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Highlights High‐density polyethylene (HDPE) nanocomposites containing different optimized fractions of carbon nanofiber (CNF) at 6 wt.%, polyethylene glycol (PEG) at 4 wt.%, and copper oxide (CuO) nanorods in concentration ranges of 0.15, 0.5, and 2 wt.% were successfully melt processed using corotating twin extrusion and compression molding technique. The effect of PEG and CuO nanofiller on the HDPE matrix were studied, particularly for the percolation threshold for electrical conductivity, structural morphology, and other properties including thermal stability, thermal conductivity (TC), dielectric, and UV protection properties. It is observed that PEG acts as a good compatibilizer, facilitating better interfacial connection between CNF and HDPE matrix. The optimized composite with 0.15 wt.% CuO nanorods (H/C6/P4/Cu0.15) shows a fine morphology and strong interfacial connections between fillers and the matrix, as observed in FE‐SEM micrographs. This optimized composite exhibits improved thermal stability, higher thermal conductivity (0.0404 W.K−1.m−1), increased dielectric constant, reduced electrical volume resistivity (from 2.1 × 1015 to 2.1 × 106 Ω.cm), and lower optical band gap value (2.74 eV). Additionally, all prepared nanocomposites offer approximately 100% Ultraviolet Protection Factor (UPF) rating for UV protection. The transformation of insulating HDPE into conducting HDPE composites. The effect of CuO nanorods was investigated in compatibilized HDPE composites. A percolation is achieved in the HDPE composite at 0.15 wt.% of CuO nanorods. PEG and CuO nanorods improved the multifunctional properties of the composite. [ABSTRACT FROM AUTHOR]

Recently, Bi 2 S 3 has garnered significant interest in the thermoelectric field due to its abundant and low-toxicity constituents. Nevertheless, pure Bi 2 S 3 material has not been utilized in thermoelectric applications because of its low electrical conductivity. This study presents the fabrication of the Bi 0.33 (Bi 6 S 9)Br-doped Bi 2 S 3 bulk samples with high electrical conductivity and mechanical performance via the melting method in conjunction with spark plasma sintering technology. The increased electron concentration is attributed to the replacement of S2− by Br− and the introduction of extra Bi in the lattice. At 323 K, the electrical conductivity of the Bi 2 S 3 + 3 wt% Bi 0.33 (Bi 6 S 9)Br sample increased to 208 Scm−1, signifying a 3-order-of-magnitude enhancement compared to the pure sample. The enhanced electrical conductivity led to the optimization of the electrical transport properties. At 573 K, the Bi 2 S 3 + 2 wt% Bi 0.33 (Bi 6 S 9)Br bulk sample achieved a peak power factor value of 481 μWm−1K−2, which is four times higher than that of the pure sample. Notably, the low lattice thermal conductivity of the Bi 2 S 3 + 5 wt% Bi 0.33 (Bi 6 S 9)Br sample was 0.56 W−1 m−1K−1 at 673 K. Given the significantly enhanced electrical transport properties and suppressed thermal conductivity, the Bi 2 S 3 + 2 wt% Bi 0.33 (Bi 6 S 9)Br sample achieved a peak ZT value of 0.45 at 673 K and a high ZT ave value of 0.33 from 373 to 673 K. Compared to the pure Bi 2 S 3 sample, these values are 5 times and 3 times higher, respectively. Such advancements can be implemented in the domain of power generation. Additionally, the mechanical properties of the sample exhibited substantial enhancement, and the average hardness of the 2 wt% Bi 0.33 (Bi 6 S 9)Br-doped sample increased from 2.73 GPa of the pure sample to 3.03 GPa. This novel strategy of dual point defects modulation provides a new pathway to enhance the thermoelectric performance of Bi 2 S 3 and other material systems. [Display omitted] • The Bi 0.33 (Bi 6 S 9)Br doped Bi 2 S 3 bulk samples are fabricated by solid states reaction combined with the SPS technology. • A high power factor (481 μW m−1 K−1) were obtained at 573 K. • The mechanical properties of the doped sample showed significant improvement. • A peak ZT value of∼0.45 at 673 K and ZT ave value of∼0.33 from 373 to 673 K were obtained. [ABSTRACT FROM AUTHOR]

In this study, WO3 nanorods are directly blended with polyamic acid (PAA) solutions to improve the electrochromic capacity of WO3/PAA composite films. Specifically, the hexagonal WO3 nanorods are prepared as inorganic reinforcements using a hydrothermal method and modified by γ‐aminopropyl triethoxysilane. After curing at 300 °C, the WO3 nanorods/polyimide (PI) composite films demonstrate excellent mechanical and thermal properties. The tensile strength of the 1 wt% WO3/PI composite film is ≈110.27 MPa. The thermal stability of the 5 wt% WO3/PI composite film is better than that of the others, and the T5 (5% thermal weight loss temperature) value is ≈560.05 °C. Moreover, the WO3/PAA composite films demonstrate electrochromic behaviors. The electrochromic range of the 5 wt% WO3/PAA composite film exceeds to 68%. For the WO3/PAA samples, the oxidation peak of the WO3 nanorods is evident in the cyclic voltammetry curves. The color contrast of WO3/PI nanocomposites can be enhanced owing to the significant synergistic effects of the electron donor–acceptor system. [ABSTRACT FROM AUTHOR]

[Display omitted] • Gold nanorods were synthesized using hydroquinone (HQ) and ascorbic acid (AA). • Ascorbic acid-reduced gelatin-coated gold nanorods are more thermally stable. • A high gelatin volume ratio affects the photothermal response of the gold nanorods. • Ascorbic acid-reduced gelatin-coated gold nanorods gave a better photothermal response. The development of Gold nanorods (AuNRs) as phototherapeutic agents (PTAs) has attracted much interest from researchers in recent decades. The majority of their synthetic methods use Hydroquinone (HQ) and Ascorbic acid (AA) as the reducing agent, and these have been shown to affect the properties of AuNRs. However, no study has been conducted on how these two reducing reagents can affect their application, especially after coating. Therefore, we herein report a seed-mediated synthesis of AuNRs using two reducing agents and coating them with gelatin at different volume ratios (1:5, 1:2, 1:1,2:1, and 5:1). The HQ-reduced AuNRs and AA-reduced AuNRs absorbed at TSPR of 512 nm and 514 nm and LSPR of 914 nm and 847 nm, respectively. The gelatin-coated HQ-reduced and AA-reduced AuNRs did not show significant LSPR wavelength changes for all the volume ratios. However, a slight increase in the TSPR and the absorbance at regions below 550 nm was seen for volume ratios 1:1, 2:1, and 5:1. The thermal stability studies at 70 ℃ for the coated materials revealed that AA-reduced AuNRs were more thermally stable than HQ-reduced AuNRs, with the less optical shift. The coated AA-reduced AuNRs were further tested for photothermal responses. The results show that the high gelatin volume during coating affects the photothermal response of the AuNRs. This study indicates volume ratio of 1:5 and 1:2 has good stability while maintaining the good photothermal profiling needed in PTT applications. Hence Gel@AuNRs synthesised with AA is an excellent PTT agent for phototherapy applications. [ABSTRACT FROM AUTHOR]

Unveiling the thermal transport properties of various one-dimensional (1D) or quasi-1D materials like nanowires, nanotubes, and nanorods is of great importance both theoretically and experimentally. The dimension or size dependence of thermal conductivity is crucial in understanding the phonon–phonon interaction in the low-dimensional systems. In this paper, we experimentally investigate the size-dependent thermal conductivity of individual single crystalline α-Fe2O3 nanowires collaborating the suspended thermal bridge method and the focused electron-beam self-heating technique, with the sample diameter (d) ranging from 180 nm to 661 nm and length (L) changing from 4.84 μm to 20.73 μm. An empirical relationship for diameter-/length-dependent thermal conductivity is obtained, which shows an approximately linear dependence on the aspect ratio (L/(1 + Cd)) at T = 300 K, where C is a fitting parameter. This is related to the boundary scattering and diameter effect of α-Fe2O3 nanowires although rigorous calculations are needed to confirm the result. [ABSTRACT FROM AUTHOR]

The thermal stability of materials directly influences their applications. This present work investigates the difference of thermal decomposition behaviors of alpha (α) and beta (β) manganese dioxide (MnO 2) nanorods. Differential scanning calorimeter coupled with thermogravimetric analysis is conducted to find the difference of thermal process. The X-ray diffraction analysis and scanning electron microscope are employed to test crystal structures and morphologies at various roasted temperatures, respectively. The activation energy and Debye temperature are calculated to explain the difference in the decomposition process. It is found that β-MnO 2 can be fully converted to Mn 2 O 3 after roasting at 650 °C, whereas only part of α-MnO 2 has changed. Besides, the β-MnO 2 nanorods go through a continuous thinning from room temperature to 500 °C, while the morphology of α-MnO 2 remains the same until it reaches over 300 °C. These results suggest that α-MnO 2 nanorods have better thermal resistance than β-MnO 2 , which could facilitate the selection of thermal stable materials for electrochemistry industries and energy materials application. • The evolution of two types MnO 2 nanorods morphologies are investigated when roasting. • The different thermal properties of α- and β-MnO 2 nanorods are reported at different temperatures. • The kinetics of thermal decomposition reaction of α- and β-MnO 2 nanorods are calculated and analyzed. • The first principles are employed to explained the difference on thermal properties of two types MnO 2. [ABSTRACT FROM AUTHOR]

Conventional polyimide nanocomposites reinforced with graphene-based nanofillers usually possess excellent properties, such as high thermal decomposition temperature, enhanced tensile strength, tensile modulus, etc. However, the elongation at break of the nanocomposites is reduced. Here, we prepared N-doped graphene quantum dots/colorless polyimide nanocomposite (N-GQDs/CPI) films for the first time by in-situ polymerization, whose elongation at break is about 2 times that of the pure film. Meanwhile, the thermal properties and other mechanical properties of the films are improved. Through analyzing FT-IR, XPS, XRD, TAG SEM, etc. of N-GQDs and the films, we consider that the strengthening mechanism of matrix performance is attributed to N-GQDs' well dispersion, its small size effects and strong interface interaction with the matrix. Furthermore, at the indicative wavelength of 550 nm, the optical transmittance of the film with 1 wt% N-GQDs still maintains 79%, indicating the resulting films have excellent optical transmittance. The hydrophilic properties of the prepared films' surface is reduced, their water surface contact angle are increased from 63 ± 2.7° to 92 ± 1.7° with the content of N-GQDs increasing. This research shows that N-GQDs can enhance the various properties of polyimide and provides a high performance nanocomposite films for potential flexible substrates. [ABSTRACT FROM AUTHOR]

Gelatin/hydroxyapatite (HAp) composites are of great interest in the biomedical applications because of their excellent biocompatibility, biodegradability, and bioactivity. However, little attention has been paid to synthesis of the gelatin/HAp composites with photo-thermal property. In this study, near-infrared (NIR) responsive gold nanorod (GNR) doped gelatin/HAp composite microspheres were synthesized via an emulsion technique and their microstructure and NIR-responsive photo-thermal property were investigated. SEM observations showed that the composite microspheres were spherical and their diameter was ranged from 10 to 50 µm. XRD patterns showed that the composite microspheres presented the typical diffraction peaks of HAp and GNR components. FT-IR spectra showed that P-O-P bonds, -COOH groups and –NH 2 groups were involved in the composite microspheres. Under an 808-nm NIR light irradiation, the temperature of the suspension of composite microspheres was increased from 37 °C to 42 °C due to the presence of GNR component, indicating that the composite microspheres possessed NIR-responsive photo-thermal property. [ABSTRACT FROM AUTHOR]

In this study, modified wollastonite nanorods (MWNRs) as core and polystyrene (PS) as a shell [Core-shell nanorods (CSNRs)] was synthesized using atomized microemulsion technique. CSNRs were compounded with styrene butadiene rubber (SBR) on a two-roll mill and compressed into sheet form using compression moulding machine. The encapsulation of MWNRs into PS was confirmed by field emission scanning electron microscope (FE-SEM), transmission electron microscope, X-ray diffraction spectrophotometer (XRD) and Fourier transform infrared spectroscopy. CSNRs/SBR nanocomposites were also characterized by XRD, FE-SEM, differential scanning calorimetry, thermogravimetric analysis, universal testing machine and Mooney viscometer. Incorporation of CSNRs resulted in improvement in rheological, thermal and mechanical properties of the nanocomposites. FE-SEM images showed a perfect dispersion of the CSNRs in SBR matrix at <1 wt% loading. Thermal stability of CSNRs/SBR nanocomposites was also increased significantly by the addition of CSNRs. Graphical abstract: [ABSTRACT FROM AUTHOR]

Tin oxide (SnO 2 ) nanorods (NRs) were successfully grown using a two-step seed-mediated hydrothermal method in the absence of surfactants. The enhanced mechanical properties of the impact absorbed energy (71.65%), ultimate tensile strength (35.07%), in-plane shear strength (49.07%) and elastic modulus (44.15%) were obtained for 70 mM of SnO 2 –woven carbon fiber (WCF) composites. The higher electrical resistive heating in the interlaminar region of electrified SnO 2 (70 mM)–WCF composite sheets was observed at 108.92% improvement of an average temperature under an applied current of 3 A for 20 min. It was attributed to the fact that a higher SnO 2 NR content provided secondary reinforcement and subsidiary electrified heat traps by modifying the interphase region between the CFs and polymers. X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to examine the morphology and phase structure of one-dimensional (1D) grown SnO 2 NR arrays. The crystalline 1D SnO 2 nanostructure evolved via a self-assembly mechanism that depended on nuclei of Sn 4+ /OH − ions in a supersaturated solution at a pH of about 13. This facile controlled growth of SnO 2 embedded in CF composites is relevant to engineering applications requiring higher mechanical performance and thermal heating than attainable with conventional CF-reinforced polymer composites. [ABSTRACT FROM AUTHOR]

We report on a rapid and simple method to fabricate polyethylene (PE) nanofibers by one-step drawing from PE solution. The diameter of the fiber prepared with this method can be as small as 40 nm. The thermal conductivity of the drawn PE nanofiber was measured with suspended microdevices, and the highest value obtained is 8.8Wm–1 K–1, which is very close to that of electrospun PE nanofibers, and over 20 times higher than bulk value. Raman spectra of these drawn PE nanofibers indicate that molecular chains in these fibers can be as well aligned as that in electrospun fibers, which results in the enhanced thermal conductivity of the drawn PE nanofibers. [ABSTRACT FROM AUTHOR]

The binary hybrid-filled layer by layer coating, composed of graphene oxide and β-FeOOH nanorods, was fabricated onto flexible polyurethane (FPU) foams by layer by layer assembly technique to reduce its flammability. Scanning electron microscopy images showed that the coexistence phenomenon between GO nanosheets with β-FeOOH nanorods can be found to cover on the FPU foam surface. The analysis by thermogravimetric analysis/infrared spectrometry (TGA-IR) indicated that the binary-hybrid filled coating has greater advantages in suppression of gaseous product generation, meaning that less “fuel” was fed back to the flame. Compared with the single component (graphene oxide or β-FeOOH nanorods)-filled coatings, the binary hybrid-filled coating has greater reduction (49.5%) in peak heat release rate (PHRR) and could almost eliminate the second PHRR for FPU foams in the cone test, which indicates its superiority. As a result, the complementary effect between graphene oxide nanosheets with β-FeOOH nanorods enhanced the flame retardant effect for FPU foams. [ABSTRACT FROM AUTHOR]

Quantitative characterization of thermal properties of nanorod (NR) arrays appears to be challenging due to the complex combination of high volume of air voids, anisotropy, and structural non-uniformity. This work investigates the structure-thermal property correlation of arrays consisting of either vertically aligned or slanted silicon dioxide (SiO2) NRs, fabricated by the dynamic shadowing growth technique. We apply the frequency-dependent time-domain thermoreflectance method to quantify the thermal properties of SiO2 NR arrays that may possess inhomogeneity along the depth direction. The effective thermal conductivities of four SiO2 NR array films and one reference capping layer for the SiO2 NR array are obtained. The impact of the structure on the effective thermal conductivities of the SiO2 NR array is discussed. The lowest effective thermal conductivity among all samples in this work is found to be 0.13W m-1 K-1 for the slanted NR array. We attribute the reduction in the effective thermal conductivity of the NR array to the discontinuous nature of SiO2 NRs, which reduces the density of the thermal transport channels and thus prevents heat flux from propagating downwards along the through-plane direction. The results from this work facilitate the potential applications of NR-array-based thermal insulators for micro-thermal devices. [ABSTRACT FROM AUTHOR]

The nanowire and nanorod morphologyoffers great advantages for application in a range of optoelectronicdevices, but these high-quality nanorod arrays are typically basedon high temperature growth techniques. Here, we demonstrate the successfulroom temperature growth of a hybrid perovskite (CH3NH3PbBr3) nanorod array, and we also introduce a newlow temperature anion exchange technique to convert the CH3NH3PbBr3nanorod array into a CH3NH3PbI3nanorod array while preserving morphology.We demonstrate the application of both these hybrid perovskite nanorodarrays for LEDs. This work highlights the potential utility of postsyntheticinterconversion of hybrid perovskites for nanostructured optoelectronicdevices such as LEDs, which enables new strategies for the applicationof hybrid perovskites. [ABSTRACT FROM AUTHOR]

Novel palygorskite/polystyrene (PLG/PS) nanocomposites were synthesized via the facile in-situ bulk radical polymerization of styrene in the presence of the organo-palygorskite (Org-PLG) nanorods, which was prepared by the modification of the acid-activated palygorskite (A-PLG) nanorods with the functional silane (γ-methacryloxypropyl trimethoxy silane (MPS)). The micro-gels with the Org-PLG nanorods as crosslinker were produced in the PLG/PS nanocomposites regardless of the polymerizing conditions, such as the feeding ratios of the Org-PLG, initiator and N 2 atmosphere. Based on the gelation and thermal properties of the PLG/PS nanocomposites, the optimal preparation condition via the in-situ bulk polymerization was achieved and the crosslinking mechanism to the micro-gels was also depicted. This understanding should lead to a better design of clay mineral modifications for use in polymer nanocomposites. [ABSTRACT FROM AUTHOR]

This paper presents an investigation on the synthesis and characterization of Cu3BiS3 nanosheet films on a TiO2/FTO substrate by a solvothermal route and the photoelectrochemical characteristics of the Cu3BiS3/TiO2 composite films are demonstrated as well. The results show that Cu3BiS3 nanosheets with an average thickness of 30 nm were successfully synthesized on the surface of TiO2 nanorod arrays. The photoelectric properties of the Cu3BiS3/TiO2 composite film indicate that the fill factor of the film photoelectrode is 60.8%, and the energy conversion efficiency is 1.281%, which is higher than that of a bare TiO2 nanorod array photoelectrode. [ABSTRACT FROM AUTHOR]

Nanorod forms of metal oxides are recognized as one of the most remarkable morphologies. Their structure and functionality have driven important advancements in a vast range of electronic devices and applications. In this work, we postulate a novel concept to explain how numerous localized surface states can be engineered into the bandgap of niobium oxide nanorods using tungsten. We discuss their contributions as local state surface charges for the modulation of a Schottky barrier height, the relative dielectric constant and their respective conduction mechanisms. Their effects on hydrogen gas molecule interaction mechanisms are also examined herein. We synthesized niobium tungsten oxide (Nb17W2O25) nanorods via a hydrothermal growth method and evaluated the Schottky barrier height, ideality factor, dielectric constant and trap energy level from the measured I–V versus temperature characteristics in the presence of air and hydrogen to show the validity of our postulations. [ABSTRACT FROM AUTHOR]

Currently, gold nanorods can be synthesized in a wide range of sizes. However, for the intended biological applications gold nanorods with approximate dimensions 50 nm × 15 nm are used. We investigate by computer simulation the effect of particle dimensions on the optical and thermal properties in the context of the specific applications of photoacoustic imaging. In addition we discuss the influence of particle size in overcoming the following biophysical barriers when administrated in vivo: extravasation, avoidance of uptake by organs of the reticuloendothelial system, penetration through the interstitium, binding capability and uptake by the target cells. Although more complex biological influences can be introduced in future analysis, the present work illustrates that larger gold nanorods, designated by us as 'nanobig rods', may perform better at meeting the requirements for successful in vivo applications compared to their smaller counterparts, which are conventionally used. [ABSTRACT FROM AUTHOR]

Abstract: The paper reports the synthesis of high yield of a-Se100−x Te x (x =3, 6, 9 and 12) nanorods using one of the simplest approaches i.e. melt quenching technique. The morphology and microstructure of as-prepared alloys is studied using scanning Electron Microscopy (SEM) and transmission electron microscopy (TEM). From SEM investigation, it is observed that these powder samples of a-Se x Te100−x contain high yield of nanorods and their diameter is of the order of several hundred nanometers. The XRD patterns of these samples suggest that these nanorods are amorphous in nature. Crystallization kinetics in these nanorods of amorphous Se x Te100−x glasses are studied at different heating rates (5, 10, 15 and 20Kmin−1) under non-isothermal condition using differential scanning calorimetry. It is observed that the value of glass transition temperature and crystallization temperature varies with the composition and heating rate. From the heating rate dependence of glass transition temperature and crystallization temperature, the activation energy for structural relaxation (ΔE t ), the activation energy of crystallization (ΔE c ) and the order parameter (n) have been calculated. The composition dependence of the activation energy for thermal relaxation and activation energy for crystallization is discussed in terms of the structure of Se–Te glassy system. [Copyright &y& Elsevier]

Abstract: Single-crystalline nanorods of γ-MnOOH (manganite) phase with diameters of 120nm and lengths of 1100nm have been prepared using a new cluster growth route under low-temperature hydrothermal conditions starting from [Mn12O12(CH3COO)16(H2O)4]·2CH3COOH·4H2O or [Mn12O12(C2H5COO)16(H2O)3]·4H2O without any catalyst or template agents. The so-obtained nanorods were studied by X-ray diffraction (XRD), infrared (IR) spectroscopy, Raman spectroscopy and high resolution transmission electron microscopy (HRTEM). Their thermal conversion opens an access to Mn3O4 (hausmannite) and β-MnO2 (pyrolusite) nanorods, respectively, under argon or air atmosphere. A coercive field of 12.4kOe was obtained for the Mn3O4 nanorods. [Copyright &y& Elsevier]

Poly(vinyl alcohol) nanofibrous mats containing ad hoc synthesized gold nanostructures were prepared via a single-step electrospinning procedure and investigated as a novel composite platform with several potential applications. Specifically, the effect of differently shaped and sized gold nanostructures on the resulting mat physical-chemical properties was investigated. In detail, nearly spherical nanoparticles and nanorods were first synthesized through a chemical reduction of gold precursors in water by using (hexadecyl)trimethylammonium bromide as the stabilizing agent. These nanostructures were then dispersed in poly(vinyl alcohol) aqueous solutions to prepare nanofibrous mats, which were then stabilized via a humble thermal treatment able to enhance their thermal stability and water resistance. Remarkably, the nanostructure type was proven to influence the mesh morphology, with the small spherical nanoparticles and the large nanorods leading to thinner well defined or bigger defect-rich nanofibers, respectively. Finally, the good mechanical properties shown by the prepared composite mats suggest their ease of handleability thereby opening new perspective applications. [ABSTRACT FROM AUTHOR]

The cell surface is made electrochemically active by interfacing with graphene sheets. The electrical and thermal properties of graphene allow the control of cell surface potential for electrochemical synthesis. Using this approach radially projecting ZnO nanorods are templated on the surface of single cells. This reported single cell photosensor has superior performance than similar devices made on planar surfaces. [ABSTRACT FROM AUTHOR]

The composites based on basalt fibres and poly(lactic acid) (PLA) show promising applications in biomedical and automotive fields, but their mechanical performance is still largely hindered by poor interfacial properties. Zinc oxide nanorods have been successfully used to tune the PLA/basalt fibre interface by growing them on commercially available basalt fabrics. The hierarchical fibres significantly enhanced the mechanical properties of PLA-based composites, especially their flexural strength and stiffness. These values are 26% and 22% higher than those of unmodified basalt/PLA composites, and 24% and 34% higher than those of glass/PLA composites used as a baseline. The increase in tensile and flexural properties hinges on the mechanical interlocking action promoted by ZnO nanorods and on the creation of a compact transcrystallinity structure. A degradation of PLA matrix was detected but it was positively counteracted by the better interfacial stress transfer. This study offers a novel approach for modifying the fibre–matrix interface of biocomposites intended for high-performance applications. [ABSTRACT FROM AUTHOR]

Here, microspheres of self-assembled CuO rectangular nanorods and hierarchical structures of self-assembled Cu 2 O nanospheres have been synthesized from single precursor (copper (II) acetate monohydrate) using hydrothermal method. The utility of NH 3 and N 2 H 4 ·H 2 O as reducing agents for the formation of phases and morphology of CuO and Cu 2 O has been investigated. The XRD patterns and Raman spectra indicate that the synthesized CuO and Cu 2 O nanostructures are single phase and high crystalline. The SEM images clearly show that the rectangular shaped CuO nanorods are densely packed and self-organized into microspheres whereas self-assembled Cu 2 O nanospheres makes hierarchical Cu 2 O structures. The TEM images reveal that the individual CuO rectangular nanorod is having ends with a small faceted nano-tip-like structure while the hierarchical nanostructures of Cu 2 O consist of agglomerated nanospheres with distinguishable grain boundaries. The presence of vibrational modes, associated with the relative motion of both copper and oxygen atoms, in the FTIR spectra also supports the formation of CuO and Cu 2 O phases, respectively. The optical properties of the synthesized materials were revealed using absorption spectra. The thermal behaviour was also investigated through DSC measurements. The magnetic properties have also been investigated in order to explore new insights responsible for specific magnetic behaviour. Image 1 • Microspheres of self-assembled CuO rectangular nanorods and hierarchical structures of self-assembled Cu 2 O nanospheres were synthesized. • The utility of NH 3 and N 2 H 4.H 2 O in phase formation and morphology growth of CuO and Cu 2 O was studied, respectively. • The optical absorption and magnetic properties of the synthesized materials have been studied. [ABSTRACT FROM AUTHOR]

Thermal degradation of polystyrene/ZnO (PS/ZnO) nanocomposites was investigated in this study. PS/ZnO polymer nanocomposites were prepared by using ZnO nanorods as nanofillers that were prepared via the sol-gel route. The as-prepared ZnO nanoparticles showed nanocrystallites in rod-like shapes with a non-uniform hexagonal cross-section and diameter varying from 40 to 75 nm. PS/ZnO nanocomposites with ZnO nanoparticles content ranging from 0–3 wt% are prepared via the common casting method. Even dispersion for ZnO nanoparticles within as-prepared PS/ZnO nanocomposites was verified through SEM/EDX measurements. Thermal degradation of the samples was checked by using the thermogravimetric (TG) analysis and differential scanning calorimetry (DSC) under non-isothermal conditions and a constant heating rate of 10 °C min. The thermal stability of the nanocomposite is elevated compared to that of pristine PS due to the addition of the ZnO nanoparticles. The homogeneity of the PS/ZnO nanocomposites is verified by systematic increases in thermal degradation with increasing ZnO content. The characterization degradation temperatures at different weight loss percentages of ZnO nanoparticles increase at high ZnO wt%. Static activation energy of decomposing is based on TGA data. Activation energies showed some enhancement after the addition of ZnO nanorods into the PS matrix. Enhancing the thermal stability of PS with ZnO addition within the investigated ZnO concentration range is verified by TG, DSC results. [ABSTRACT FROM AUTHOR]

The ultraviolet (UV) photoresponses of ZnO nanorods directly grown on and between two micro Au-electrodes by using electric-field-assisted wet chemical method are measured comprehensively under different conditions, including ambient environment, applied bias voltage, gate voltage and temperature. Experimental results indicate that the photoresponses of the ZnO nanorods can be modulated by surface oxygen adsorptions, applied voltages, as well as temperatures. A model taking into account both surface adsorbed oxygen and electron-hole activities inside ZnO nanorods is proposed. The enhancement effect of the bias voltage on photoresponse is also analyzed. Experimental results shows that the UV response time (to 63%) of ZnO nanorods in air and at 59 °C could be shortened from 34.8 s to 0.24 s with a bias of 4 V applied between anode and cathode. [ABSTRACT FROM AUTHOR]

This paper presents a novel microelectrode arrays using high-temperature grown vertically aligned carbon nanotubes (CNTs) integrated on a flexible and biocompatible parylene substrate. A simple microfabrication process is proposed to unite the high quality vertical CNTs grown at high temperature with the heat sensitive parylene substrate in a highly controllable manner. Briefly, the CNTs electrode is encapsulated by two layers of parylene and the device is released using xenon difluoride (XeF2). The process is compatible with wafer-scale post complementary metal oxide semiconductor integration. Lower impedance and larger interfacial capacitance have been demonstrated using CNTs compared to a Pt electrode. The flexible CNT electrodes have been utilized for extracellular neuronal recording and stimulation in rats. The signal-to-noise ratio of the device is about 12.5. The threshold voltage for initiating action potential is about 0.5 V. [ABSTRACT FROM AUTHOR]