Journal of Nanomaterials The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Size Measurement of Nanoparticle Assembly Using Multilevel Segmented TEM Images Thu, 29 Jan 2015 14:31:52 +0000 Multilevel image segmentation is demonstrated as a rapid and accurate method of quantitative analysis for nanoparticle assembly in TEM images. The procedure incorporating K-means clustering algorithm and watershed transform is tested on transmission electron microscope (TEM) images of FePt-based nanoparticles whose diameters are less than 5 nm. By solving the nanoparticle segmentation and separation problems, this unsupervised method is useful not only in the nonoverlapping case but also for agglomerated nanoparticles. Furthermore, the method exhibits scale invariance based on comparable results from images of different magnifications. Paisarn Muneesawang and Chitnarong Sirisathitkul Copyright © 2015 Paisarn Muneesawang and Chitnarong Sirisathitkul. All rights reserved. Sensitivity of Mesoporous CoSb2O6 Nanoparticles to Gaseous CO and C3H8 at Low Temperatures Thu, 29 Jan 2015 11:24:56 +0000 Mesoporous CoSb2O6 nanoparticles, synthesized through a nonaqueous method (using cobalt nitrate, antimony trichloride, ethylenediamine, and ethanol as a solvent), were tested to establish their sensitivity to CO and C3H8 atmospheres at relatively low temperatures. The precursor material was dried at 200°C and calcined at 600°C. X-ray diffraction and scanning electron microscopy were employed to verify the existence of crystal phases () and the morphology of this trirutile-type CoSb2O6 oxide. Pyramidal and cubic shaped crystals (average size: 41.1 nm), embedded in the material’s surface, were identified. Mesopores (average size: 6.5 nm) on the nanoparticles’ surface were observed by means of transmission electron microscopy. The best sensitivity of the CoSb2O6 in a CO atmosphere was at the relatively low temperatures of 250 and 350°C, whereas, in a C3H8 atmosphere, the sensitivity increased uniformly with temperature. These results encourage using the CoSb2O6 nanoparticles as gas sensors. Héctor Guillén-Bonilla, Lorenzo Gildo-Ortiz, M. de la L. Olvera-Amador, Jaime Santoyo-Salazar, Verónica M. Rodríguez-Betancourtt, Alex Guillen-Bonilla, and Juan Reyes-Gómez Copyright © 2015 Héctor Guillén-Bonilla et al. All rights reserved. Improvement of the Magnetic Properties of Nanocrystalline Nd12.3(FeZrNbCu)81.7B6.0 Alloys with Dy Substitutions Thu, 29 Jan 2015 10:17:30 +0000 Nd12.3−xDyxFe81.7Zr0.8Nb0.8Cu0.4B6.0   ribbons have been prepared by melt-spun at 30 m/s and subsequent annealing. The influence of addition of Dy on the crystallization behavior, magnetic properties, and microstructure were investigated. Differential scanning calorimeter (DSC) and X-ray diffraction (XRD) revealed a single-phase material. Microstructure studies using transmission electron microscopy (TEM) had shown a significant microstructure refinement with Dy addition. Wohlfarth’s analysis showed that the exchange coupling interactions increased first with Dy content x increasing, reached the maximum value at , and then slightly decreased with x further increasing. Optimal magnetic properties with  T,  kA/m, and  kJ/m3 are achieved by annealing the melt-spun ribbons with at% at 700°C for 10 min. Weiwei Yang, Leichen Guo, Zhimeng Guo, Guangle Dong, Yanli Sui, and Zhian Chen Copyright © 2015 Weiwei Yang et al. All rights reserved. Nanodentistry Thu, 29 Jan 2015 09:50:28 +0000 Seunghan Oh, Young-Bum Park, Sungtae Kim, and Sungho Jin Copyright © 2015 Seunghan Oh et al. All rights reserved. Mechanochemical Preparation of Cobalt Nanoparticles through a Novel Intramolecular Reaction in Cobalt(II) Complexes Thu, 29 Jan 2015 09:48:46 +0000 A novel solid state reaction involving a series of cobalt(II) hydrazine-azides has been used to prepare metallic cobalt nanoparticles. The reactions of [Co(N2H4)(N3)2], [Co(N2H4)2(N3)2], and [Co(N2H4)(N3)Cl]H2O via NaOH, KOH as reactants were carried out in the solid state. These complexes undergo an intramolecular two-electron oxidation-reduction reaction at room temperature, producing metallic cobalt nanoparticles (Co1–Co6). The aforementioned complexes contain cobalt(II) that is an oxidizing agent and also hydrazine ligand as a reducing agent. Other products produced include sodium azide and ammonia gas. The cobalt metal nanoparticles were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). The synthesized cobalt nanoparticles have similar morphologies; however, their particle size distributions are different. Seyed Abolghasem Kahani and Massumeh Khedmati Copyright © 2015 Seyed Abolghasem Kahani and Massumeh Khedmati. All rights reserved. Synthesis, Characterization and Evaluation of the Cytotoxicity of Ni-Doped Zn(Se,S) Quantum Dots Thu, 29 Jan 2015 07:13:52 +0000 Quantum dots (QDs) are semiconductor nanocrystals with desirable optical properties for biological applications, such as bioimaging and drug delivery. However, the potential toxicity of these nanostructures in biological systems limits their application. The present work is focused on the synthesis, characterization, and evaluation of the toxicity of water-stable Ni-doped Zn(Se,S) QDs. Also, the study of nondoped nanostructures was included for comparison purposes. Ni-doped nanostructures were produced from zinc chloride and selenide aqueous solutions in presence of 3-mercaptopropionic acid and Ni molar concentration of 0.001 M. In order to evaluate the potential cytoxicity of these doped nanostructures, human pancreatic carcinoma cells (PANC-1) were used as model. The cell viability was monitored in presence of Ni-doped Zn(Se,S) QDs at concentrations ranging from 0 μg/mL to 500 μg/mL and light excited Ni-doped Zn(Se,S) nanostructures were evaluated at 50 μg/mL. Results suggested that Ni-doped Zn(Se,S) nanostructures were completely safe to PANC-1 when concentrations from 0 μg/mL to 500 μg/mL were used, whereas non-doped nanostructures evidenced toxicity at concentrations higher than 200 μg/mL. Also, Ni-doped Zn(Se,S) QDs under light excitation do not evidence toxicity to PANC-1. These findings suggest strongly that Zn(Se,S) nanostructures doped with nickel could be used in a safe manner in light-driving biological applications and drug delivery. Melissa Cruz-Acuña, Sonia Bailón-Ruiz, Carlos R. Marti-Figueroa, Ricardo Cruz-Acuña, and Oscar J. Perales-Pérez Copyright © 2015 Melissa Cruz-Acuña et al. All rights reserved. Luminescence Properties of CaF2 Nanostructure Activated by Different Elements Thu, 29 Jan 2015 06:33:40 +0000 Nanostructures of calcium fluoride (CaF2) doped with Eu, Tb, Dy, Cu, and Ag were synthesized by the coprecipitation method and studied for their thermoluminescence (TL) and photoluminescence (PL) properties. The PL emission spectrum of pure CaF2 nanostructure has a broad band in the 370–550 nm range. Similar spectra were observed in case of doped samples, beside extra bands related to these impurities. The maximum PL intensity was observed in Eu doped sample. The TL results of Eu, Cu, Ag, and Tb doped samples show weak glow peaks below 125°C, whereas Dy doped one is found to be highly sensitive with a prominent peak at 165°C. This sample was further exposed to a wide range of gamma rays exposures from 137Cs source. The response curve is linear in the 100 Gy-10 kGy range. It is also observed that the particle size of CaF2 nanostructure was significantly reduced by increasing Dy concentration. These results showed that Dy is a proper activator in the host of CaF2 nanostructure, providing a highly sensitive dosimeter in a wide range of exposures and also plays a role as a controlling agent for particle size growth. Numan Salah, Najlaa D. Alharbi, Sami S. Habib, and S. P. Lochab Copyright © 2015 Numan Salah et al. All rights reserved. Ni/SiO2 Catalyst Prepared with Nickel Nitrate Precursor for Combination of CO2 Reforming and Partial Oxidation of Methane: Characterization and Deactivation Mechanism Investigation Wed, 28 Jan 2015 16:44:53 +0000 The performance of Ni/SiO2 catalyst in the process of combination of CO2 reforming and partial oxidation of methane to produce syngas was studied. The Ni/SiO2 catalysts were prepared by using incipient wetness impregnation method with nickel nitrate as a precursor and characterized by FT-IR, TG-DTA, UV-Raman, XRD, TEM, and H2-TPR. The metal nickel particles with the average size of 37.5 nm were highly dispersed over the catalyst, while the interaction between nickel particles and SiO2 support is relatively weak. The weak NiO-SiO2 interaction disappeared after repeating oxidation-reduction-oxidation in the fluidized bed reactor at 700°C, which resulted in the sintering of metal nickel particles. As a result, a rapid deactivation of the Ni/SiO2 catalysts was observed in 2.5 h reaction on stream. Sufang He, Lei Zhang, Suyun He, Liuye Mo, Xiaoming Zheng, Hua Wang, and Yongming Luo Copyright © 2015 Sufang He et al. All rights reserved. Retracted: Mechanical and Thermal Stability Properties of Modified Rice Straw Fiber Blend with Polycaprolactone Composite Wed, 28 Jan 2015 14:39:31 +0000 Journal of Nanomaterials Copyright © 2015 Journal of Nanomaterials. All rights reserved. Microbe-Assisted Synthesis and Luminescence Properties of Monodispersed Tb3+-Doped ZnS Nanocrystals Wed, 28 Jan 2015 13:52:02 +0000 Tb3+-doped zinc sulfide (ZnS:Tb3+) nanocrystals were synthesized by spray precipitation with sulfate-reducing bacterial (SRB) culture at room temperature. The morphology of the SRB and ZnS:Tb3+ nanocrystals was examined by scanning electron microscopy, and the ZnS:Tb3+ nanocrystals were characterized by X-ray diffractometry and photoluminescence (PL) spectroscopy. The PL mechanism of ZnS:Tb3+ nanocrystals was further analyzed, and the effects of Tb3+ ion concentration on the luminescence properties of ZnS:Tb3+ nanocrystals were studied. ZnS:Tb3+ nanocrystals showed a sphalerite phase, and the prepared ZnS:Tb3+ nanocrystals had high luminescence intensity under excitation at 369 nm. The main peak position of the absorption spectra positively blueshifted with increasing concentrations of Tb3+ dopant. Based on the strength of the peak of the excitation and emission spectra, we inferred that the optimum concentration of the Tb3+ dopant is 5 mol%. Four main emission peaks were obtained under excitation at 369 nm:489 nm (5D4→7F6), 545 nm (5D4→7F5), 594 nm (5D4→7F4), and 625 nm (5D4→7F3). Our findings suggest that nanocrystals have potential applications in photoelectronic devices and biomarkers. Zhanguo Liang, Jun Mu, Lei Han, and Hongquan Yu Copyright © 2015 Zhanguo Liang et al. All rights reserved. Synthesis of Nanoscale Heterostructures Comprised of Metal Nanowires, Carbon Nanotubes, and Metal Nanoparticles: Investigation of Their Structure and Electrochemical Properties Wed, 28 Jan 2015 13:45:56 +0000 One-dimensional nanoscale heterostructures comprised of multisegment gold-nickel nanowires, carbon nanotube, and nickel nanoparticles were fabricated in a unique approach combining top-down and bottom-up assembly methods. Porous alumina template was utilized for sequential electrodeposition of gold and nickel nanowire segments. This was followed by chemical vapor deposition growth of carbon nanotubes on multisegment gold-nickel nanowires, where nickel segment also acted as a carbon nanotube growth catalyst. The aligned arrays of these gold-nickel-carbon nanotube heterostructures were released from porous alumina template and then subjected to wet-chemical process to be decorated with nickel/nickel oxide core/shell nanoparticles. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy were utilized for morphology, interface, defect, and structure characterization. The electrochemical performance of these heterostructures was studied using cyclic voltammetry method and the specific capacitance of various heterostructures was estimated and compared. Nitin Chopra, Junchi Wu, and Paaras Agrawal Copyright © 2015 Nitin Chopra et al. All rights reserved. Osseointegration of Implants Surface-Treated with Various Diameters of TiO2 Nanotubes in Rabbit Wed, 28 Jan 2015 13:17:07 +0000 The aim of this study was to evaluate the osseointegration of implants which were surface-treated with various diameters of TiO2 nanotubes (30 nm, 70 nm, and 100 nm) in rabbit. Resorbable blast media (RBM) surfaced implants (Osstem, Busan, Korea) 3.5 mm in diameter and 8.5 mm in length were designated as the control group and the implants surface-treated with various diameters of nanotubes (30 nm, 70 nm, and 100 nm) with the same shapes were designated as the experimental groups. The implants were maintained unloaded for 4 and 12 weeks. After this period, the animals were sacrificed and micro-CT analysis, histomorphometric analysis (bone to implant contact (BIC), bone volume (BV)), and removal torque test were performed. Micro-CT analysis, histomorphometric analysis, and removal torque test results all showed the similar pattern, showing that 70 nm experimental group had the highest value at 4 weeks while 30 nm experimental group had the highest value at 12 weeks. Therefore, on the basis of the results above, it can be concluded that 30 nm and 70 nm TiO2 nanotubes may have positive effects on osteogenesis and osseointegration depending on the healing time. Cheul-Goo Kang, Young-Bum Park, Hyunmin Choi, Seunghan Oh, Keun-Woo Lee, Seong-Ho Choi, and June-Sung Shim Copyright © 2015 Cheul-Goo Kang et al. All rights reserved. The Evaluation of Osseointegration of Dental Implant Surface with Different Size of TiO2 Nanotube in Rats Wed, 28 Jan 2015 13:02:46 +0000 With the development of nanotechnology, many researches have shown that nanometer-scaled materials especially TiO2 nanotube have a positive effect on cellular behavior and surface characteristics of implant, which are considered to be crucial factors in osseointegration. However, it has not yet been verified which nanotube size is effective in osseointegration in vivo. The aim of this study was to evaluate the effect of implant surface-treated with different size of TiO2 nanotubes on osseointegration in rat femur. The customized implants (threaded and nonthreaded type), surface-treated with different diameter of TiO2 nanotubes (30 nm, 50 nm, 70 nm, and 100 nm nanotube), were placed on both sides of the femur of 50 male Sprague-Dawley rats (6 weeks old). Rats were sacrificed at 2 and 6 weeks following surgery; then the specimens were collected by perfusion fixation and the osseointegration of implants was evaluated by radiographic and histologic analyses and removal torque value test. The mean of bone area (%) and the mean of removal torque were different in each group, indicating that the difference in TiO2 nanotube size may influence new bone formation and osseointegration in rats. Young-Ah Yi, Young-Bum Park, Hyunmin Choi, Keun-Woo Lee, Sun-Jai Kim, Kwang-Mahn Kim, Seunghan Oh, and June-Sung Shim Copyright © 2015 Young-Ah Yi et al. All rights reserved. Visible-Light Photocatalytic Activity of N-Doped TiO2 Nanotube Arrays on Acephate Degradation Wed, 28 Jan 2015 12:01:46 +0000 Highly ordered nitrogen-doped titanium dioxide (N-doped TiO2) nanotube arrays were prepared by anodic oxidation method and then annealed in a N2 atmosphere to obtain N-doped TiO2 nanotube arrays. The samples were characterized with scanning electron microscope (SEM), X-ray powder diffraction (XRD), X-ray photoelectron spectrum (XPS), and UV-visible spectrophotometry (UV-vis) spectrum. Degradation of the insecticide acephate under the visible light was used as a model to examine the visible-light photocatalytic activity of N-doped TiO2 nanotube arrays. The results show that N type doping has no notable effects on the morphology and structure of TiO2 nanotube arrays. After N type doping, the N replaces a small amount of O in TiO2, forming an N–Ti–O structure. This shifts the optical absorption edge and enhances absorption of the visible light. N-doped TiO2 nanotube arrays subjected to annealing at 500°C in N2 atmosphere show the strongest photocatalytic activity and reach a degradation rate of 84% within 2 h. Xinlei Zhang, Juan Zhou, Yufen Gu, and Ding Fan Copyright © 2015 Xinlei Zhang et al. All rights reserved. Recent Trends in Preparation of Poly(lactide-co-glycolide) Nanoparticles by Mixing Polymeric Organic Solution with Antisolvent Wed, 28 Jan 2015 08:57:07 +0000 In recent years, there have been a plethora of nanoengineering approaches for the development of poly(lactide-co-glycolide) (PLGA) nanoparticulate carrier systems. However, overlooking the multifaceted issues in the preparation and characterization of PLGA-based nanoparticles, many reports have been focused on their in vivo behaviors. It is imperative to fully assess technological aspects of a nanoencapsulation method of choice and to carefully evaluate the nanoparticle quality. The selection of a nanoencapsulation technique should consider drug property, nanoparticle quality, scale-up feasibility, manufacturing costs, personnel safety, environmental impact, waste disposal, and the like. Made in this review are the fundamentals of classical emulsion-templated nanoencapsulation methods used to prepare PLGA nanoparticles. More specifically, this review provides insight into emulsion solvent evaporation/extraction, salting-out, nanoprecipitation, membrane emulsification, microfluidic technology, and flow focusing. Innovative nanoencapsulation techniques are being developed to address many challenges existing in the production of PLGA-based nanoparticles. In addition, there are various out-of-the-box approaches for the development of novel PLGA hybrid systems that could deliver multiple drugs. Latest trends in these areas are also dealt with in this review. Relevant information might be helpful to those who prepare and develop PLGA-based nanoparticles that meet their specific demands. Edel Sah and Hongkee Sah Copyright © 2015 Edel Sah and Hongkee Sah. All rights reserved. Current-Voltage Characteristics of the Composites Based on Epoxy Resin and Carbon Nanotubes Wed, 28 Jan 2015 07:43:34 +0000 Polymer composites based on epoxy resin were prepared. Multiwalled carbon nanotubes synthesized on iron-cobalt catalyst were applied as a filler in a polymer matrix. Chlorine or hydroxyl groups were incorporated on the carbon nanotubes surface via chlorination or chlorination followed by hydroxylation. The effect of functionalized carbon nanotubes on the epoxy resin matrix is discussed in terms of the state of CNTs dispersion in composites as well as electrical properties. For the obtained materials current-voltage characteristics were determined. They had a nonlinear character and were well described by an exponential-type equation. For all the obtained materials the percolation threshold occurred at a concentration of about 1 wt%. At a higher filler concentration >2 wt%, better conductivity was demonstrated by polymer composites with raw carbon nanotubes. At a lower filler concentration <2 wt%, higher values of electrical conductivity were obtained for polymer composites with modified carbon nanotubes. Iwona Pełech, Agnieszka Kaczmarek, and Robert Pełech Copyright © 2015 Iwona Pełech et al. All rights reserved. Synthesis and Catalytic Performance of Ni/SiO2 for Hydrogenation of 2-Methylfuran to 2-Methyltetrahydrofuran Tue, 27 Jan 2015 09:15:05 +0000 A series of Ni/SiO2 catalysts with different Ni content were prepared by sol-gel method for application in the synthesis of 2-methyltetrahydrofuran (2-MTHF) by hydrogenation of 2-methylfuran (2-MF). The catalyst structure was investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and temperature programmed reduction (TPR). It is found that structures and catalytic performance of the catalysts were highly affected by the Ni content. The catalyst with a 25% Ni content had an appropriate size of the Ni species and larger BET surface area and produced a higher 2-MF conversion with enhanced selectivity in 2-MTHF. Fu Ding, Yajing Zhang, Guijin Yuan, Kangjun Wang, Ileana Dragutan, Valerian Dragutan, Yunfeng Cui, and Jing Wu Copyright © 2015 Fu Ding et al. All rights reserved. Ultraviolet Beam Focusing in Gallium Arsenide by Direct Excitation of Surface Plasmon Polaritons Tue, 27 Jan 2015 08:23:31 +0000 This paper proposed that ultraviolet beam could be focused by gallium arsenide (GaAs) through direct excitation of surface plasmon polaritons. Both theoretical analysis and computer simulation showed that GaAs could be a reasonably good plasmonic material in the air in the deep ultraviolet waveband. With a properly designed bull’s eye structure etched in GaAs, the ultraviolet electric field could be enhanced to as high as 20 times the incident value, and the full-width-half-maximum (FWHM) of the light beam could be shrunk from ~48° to ~6°. As a plasmonic material, GaAs was compared to Ag and Al. Within the studied ultraviolet waveband, the field enhancement in GaAs was much stronger than Ag but not as high as Al. Senfeng Lai, Wen Wu, and Wenhua Gu Copyright © 2015 Senfeng Lai et al. All rights reserved. Dispersion Features of Conducting Sheath Helix Embedded Elliptical and Circular Fibers with Chiral Nihility Core Mon, 26 Jan 2015 11:31:54 +0000 Discussions have been made of the electromagnetic wave propagation through optical fibers of elliptical and circular cross-sections with the loadings of conducting sheath helix at the core-clad interface with particular orientations. In both geometrical situations, the core section of fiber is assumed to be composed of chiral nihility medium, and the clad remains linear, homogeneous, isotropic, and nonmagnetic dielectric. Dispersion relations are deduced for both fiber structures, followed by the analysis of dispersion features considering a few low-order EH modes. Furthermore, the effects of conducting helix pitch angle on the features of wave propagation are also discussed. N. Iqbal, M. A. Baqir, and P. K. Choudhury Copyright © 2015 N. Iqbal et al. All rights reserved. Preparation and Characterization of Nanofibrous Polymer Scaffolds for Cartilage Tissue Engineering Thu, 22 Jan 2015 13:26:28 +0000 Polymer substrates obtained from poly(lactic acid) (PLA) nanofibres modified with carbon nanotubes (CNTs) and gelatin (GEL) for cartilage tissue engineering are studied. The work presents the results of physical, mechanical, and biological assessment. The hybrid structure of PLA and gelatine nanofibres, carbon nanotubes- (CNTs-) modified PLA nanofibres, and pure PLA-based nanofibres was manufactured in the form of fibrous membranes. The fibrous samples with different microstructures were obtained by electrospinning method. Microstructure, physical and mechanical properties of samples made from pure PLA nanofibres, CNTs-, and gelatin-modified PLA-nanofibres were studied. The scaffolds were also tested in vitro in cell culture of human chondrocytes collected from patients. To assess the influence of the nanofibrous scaffolds upon chondrocytes, tests for cytotoxicity and genotoxicity were performed. The work reveals that the nanofibrous structures studied were neither genotoxic nor cytotoxic, and their microstructure, physical and mechanical properties create promising scaffolds for potential use in cartilage repairing. Jarosław Markowski, Anna Magiera, Marta Lesiak, Aleksander L. Sieron, Jan Pilch, and Stanislaw Blazewicz Copyright © 2015 Jarosław Markowski et al. All rights reserved. Effect of CdS/Mg-Doped CdSe Cosensitized Photoanode on Quantum Dot Solar Cells Thu, 22 Jan 2015 08:55:47 +0000 Quantum dots have emerged as a material platform for low-cost high-performance sensitized solar cells. And doping is an effective method to improve the performance of quantum dot sensitized solar cells (QDSSCs). Since Kwak et al. from South Korea proved the incorporation of Mg in the CdSe quantum dots (QDs) in 2007, the Mg-doped CdSe QDs have been thoroughly studied. Here we report a new attempt on CdS/Mg-doped CdSe quantum dot cosensitized solar cells (QDCSSC). We analyzed the performance of CdS/Mg-doped CdSe quantum dot cosensitized solar cells via discussing the different doping concentration of Mg and the different SILAR cycles of CdS. And we studied the mechanism of CdS/Mg-doped CdSe QDs in detail for the reason why the energy conversion efficiency had been promoted. It is a significant instruction on the development of Mg-doped CdSe quantum dot sensitized solar cells (QDSSCs). Yingxiang Guan, Xiaoping Zou, and Sheng He Copyright © 2015 Yingxiang Guan et al. All rights reserved. Synthesis of Boron Nanowires, Nanotubes, and Nanosheets Thu, 22 Jan 2015 08:02:11 +0000 The synthesis of boron nanowires, nanotubes, and nanosheets using a thermal vapor deposition process is reported. This work confirms previous research and provides a new method capable of synthesizing boron nanomaterials. The materials were made by using various combinations of MgB2, Mg(BH4)2, MCM-41, NiB, and Fe wire. Unlike previously reported methods, a nanoparticle catalyst and a silicate substrate are not required for synthesis. Two types of boron nanowires, boron nanotubes, and boron nanosheets were made. Their morphology and chemical composition were determined through the use of scanning electron microscopy, transmission electron microscopy, and electron energy loss spectroscopy. These boron-based materials have potential for electronic and hydrogen storage applications. Rajen B. Patel, Tsengming Chou, and Zafar Iqbal Copyright © 2015 Rajen B. Patel et al. All rights reserved. Photoinduced Electron Spin Resonance Phenomenon in α-Cr2O3 Nanospheres Wed, 21 Jan 2015 06:27:05 +0000 The photoinduced phenomenon in α-Cr2O3 nanoscaled spherical particles was investigated in the temperature range of 150 up to 315 K. An X-band electron-spin resonance spectrometry was employed to probe the magnetic behavior in α-Cr2O3 under an IR illumination in the nanosecond regime. The photoinduced effect on both low and high field ESR signals appears above 280 K and is remarkably enhanced just below Néel temperature . Such a photoinduced ESR phenomenon disappears in a reproducible way in the paramagnetic insulating state which occurs above of crystalline α-Cr2O3. In the antiferromagnetic phase, that is, below , the shift of the low field absorption could be attributed to the interaction of the light with specific Cr3+ ions located in strongly distorted sites correlated to strong ligand-field effect. S. Khamlich, V. V. Srinivasu, A. Konkin, N. Cingo, F. T. Thema, A. Benyoussef, and M. Maaza Copyright © 2015 S. Khamlich et al. All rights reserved. Enhanced Efficiency of Dye-Sensitized Solar Cells by Trace Amount Ca-Doping in TiO2 Photoelectrodes Tue, 20 Jan 2015 13:43:29 +0000 Trace amount Ca-doped TiO2 films were synthesized by the hydrothermal method and applied as photoanodes of dye-sensitized solar cells (DSSCs). To prepare Ca-doped TiO2 film electrodes, several milliliters of Ca(NO3)2 solution was added in TiO2 solution during the hydrolysis process. The improvements of DSSCs were confirmed by photocurrent density-voltage (J-V) characteristics, electrochemical impedance spectroscopy (EIS) measurements. Owing to the doping effect of Ca, the Ca-doped TiO2 thin film shows power conversion efficiency of 7.45% for 50 ppm Ca-doped TiO2 electrode, which is higher than that of the undoped TiO2 film (6.78%) and the short-circuit photocurrent density increases from 13.68 to 15.42 mA·cm−2. The energy conversion efficiency and short-circuit current density of DSSCs were increased due to the faster electron transport in the Ca-doped TiO2 film. When Ca was incorporated into TiO2 films, the electrons transport faster and the charge collection efficiency is higher than that in the undoped TiO2 films. Mengmei Pan, Hanjun Liu, Zhongyu Yao, and Xiaoli Zhong Copyright © 2015 Mengmei Pan et al. All rights reserved. Preparation and Evaluation of PEGylated and Folate-PEGylated Liposomes Containing Paclitaxel for Lymphatic Delivery Tue, 20 Jan 2015 13:10:42 +0000 This study attempted to prepare polyethylene-glycol modified (PEGylated) and folate-PEGylated liposomes containing paclitaxel (Ptx) in order to reduce the toxicity and improve the bioavailability and biocompatibility by targeting drugs to the lymphatics using cancer cell specific ligand folate to prevent metastasis via the lymphatic system. Liposomes were prepared by lipid film hydration method using PEG and folate-PEG as surface modifiers. The mean particle size and encapsulation efficiency of liposomes were  nm and % for PEGylated liposome and  nm and % for folate-PEGylated liposome, respectively. According to stability test, it could be confirmed that PEGylated and folate-PEGylated liposomes were stable for at least 5 days. After intravenous administration of the PEGylated and folate-PEGylated liposomes to rats, the (total clearance) and (half-life) were significantly different () compared with those of PADEXOL Inj. In targeting efficiency, calculated as the concentration ratio of Ptx in lymph nodes and plasma, there was significant increase in targeting efficiency at lymph nodes (). From these results, we could conclude that the prepared Ptx-containing PEGylated and folate-PEGylated liposomes are good candidates for the targeted delivery of the drug to lymphatic system. Hea-Young Cho, Chong Ki Lee, and Yong-Bok Lee Copyright © 2015 Hea-Young Cho et al. All rights reserved. High Performance Indium-Doped ZnO Gas Sensor Tue, 20 Jan 2015 10:28:01 +0000 Gas sensors for ethanol and acetone based on ZnO nanobelts with doping element indium were fabricated. Excellent sensitivity accompanied with short response time (10 s) and recovery time (23 s) to 150 ppm ethanol is obtained. For In-doped sensors, a minimum concentration of 37.5 ppm at 275°C in acetone was observed with an average sensitivity of 714.4, which is 7 times larger than that of the pure sensors and much larger than that reported response (16) of Co-doped ZnO nanofibers to acetone. These results indicate that doping elements can improve gas sensitivity, which is associated with oxygen space and valence ions. In-doped ZnO nanobelts exhibit higher sensitivity to acetone than that to ethanol. These results indicate that doped ZnO nanobelts can successfully distinguish acetone and ethanol, which can be put into various practical applications. Junjie Qi, Hong Zhang, Shengnan Lu, Xin Li, Minxuan Xu, and Yue Zhang Copyright © 2015 Junjie Qi et al. All rights reserved. In Situ Synthesis and Characterization of Polyethyleneimine-Modified Carbon Nanotubes Supported PtRu Electrocatalyst for Methanol Oxidation Mon, 19 Jan 2015 12:20:52 +0000 PtRu bimetallic nanoparticles were successfully synthesized on polyethyleneimine- (PEI-) functionalized multiwalled carbon nanotubes (MWCNTs) via an effective and facile polyol reduction approach. Noncovalent surface modification of MWCNTs with PEI was confirmed by FTIR and zeta potential measurements. The morphology, crystalline structure, and composition of the hybrid material were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and energy dispersive X-ray spectroscopy (EDX), respectively. According to SEM and TEM observations, PtRu nanoparticles with narrow size distribution were homogeneously deposited on PEI-MWCNTs. Cyclic voltammetry tests demonstrated that the as-prepared PtRu/PEI-MWCNTs nanocomposite had a large electrochemical surface area and exhibited enhanced electrocatalytic activity towards methanol oxidation in comparison with oxidized MWCNTs as catalyst support. PEI-functionalized CNTs, as useful building blocks for the assembly of Pt-based electrocatalyst, may have great potential for applications such as direct methanol fuel cell (DMFC). Xi Geng, Jieying Jing, Yinjie Cen, Ravindra Datta, and Jianyu Liang Copyright © 2015 Xi Geng et al. All rights reserved. Synthesis Method Effect of CoFe2O4 on Its Photocatalytic Properties for H2 Production from Water and Visible Light Sun, 18 Jan 2015 14:34:45 +0000 Currently, the need for more efficient materials that work in the visible light spectrum for hydrogen production has been increasing. Under this criterion, ferrites are ideal because their energetic properties are favorable to photocatalysis as they have a low band gap (1.5 to 3 ev). In this particular research, ferrite is presented as a hydrogen producer. Cobalt ferrites were synthesized by chemical coprecipitation (CP) and ball milling (BM) for comparison of their performance. The characterization of the materials was carried out with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), BET surface area, UV-VIS spectroscopy, and water adsorption/desorption tests. Evaluation of the photocatalytic activity under visible light was followed by gas chromatography. The results showed that cobalt ferrite by ball milling had a higher photocatalytic activity; this is attributed to the vacancies generated during the milling process at which the sample was exposed. Yudith Ortega López, Hugo Medina Vázquez, Jesús Salinas Gutiérrez, Vanessa Guzmán Velderrain, Alejandro López Ortiz, and Virginia Collins Martínez Copyright © 2015 Yudith Ortega López et al. All rights reserved. Estimating Young’s Modulus of Single-Walled Zirconia Nanotubes Using Nonlinear Finite Element Modeling Sun, 18 Jan 2015 13:57:06 +0000 The single-walled zirconia nanotube is structurally modeled and its Young’s modulus is valued by using the finite element approach. The nanotube was assumed to be a frame-like structure with bonds between atoms regarded as beam elements. The properties of the beam required for input into the finite element analysis were computed by connecting energy equivalence between molecular and continuum mechanics. Simulation was conducted by applying axial tensile strain on one end of the nanotube while the other end was fixed and the corresponding reaction force recorded to compute Young’s modulus. It was found out that Young’s modulus of zirconia nanotubes is significantly affected by some geometrical parameters such as chirality, diameter, thickness, and length. The obtained values of Young’s modulus for a certain range of diameters are in agreement with what was obtained in the few experiments that have been conducted so far. This study was conducted on the cubic phase of zirconia having armchair and zigzag configuration. The optimal diameter and thickness were obtained, which will assist in designing and fabricating bulk nanostructured components containing zirconia nanotubes for various applications. Ibrahim Dauda Muhammad, Mokhtar Awang, Othman Mamat, and Ku Zilati Ku Shaari Copyright © 2015 Ibrahim Dauda Muhammad et al. All rights reserved. Nanostructured Polylactic Acid/Candeia Essential Oil Mats Obtained by Electrospinning Thu, 15 Jan 2015 11:42:45 +0000 This work aims to evaluate the effect of inclusion of different contents of candeia (Eremanthus erythropappus) essential oil (whose alpha-bisabolol is the main terpene) on the properties of polylactic acid (PLA) nanostructured mats and their relationship with fiber morphology and structure. The interaction occurring between the PLA and the candeia essential oil was confirmed by thermal and microscopy analysis. Addition of candeia essential oil increased nanofiber diameter and decreased the glass transition and melting temperatures of the nanofibers, suggesting lower energy input for processing. Scanning electron microscopy (SEM) images provided evidence of a homogeneous structure for the nanostructured mats. X-ray diffraction did not show differences in the crystallization of the nanofibers. This ongoing research confirms the possibility of incorporation of candeia essential oil in the production of nanofibers that will be studied for multipurpose applications. Cláudia L. S. de Oliveira Mori, Nathália Almeida dos Passos, Juliano Elvis Oliveira, Thiza Falqueto Altoé, Fábio Akira Mori, Luiz Henrique Capparelli Mattoso, José Roberto Scolforo, and Gustavo Henrique Denzin Tonoli Copyright © 2015 Cláudia L. S. de Oliveira Mori et al. All rights reserved.