Malus domestica and Solanum lycopersicum Mixtures for the Synthesis of Graphene Silver and Zinc Oxide Nanocomposites

This study reports on the novel and simple green method involving the use of apple (Malus domestica) and tomato (Solanum lycopersicum) extracts in the synthesis of electroactive layers of silver nanoparticles|graphene oxide (AgNPs|GO) and zinc oxide nanoparticles|graphene oxide (ZnONPs|GO). The surface morphology of the green synthesized nanocomposites was studied using High-Resolution Transmission Electron Microscopy (HRTEM), High-Resolution Scanning Electron Microscopy (HRSEM) while the elemental analysis was studied using Fourier Transform Infrared Spectroscopy (FTIR), Raman spectroscopy and X-Ray diffraction (XRD) and their optical properties were further characterised using Ultraviolet Spectroscopy (UV-vis). The electrochemical studies of these nanocomposites were achieved using cyclic voltammetry (CV) where an increase in electron conductivity of the AgNPs|GO and ZnONPs|GO nanocomposite was observed. Comparatively, the silver nanoparticulate-based platforms were observed to have superior electrochemical properties as opposed to the zinc oxide-based platform. The observed electrochemical activities of the synthesized nanocomposites are a good indication of their suitability as electroactive platforms towards the development of electrochemical sensors. Electrochemical sensors are popular in the Electrochemistry field because they may be developed using different methods in order to suit their intended analytes. As such, the synthesis of a variety of electrochemical platforms provides researchers with a vast range of options to select from for the detection of analytes.

Catalytic performance of Ag/Co-Ce composite oxides during soot combustion in O_2 and NO_x:Insights into the effects of silver

The composite oxides xAg/Co_（0.93）Ce_（0.07）（x=Ag/（Co＋Ce） molar ratio）,intended for use as high performance catalytic materials,were successfully prepared via citric acid complexation.The effects of silver on the performance of these substances during soot combustion were subsequently investigated.Under O_2,the 0.3Ag/Co_（0.93）Ce_（0.07） catalyst resulted in the lowest ignition temperature,T_（10）,of197 ℃,while the minimum light-off temperature was obtained from both 0.2Ag/Co_（0.93）Ce_（0.07） and0.3Ag/Co_（0.93）Ce_（0.07） in the NO_x atmosphere.These materials were also characterized by various techniques,including H_2,soot and NO_x temperature programmed reduction,X-ray diffraction,and electron paramagnetic resonance,Raman,X-ray photoelectron,and Fourier transform infrared spectroscopic analyses.The results demonstrated that silver significantly alters the catalytic behavior under both O_2 and NO_x,even though the lattice structure of the mixed oxide is not affected.Surface silver oxides generated under the O_2 atmosphere favor soot combustion by participating in the redox cycles between soot and the silver oxide,whereas the AgNO_3 that forms in a NO_x-rich atmosphere facilitates soot abatement at a lower temperature.The inferior activity of AgNO_3 relative to that of Ag_2O results in the different catalytic performance in the presence of NO_x or O_2.

Preparation and characterization of composite microspheres of nano zinc ferrite/poly(D,L-lactide-co-alanine)

Magnetic nano zinc ferrite fliuds were synthesized using an improved liquid phase chemical method, which would be used to replace tradditional iron oxides magnetic material. A novel copolymer （PLAA） with D, L-lactide （D, L-LA） and alanine was synthesized using stannous octoate as initiator. Magnetic polymer microspheres were fabricated with nano zinc ferrite fluid coated with alanine modified poly lactide. These as-prepared zinc ferrite fluids, modified poly lactide and magnetic composites, were characterized with X-ray diffraction diffractometer, FT-IR spectrometer, nuclear magnetic resonance spectrometer, scanning electron microscope, transmission electron microscope, vibrating sample magnetometer, and thermogravimetric analyzer. The results demonstrate that the as-prepared zinc ferrite is spinel type of ZnFe2O4 nano crystals with particle size of 20-45 nm and magnetization of 32×10^-3 A.m2. Alanine is copolymerized with lactide, and the prepared composite magnetic microsphere is coated with the modified polylactide, with mass fraction of 45.5% of PLA, particle size ranging from 80-300 nm, and magnetization of 10.6×10^-3 A·m^2, which suggests ZnFe2O4 enjoys a stable magnetization after being coated by polymer.

Reduction process and zinc removal from composite briquettes composed of dust and sludge from a steel enterprise

In this study, composite briquettes were prepared using gravity dust and converter sludge as the main materials; these briquettes were subsequently reduced in a tube furnace at 1000-1300℃ for 5-30 min under a nitrogen atmosphere. The effects of reaction temperature, reaction time, and carbon content on the metallization and dezincification ratios of the composite briquettes were studied. The reduced com- posite briquettes were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and energy-dispersive spectroscopy （EDS）. The results show that the gravity dust and converter sludge are combined into the composite briquettes and a reasonable combination not only improves the performance of the composite briquettes, but also leads to the reduction with no or little reductant and flux. As the re- action temperature is increased and the reaction time is extended, the metallization and dezincification ratios of the composite briquettes in- crease gradually. When the composite briquettes are roasted at 1300℃ for 30 rain, the metallization ratio and dezineification ratio reaches 91.35% and 99.25%, respectively, indicating that most of the iron oxide is reduced and the zinc is almost completely removed. The carbon content is observed to exert a lesser effect on the reduction process; as the C/O molar ratio increases, the metallization and dezincification ra- tios first increase and then decrease.

Fabrication of Polyaniline/Silver Nanocomposite Under Gamma-ray Irradiation

Polyaniline （PANI）/silver composite was one-step synthesized under γ-ray irradiation. The structure of the composite was characterized by Fourier transform infrared spectroscopy, UV-Visible, and X-ray diffraction, which indicated that PANI and face-centered-cubic silver were synthesized under γ-ray irradiation. The reaction mechanism were discussed, which revealed that the PANI was formed by the reaction of aniline cation radicals formed by the reaction of aniline cation and -OH, and Ag was formed by the reaction of Ag＋ and eaq. The morphology of the composite consisted of PANI nanofibers and Ag nanoparticles, and the mechanism of the morphology formation was discussed, which revealed that the rapid mixing like polymerization process might play an important role. It was revealed that the transport behavior of the composite well fitted with the variable-range-hopping model in 80-300 K and deviated from the model below 80 K.

One-year water-ageing of calcium phosphate composite containing nano-silver and quaternary ammonium to inhibit biofilms

Dental composites are commonly used restorative materials; however, secondary caries due to biofilm acids remains a major problem. The objectives of this study were （1） to develop a composite containing quaternary ammonium dimethacrylate （QADM）, nanoparticles of silver （NAg）, and nanoparticles of amorphous calcium phosphate （NACP）, and （2） to conduct the first investigation of the mechanical properties, biofilm response and acid production vs water-ageing time from 1 day to 12 months. A 4 x 5 design was utilized, with four composites （NACP-QADM composite, NACP-NAg composite, NACP-QADM-NAg composite, and a commercial control composite）, and five water-ageing time periods （1 day, and 3, 6, 9, and 12 months）. After each water- ageing period, the mechanical properties of the resins were measured in a three-point flexure, and antibacterial properties were tested via a dental plaque biofilm model using human saliva as an inoculum. After 12 months of water-ageing, NACP-QADM- NAg had a flexural strength and elastic modulus matching those of the commercial control （P〉 0.1）. Incorporation of QADM or NAg into the NACP composite greatly reduced biofilm viability, metabolic activity and acid production. A composite containing both QADM and NAg possessed a stronger antibacterial capability than one with QADM or NAg alone （P〈0.05）. The anti-biofilm activity was maintained after 12 months of water-ageing and showed no significant decrease with increasing time （P〉0.1）. In conclusion, the NACP-QADM-NAg composite decreased biofilm viability and lactic acid production, while matching the load- bearing capability of a commercial composite. There was no decrease in its antibacterial properties after 1 year of water-ageing. The durable antibacterial and mechanical properties indicate that NACP-QADM-NAg composites may be useful in dental restorations to combat caries.

Properties of a new type Al/Pb-0.3%Ag alloy composite anode for zinc electrowinning

An A1/Pb-0.3%Ag alloy composite anode was produced via composite casting. Its electrocatalytic activity for the oxygen evolution reaction and corrosion resistance was evaluated by anodic polarization curves and accelerated corro- sion test, respectively. The microscopic morphologies of the anode section and anodic oxidation layer during accelerated corrosion test were obtained by scanning electron microscopy. It is found that the composite anode （hard anodizing） dis- plays a more compact interracial combination and a better adhesive strength than plating tin. Compared with industrial Pb-0.3%Ag anodes, the oxygen evolution overpotentials of A1/Pb-0.3%Ag alloy （hard anodizing） and A1/Pb-0.3%Ag alloy （plating tin） at 500 A.m-2 were lower by 57 and 14 mV, respectively. Furthermore, the corrosion rates of Pb-0.3%Ag alloy, A1/Pb-0.3%Ag alloy （hard anodizing）, and A1/Pb-0.3%Ag alloy （plating tin） were 13.977, 9.487, and 11.824 g.m-2.h-1, respectively, in accelerated corrosion test for 8 h at 2000 A-m-2. The anodic oxidation layer of A1/Pb-0.3%Ag alloy （hard anodizing） is more compact than Pb-0.3%Ag alloy and A1/Pb-0.3%Ag alloy （plating tin） after the test.

Synthesis of zinc oxide–montmorillonite composite and its effect on the removal of aqueous lead ions

Lead adsorption of zinc oxide-coated ACOR montmorillonite was investigated in batches and under reducing conditions at ambient temperature. The presence of zinc oxide coating significantly enhanced the adsorption of Pb^(2+) ions by ACOR montmorillonite. Characterization of adsorbents involved the use of X-ray diffraction, sodium saturation techniques, coulter laser analysis, scanning electron microscopy, and electron dispersive spectroscopy.Synthesis involved the trimetric process, activation of the ACOR montmorillonite and reacting of the same with zinc nitrate to produce a zinc oxide composite solid at 450 °C.The reaction mechanism indicated less than one proton coefficient, and higher mass transfer rates, when compared with bare montmorillonite. Intraparticle diffusion was higher than the value recorded for the bare montmorillonite. Reactions based on initial Pb^(2+) concentration indicated that coated montmorillonite gradually became saturated as the concentration was increased. Reactions based on solid concentration demonstrated a complex change in the capacity of adsorption over different Pb^(2+) concentrations(10–40 mg L^(-1)) and solid concentrations(2–10 g L^(-1)). The specific surface area reduction, particle size increase, mineral aggregation, and concentration gradient effect controlled the complex changes in adsorption.

Molten salt synthesis of α-MnO_(2)/Mn_(2)O_(3) nanocomposite as a high-performance cathode material for aqueous zinc-ion batteries

Thanks to low cost,high safety,and large energy density,aqueous zinc-ion batteries have attracted tremendous interest worldwide.However,it remains a challenge to develop high-performance cathode materials with an appropriate method that is easy to realize massive production.Herein,we use a molten salt method to synthesize nanostructured manganese oxides.The crystalline phases of the manganese oxides can be tuned by changing the amount of reduced graphene oxide added to the reactant mixture.It is found that the α-MnO_(2)/Mn_(2)O_(3) nanocomposite with the largest mass ratio of Mn_(2)O_(3) delivers the best electrochemical performances among all the products.And its rate capability and cyclability can be significantly improved by modifying the Zn anode with carbon black coating and nanocellulose binder.In this situation,the nanocomposite can deliver high discharging capacities of 322.1 and 213.6 mAh g^(-1) at 0.2 and 3 Ag^(-1),respectively.After 1000 cycles,it can retain 86.2% of the capacity at the 2 nd cycle.Thus,this nanocomposite holds great promise for practical applications.

Effect of Silver Element on Microstructure and Properties of W-30Cu/TiC Composites

W-30 wt%Cu and TiC-50 wt%Ag were successfully synthesized by a novel simplified pretreatment followed by electroless plating. The 0 wt% TiC, 0.5 wt% TiC, and 0.5 wt%TiC-0.5 wt%Ag composite powders were added to W-30 wt%Cu composite powders by blending, and then reduced. The reduced W-30 Cu, W-30 Cu/0.5 TiC, and W-30 Cu-0.5 Ag/0.5 TiC composite powders were then compacted and sintered at 1 300 ℃ in protective hydrogen for 60 min. The phase and morphology of the composite powders and materials were analyzed using X-ray diffraction and field emission scanning electron microscopy. The relative density, electrical conductivity, and hardness of the sintered samples were examined. Results showed that W-30 Cu and TiC-Ag composite powders with uniform structure were obtained using simplified pretreatment followed by electroless plating. The addition of TiC particles can significantly increase the compressive strength and hardness of the W-30 Cu composite material but decrease the electrical conductivity. Next, 0.5 wt% Ag was added to prepare W-30 Cu-0.5 Ag/TiC composites with excellent electrical conductivity. The electrical conductivity of these composites(61.2%) is higher than that in the national standard(the imaginary line denotes electrical conductivity of GB IACS 42%) of 45.7%.

Properties of Al/Conductive Coating/α-PbO2-CeO2-TiO2/β-PbO2-WC-ZrO2 Composite Anode for Zinc Electrowinning

The properties of Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-WC-ZrO2 composite anode for zinc electrowinning were investigated. The electrochemical performance was studied by Tafel polarization curves（Tafel）, electrochemical impedance spectroscopy（EIS） and corrosion rate obtained in an acidic zinc sulfate electrolyte solution. Scanning electron microscopy（SEM）, X-ray diffraction（XRD）, and energy dispersive X-ray spectroscopy（EDXS） were used to observe the microstructural features of coating. Anodes of Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2, Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-WC, Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-ZrO2, and Pb-1%Ag anodes were also researched. The results indicated that the Al/conductive coating/α-PbO2-CeO2-TiO2/β-PbO2-WC-ZrO2 showed the best catalytic activity and corrosion resistant performance; the intensity of diffraction peak exhibited the highest value as well as a new PbWO4 phase; the content of WC and ZrO2 in coating showed the highest value as well as the finest grain size.

Zinc Oxide Nano Particles Integrated Kenaf/Unsaturated Polyester BioComposite

Increasing need for materials with special features have brought various new inventions,one of the most promising hope for new material with special features and functionalities is composites materials.Thus,this study report an integration of zinc nanoparticles into kenaf/polyester polymer composite to introduce new behavior to the composite.The composite behaviors were compared for mechanical,thermal,moisture absorption and biodegradability properties.Prepared Zinc Oxide nanoparticles entrenched in the kenaf/polyestaer composites net structure through chemical bonds between kenaf/ZnO/polyester resin,existence of ZnO significantly influence the mechanical and thermals properties of composites.Thermal analysis based on(TGA)response revealed the integration of ZnO nanoparticles improved the thermal stability when thermal decomposition temperature beyond 3650 C.The thermal cracking decreased with present of ZnO and increase with kenaf content(layers).The modulus,Tensile strength,break at elongation,flexural modulus,flexural strength and impact strength of the composites with higher content kenaf/ZnO nanoparticle are 560 MPa,58MPa,1.8%,1300 PMa,68 MPa and 31 MPa,respectively.Thus,addition of kenaf layers and ZnO results in larger mechanical properties enhancement,the results of the contact angle show improvement in wetting of the fibres with addition of ZnO nanoparticles.

Synthesis and Characterization of Polymeric Composites Embeded with Silver Nanoparticles

Silver nanoparticles were synthesized by chemical reduction method. The Ag nanoparticles (AgNP) were characterized using UV-Vis spectroscopy which shows an absorption band at 420 nm confirming the formation of nanoparticles. For any practical application of the silver nanoparticles it is necessary to stabilize it which can be done by making a composite. In the present studies three polymers were chosen such that AgNP could be put to some practical use. Polyvinyl Alcohol (PVA), Polypyrrole (Ppy) and Carboxymethyl cellulose (CMC) are important for use in textiles, electronics and food/drug technologies respectively. Polymeric composites of PVA, PPy, and CMC were prepared by mixing the aqueous solutions of the respective polymers and the colloidal suspension of preformed silver nanoparticles. Various compositions containing 1% to 5% of Ag nanoparticles were prepared. Thin films of these composites were characterized by UV-Vis spectroscopy, X-ray diffraction and Scanning electron microscopy. X-ray diffraction showed the presence of the peaks at 2θ values of 38.1°, 44.2°, 64.4 and 78.2° corresponding to cubic phase of silver metal. SEM photographs revealed the presence of Ag nanoparticles of sizes varying from 40 to 80 nm. The electrical conductivity of these materials was studied using the four probe method. The conductivity was found to increase from 10–6 for control samples to 10–3 S/cm after the formation of the nanocomposites.

Microstructure and Eutectic Transformation of Squeeze Casting Alumina/Zinc Alloy Composites

Alumina fiber-reinforced zinc alloy composites were manufactured by squeeze casting, and the eutectic transformation in the zinc alloy composites was studied. The results indicate that there is a fine and close interface between the fiber and the matrix, and the alloy elements can improve the combination between the fibers and the matrix in the composites. The fibers can serve as the sites of heterogeneous nucleation of the eutectic in the zinc alloy during the solidification of the composites, and the silicon on the interface between the fibers and the matrix plays a leading role during the coupled growth of the eutectic so that the eutectic transformation of the composites consists of Al-Si eutectic transformation and Zn-AI eutectic transformation.

Characterization and Synthesis Mechanism of Nanosilver/PAMPS Composites by Microwave

Nanosilver/Poly(2-acrylamido-2-methylpropanesulfonate sodium (AMPS)) composites were synthesized with sliver nitrate solution containing AMPS monomer in situ by microwave radiation without addition of any reducer. The composites were characterized by means of UV-Vis, XRD, FTIR, TEM and XPS respectively. The results show that silver nanoparticles are dispersed highly and homogeneously in PAMPS matrix and possessed face-centered cubic structure. The morphology of nanosilver particles is not affected by microwave treatment and AMPS polymerization. XPS analysis reveals that there is an interaction among silver nanoparticles with nitrogen atoms and carbonyl oxygen atoms from AMPS polymer. Thermoanalysis proves that thermal stability of the PAMPS nanocomposites is decreasing with silver nanoparticles dispersed in the composites. The mechanism of silver ion reduced to nanosilver particles catalysized by PAMPS under microwave is discussed.

Zinc Oxide Composites of Doxorubicin in the Form of Coating, Composite Films and Gels with a High Antitumor Activity and Low Toxicity

This work is devoted to the formation doxorubicin (DOX) zinc oxide composites in the form of coating (DOX + ZnO), hydrogels and composite films of DOX with polyvinyl alcohol (DOX + PVA + ZnO) by DC-magnetron deposition of ZnO nanoscale particles (ZnO NPs) on their surfaces (DOX, DOX + PVA) with higher (two times and more) antitumor activity and considerable smaller toxicity at low doses of DOX in compositions compared to the initial drug. Using the methods of spectroscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray Powder Diffraction (XRD), the role of ZnO NPs size on the antitumor activity of doxorubicin zinc oxide compositions is shown. AFM shows presence of many ZnO NPs on the surface DOX. A comparison of the FTIR spectra of DOX and its zinc oxide compositions has shown the presence of new bands of OH valence and deformation vibrations. It is possible to assume that interaction between ZnO and DOX takes place in the form of hydrogen bond, promoting the complexes formation. It is possible that both synergic and hydrogen-bonding ZnO with DOX increase the antitumor activity.

Increased performance of an organic light-emitting diode by employing a zinc phthalocyanine based composite hole transport layer

We demonstrate that the electroluminescent performances of organic light-emitting diodes are significantly improved by employing a zinc phthalocyanine （ZnPc）-based composite hole transport layer （c-HTL）. The optimum ris-（8-hydroxyquinoline）aluminum （Alq3）-based organic light-emitting diode with a c-HTL exhibits a lower turn-on voltage of 2.8 V, a higher maximum current efficiency of 3.40 cd/A and a higher maximum power efficiency of 1.91 lm/W, which are superior to those of the conventional device （turn-on voltage of 3.8 V, maximum current efficiency of 2.60 cd/A, and maximum power efficiency of 1.21 lm/W）. We systematically studied the effects of different kinds of N’-diphenyl-N,N’-bis（1-naphthyl）（1,1’-biphenyl）-4,4’diamine （NPB）：ZnPc c-HTL. Meanwhile, we also investigate their mechanisms different from that in the case of using ZnPc as buffer layer. The specific analysis is based on the absorption spectra of the hole transporting material and current density–voltage characteristics of the corresponding hole-only devices.

Electrical properties of nano-silver/polyacrylamide/ethylene vinyl acetate composite

Nano-Ag particles/polyacrylamide （PAM） composites were synthesized by γ irradiation method and then blended with ethylene vinyl acetate （EVA）. Dielectric behaviors of the Ag/PAM/EVA composites are investigated as a function of both the concentration and size of Ag particles. When concentration of the Ag fillers is rarely low, dielectric anomalies were first observed in contrast to the traditional percolation theory. As concentration of Ag increases, volume resistivity and breakdown field strength are enhanced, loss tangent （tan δ） reduced and dielectric constant kept invariable. In addition, the above variation became larger when the diameter of the Ag nano-particles is smaller. Such dielectric anomalies may be understood by considering the unique ＂Coulomb Blockade Effect＂ of the nano-sized Ag particles.

Dry Sliding Wear Behaviour of SiC Particles Reinforced Zinc-Aluminium (ZA43) Alloy Metal Matrix Composites

The present paper reveals the wear behaviour of Zinc - Aluminium alloy reinforced with SiC particulate metal matrix composite. The composite is prepared using liquid metallurgy technique. The unlubricated pin-on disc wear test is conducted to find the wear behaviour of the ZA43 alloy based composite. The sliding wear test is conducted for different load, speed and time. The result reveals that wear rates of composite is reduced as reinforcement increases. For the same working conditions wear rate increases with increasing load and with increasing speed. The tested samples are examined by taking micro structure photos and analyzed for the type of wear. Dominating wear types observed are delamination and abrasion.

Composite corrosion inhibitors for secondary alkaline zinc anodes

The corrosion inhibition property of PEG600 and In（OH）3 as composite corrosion inhibitors for （second-）（ary） alkaline zinc electrodes was studied, and the inhibition efficiency was determined as 81.9%. The research focused on the mechanism by the methods of electrochemical impedance spectroscopy, polarization curves and IR spectroscopy. The results indicate that the corrosion inhibition effectiveness is attributed to the joint inhibition of anodic zinc dissolution and cathodic hydrogen evolution. And the anodic process is depressed to a greater extent than the cathodic process. The synergistic mechanism of the composite inhinbitors proves to be the enhancement of adsorption of PEG600 by In（OH）3. Potentiostatic experiment results and SEM images verify the inhibition of dendritic growth by the composite inhibitors.