Journal of Nanomaterials The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Carbon Nanomaterials and Related Nanostructures: Synthesis, Characterization, and Application Sun, 31 Aug 2014 07:48:42 +0000 Jinlong Jiang, Jun Yang, Jian Lin, Zhenghong Huang, and S. C. Wang Copyright © 2014 Jinlong Jiang et al. All rights reserved. Microstructure and Properties of SCE-Al2O3/PES-MBAE Composite Thu, 28 Aug 2014 11:48:03 +0000 SCE-Al2O3 was the nano-Al2O3 modified by supercritical ethanol and the surface of SCE-Al2O3 was coated with active group. 4,4′-diaminodiphenylmethane bismaleimide (MBMI) was used as matrix; 3,3′-diallyl bisphenol A (BBA) and bisphenol-A diallyl ether (BBE) were used as reactive diluent, polyethersulfone (PES) as toughening agent, and SCE-Al2O3 as modifier; SCE-Al2O3/PES-MBAE nanocomposite was prepared through in situ sol-gel method. The mechanism of composite toughened by PES was observed and analyzed. FTIR indicated that the reaction between MBMI and allyl compound occurred and SCE-Al2O3 had doped into the polymer matrix. SEM showed that PES particle was inlaid in matrix and presented as a two-phase structure in matrix. The heat resistance, dielectric properties, and mechanical properties of SCE-Al2O3/PES-MBAE nanocomposites were evaluated. The results showed that with the incorporation of PES, although the toughness of the material improved, the heat resistance and dielectric properties of material declined, meanwhile. The adulteration of SCE-Al2O3 could remedy the harmful effect caused by PES, while the content of SCE-Al2O3 was reasonable. The decomposition temperature, dielectric constant, and dielectric loss of composite were 441.23°C, 3.63 (100 Hz), and 1.52 × 10−3 (100 Hz); the bending strength and impact strength were 129.22 MPa and 13.19 kJ/mm2, respectively, when the content of SCE-Al2O3 was 3 wt% and PES was 5 wt%. Yufei Chen, Qiwang Dai, Xiwang Zhang, and Tao Feng Copyright © 2014 Yufei Chen et al. All rights reserved. Systematic Evaluation and Mechanistic Investigation of Antioxidant Activity of Fullerenols Using β-Carotene Bleaching Assay Thu, 28 Aug 2014 09:43:31 +0000 Antioxidant activity of hydroxylated fullerenes, so-called fullerenols, against lipid peroxyl radical was evaluated by β-carotene bleaching assay. All samples showed moderate to high antioxidant activity (%AOA), especially for C60(OH)12 (70.1) and C60(OH)44 (66.0) as compared with 8, 24, 26, and 36 hydroxylated ones (31.7–62.8). The detection of the possible products was conducted in the model reaction of both fullerenols and C60 with methyl linoleate by MALDI-TOF-MS. These results suggested that the two possible mechanisms, such as C-addition to double bonds and H-abstraction from –OH groups, are involved in the present radical scavenging reaction. Hiroshi Ueno, Shizuka Yamakura, Riya S. Arastoo, Takumi Oshima, and Ken Kokubo Copyright © 2014 Hiroshi Ueno et al. All rights reserved. The Influence of Electrophoretic Deposition for Fabricating Dye-Sensitized Solar Cell Thu, 28 Aug 2014 00:00:00 +0000 Titanium dioxide (TiO2) film was deposited on fluorine-doped tin oxide (FTO) glass substrate by electrophoretic deposition method (EPD). TiO2 films were prepared with different I2 dosages, electric field intensities and deposition time (D.T.), electrophotic deposition times. By different I2 dosages, electric field intensities, deposition time, electrophotic deposition times fabricated TiO2 films and compared photoelectric characteristics of TiO2 films to find optimal parameters which were the highest photovoltaic conversion efficiency. And use electrochemical impedance spectroscopy (EIS) to measure the Nyquist plots under different conditions and analyze the impendence of dye-sensitized solar cells at the internal heterojunction. According to the experimental results, the I2 dosage was 0.025 g which obtained the optimal characteristic parameters. Thickness of TiO2 film was 10.6 μm, the open-circuit voltage () was 0.77 V, the short-circuit current density () was 7.20 mA/cm2, the fill factor (F.F.) was 53.41%, and photovoltaic conversion efficiency (η) was 2.96%. Jung-Chuan Chou, Shen-Chang Lin, Yi-Hung Liao, Jui-En Hu, Shen-Wei Chuang, and Chin-Hui Huang Copyright © 2014 Jung-Chuan Chou et al. All rights reserved. Time-Evolution Contrast of Target MRI Using High-Stability Antibody Functionalized Magnetic Nanoparticles: An Animal Model Wed, 27 Aug 2014 12:29:19 +0000 In this work, high-quality antibody functionalized Fe3O4 magnetic nanoparticles are synthesized. Such physical characterizations as particle morphology, particle size, stability, and relaxivity of magnetic particles are investigated. The immunoreactivity of biofunctionalized magnetic nanoparticles is examined by utilizing immunomagnetic reduction. The results show that the mean diameter of antibody functionalized magnetic nanoparticles is around 50 nm, and the relaxivity of the magnetic particles is 145 (mM·s)−1. In addition to characterizing the magnetic nanoparticles, the feasibility of using the antibody functionalized magnetic nanoparticles for the contrast medium of target magnetic resonance imaging is investigated. These antibody functionalized magnetic nanoparticles are injected into mice bearing with tumor. The tumor magnetic-resonance image becomes darker after the injection and then recovers 50 hours after the injection. The tumor magnetic-resonance image becomes the darkest at around 20 hours after the injection. Thus, the observing time window for the specific labeling of tumors with antibody functionalized magnetic nanoparticles was found to be 20 hours after injecting biofunctionalized magnetic nanoparticles into mice. The biopsy of tumor is stained after the injection to prove that the long-term darkness of tumor magnetic-resonance image is due to the specific anchoring of antibody functionalized magnetic nanoparticles at tumor. K. W. Huang, S. Y. Yang, H. E. Horng, J. J. Chieh, H. H. Chen, C. C. Wu, J. H. Chen, I.T. Lin, C. C. Yang, and H. C. Yang Copyright © 2014 K. W. Huang et al. All rights reserved. Size, Temperature, and Strain-Rate Dependence on Tensile Mechanical Behaviors of Ni3Sn4 Intermetallic Compound Using Molecular Dynamics Simulation Wed, 27 Aug 2014 08:36:11 +0000 This study focuses on exploring the mechanical properties and nonlinear stress-strain behaviors of monoclinic Ni3Sn4 single crystals under uniaxial tensile test and also their size, temperature, and strain-rate dependence through constant temperature molecular dynamics (MD) simulation using Berendsen thermostat. The deformation evolution of the Ni3Sn4 atomic nanostructure during the tensile test is observed. In addition, the tensile yield strains of various Ni3Sn4 single crystals at different strain rates and temperatures are characterized through unloading process. At last, by way of linear regression analysis, the corresponding normal elastic stiffness constants are approximated and then compared with the literature theoretical data. The radial distribution function analysis shows that Ni3Sn4 single crystal in a one-dimensional nanowire configuration would become a highly disordered structure after thermal equilibration, thereby possessing amorphous-like mechanical behaviors and properties. The initial elastic deformation of Ni3Sn4 single crystal is governed by the reconfiguration of surface atoms, and its deformation evolution after further uniaxial tensile straining is characterized by Ni=Sn bond straightening, bond breakage, inner atomic distortion, cross-section shrinking, and rupture. The calculated normal elastic constants of Ni3Sn4 single crystal are found to be consistent with the literature theoretical data. Hsien-Chie Cheng, Ching-Feng Yu, and Wen-Hwa Chen Copyright © 2014 Hsien-Chie Cheng et al. All rights reserved. Oxidized Nano-Porous-Silicon Buffer Layers for Suppressing the Visible Photoresponsivity of ZnO Ultraviolet Photodetectors on Si Substrates Tue, 26 Aug 2014 12:42:07 +0000 This paper demonstrated the fabrication and optoelectronic characteristics of ZnO ultraviolet (UV) photodetectors fabricated on Si substrates with oxidized nano-porous-Si (ONPS) buffer layers. ONPS layers were prepared on the surfaces of Si substrates by use of an electrochemical anodization technique following a rapid-thermal-oxidation process. Experimental results indicated that application of ONPS buffer layers not only improved the crystallinty of the deposited ZnO thin films but also greatly restricted the visible-to-infrared photoresponse that was generated from the light absorption of Si substrates. The developed ZnO-on-ONPS photodiodes achieved high photoresponsivity for the incident UV light of 300 ∼ 400 nm and got a large photo-to-dark current ratio up to 104 at wavelength of 375 nm under a bias of 5 V. Therefore, ZnO on ONPS provides a highly potential approach for the development of low-cost visible-blind UV photodetectors. Kuen-Hsien Wu Copyright © 2014 Kuen-Hsien Wu. All rights reserved. Preparation and Characterization of Chitosan Nanoparticles-Doped Cellulose Films with Antimicrobial Property Tue, 26 Aug 2014 12:26:19 +0000 Cellulose films with antimicrobial property were prepared by incorporation of chitosan nanoparticles as antimicrobial agents into the cellulose films. The antimicrobial property of these chitosan nanoparticles-doped cellulose films against Escherichia coli (E. coli) was evaluated via diffusion assay method, minimum inhibitory concentration (MIC) method, and minimum bactericidal concentration (MBC) method. The effects of antimicrobial agent amount, size-related property (nanoparticles and bulk chitosan), and crosslinking by citric acid on antimicrobial activity of cellulose films were studied. It was observed that the antimicrobial activity was enhanced when chitosan nanoparticles were used as compared to when bulk chitosan was used. A maximum E. coli inhibition of 85% was achieved with only 5% (v/v) doping of chitosan nanoparticles into the cellulose films. Crosslinking of the cellulose films with citric acid was observed to have resulted in 50% reduction of water absorbency and a slight increase of E. coli inhibition by 3% for chitosan nanoparticles-doped cellulose films. Ain Nadirah Binti Romainor, Suk Fun Chin, Suh Cem Pang, and Lesley Maurice Bilung Copyright © 2014 Ain Nadirah Binti Romainor et al. All rights reserved. Electrospun Polymer Nanomaterials: Preparation, Characterization, and Application Tue, 26 Aug 2014 10:53:50 +0000 Aihua He, Ruigang Liu, Huarong Nie, and Yaqin Huang Copyright © 2014 Aihua He et al. All rights reserved. Study on the Size-Dependent Oxidation Reaction Kinetics of Nanosized Zinc Sulfide Tue, 26 Aug 2014 09:05:46 +0000 Numerous oxidation problems of nanoparticles are often involved during the preparation and application of nanomaterials. The oxidation rate of nanomaterials is much faster than bulk materials due to nanoeffect. Nanosized zinc sulfide (nano-ZnS) and oxygen were chosen as a reaction system. The influence regularities were discussed and the influence essence was elucidated theoretically. The results indicate that the particle size can remarkably influence the oxidation reaction kinetics. The rate constant and the reaction order increase, while the apparent activation energy and the preexponential factor decrease with the decreasing particle size. Furthermore, the logarithm of rate constant, the apparent activation energy and the logarithm of preexponential factor are linearly related to the reciprocal of particle diameter, respectively. The essence is that the rate constant is influenced by the combined effect of molar surface energy and molar surface entropy, the reaction order by the molar surface area, the apparent activation energy, by the molar surface energy, and the preexponential factor by the molar surface entropy. The influence regularities and essence can provide theoretical guidance to solve the oxidation problems involved in the process of preparation and application of nanomaterials. Qing-Shan Fu, Yong-Qiang Xue, Zi-Xiang Cui, and Ming-Fang Wang Copyright © 2014 Qing-Shan Fu et al. All rights reserved. Emission Mechanisms of Si Nanocrystals and Defects in SiO2 Materials Tue, 26 Aug 2014 06:34:09 +0000 Motivated by the necessity to have all silicon optoelectronic circuits, researchers around the world are working with light emitting silicon materials. Such materials are silicon dielectric compounds with silicon content altered, such as silicon oxide or nitride, enriched in different ways with Silicon. Silicon Rich Oxide or silicon dioxide enriched with silicon, and silicon rich nitride are without a doubt the most promising materials to reach this goal. Even though they are subjected to countless studies, the light emission phenomenon has not been completely clarified. So, a review of different proposals presented to understand the light emission phenomenon including emissions related to nanocrystals and to point defects in SiO2 is presented. José Antonio Rodríguez, Marco Antonio Vásquez-Agustín, Alfredo Morales-Sánchez, and Mariano Aceves-Mijares Copyright © 2014 José Antonio Rodríguez et al. All rights reserved. The Cellulose Nanofibers for Optoelectronic Conversion and Energy Storage Mon, 25 Aug 2014 09:14:08 +0000 Cellulose widely exists in plant tissues. Due to the large pores between the cellulose units, the regular paper is nontransparent that cannot be used in the optoelectronic devices. But some chemical and physical methods such as 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) oxidation can be used to improve the pores scale between the cellulose units to reach nanometer level. The cellulose nanofibers (CNFs) have good mechanical strength, flexibility, thermostability, and low thermal expansion. The paper made of these nanofibers represent a kind of novel nanostructured material with ultrahigh transparency, ultrahigh haze, conductivity, biodegradable, reproducible, low pollution, environment friendly and so on. These advantages make the novel nanostructured paper apply in the optoelectronic device possible, such as electronics energy storage devices. This kind of paper is considered most likely to replace traditional materials like plastics and glass, which is attracting widespread attention, and the related research has also been reported. The purpose of this paper is to review CNFs which are applied in optoelectronic conversion and energy storage. Yongfeng Luo, Jianxiong Zhang, Xi Li, Chunrong Liao, and Xianjun Li Copyright © 2014 Yongfeng Luo et al. All rights reserved. Fabrication, Characterization, Properties, and Applications of Low-Dimensional BiFeO3 Nanostructures Mon, 25 Aug 2014 08:19:43 +0000 Low-dimensional BiFeO3 nanostructures (e.g., nanocrystals, nanowires, nanotubes, and nanoislands) have received considerable attention due to their novel size-dependent properties and outstanding multiferroic properties at room temperature. In recent years, much progress has been made both in fabrications and (microstructural, electrical, and magnetic) in characterizations of BiFeO3 low-dimensional nanostructures. An overview of the state of art in BiFeO3 low-dimensional nanostructures is presented. First, we review the fabrications of high-quality BiFeO3 low-dimensional nanostructures via a variety of techniques, and then the structural characterizations and physical properties of the BiFeO3 low-dimensional nanostructures are summarized. Their potential applications in the next-generation magnetoelectric random access memories and photovoltaic devices are also discussed. Finally, we conclude this review by providing our perspectives to the future researches of BiFeO3 low-dimensional nanostructures and some key problems are also outlined. Heng Wu, Jun Zhou, Lizhi Liang, Lei Li, and Xinhua Zhu Copyright © 2014 Heng Wu et al. All rights reserved. Bimetallic Nanomaterials: Functional Efficacy towards Synthesis, Photocatalytic Degradation, and Biomedical Catalysts Sun, 24 Aug 2014 09:23:28 +0000 S. Mohana Roopan, Amir Kajbafvala, Arash Dehghan Banadaki, G. Madhumitha, and Karthik S. Pillai Copyright © 2014 S. Mohana Roopan et al. All rights reserved. Novel Approach: Tungsten Oxide Nanoparticle as a Catalyst for Malonic Acid Ester Synthesis via Ozonolysis Sun, 24 Aug 2014 06:32:31 +0000 Malonic acid ester was synthesized via the one-step ozonolysis of palm olein. Malonic acid ester was spectroscopically characterized using gas chromatography mass spectroscopy (GC-MS). Tungsten oxide nanoparticles were used as the catalyst, which was characterized via X-ray powder diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). Tungsten oxide provided several advantages as a catalyst for the esterification malonic acid such as simple operation for a precise ozonation method, an excellent yield of approximately 10%, short reaction times of 2 h, and reusability due to its recyclability. Bilal A. Wasmi, Ahmed A. Al-Amiery, Abdul Amir H. Kadhum, and Abu Bakar Mohamad Copyright © 2014 Bilal A. Wasmi et al. All rights reserved. Synthesis and Catalytic Performance of Graphene Modified CuO-ZnO- for Hydrogenation to Methanol Sun, 24 Aug 2014 05:52:08 +0000 CuO-ZnO-Al2O3 and graphene nanosheet (GNS) were synthesized by coprecipitation route and reduction of exfoliated graphite oxides method, respectively. GNS modified CuO-ZnO-Al2O3 nanocomposites were synthesized by high energy ball milling method. The structure, morphology, and character of the synthesized materials were studied by BET, XRD, TEM, and H2-TPR. It was found that by high energy ball milling method the CuO-ZnO-Al2O3 nanoparticles were uniformly dispersed on GNS surfaces. The catalytic performance for the methanol synthesis from CO2 hydrogenation was also tested. It was shown experimentally that appropriate incorporation of GNS into the CuO-ZnO-Al2O3 could significantly increase the catalyst activity for methanol synthesis. The 10 wt.% GNS modified CuO-ZnO-Al2O3 catalyst gave a methanol space time yield (STY) of 92.5% higher than that on the CuO-ZnO-Al2O3 catalyst without GNS. The improved catalytic performance was attributed to the excellent promotion of GNS to dispersion of CuO and ZnO particles. Zheng-juan Liu, Xing-jiang Tang, Shan Xu, and Xiao-lai Wang Copyright © 2014 Zheng-juan Liu et al. All rights reserved. Photothermal Therapy Using Gold Nanorods and Near-Infrared Light in a Murine Melanoma Model Increases Survival and Decreases Tumor Volume Thu, 21 Aug 2014 13:13:31 +0000 Photothermal therapy (PTT) treatments have shown strong potential in treating tumors through their ability to target destructive heat preferentially to tumor regions. In this paper we demonstrate that PTT in a murine melanoma model using gold nanorods (GNRs) and near-infrared (NIR) light decreases tumor volume and increases animal survival to an extent that is comparable to the current generation of melanoma drugs. GNRs, in particular, have shown a strong ability to reach ablative temperatures quickly in tumors when exposed to NIR light. The current research tests the efficacy of GNRs PTT in a difficult and fast growing murine melanoma model using a NIR light-emitting diode (LED) light source. LED light sources in the NIR spectrum could provide a safer and more practical approach to photothermal therapy than lasers. We also show that the LED light source can effectively and quickly heat in vitro and in vivo models to ablative temperatures when combined with GNRs. We anticipate that this approach could have significant implications for human cancer therapy. Mary K. Popp, Imane Oubou, Colin Shepherd, Zachary Nager, Courtney Anderson, and Len Pagliaro Copyright © 2014 Mary K. Popp et al. All rights reserved. The Carbon Nanotube Fibers for Optoelectric Conversion and Energy Storage Thu, 21 Aug 2014 00:00:00 +0000 This review summarizes recent studies on carbon nanotube (CNT) fibers for weavable device of optoelectric conversion and energy storage. The intrinsic properties of individual CNTs make the CNT fibers ideal candidates for optoelectric conversion and energy storage. Many potential applications such as solar cell, supercapacitor, and lithium ion battery have been envisaged. The recent advancement in CNT fibers for optoelectric conversion and energy storage and the current challenge including low energy conversion efficiency and low stability and future direction of the energy fiber have been finally summarized in this paper. Yongfeng Luo, Xi Li, Jianxiong Zhang, Chunrong Liao, and Xianjun Li Copyright © 2014 Yongfeng Luo et al. All rights reserved. Highly Enhanced Vapor Sensing of Multiwalled Carbon Nanotube Network Sensors by n-Butylamine Functionalization Thu, 21 Aug 2014 00:00:00 +0000 The sensing of volatile organic compounds by multiwall carbon nanotube networks of randomly entangled pristine nanotubes or the nanotubes functionalized by n-butylamine, which were deposited on polyurethane supporting electrospinned nonwoven membrane, has been investigated. The results show that the sensing of volatile organic compounds by functionalized nanotubes considerably increases with respect to pristine nanotubes. The increase is highly dependent on used vapor polarity. For the case of highly polar methanol, the functionalized MWCNT network exhibits even more than eightfold higher sensitivity in comparison to the network prepared from pristine nanotubes. P. Slobodian, P. Riha, P. Cavallo, C. A. Barbero, R. Benlikaya, U. Cvelbar, D. Petras, and P. Saha Copyright © 2014 P. Slobodian et al. All rights reserved. Enhanced Light Output of Dipole Source in GaN-Based Nanorod Light-Emitting Diodes by Silver Localized Surface Plasmon Wed, 20 Aug 2014 12:27:18 +0000 The light output of dipole source in three types of light-emitting diodes (LEDs), including the conventional planar LED, the nanorod LED, and the localized surface plasmon (LSP) assisted LED by inserting silver nanoparticles in the gaps between nanorods, was studied by use of two-dimensional finite difference time domain method. The height of nanorod and the size of silver nanoparticles were variables for discussion. Simulation results show that a large height of nanorod induces strong wavelength selectivity, which can be significantly enhanced by LSP. On condition that the height of nanorod is 400 nm, the diameter of silver nanoparticle is 100 nm, and the wavelength is 402.7 nm, the light-output efficiency for LSP assisted LED is enhanced by 190% or 541% as compared to the nanorod counterpart or the planar counterpart, respectively. The space distribution of Poynting vector was present to demonstrate the significant enhancement of light output at the resonant wavelength of LSP. Huamao Huang, Haiying Hu, Hong Wang, and Kuiwei Geng Copyright © 2014 Huamao Huang et al. All rights reserved. Effect of a Silver Nanoparticles Solution on Staphylococcus aureus and Candida spp. Wed, 20 Aug 2014 00:00:00 +0000 An AgNPs solution was synthesized by chemical reduction, characterized, and tested against Candida glabrata, Candida tropicalis, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus (MRSA). Minimum inhibitory (MICs) and minimum fungicidal/bactericidal concentrations (MFC/MBC) were determined on planktonic cells. Also, total biofilm mass was determined by crystal violet (CV) staining and morphological changes by scanning electron microscope (SEM). MICs for C. glabrata, C. tropicalis, S. aureus, and MRSA were 15.63, 3.91, 1.95, and 1.95 µg/mL, respectively. MFC for C. glabrata was 62.5 µg/mL and for C. tropicalis 15.63 µg/mL The same MBC (3.91 µg/mL) was observed for S. aureus and MRSA. CV assay showed that the AgNPs (1000 μg/mL) promoted reductions in biofilm mass of ~60% for C. glabrata and ~35% for C. tropicalis. A reduction of ~20% in C. tropicalis biomass was also observed at the concentration of 3.91 µg/mL. No significant effect on total biomass was found for S. aureus and MRSA. SEM images revealed that C. glabrata and C. tropicalis biofilm cells, exposed to the AgNPs (1000 μg/mL), had an irregular and shriveled appearance. AgNPs solution exhibited considerable antimicrobial activity against important fungal and bacterial pathogens, associated with several oral and systemic diseases, and has potential as an antimicrobial agent. Amanda Fucci Wady, Ana Lucia Machado, Camila Cristina Foggi, Camila Andrade Zamperini, Valtencir Zucolotto, Eduardo Buozi Moffa, and Carlos Eduardo Vergani Copyright © 2014 Amanda Fucci Wady et al. All rights reserved. Effect of Chromium Interlayer Thickness on Optical Properties of Au-Ag Nanoparticle Array Tue, 19 Aug 2014 13:23:31 +0000 The effect of chromium interlayer thickness on optical properties of array of hybrid Au-Ag triangular nanoparticles is systematically investigated. The optical spectrum simulated by discrete dipole approximation (DDA) numerical method shows that with increase of the chromium interlayer thickness both refractive index sensitivity (RIS) and figure of merit (FOM) of localized surface plasmon resonance from the hybrid nanostructures experience remarkable change and the intensity of the extinction efficiency decreases. The nanosphere lithography (NSL) is used to fabricate the hybrid nanostructure arrays with different chromium interlayer thicknesses. The experiment demonstrates that the spectrum as measured from the as-fabricated hybrid nanostructure arrays is essentially in agreement with the simulated results. Jing Liu, Haoyuan Cai, Lingqi Kong, and Xianfang Zhu Copyright © 2014 Jing Liu et al. All rights reserved. One-Step Thermolysis Synthesis of Divalent Transition Metal Ions Monodoped and Tridoped CdS and ZnS Luminescent Nanomaterials Tue, 19 Aug 2014 13:21:39 +0000 Mn2+, Co2+, or Ni2+ monodoped CdS (or ZnS) and Mn2+-Co2+-Ni2+ tridoped CdS (or ZnS) have been successfully synthesized by novel one-step thermolysis method using thiourea as a sulphur source. The synthesized nanomaterials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). It is found that the average diameter and morphology of the synthesized samples varied with the nature of dopant ion. The successful doping of Mn2+-Co2+-Ni2+ tridoped ions into the host CdS (or ZnS) was proved by the EDX spectra. The luminescence of CdS is only enhanced when monodoped with Mn2+ whereas it is enhanced when ZnS is either monodoped with Mn2+, Co2+, or Ni2+ or tridoped with Mn2+-Co2+-Ni2+. The synthesized samples could therefore offer opportunities for further fundamental research and technological applications. S. E. Saeed, M. M. S. Abdel-Mottaleb, and M. S. A. Abdel-Mottaleb Copyright © 2014 S. E. Saeed et al. All rights reserved. Synthesis and Characterization of Nanostructured Nickel Diselenide NiSe2 from the Decomposition of Nickel Acetate, (CH3CO2)2Ni Tue, 19 Aug 2014 12:17:03 +0000 Solution processed NiSe2 nanorods were synthesized by a modified colloidal synthesis technique, by chemical reaction of TOPSe and nickel acetate at . The rods exist as an oleic acid ligand stabilized solution, with oleic acid acting as a capping group. Structural characterization by X-ray diffraction and transmission electron microscopy indicates that the particles are rod-like shaped crystals with a high and relatively constant aspect ratio (30 : 1). TEM shows that the width and the length of the nanorods are in the range 10–20 nm and 300–350 nm, respectively. XRD indicates that the nanorods are pure and well crystallized. The size of nanorods based on the Debye-Scherrer effect, was 150 nm, the average value of length and width. They display thermal stability over prolonged heating times (<100 hours) at , for which the average particle size is roughly constant. After about 100 hours of heating time there is an onset and growth of micron sized cubes and concurrent decomposition of NiSe2 to Ni and NiSe at . Ming Yin and Stephen O’Brien Copyright © 2014 Ming Yin and Stephen O’Brien. All rights reserved. Effects of Acid Characteristics of Nanoporous MCM-48 on the Pyrolysis Product Distribution of Waste Pepper Stem Tue, 19 Aug 2014 06:10:25 +0000 Nanoporous catalysts Si-MCM-48 and Al-MCM-48 were applied for the first time to the catalytic pyrolysis of waste pepper stem. Pyrolysis experiments were conducted at 550°C using Py-GC/MS to examine the product distribution rapidly. Phenolics were shown to be the most abundant product species of noncatalytic pyrolysis, whereas aliphatic and aromatic hydrocarbons were produced marginally. On the other hand, much larger quantities of furans and aliphatic and aromatic hydrocarbons were produced from the catalytic pyrolysis over MCM-48, while the production of phenolics was suppressed significantly. Al-MCM-48 showed a much higher catalytic activity than Si-MCM-48, which was attributed to its much higher acidity. The results of this study indicate that valuable chemicals can be produced from waste pepper stem using catalytic pyrolysis over an acidic nanoporous catalyst. Young-Kwon Park, Myung Lang Yoo, and Sung Hoon Park Copyright © 2014 Young-Kwon Park et al. All rights reserved. Synthesis and Characterization of Silicon Nanoparticles Inserted into Graphene Sheets as High Performance Anode Material for Lithium Ion Batteries Tue, 19 Aug 2014 00:00:00 +0000 Silicon nanoparticles have been successfully inserted into graphene sheets via a novel method combining freeze-drying and thermal reduction. The structure, electrochemical performance, and cycling stability of this anode material were characterized by SEM, X-ray diffraction (XRD), charge/discharge cycling, and cyclic voltammetry (CV). CV showed that the Si/graphene nanocomposite exhibits remarkably enhanced cycling performance and rate performance compared with bare Si nanoparticles for lithium ion batteries. XRD and SEM showed that silicon nanoparticles inserted into graphene sheets were homogeneous and had better layered structure than the bare silicon nanoparticles. Graphene sheets improved high rate discharge capacity and long cycle-life performance. The initial capacity of the Si nanoparticles/graphene keeps above 850 mAhg−1 after 100 cycles at a rate of 100 mAg−1. The excellent cycle performances are caused by the good structure of the composites, which ensured uniform electronic conducting sheet and intensified the cohesion force of binder and collector, respectively. Yong Chen, Xuejun Zhang, Yanhong Tian, and Xi Zhao Copyright © 2014 Yong Chen et al. All rights reserved. Nonlinear Electrical Conductivity Properties of Au Films Prepared by Sputtering Wed, 13 Aug 2014 08:01:31 +0000 Metal-based films with tunable electrical conductivity have played an important role in developing new types of electric devices for future application. In this work, a sputtering method was used to obtain Au films on silicon substrate in a hypobaric atmosphere. Scanning electron microscope (SEM) shows that the interspaces between the Au nanoparticles were highly uniform and orderly distributed, with the width of several nanometers at the surface. By measuring the I-V curves of the films with thickness less than 20 nm, the nonlinear behaviors of electrical resistivity became gradually obvious as the decrease of the film thickness. For example, upon the thickness reducing to 10 nm, remarkable discontinuous step phenomenon appeared. Moreover, a computational simulation was carried on the electrical conductivity of films under normal temperature based on the Coulomb blockade theory and scattering theory, in which the electric current was in the range from 0 to 1.5 × 10−5 A. The computational results were consistent well with the experimental observations, which confirm that the nonlinear and step phenomenon can be assigned to the Coulomb blockade effect when electrons transfer occurs in the interspaces between the nanoparticles. Qingyun Meng, Yixin Kang, Xiaoyu Zhai, Ziwen Yin, and Dongpeng Yan Copyright © 2014 Qingyun Meng et al. All rights reserved. Quantitative Analysis of Isolated Single-Wall Carbon Nanotubes with Their Molar Absorbance Coefficients Tue, 12 Aug 2014 09:49:06 +0000 The molar absorbance coefficients of metallic, semiconducting, and (6,5) chirality enriched single-wall carbon nanotubes were evaluated by a spray technique combined with atomic force microscopy. Single-wall carbon nanotubes with isolated and a single predominant electronic type were obtained by using the density-gradient ultracentrifugation technique. In the visible region, all coefficients had similar values around 2–5 × 109/mL mol−1 cm−1, independent of their diameter distribution and the electronic types of single-wall carbon nanotubes, and the / and / were estimated to be 1.0 and 4.0, respectively. The coefficient strongly depends on the length of single-wall carbon nanotubes, independent of their electronic types and chirality. Shota Kuwahara, Yuki Kuwahara, and Hisanori Shinohara Copyright © 2014 Shota Kuwahara et al. All rights reserved. Synthesis and Antibacterial Testing of Silver/Poly (Ether Amide) Composite Nanofibers with Ultralow Silver Content Mon, 11 Aug 2014 12:51:03 +0000 Antimicrobial materials have attracted much attention all over the world. Herein, a new kind of antimicrobial material, poly (ether amide) (Pebax) nanofibers containing Ag nanoparticles, was prepared by electrospinning method. The Ag/Pebax composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), and thermogravimetric analyzer (TGA) measurements. The antimicrobial properties of Ag/Pebax composites against Escherichia coli (E. coli; ATCC25922 and avirulent) and Staphylococcus aureus (S. aureus; ATCC6538 and avirulent) were evaluated by membrane adhering method. It was found that the Ag content played an important part in the antimicrobial ability of Ag/Pebax composites. When the mass ratio of AgNO3 to Pebax in the precursor was 0.15, the inhibition rate can reach >99.9% and antimicrobial activity against E. coli and S. aureus was 5.8 and 5.6, respectively, exceeding the antimicrobial testing standards JIS Z 2801. The above results indicated that the Ag/Pebax composite was a promising antimicrobial material that can be used in many applications. Shuai Liang, Geng Zhang, Jianzhong Min, Junqiao Ding, and Xingmao Jiang Copyright © 2014 Shuai Liang et al. All rights reserved. Experimental Investigation and Theoretical Modeling of Nanosilica Activity in Concrete Mon, 11 Aug 2014 11:24:32 +0000 This paper presents experimental investigations and theoretical modeling of the hydration reaction of nanosilica blended concrete with different water-to-binder ratios and different nanosilica replacement ratios. The developments of chemically bound water contents, calcium hydroxide contents, and compressive strength of Portland cement control specimens and nanosilica blended specimens were measured at different ages: 1 day, 3 days, 7 days, 14 days, and 28 days. Due to the pozzolanic reaction of nanosilica, the contents of calcium hydroxide in nanosilica blended pastes are considerably lower than those in the control specimens. Compared with the control specimens, the extent of compressive strength enhancement in the nanosilica blended specimens is much higher at early ages. Additionally, a blended cement hydration model that considers both the hydration reaction of cement and the pozzolanic reaction of nanosilica is proposed. The properties of nanosilica blended concrete during hardening were evaluated using the degree of hydration of cement and the reaction degree of nanosilica. The calculated chemically bound water contents, calcium hydroxide contents, and compressive strength were generally consistent with the experimental results. Han-Seung Lee, Hyeong-Kyu Cho, and Xiao-Yong Wang Copyright © 2014 Han-Seung Lee et al. All rights reserved.