Steeleheide2910

The Curie temperature was found to be 561 and 566 0C for the iron oxide nanoparticles synthesized at 45 and 85 °C, respectively. The FTIR spectrum of the iron oxide nanoparticles synthesized at different temperatures exhibited the characteristic peaks that corresponded to the stretching of bonds between octahedral and tetrahedral metal ions to oxide ions. Our results showed that the ferrite nanoparticle size can be varied by controlling the reaction temperature inside a microwave reactor.Gd2O3Eu3+Al3+ phosphors are synthesized by wet chemical method and its photoluminescence properties are studied at different concentrations of Eu3+ and A13+. In emission spectra, the dominant peak observed at 611 nm corresponds to hypersensitive electric dipole transition in Eu3+. For Eu3+ concentration of 0.02, a good emission profile is observed and further its emission studies are carried out for the phosphor annealed at different temperatures and with the addition of A13+. The critical distance between the luminescent center is calculated to study the concentration quenching phenomenon. Enhancement of energy transfer occurs on introducing Al3+ in Gd2O3Eu3+ phosphor. CIE coordinates are also calculated for Gd2O3Eu3+ A13+ to estimate the color purity of the phosphor.The synthesis of silver nanoparticles (AgNPs) controlled by active participation of 3-Amino-propyltrimethoxysilane (3-APTMS) and 3-Glycidoxypropyltrimethoxysilane (GPTMS) is found to be function of two sequential processes; (1) interaction of metal ions with 3-APTMS and (2) interaction of GPTMS with 3-APTMS capped metal ions. The mechanism of such process as evidenced from visual photographs, UV-visible spectroscopy, energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM) is reported. The experimental findings demonstrate the followings; (1) There is faster interaction of 3-APTMS with gold ions as compared to that of silver ions under similar conditions, (2) Methanolic solution of GPTMS undergo interaction with 3-APTMS and the same is facilitated in the presence of 3-APTMS treated silver ions, (3) The size of as synthesized AgNPs increases with an increase in 3-APTMS concentration whereas reverse is recorded for change in GPTMS concentration, (4) The molar ratio of 3-APTMS/GPTMS control the nanogeometry as well as the dispersibility of AgNPs in both aqueous and non aqueous media, (5) The dispersion ability of AgNPs is attributed to the hydrophobic alkyl chain of the reaction product of GPTMS and 3-APTMS (6) AgNPs shows absorption maxima as a function of refractive index of the medium and (7) The as synthesized AgNPs behave as peroxidase mimetic in both aqueous and non-aqueous medium justifying the potential typical applications.The influence of the distribution of particle shapes, locations and orientations on the mechanical behavior of the particle reinforced Metal-Matrix Composite (MMC) is studied through finite element (FE) method under different loading conditions in this investigation. The FE-model with multi-particle is generated through the random sequential adsorption algorithm, with the particles treated respectively as elastic-brittle circular, regular octagon and hexagon and square shape. Ductile failure in metal matrix, brittle fracture of particles and interface debonding are taken into account during the simulations. 2D cohesive element is applied to simulate the debonding behavior of interface. The damage models based on the stress triaxial indicator and maximum principal stress criterion are developed to simulate the ductile failure of metal matrix and brittle cracking of particles, respectively. Simulation results show that the interface debonding dominates the failure process under the loading, while the damage in particle grows at slowest rate compared with those in matrix and interface.Gold nanoparticles (AuNPs) have been chemically functionalized onto multiwalled carbon nanotubes (MWCNT) through a metallopolymer linker-bis (2,2'6'2"-terpyridine) ruthenium(II)-connected diblock poly(N-isopropyacryamide). A "nano-snowflower" pattern was formed by self-assembly MWCNT-AuNP nanocomposite with anti-DNP IgE antibody. MWCNT-AuNP nanohybrid has unique biocompatibility and electronic current-voltage properties. This nanohybrid shows the potential application for IgE biosensor to diagnose cancer cells. We represent a step towards building complex electronic circuits response by providing molecular recognition properties.This article reports the preparation of composites and nanocomposites of polypropylene and titanium dioxide particles, with our without surface modification, to obtain photodegradable or photostable materials with less severe environmental impacts. The modification of the titanium dioxide was carried out in the laboratory using propionic acid to improve the interaction of titanium dioxide with the polymer matrix. The composites and nanocomposites were prepared by melt extrusion using a single-screw extruder. The materials obtained were characterized by nuclear magnetic resonance relaxometry, X-ray diffraction, Raman spectroscopy, thermogravimetric analysis and mechanical analysis (tension). The results showed that the surface modification of the titanium dioxide particles promoted their better dispersion, distribution and interaction with the polypropylene matrix, generating a nanocomposite material. The NMR relaxometry results showed that the modified particles changed the molecular dynamics, indicating the formation of nanocomposites. In the Raman spectra, peaks related to the titanium dioxide only appeared at a concentration of 1%, and there was an inversion between crystalline and amorphous phase regions in the samples with the organophilic titanium dioxide, indicating the formation of a nanocomposite. The best modified PP/TiO2 compositions were those containing 0.25 and 0.50% modified TiO2 particles. The incorporation of the titanium dioxide particles, in rutile form, promoted photostabilization of the composites and nanocomposites at all ratios, and the composition containing 0.50% modified TiO2 presented the best photostabilization.In this paper, we report on the structural and electrical properties of graphene oxide (GO) incorporated Nylon66 (N66) composite nanofibers prepared via electrospinning technique. Different types of composite nanofibers were electrospun by varying the weight percentage of GO in the polymer solution. Scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy, as well as current-voltage (I-V) measurements were used to characterize the N66/GO composite nanofibers. The morphology of the N66/GO composite nanofibers exhibited densely arranged mesh-like ultrafine nanofibers which were strongly bound in between the main fibers. The I-V characteristics of the N66/GO composite nanofibers demonstrated that the blending of GO in to N66 nanofibers led to a dramatic improvement of the electrical conduction compared to that of pristine N66 nanofibers which can be utilized for the various technological applications.Reduced graphene oxide and palladium nanoparticle (r-GO/Pd) nanocomposites were synthesized by an ecofriendly one-pot solid-state reduction method using ascorbic acid as a reducing agent. The coordinated formation of r-GO/Pd nanocomposite was observed within 2 min. The formed Pd nanoparticles (5 nm size) were uniformly distributed over the r-GO as characterized by X-ray powder diffraction, raman spectroscopy, scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, and transmission electron microscopy. The cyclic voltammetric study revealed that the r-GO/Pd nanocomposite exhibited excellent electrocatalytic behavior toward the oxidation of alcohols in an alkaline medium. Our study proposes a cost-effective, easy, rapid, scalable, and environmentally friendly method for the synthesis of GO/metal nanoparticles hybrid catalytic material for electrochemical energy applications.Owing to the scattering and trapping effects, the interfaces of dielectric/graphene or substrate/graphene can tailor the performance of field-effect transistor (FET). In this letter, the polymer of benzocyclobutene (BCB) was used as an amphibious buffer layer and located at between the layers of substrate and graphene and between the layers of dielectric and graphene. Interestingly, with the help of nonpolar and hydrophobic BCB buffer layer, the large-scale top-gated, chemical vapor deposited (CVD) graphene transistors was prepared on Si/SiO2 substrate, its cutoff frequency (fT) and the maximum cutoff frequency (fmax) of the graphene field-effect transistor (GFET) can be reached at 12 GHz and 11 GHz, respectively.The electrocatalytic activities of metal-decorated graphene oxide (GO) catalysts were investigated. Electrochemically reduced GO-S-(CH2)4-S-Pd [ERGO-S-(CH2)4-S-Pd] and GO-S-(CH2)4-S-PdAg alloy [ERGO-S-(CH2)4-S-PdAg] were obtained through the electrochemical reduction of GO-S-(CH2)4-S-Pd and GO-S-(CH2)4-S-PdAg in a pH 5 PBS solution. It was demonstrated that the application of ERGO-S-(CH2)4-S-Pd and ERGO-S-(CH2)4-S-PdAg used in a modified GCE improves the electrocatalytic oxidation of formic acid. The addition of an Ag nanoparticle with a carbon chain-Pd in the electrode provides an electrode with very interesting properties for the electrocatalytic oxidation of formic acid. The ERGO-S-(CH2)4-S-Pd and ERGO-S-(CH2)4-S-PdAg were characterized via X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). ERGO-S-(CH2)4-S-Pd and ERGO-S-(CH2)4-S-PdAg can be employed for the electrocatalytic oxidation of formic acid. The electrochemical behaviors of this electrode were investigated using cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS).A novel biosensor for the determination of hydrogen peroxide and glucose was developed based on EGN-TDZ-Pd, as an electrocatalyst. The preparation of graphene oxide (GO) nanosheets was functionalized by combining it with 5-amino-1,3,4-thiadiazole-2-thiol (TDZ) and by covalently bonding it to palladium (Pd) nanoparticles (GO-TDZ-Pd). In the electrochemical investigation, EGN-TDZ-Pd was characterized via scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and electrochemical impedance spectroscopy (EIS). Cyclic voltammetry (CV) and chronoamperometry (CA) were used to characterize the performance of EGN-TDZ-Pd. The proposed H2O2 biosensor exhibited a wide linear range from 10 µM to 6.5 mM. Also, a glucose biosensor was prepared using glucose oxidase and EGN-TDZ-Pd placed onto a glassy carbon electrode (GCE). The GOx/EGN-TDZ-Pd/GCE was easily prepared using a rapid and simple procedure, and it was utilized for highly sensitive glucose determination.Poly(3,4-ethylenedioxythiophene)-(PEDOT)-functionalized reduced graphene oxide (rGO) with MnO2 nanoparticles (MnO2/PEDOT/rGO) was prepared using electrochemical methods. The MnO2/ PEDOT/rGO was obtained through the electrochemical reduction of PEDOT/GO and under electrochemical treatment in KMnO4. The PEDOT/rGO and MnO2/PEDOT/rGO were characterized by several instrumental and electrochemical methods. The electrocatalytic 02 reduction for both electrodes was investigated via cyclic and hydrodynamic voltammetry in 0.1 M KOH aqueous solutions. MLN7243 cost The kinetic analysis in comparison to PEDOT/rGO a significant enhancement was found for the MnO2/PEDOT/rGO. The proposed main path in the oxygen reduction reaction (ORR) mechanism on the MnO2/PEDOT/rGO was the direct four-electron transfer process with faster transfer kinetic rate. The better ORR kinetics were obtained due to the excellent composite formation and well attachment of MnO2 NPs within oxide form. The PEDOT/rGO was less stable for long term use than MnO2/PEDOT/rGO.