 mg kg−1 Cd and 20 mg kg−1 Cu mixture, the expression of gibberellin gene in this treatment was upregulated 1.29 times), which lead to decreases in the length and dry weight of carrots. The expression of the carotene gene in mixed treatments downregulated more than that in single treatments, which could reduce the ability of carrots to resist oxidative damage, as suggested by the significant increase in the MDA content. In the addition with mixtures of Cd and Cu, compared with the control, the expression of the glycogene was downregulated by 1.42–59.40 times, which can cause a significant reduction in the sugar content in carrots and possibly further reduce their ability to resist heavy metal damage. A cluster analysis showed that in the additions with mixtures of Cd and Cu, the plant phenotype was affected first, and then with increases in the added concentration, the expression of genes was also affected. In summary, in the additions with mixtures of Cd and Cu, plants were damaged as Cd and Cu concentrations increased.

Enzymatic and non-enzymatic detoxification in Lycosa terrestris and Pardosa birmanica exposed to single and binary mixture of copper and lead

Organisms employ various enzymatic and non-enzymatic detoxification mechanisms to minimize the harmful effects of metal pollution in the terrestrial environment. We examined the effects of copper (Cu), lead (Pb) and their mixture (Cu + Pb) on glutathione (GSH), metallothionein (MTs), cytochrome P450 (CYP 450), carboxylesterase (CarbE), acetylcholinesterase (AchE) and glutathione S-transferase (GST) in Lycosa terrestris and Pardosa birmanica via two exposure routes, i.e., soil and food for 10, 20 and 40 days. The present results revealed that the accumulation of Cu and Pb in both spiders’ species increase with exposure duration and depend on the route of exposure and type of metal. The activities of CarbE, GST, and MTs significantly increased with increasing metal body burden for all experimental treatments. The CYP 450 activity exhibited a significant time-dependent decrease with increasing Cu concentration in both species. The AchE activity was significantly inhibited on Pb exposure via soil and Cu + Pb exposure via both routes. The decrease in the level of GSH was measured on Cu + Pb exposure via both routes. Thus, all these enzymatic and non-enzymatic responses are sensitive to the metals tested and could serve as early warning indicators for assessing the effects of metal pollution in these species.

Copper Deposition from Its Sulfate Solution onto Titanium Powder with the Simultaneous Mechanical Activation of the Mixture

To fabricate Cu–Ti composite particles, the method of copper deposition from its sulfate solution on titanium powder particles with the simultaneous mechanical activation (MA) of the mixture in an AGO‑2 planetary ball mill for 5 min is used. The CuSO4 ⋅ 5H2O concentration in solutions is 10 and 16%, which provides molar ratio Cu/Ti = 0.85 and 1.36, respectively, with the complete reduction of copper. The rapid reduction of copper in the form of highly dispersed partially amorphized powder occurs during MA, and composite particles with a thin laminate structure and high reaction ability are formed. Prepared composites are rinsed and stored in argon because reduced copper possesses high activity and rapidly oxidizes in air to oxide Cu2O. After drying, the additional MA of the mixture is performed for 5 min. Pellets 3 mm in diameter and up to 1.5 mm in height are compacted from prepared powders and heated in argon to 700–1200°C. An intense reaction with heat liberation (heat explosion) and the formation of TiCu, Ti2Cu3, and Ti2Cu intermetallic compounds starts upon sample heating. The critical inflammation temperature for composite powders formed by MA with simultaneous copper deposition from the solution is 480°C, which is 400°C below the inflammation temperature of the usual powder mixture of titanium and copper. The alloy has a dendritic structure at a heating temperature close to the melting point, while, if it is exceeded by more than 100°C, the phase distribution in the alloys becomes more uniform and their size decreases.

Facilitated Transport of Copper(II) across Polymer Inclusion Membrane with Triazole Derivatives as Carrier.

This study investigates copper(II) ion transport through a polymer inclusion membrane (PIM) containing 1-alkyl-1,2,4-triazole (n = 8, 9, 10, 11, 12, 14), o-nitrophenyl octyl ether as the plasticizer and cellulose triacetate as the polymer matrix. The feeding phase was a solution of 0.1 mol/dm3 CuCl2 and an equimolar (0.1 mol/dm3) mixture of copper, nickel, and cobalt chlorides with varying concentrations of chloride anions (from 0.5 to 5.0 mol/dm3) established with NaCl. The receiving phase was demineralized water. The flow rate of the source and receiving phases through the membrane module was within the range from 0.5 cm3/min to 4.5 cm3/min. The tests were carried out at temperatures of 20, 30, 40 and 50 °C. Transport of NaCl through the membrane was excluded for the duration of the test. It was noted that the flow rate through the membrane changes depending on the length of the carbon chain in the alkyl substituent from 16.1 μmol/(m2s) to 1.59 μmol/(m2s) in the following order: C8 > C9 > C10 > C11 > C12 > C14. The activation energy was 71.3 ± 3.0 kJ/mol, indicating ion transport through the PIM controlled with a chemical reaction. Results for transport in case of the concurrent separation of copper(II), nickel(II), and cobalt(II) indicate a possibility to separate them in a selective manner.

Effect of adsorption on photocatalytic activity for rhodamine B degradation of copper-doped tungsten disulfide

In this study, the Cu-doped WS2 materials were synthesized by a simple solid-state calcination of mixture of tungstic acid, thiourea and copper (II) acetate monohydrate in Ar gas at 650 oC for 1h, and denoted as xCu-WS2, where x is atomic percentage ratios of Cu/W (x= 1, 3, 5%) and weigh ratio of tungstic acid/thiourea is constant (1:5). The obtained products were characterized by X-ray diffraction, infrared, energy-dispersive X-ray spectroscopy, scan electron microscopy and UV-Vis diffuse reflectance spectroscopy. The photocatalytic performance of the samples was assessed through photodegradation of rhodamine B (RhB). Interestingly, there is a synergistic relationship between adsorption and photocatalysis, in which, a higher relative adsorption might give a better photocatalytic results due to reactive species reacting with absorbed organic matter on the catalyst surface rather than in the bulk of solution. The photodegradation of RhB over the 1Cu-WS2 catalyst was enhanced significantly with the highest efficiency up to 95.35% at pH 8 for 6 hours of visible light irradiation, which is attributed to the high adsorption of RhB cationic dye on the material surface. The photocatalytic mechanism was discussed as well.

Preparation and Characteristic of Ultrafine Copper-Based Powders Reduced by a Two-Step Reduction Method

In this study, the ultrafine copper-based powders were fabricated by a facile two-step chemical reduction method. Glucose (C6H12O6) and ascorbic acid (AA) were taken as a pre-reductant and a second reductant, respectively. Polyvinylpyrrolidone (PVP) was applied as the capping agent. Effects of parameters, such as glucose content, PVP content and PH value on the ultimate reduction products were analyzed. Microstructure and composition of the products were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). It was found that when the amount of glucose was increased from half to full and then excessive, the powder gradually changed from flaky to spherical, from pure copper powder to a mixture of copper and cuprous oxide (Cu2O). With the amount of PVP increasing from 0g to 0.64 g, the shape of the pure copper powder changed from cubic to spherical or HYPERLINK "javascript:void (0);" icosahedron. When the PH value changed from 10-14, the powder changed from spherical to regular octahedron and Irregular polyhedron, from pure copper powder to pure cuprous oxide powder. Therefore, copper-based powders with different morphologies and different compositions can be prepared by changing PH value and the amount of reductant.

Toxicity of binary mixtures of Cu, Cr and As to the earthworm Eisenia andrei

Chromated copper arsenate (CCA) mixtures were used in the past for wood preservation, leading to large scale soil contamination. This study aimed at contributing to the risk assessment of CCA-contaminated soils by assessing the toxicity of binary mixtures of copper, chromium and arsenic to the earthworm Eisenia andrei in OECD artificial soil. Mixture effects were related to reference models of Concentration Addition (CA) and Independent Action (IA) using the MIXTOX model, with effects being related to total and available (H2O and 0.01 M CaCl2 extractable) concentrations in the soil. Since only in mixtures with arsenic dose-related mortality occurred (LC50 92.5 mg/kg dry soil), it was not possible to analyze the mixture effects on earthworm survival with the MIXTOX model. EC50s for effects of Cu, Cr and As on earthworm reproduction, based on total soil concentrations, were 154, 449 and 9.1 mg/kg dry soil, respectively. Effects of mixtures were mainly antagonistic when related to the CA model but additive related to the IA model. This was the case when mixture effects were based on total and H2O-extractable concentrations; when based on CaCl2-extractable concentrations effects mainly were additive related to the CA model except for the Cr–As mixture which acted antagonistically. These results suggest that the CCA components do interact leading to a reduced toxicity when present in a mixture.

THE STRUCTURE OF PRODUCTIVITY OF SPRING WHEAT DEPENDING ON THE VARIETY AND FOLIAR TREATMENT WITH MANGANESE, COPPER AND MOLYBDENUM

The article presents the results of research on the structure of productivity of spring wheat depending on the variety and use of trace elements of manganese, copper, molybdenum and Ultramag Combi. It was found that the best productivity indicators were formed by the spring wheat variety Yoldyz. The optimal combination of microelements that positively affect the structure of spring wheat productivity has been established. The best indicators of the structure of the spring wheat yield of Tulaykovskaya 10 and Tulaykovskaya 108 varieties were formed when foliar treatment of crops with a paired mixture of copper and molybdenum with nitrogen, and Yoldyz varieties - manganese and copper, as well as manganese and molybdenum with nitrogen. Foliar treatment with a multi-component preparation Ultramag Combi, as well as separately applied nitrogen in amide form, was less effective.

Copper film deposition using a helium dielectric barrier discharge jet

AbstractThis study demonstrates that plasma‐enhanced chemical vapor deposition of copper films can be achieved in ambient air and at low temperature. A helium dielectric barrier discharge jet with a small mixture of hydrogen and copper(II) acetylacetonate vapor is utilized as the nonthermal plasma source to deposit conductive copper films with low electrical resistivity (&lt;1 × 10−7 Ω·m). The deposited film appears to have three distinct regions (reddish brown, dark blue, and yellowish) from center to edge. Copper nanograins (~50 nm) are observed in both the reddish‐brown and the dark‐blue regions, whereas the yellowish region exhibits a continuous structure containing copper oxide. The copper films are further deposited on various temperature‐sensitive substrates, including plastic, cardboard, agar, and pork skin.

Fabrication of Few-Layer Graphene-Supported Copper Catalysts Using a Lithium-Promoted Thermal Exfoliation Method for Methanol Oxidative Carbonylation.

Exfoliation of graphene oxide (GO) via thermal expansion is regarded as the most promising approach to obtain few-layer graphene (FLG) in bulk. Herein, we introduce an efficient strategy for improving the exfoliation process by adding a tiny amount of lithium nitrate in the precursors, which significantly enhances the removal of oxygen-containing functional groups and produces 1-2 layer graphene. FLG-supported highly dispersed Cu nanoparticles (NPs, ≈4.2 nm) can be further synthesized through exfoliating the mixture of GO, lithium nitrate, and copper(II) nitrate, which displayed superior catalytic activity and stability in the synthesis of dimethyl carbonate (DMC) using liquid methanol oxidative carbonylation. The characterization results demonstrate that during the thermal expansion process, lithium nitrate was decomposed to Li2O and immediately reacted with CO2 released by the decomposition of GO to form stable Li2CO3, which promotes efficient charge transfer and produces Cuδ+ (0 < δ < 1) species in the Cu/Li-PGO catalyst. Density functional theory calculations prove that the presence of Cuδ+ markedly facilitates CO adsorption over the resulting catalyst and causes a decrease of the energy barrier of the rate-limiting step for DMC formation (CO insertion). These findings give a theoretical explanation of the enhanced catalytic performance of the Cu/Li-PGO catalyst. The present work provides a simple and practical avenue to the exfoliation of graphene and the dispersions of metal NPs on graphene sheets.

Novel antimicrobial nanocomposite based on polypropylene non-woven fabric, biopolymer alginate and copper oxides nanoparticles

The objective of this study was to develop novel antimicrobial nanocomposite material based on polypropylene (PP) non-woven fabric, biopolymer alginate and copper oxides nanoparticles. In order to introduce polar groups onto the surface of PP fibers necessary for binding of alginate, non-woven fabric was activated by corona discharge. Carboxylate groups of alginate were further utilized for binding of Cu2+-ions which were reduced with sodium borohydride as a conventional and ascorbic acid as a green reducing agent. Characteristic morphological and chemical changes induced by corona activation and alginate impregnation were confirmed by FTIR, XPS and FESEM analyses. AAS measurements showed that the amounts of generated nanoparticles depend on applied reducing agent and the concentration of precursor salt. XPS analysis suggested that nanoparticles were mixture of copper (I) and (II) oxides. XPS depth profiling gave an exceptional insight into chemical changes within the thin layer on the fiber surface and formation of certain interfaces induced by each treatment. All fabricated nanocomposites provided excellent antimicrobial activity against Gram-negative bacteria E. coli, Gram-positive bacteria S. aureus and yeast C. albicans. The cytotoxicity assay indicated that maximum amount of Cu2+-ions released from synthetized nanocomposite within 24 h was not cytotoxic to human keratinocyte (HaCaT) cells.

Dental Materials Incorporated with Nanometals and Their Effect on the Bacterial Growth of Staphylococcus aureus.

PurposeThe purpose of this study was to investigate the effect of different commercially used dental materials (RelyX Luting Plus and Dyract Extra) mixed with either a metallic ionic solution or a colloidal suspension of metallic nanoparticles. Both the solution and the suspension contained a mixture of silver, copper, and lithium ions.MethodsThe metal/ion-incorporated dental materials were prepared into disk-shaped samples and tested against the growth of Staphylococcus aureus. The susceptibility of bacteria against the antibacterial dental disks was tested using two methods: counting the colony-forming units per milliliter and disk diffusion (Kirby–Bauer). The incorporated materials (Dyract and Rely cement) were tested for ion release using flame atomic absorption spectroscopy.ResultsAssessment showed efficient antibacterial activity of metal ion–incorporated Rely luting cement, exhibited by the formation of inhibition zones larger than those formed by the standard antibiotic, as well as a reduction in bacterial number of sevenfold after incubation for 24 hours. Dyract material incorporated with nanoparticles showed no significant clear zones and had no inhibiting effect on bacterial colony numbers after incubation for 24 hours. The release of silver, copper, and lithium metal ions depended on the type of both dental material and the incorporated nanoagents. The metal ion–incorporated Rely Plus cement released the highest levels of metal ions, which was attributed to its antibacterial efficiency.ConclusionRely Plus cement incorporated with the nanoparticle suspension demonstrated high antibacterial potency, due to the release of the highest concentrations of silver, copper, and lithium metal ions. This work is the first direct comparative study of dental materials with different forms of nanomixtures (metallic nanoparticles and soluble metallic ions) and their antibacterial effects after incubation with bacterial culture for 24 hours.

Statistical analysis of homogeneous nucleation of metallic nanoparticles during gas-phase synthesis

In this work, we set out to develop a model of gas-phase nucleation in a mixture of copper and argon atoms, which can be further used for analysing macro-systems. Processes occurring at the atomic level are described using coefficients obtained by statistical analysis of molecular dynamic (MD) data on interactions of metal clusters with metal and argon atoms. The MD simulation results are compared with those obtained using the proposed macroscopic model. It is found that the coefficients obtained by averaging the interaction data suitably represent the integral value of the heat of condensation, although result in the smoothing of the energy distribution functions of the clusters. Analysis of the evolution of the number of clusters has shown that the values of their increase rate were lower than those obtained by MD simulation. The conclusion is made, that in order to improve the precision of the developed gas-phase condensation model, it should be supplemented by cluster coagulation.

Fabrication of TiC from the Cu–Ti–C system under the super-gravity field

Abstract An innovative approach of fabricating fine TiC particles through the dissolution of solid carbon in the CuxTi melt and subsequently separation with super-gravity is proposed in this study. The reactant mixtures of titanium sponge, copper and carbon particles reacted at 1573 K for 4 h and then the near-spheroidal TiC grains gradually precipitated out of the Cu–Ti–C system. The influences of copper content, separating temperature, gravity coefficient and separating time on the separation of precipitated TiC from the Cu–Ti–C melt have been studied. The particle size distribution and stoichiometric of TiC were calculated, and the detailed mechanism of fabricating TiC was discussed. The experimental results showed that the mass fraction of copper mixed with TiC in the residue was 6.5 wt% and the yield of the copper-rich phase exceeded 89 wt% under super-gravity treatment with the conditions of χCu = 90 wt%, T = 1523 K, t = 120 s and G = 600. After leaching with the sulfuric acid solution, the purity of TiC particulates was 99 wt% and the removal rate of the copper impurity could be up to 97.8%. Finally, the product of the homogeneous and fine TiC particles with good dispersibility was obtained. The circle equivalent diameter and the median diameter of the TiC particulates were found to be 2.09 μm and 2.12 μm, respectively. The elongation and the aspect ratio of the TiC particulates were 83.4% and 74.4%, respectively. Moreover, the lattice parameter of the purified TiC particulates was calculated by the Nelson-Riley extrapolation function which was near to the standard value, and the stoichiometry of TiC particulates obtained in this work was close to 1.

Antibacterial activity of a glass ionomer cement doped with copper nanoparticles.

Copper nanoparticles (NCu) were synthetized and added to commercial glass ionomer cement, to evaluate in vitro its antibacterial activity against oral cavity strains. The NCu were synthesized by copper acetate reduction with L-ascorbic acid and characterized by FTIR, Raman, XPS, XRD and TEM. Then, commercial glass ionomer cement (GIC) was modified (MGIC) with various concentrations of NCu and physicochemically characterized. Cell viability was tested against human dental pulp fibroblasts (HDPFs) by Alamar-Blue assay and antibacterial test was performed against S. mutans and S. sanguinis by colony forming unit (CFU) growth method. Synthesized NCu rendered a mixture of both metallic copper and cuprous oxide (Cu2O). HDPF viability reduces with exposure time to the extracts (68-72% viability) and MGIC with 2-4 wt% NCu showed antimicrobial activity against the two tested strains.