Journal of Nanomaterials The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Synthesis of ZnO-CuO Nanocomposite Aerogels by the Sol-Gel Route Sun, 23 Nov 2014 00:00:00 +0000 The epoxide addition sol-gel method has been utilized to synthesize porous zinc-copper composite aerogels in the zinc-to-copper molar ratios of 50 : 50 to 90 : 10. A two-step mixing approach has been employed to produce aerogels composed of nano- to micrometer sized particles. The aerogels were characterized by ultrahigh resolution scanning electron microscopy, transmission electron microscopy, and powder X-ray diffraction. The as-synthesized aerogels had a thin flake- or petal-like microstructure comprised of clustered flakes on two size scales; they were identified as being crystalline with the crystalline species identified as copper nitrate hydroxide, zinc hydroxide chloride hydrate, and zinc hydroxide nitrate hydrate. Annealing of the aerogel materials at a relatively low temperature (400°C) resulted in a complete phase transition of the material to give highly crystalline ZnO-CuO aerogels; the aerogels consisted of networked nanoparticles in the ~25–550 nm size range with an average crystallite size of ~3 nm and average crystallinity of 98%. ZnO-CuO aerogels are of particular interest due to their particular catalytic and sensing properties. This work emphasizes the versatility of this sol-gel route in synthesizing aerogels; this method offers a possible route for the fabrication of aerogels of different metal oxides and their composites. Rula M. Allaf and Louisa J. Hope-Weeks Copyright © 2014 Rula M. Allaf and Louisa J. Hope-Weeks. All rights reserved. Synthesis and Magnetic Properties of Hematite Particles in a “Nanomedusa” Morphology Thu, 20 Nov 2014 11:44:34 +0000 We present the synthesis, characterization, and magnetic properties of hematite particles in a peculiar “nanomedusa” morphology. The particles were prepared from an iron-silica complex by a hydrothermal process in a solution consisting of ethyl acetate and ethanol. The particles’ morphology, structure, and chemical composition were investigated by transmission electron microscopy, powder X-ray diffraction, and scanning electron microscope equipped with an energy-dispersive X-ray spectrometer. The “hairy” particles consist of a spherical-like core of about 100 nm diameter and fibrous exterior composed of thin “legs” of 5 nm diameter grown along one preferential direction. The particles’ cores are crystalline and undergo a magnetic phase transition to a weakly ferromagnetic state at a temperature of 930 K that matches reasonably the Néel temperature of bulk hematite. However, unlike bulk hematite that undergoes Morin transition to an antiferromagnetic state around room temperature and small hematite nanoparticles that are superparamagnetic, the “nanomedusa” particles remain weakly ferromagnetic down to the lowest investigated temperature of 2 K. Each particle thus represents a nanodimensional “hairy” ferromagnet in a very broad temperature interval, extending much above the room temperature. Such high-temperature ferromagnetic nanoparticles are not frequently found among the nanomaterials. Jin Bae Lee, Hae Jin Kim, Janez Lužnik, Andreja Jelen, Damir Pajić, Magdalena Wencka, Zvonko Jagličić, Anton Meden, and Janez Dolinšek Copyright © 2014 Jin Bae Lee et al. All rights reserved. Influence of the Hydrothermal Method Growth Parameters on the Zinc Oxide Nanowires Deposited on Several Substrates Tue, 18 Nov 2014 11:24:43 +0000 We report the synthesis of ZnO nanowires grown on several substrates (PET, glass, and Si) using a two-step process: (a) preparation of the seed layer on the substrate by spin coating, from solutions of zinc acetate dihydrate and 1-propanol, and (b) growth of the ZnO nanostructures by dipping the substrate in an equimolar solution of zinc nitrate hexahydrate and hexamethylenetetramine. Subsequently, films were thermally treated with a commercial microwave oven (350 and 700 W) for 5, 20, and 35 min. The ZnO nanowires obtained were characterized structurally, morphologically, and optically using XRD, SEM, and UV-VIS transmission, respectively. XRD patterns spectra revealed the presence of Zn(OH)2 on the films grown on glass and Si substrates. A preferential orientation along c-axis directions for films grown on PET substrate was observed. An analysis by SEM revealed that the growth of the ZnO nanowires on PET and glass is better than the growth on Si when the same growth parameters are used. On glass substrates, ZnO nanowires less than 50 nm in diameter and between 200 nm and 1200 nm in length were obtained. The ZnO nanowires band gap energy for the films grown on PET and glass was obtained from optical transmission spectra. Concepción Mejía-García, Elvia Díaz-Valdés, Marco Alberto Ayala-Torres, Josué Romero-Ibarra, and Máximo López-López Copyright © 2014 Concepción Mejía-García et al. All rights reserved. Comparison of Apoptotic Inducing Effect of Zerumbone and Zerumbone-Loaded Nanostructured Lipid Carrier on Human Mammary Adenocarcinoma MDA-MB-231 Cell Line Tue, 18 Nov 2014 07:59:22 +0000 This study investigated the anticancer effect of zerumbone (ZER) and zerumbone-loaded nanostructured lipid carrier (ZER-NLC) on the human mammary gland adenocarcinoma (MDA-MB-231) cell line. The effect of ZER and ZER-NLC on MDA-MB-231 cells was determined via electron and fluorescent microscopy and flow cytometry using the Annexin V, cell cycle, and Tdt-mediated dUTP nick-end labeling assays. We demonstrated that ZER and ZER-NLC significantly suppressed the proliferation of MDA-MB-231 cells with an IC50 of 5.96 ± 0.13 and 6.01 ± 0.11 μg/mL, respectively. ZER and ZER-NLC arrested MDA-MB-231 cell cycle at the G2/M phase. The induction of apoptosis by ZER and ZER-NLC was via the intrinsic pathway through the release of cytochrome c and activation of caspase-3 and caspase-9. The treatments also caused the downregulation of antiapoptotic Bcl-2, Bcl-xL proteins, and proliferating cell nuclear protein and upregulation of proapoptotic Bax protein. Therefore, loading of ZER into NLC did not compromise the anticancer effects of ZER on MDA-MB-231 cells. In conclusion, ZER-NLC, which increased the bioavailability of ZER, is an effective agent in the treatment of cancers. Mahnaz Hosseinpour, Ahmad Bustamam Abdul, Heshu Sulaiman Rahman, Abdullah Rasedee, Swee Keong Yeap, Negin Ahmadi, Hemn Hassan Othman, and Max Stanley Chartrand Copyright © 2014 Mahnaz Hosseinpour et al. All rights reserved. Combining Hyaluronic Acid with Chitosan Enhances Gene Delivery Tue, 18 Nov 2014 00:00:00 +0000 The low gene transfer efficiency of chitosan-DNA polyplexes is a consequence of their high stability and consequent slow DNA release. The incorporation of an anionic polymer is believed to loosen chitosan interactions with DNA and thus promote higher transfection efficiencies. In this work, several formulations of chitosan-DNA polyplexes incorporating hyaluronic acid were prepared and characterized for their gene transfection efficiency on both HEK293 and retinal pigment epithelial cells. The different polyplex formulations showed morphology, size, and charge compatible with a role in gene delivery. The incorporation of hyaluronic acid rendered the formulations less stable, as was the goal, but it did not affect the loading and protection of the DNA. Compared with chitosan alone, the transfection efficiency had a 4-fold improvement, which was attributed to the presence of hyaluronic acid. Overall, our hybrid chitosan-hyaluronic acid polyplexes showed a significant improvement of the efficiency of chitosan-based nonviral vectors in vitro, suggesting that this strategy can further improve the transfection efficiency of nonviral vectors. Ana V. Oliveira, Diogo B. Bitoque, and Gabriela A. Silva Copyright © 2014 Ana V. Oliveira et al. All rights reserved. A Novel Micro-Nano Structure Profile Control Agent: Graphene Oxide Dispersion Sun, 16 Nov 2014 12:02:37 +0000 Graphite oxide sheet, now referred to as graphene oxide (GO), is the product of chemical exfoliation of graphite and has been known for more than a century. A GO sheet is characterized by two abruptly different length scales; the apparent thickness of the functionalized carbon sheet is approximately 1 nm, but the lateral dimensions can range from a few nanometers to micrometers. In this paper, an improved method for the preparation of graphene oxide within a mild condition is described. We have found that cancelling the high-temperature stage and prolonging the reaction time of mid-temperature can improve the efficiency of oxidation process. We utilized FTIR, XRD, Ultraviolet-visible, TGA, Raman spectrum, and XPS measurements to characterize the successfully synthesized GO. SEM images were employed to reveal the interior microstructure of as-prepared GO dispersion. We also wondrously found that the GO dispersion could be used as profile control agent in the oilfield water-flooding. Flooding experiments showed that the GO dispersion has an ability to adjust water injection profile, reduce permeability ratio, and improve conformance factor. So the GO dispersion would have potential applications in oilfield exploitation. Zhong-Bin Ye, Yuan Xu, Hong Chen, Chen Cheng, Li-Juan Han, and Lin Xiao Copyright © 2014 Zhong-Bin Ye et al. All rights reserved. Properties of Y-Shaped PFO-DBT Nanotubes Sun, 16 Nov 2014 09:30:33 +0000 Immersion of template into solution is used to synthesize the Y-shaped poly[2,7-(9,9-dioctylfluorene)-alt-4,7-bis(thiophen-2-yl)benzo-2,1,3-thiadiazole] (PFO-DBT) nanotubes. Solution annealing and different aging times (1, 24, and 72 hours) are conducted to synthesize the Y-shaped PFO-DBT nanotubes and the effects on the morphological, structural, and optical properties of Y-shaped PFO-DBT nanotubes are investigated. The dense, aligned, and elongated Y-shaped PFO-DBT nanotubes have been successfully fabricated by aging the PFO-DBT solution for 72 hours. Enhanced light absorption with less light scattering can be exhibited from the elongated Y-shaped PFO-DBT nanotubes. Partial and complete infiltration is governed by 1 hour and 72 hours of aging time, respectively. Preformed nanofibres are initiated by the process of annealing and aging of PFO-DBT solution. During the aging process, PFO-DBT nanofibres are formed to coat the pores’ wall and replicated the Y-branched nanopores for the production of Y-shaped PFO-DBT nanotubes. The effects of solution annealing and aging process are essential for the improvement on the morphological, structural, and optical properties of Y-shaped PFO-DBT nanotubes. Muhamad Saipul Fakir, Azzuliani Supangat, and Khaulah Sulaiman Copyright © 2014 Muhamad Saipul Fakir et al. All rights reserved. Novel Alginate-Gelatin Hybrid Nanoparticle for Drug Delivery and Tissue Engineering Applications Sun, 16 Nov 2014 07:37:03 +0000 Novel alginate-gelatin hybrid nanoparticles were fabricated using single oil in water (O/W) emulsification techniques. Physicochemical property of the particle was characterized using scanning electron microscopy and Fourier’s transmission infrared spectroscopy. Particle size was determined using zeta potential metastasize analyzer and was found to be in range of 400–600 nm. AGNPs were used for culturing human keratinocytes for two weeks to check biocompatibility of synthesized AGNPs. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed increased metabolic activity of cells cultured on AGNPs in comparison to two-dimensional (2D) system (control). Cellular attachment on nanoparticle was further confirmed using SEM and 4′,6-diamidino-2-phenylindole staining. The drug release profile shows possible electrostatic bond between alginate and gelatin resulting in controlled release of drug from AGNPs. For the first time alginate-gelatin hybrid nanosystem has been fabricated and all results showed it can be used as potential system for delivery of drug and therapeutical agents to cells and can also be used for regenerative medicine applications. Eun Mi Lee, Deepti Singh, Dolly Singh, Soon Mo Choi, Sun Mi Zo, Seon Joo Park, and Sung Soo Han Copyright © 2014 Eun Mi Lee et al. All rights reserved. Synthesis and Characterization of Rhodium Doped on TiO2/HCP for Enhanced Photocatalytic Performance on Pentachlorophenol Thu, 13 Nov 2014 11:35:47 +0000 Visible-light-responsive material based on Rhodium doped on titanium dispersed on dealuminated clinoptilolite (TiO2/HCP) was synthesized via a combination of the sol-gel method and photoreductive deposition technique. The photocatalyst surface characterization, structural and optical properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDAX), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), and UV-visible spectra (UV-VIS). Doping TiO2/HCP with Rh imparts a red shifting of the absorption band into the visible light region according to UV-VIS. The prepared composite materials were evaluated for their photocatalytic activities on pentachlorophenol (PCP) degradation under sunlight irradiation. The Rhodium doped TiO2/HCP exhibited enhanced photocatalytic activity and can be considered as a potential photocatalyst in wastewater treatment. Saheed Olalekan Sanni and Omoruyi Gold Idemudia Copyright © 2014 Saheed Olalekan Sanni and Omoruyi Gold Idemudia. All rights reserved. Fabrication of Novel 2D NiO Nanosheet Branched on 1D-ZnO Nanorod Arrays for Gas Sensor Application Thu, 13 Nov 2014 09:48:53 +0000 Fabrication of 3D structures composed of 1D n-type ZnO nanorods (NRs) and 2D p-type NiO nanosheets (NSs) by a low-cost, low-temperature, and large-area scalable hydrothermal process and its use in highly sensitive NO2 gas sensors were studied. The p-n heterojunctions formed by NiO-ZnO interfaces as well as large area two-dimensional NiO NSs themselves increased the adsorption of NO2. Moreover, the charge transfer between NiO and ZnO enhanced the responsivity and sensitivity of NO2 sensing even at a concentration of 1 ppm. The 30-min NiO NS growth on ZnO NRs in the hybrid sensor showed the highest sensitivity due to the formation of optimum p-n heterojunctions between ZnO NRs and NiO NSs for gas adsorption and carrier transport. Low responsivity toward reducing gases was also observed. Le Thuy Hoa, Huynh Ngoc Tien, and Seung Hyun Hur Copyright © 2014 Le Thuy Hoa et al. All rights reserved. Effect of Process Parameters of CNT Containing Friction Powder on Flexural Properties and Friction Performance of Organic Brake Friction Materials Wed, 12 Nov 2014 11:50:08 +0000 This research is to investigate the influences of carbon nanotube (CNT) containing friction powder prepared through different process parameters on flexural properties and friction performance of organic brake friction materials. Experimental results indicate significant influence on flexural property and friction performance of organic brake friction materials when the modified CNT/friction powders are adopted. Particularly for the specimens adopted the modified CNT/friction powders prepared through 2.0 M concentration of catalyst and 30% C2H2 show the highest flexural strength, better ductility and toughness, most stable friction coefficient, and lowest weight loss. However, too many amorphous carbon clusters and CNTs aggregation derived from higher concentration of catalyst and ratio of C2H2/N2 would cause poor formation of specimens and reduction of reinforcement effectiveness. Kuo-Jung Lee, Mao-Hsiang Hsu, and Huy-Zu Cheng Copyright © 2014 Kuo-Jung Lee et al. All rights reserved. Intercalation of Aceclofenac/Sulfobutyl Ether-β-cyclodextrin Complex into Layered Double Hydroxides through Swelling/Restoration Reaction and Its Controlled-Release Properties Wed, 12 Nov 2014 00:00:00 +0000 Aceclofenac (AC)/sulfobutyl ether-β-cyclodextrin (SBE-β-CD) inclusion complex intercalated layered double hydroxides (LDHs) composite were prepared by swelling/restoration method. After swelling/restoration, the -spacing of LDHs is expanded to 2.23 nm, which clearly demonstrates the successful intercalation of AC/SBE-β-CD into LDHs layer. AC/SBE-β-CD inclusion complex in the interlayer has monolayer arrangement based on the -spacing of LDHs and torus thickness of SBE-β-CD. The AC release performances were also studied in buffer solutions with different pH values. The results show AC/SBE-β-CD intercalated LDHs not only enhance the dissolution profile of AC but also exhibit a controlled-release process, which indicates that the AC/SBE-β-CD-LDHs have a potential application in drug delivery agent. Shifeng Li, Tan Zhang, Min Xiao, Zhigang Zhang, Wenxiu Li, and Jing Bai Copyright © 2014 Shifeng Li et al. All rights reserved. ZnO Thin-Film Transistor Grown by rf Sputtering Using Carbon Dioxide and Substrate Bias Modulation Tue, 11 Nov 2014 08:23:54 +0000 ZnO thin-film transistor (TFT) grown by rf magnetron sputtering in Ar/O2 atmosphere shows inferior turn-off characteristics compared to ZnO TFT grown by other methods. We thought that reactions between Zn and O2 might produce defects responsible for the poor turn-off behavior. In order to solve this problem, we studied sputtering growth in Ar/CO2 atmosphere at 450°C. During sputtering growth, we modulated substrate dc bias to control ion supply to the substrate. After growth ZnO was annealed in CO2 and O2 gas. With these methods, our bottom-gate ZnO thin-film transistor showed 4.7 cm2/Vsec mobility, on/off ratio, and –2 V threshold voltage. Junghwan Kim, Jun Meng, Donghoon Lee, Meng Yu, Dukyean Yoo, Doo Won Kang, and Jungyol Jo Copyright © 2014 Junghwan Kim et al. All rights reserved. Antibacterial Coating for Elimination of Pseudomonas aeruginosa and Escherichia coli Tue, 11 Nov 2014 07:08:47 +0000 A polymer antibacterial surface has been successfully developed. The coating system used silane as binder and Ag particles as antibacterial agent. The silver was synthesized using precipitation method. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Brunauer-Emmett-Teller (BET) tests, energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS) were carried out to evaluate the silver particles. Antibacterial properties of the coating system were tested against gram-negative bacteria, namely, Pseudomonas aeruginosa and Escherichia coli. Different amounts of Ag were used in the coating to optimize its usage. The Japanese International Standard, JISZ2801, was used for bacteria test and the surface developed complies with the standard being antibacterial. Zainal Abidin Ali, W. Ahliah Ismail, Cheng-Foh Le, Hassan Mahmood Jindal, Rosiyah Yahya, Shamala Devi Sekaran, and R. Puteh Copyright © 2014 Zainal Abidin Ali et al. All rights reserved. Synthesis and Mechanism of Tetracalcium Phosphate from Nanocrystalline Precursor Tue, 11 Nov 2014 06:57:46 +0000 Tetracalcium phosphate (TTCP, Ca4(PO4)2O) was prepared by the calcination of coprecipitated mixture of nanoscale hydroxyapatite (HA, Ca10(PO4)6(OH)2) and calcium carbonate crystal (CaCO3), followed by cooling in the air or furnace. The effect of calcination temperature on crystal structure and phase composition of the coprecipitation mixture was characterized by transmission electron microscope (TEM), thermal analysis-thermogravimetry (DTA-TG), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), and Raman spectroscopy (RS). The obtained results indicated that the synthesized mixture consisted of nanoscale HA and CaCO3 with uniform distribution throughout the composite. TTCP was observed in the air quenching samples when the calcination temperature was above 1185°C. With the increase of the calcination temperature, the amount of the intermediate products in the air quenching samples decreased and cannot be detected when calcination temperature reached 1450°C. Unexpectedly, the mixture of HA and calcium oxide was observed in the furnace cooling samples. Clearly, the calcination temperature and cooling methods are critical for the synthesis of high-purity TTCP. The results indicate that the nanosize of precursors can decrease the calcination temperature, and TTCP can be calcinated by low temperature. Jianguo Liao, Xingze Duan, Yanqun Li, Caifeng Zheng, Zhengpeng Yang, Aiguo Zhou, and Dinghua Zou Copyright © 2014 Jianguo Liao et al. All rights reserved. Highly Sensitive Surface Enhanced Raman Spectroscopy from Ag Nanoparticles Decorated Graphene Sheet Mon, 10 Nov 2014 13:26:44 +0000 Surface enhanced Raman spectroscopy (SERS) is a powerful analytical technique and has been most intensively studied. In this work, electroless deposition is proposed for Ag nanoparticles (NPs) decorated on chemical vapor deposition (CVD) growth graphene sheets (GS) to create hybrid SERS substrate. From three aspects of size distribution, morphology, and coverage, Ag NPs controllable decoration on GS and SERS enhancement factors of the hybrid SERS substrate is investigated. 200–300 times enhanced SERS intensities are detected from the Ag NPs on GS hybrid as compared to pure GS. Controllable decoration is crucial for improving SERS enhancement factors , because from quasi cubic Ag NPs on GS is 6.53 times stronger than that from spheric one; 1.6 times is detected while the Ag NPs size distribution is reduced to half, and when the coverage is doubled, is nearly doubled. This controllable Ag NPs/GS hybrid is capable of serving as a high performance SERS substrate for efficient chemical and biological sensing applications. Hui Song, Xin Li, Sweejiang Yoo, Yuan Wu, Weihua Liu, Xiaoli Wang, and Hongzhong Liu Copyright © 2014 Hui Song et al. All rights reserved. Evaluating Stability of Aqueous Multiwalled Carbon Nanotube Nanofluids by Using Different Stabilizers Mon, 10 Nov 2014 11:30:08 +0000 The 0.5 wt.% multiwalled carbon nanotubes/water nanofluids (MWNFs) were produced by using a two-step synthetic method with different types and concentrations of stabilizers. The static position method, centrifugal sedimentation method, zeta potential measurements, and rheological experiments were used to assess the stability of the MWNFs and to determine the optimal type and fixed MWCNTs-stabilizer concentration of stabilizer. Finally, MWNFs with different concentrations of MWCNTs were produced using the optimal type and fixed concentration ratio of stabilizer, and their stability, thermal conductivity, and pH were measured to assess the feasibility of using them in heat transfer applications. MWNFs containing SDS and SDBS with MWCNTs-stabilizer concentration ratio were 5 : 2 and 5 : 4, respectively, showed excellent stability when they were evaluated by static position, centrifugal sedimentation, zeta potential, and rheological experiments at the same time. The thermal conductivity of the MWNFs indicated that the most suitable dispersing MWNF contained SDBS. MWNFs with MWCNTs concentrations of 0.25, 0.5, and 1.0 wt.% were fabricated using an aqueous SDBS solution. In addition, the thermal conductivity of the MWNFs was found to have increased, and the thermal conductivity values were greater than that of water at 25°C by 3.20%, 8.46%, and 12.49%. Tun-Ping Teng, Yan-Bo Fang, Yu-Chun Hsu, and Li Lin Copyright © 2014 Tun-Ping Teng et al. All rights reserved. Effect of Nanosheet Surface Structure of Titanium Alloys on Cell Differentiation Mon, 10 Nov 2014 00:00:00 +0000 Titanium alloys are the most frequently used dental implants partly because of the protective oxide coating that spontaneously forms on their surface. We fabricated titania nanosheet (TNS) structures on titanium surfaces by NaOH treatment to improve bone differentiation on titanium alloy implants. The cellular response to TNSs on Ti6Al4V alloy was investigated, and the ability of the modified surfaces to affect osteogenic differentiation of rat bone marrow cells and increase the success rate of titanium implants was evaluated. The nanoscale network structures formed by alkali etching markedly enhanced the functions of cell adhesion and osteogenesis-related gene expression of rat bone marrow cells. Other cell behaviors, such as proliferation, alkaline phosphatase activity, osteocalcin deposition, and mineralization, were also markedly increased in TNS-modified Ti6Al4V. Our results suggest that titanium implants modified with nanostructures promote osteogenic differentiation, which may improve the biointegration of these implants into the alveolar bone. Satoshi Komasa, Tetsuji Kusumoto, Yoichiro Taguchi, Hiroshi Nishizaki, Tohru Sekino, Makoto Umeda, Joji Okazaki, and Takayoshi Kawazoe Copyright © 2014 Satoshi Komasa et al. All rights reserved. Recent Advances in Nanocarbon Materials Sun, 09 Nov 2014 12:43:19 +0000 Naoki Kishi, Shota Kuwahara, Keita Kobayashi, and Palanisamy Ramesh Copyright © 2014 Naoki Kishi et al. All rights reserved. Automated Nanofiber Diameter Measurement in SEM Images Using a Robust Image Analysis Method Thu, 06 Nov 2014 13:00:32 +0000 Due to the high surface area, porosity, and rigidity, applications of nanofibers and nanosurfaces have developed in recent years. Nanofibers and nanosurfaces are typically produced by electrospinning method. In the production process, determination of average fiber diameter is crucial for quality assessment. Average fiber diameter is determined by manually measuring the diameters of randomly selected fibers on scanning electron microscopy (SEM) images. However, as the number of the images increases, manual fiber diameter determination becomes a tedious and time consuming task as well as being sensitive to human errors. Therefore, an automated fiber diameter measurement system is desired. In the literature, this task is achieved by using image analysis algorithms. Typically, these methods first isolate each fiber in the image and measure the diameter of each isolated fiber. Fiber isolation is an error-prone process. In this study, automated calculation of nanofiber diameter is achieved without fiber isolation using image processing and analysis algorithms. Performance of the proposed method was tested on real data. The effectiveness of the proposed method is shown by comparing automatically and manually measured nanofiber diameter values. Ertan Öznergiz, Yasar Emre Kiyak, Mustafa E. Kamasak, and Isa Yildirim Copyright © 2014 Ertan Öznergiz et al. All rights reserved. Synthesis of Multiwalled Carbon Nanotubes-Titania Nanomaterial for Desulfurization of Model Fuel Thu, 06 Nov 2014 10:02:21 +0000 This work reported on the development of novel nanomaterials of multiwalled carbon nanotubes doped with titania (CNT/TiO2) for the adsorptive desulfurization of model fuel oils. Various analytical techniques such as field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR) were used for the characterization of the nanomaterials. The initial results indicated the effectiveness of the prepared CNT/TiO2 nanomaterials in removing sulfur compounds from model fuel oil. The adsorption of DBT, BT, and thiophene from model fuel onto the derived sorbents was performed using batch mode system. These CNT/TiO2 nanomaterials initially afforded approximately 45% removal of DBT, 55% BT, and more than 65% thiophene compounds from model fuels. The CNT/TiO2 nanomaterials provided an excellent activity towards interaction with organosulfur compounds. More experiments are underway to optimize the parameters for the adsorptive desulfurization processes. We believe that these nanomaterials as adsorbents will find useful applications in petroleum industry because of their operational simplicity, high efficiency, and high capacity. Tawfik A. Saleh, Mohammad N. Siddiqui, and Abdulrahman A. Al-Arfaj Copyright © 2014 Tawfik A. Saleh et al. All rights reserved. Development and Application of TiO2 Nanoparticles Coupled with Silver Halide Thu, 06 Nov 2014 07:27:16 +0000 Titanium dioxide (TiO2) is proposed to be effective photocatalyst for wastewater treatment, air purification, and self-cleaning ability, because of its strong oxidation and superhydrophilicity. In order to conquer the limits of TiO2, a variety of methods have been used. This paper presents a critical review of novel research and achievements in the modification of TiO2 nanoparticles with silver halide (AgX, , Br, I), which aims at enhancing the visible light absorption and photosensitivity. Herein we study the synthesis, physical and chemical properties, and the mechanism of this composite photocatalyst. Xiaojia Wan, Ting Wang, Yamei Dong, and Dannong He Copyright © 2014 Xiaojia Wan et al. All rights reserved. Properties of Graphene Oxide/Epoxy Resin Composites Thu, 06 Nov 2014 07:00:08 +0000 The graphene oxide (GO) was obtained by pressurized oxidation method using natural graphite as raw materials. Then the GO/epoxy resin composites were prepared by casting. The mechanical and damping properties of composites were studied. As a result, the impact intensity of GO/epoxy resin composites was prominently improved with the content of the graphene oxide increasing. The glass transition temperature decreased and the damping capacity is improved. Jijun Tang, Haijun Zhou, Yunxia Liang, Xinlan Shi, Xin Yang, and Jiaoxia Zhang Copyright © 2014 Jijun Tang et al. All rights reserved. Synthesis of Fe-Doped ZnO Nanorods by Rapid Mixing Hydrothermal Method and Its Application for High Performance UV Photodetector Thu, 06 Nov 2014 00:00:00 +0000 We have successfully synthesized Fe-doped ZnO nanorods by a new and simple method in which the adopted approach is by using ammonia as a continuous source of for hydrolysis instead of hexamethylenetetramine (HMT). The energy dispersive X-ray (EDX) spectra revealed that the Fe peaks were presented in the grown Fe-doped ZnO nanorods samples and the X-ray photoelectron spectroscopy (XPS) results suggested that Fe3+ is incorporated into the ZnO lattice. Structural characterization indicated that the Fe-doped ZnO nanorods grow along the c-axis with a hexagonal wurtzite structure and have single crystalline nature without any secondary phases or clusters of FeO or Fe3O4 observed in the samples. The Fe-doped ZnO nanorods showed room temperature (300 K) ferromagnetic magnetization versus field (M-H) hysteresis and the magnetization increases from 2.5 μemu to 9.1 μemu for Zn0.99Fe0.01O and Zn0.95Fe0.05O, respectively. Moreover, the fabricated Au/Fe-doped ZnO Schottky diode based UV photodetector achieved 2.33 A/W of responsivity and 5 s of time response. Compared to other Au/ZnO nanorods Schottky devices, the presented responsivity is an improvement by a factor of 3.9. Chan Oeurn Chey, Ansar Masood, A. Riazanova, Xianjie Liu, K. V. Rao, Omer Nur, and Magnus Willander Copyright © 2014 Chan Oeurn Chey et al. All rights reserved. Sol-Gel Synthesis and Characterization of Cubic Bismuth Zinc Niobium Oxide Nanopowders Wed, 05 Nov 2014 00:00:00 +0000 Bismuth zinc niobium oxide (BZN) was successfully synthesized by a diol-based sol-gel reaction utilizing metal acetate and alkoxide precursors. Thermal analysis of a liquid suspension of precursors suggests that the majority of organic precursors decompose at temperatures up to 150°C, and organic free powders form above 350°C. The experimental results indicate that a homogeneous gel is obtained at about 200°C and then converts to a mixture of intermediate oxides at 350–400°C. Finally, single-phased BZN powders are obtained between 500 and 900°C. The degree of chemical homogeneity as determined by X-ray diffraction and EDS mapping is consistent throughout the samples. Elemental analysis indicates that the atomic ratio of metals closely matches a Bi1.5ZnNb1.5O7 composition. Crystallite sizes of the BZN powders calculated from the Scherrer equation are about 33–98 nm for the samples prepared at 500–700°C, respectively. The particle and crystallite sizes increase with increased sintering temperature. The estimated band gap of the BZN nanopowders from optical analysis is about 2.60–2.75 eV at 500-600°C. The observed phase formations and measured results in this study were compared with those of previous reports. Ganchimeg Perenlei, Peter C. Talbot, and Wayde N. Martens Copyright © 2014 Ganchimeg Perenlei et al. All rights reserved. Extended Surface of Materials as a Result of Chemical Equilibrium Tue, 04 Nov 2014 09:14:00 +0000 A system consisting of at least two components was considered. In this system, nanocrystalline material is formed at high temperature, at which diffusion does not limit the mass transport. The structure results from establishing an equilibrium between surface and volume of the crystallites and their surroundings in isothermal-adiabatic conditions. The surface of each crystallite is covered with another substance. On the basis of the performed energy-balance calculations it was concluded that the reduction in the surface area is associated with a decrease in the surface coverage degree and thus with the necessity to provide energy to the system in order to remove chemisorbed atoms. An increase in the temperature of a nanocrystalline substance to a temperature higher than the preparation temperature results in the formation of a new state of equilibrium. At temperatures below the maximum temperature only the equilibrium between the gas phase and the surface exists. Walerian Arabczyk, Rafał Pelka, and Izabella Jasińska Copyright © 2014 Walerian Arabczyk et al. All rights reserved. Optical Nonlinear Refractive Index of Laser-Ablated Gold Nanoparticles Graphene Oxide Composite Mon, 03 Nov 2014 06:57:01 +0000 Gold nanoparticles were prepared in graphene oxide using laser ablation technique. The ablation times were varied from 10 to 40 minutes, and the particle size was decreased from 16.55 nm to 5.18 nm in spherical shape. The nanoparticles were capped with carboxyl and the hydroxyl groups were obtained from Fourier transform infrared spectroscopy. Furthermore, the UV-visible peak shifted with decreasing of nanoparticles size, appearing from 528 nm to 510 nm. The Z-scan technique was used to measure the nonlinear refractive indices of graphene oxide with different concentrations and a gold nanoparticle graphene oxide nanocomposite. Consequently, the optical nonlinear refractive indices of graphene oxide and gold nanoparticle graphene oxide nanocomposite were shifted from  cm2/W to  cm2/W and from  cm2/W to  cm2/W, respectively. Amir Reza Sadrolhosseini, A. S. M. Noor, Nastaran Faraji, Alireza Kharazmi, and Mohd. Adzir Mahdi Copyright © 2014 Amir Reza Sadrolhosseini et al. All rights reserved. In Vitro Degradation of Poly(caprolactone)/nHA Composites Thu, 30 Oct 2014 07:41:46 +0000 The degradation behavior and mechanical properties of polycaprolactone/nanohydroxyapatite composite scaffolds are studied in phosphate buffered solution (PBS), at 37°C, over 16 weeks. Under scanning electron microscopy (SEM), it was observed that the longer the porous scaffolds remained in the PBS, the more significant the thickening of the pore walls of the scaffold morphology was. A decrease in the compressive properties, such as the modulus and the strength of the PCL/nHA composite scaffolds, was observed as the degradation experiment progressed. Samples with high nHA concentrations degraded more significantly in comparison to those with a lower content. Pure PCL retained its mechanical properties comparatively well in the study over the period of degradation. After the twelfth week, the results obtained by GPC analysis indicated a significant reduction in their molecular weight. The addition of nHA particles to the scaffolds accelerated the weight loss of the composites and increased their capacity to absorb water during the initial degradation process. The addition of these particles also affected the degradation behavior of the composite scaffolds, although they were not effective at compensating the decrease in pH prompted by the degradation products of the PCL. Esperanza Díaz, Iban Sandonis, and María Blanca Valle Copyright © 2014 Esperanza Díaz et al. All rights reserved. Synthesis, Characterization, and Thermal and Proton Conductivity Evaluation of 2,5-Polybenzimidazole Composite Membranes Wed, 29 Oct 2014 11:26:47 +0000 In this contribution, composite membranes (CM-D and CM-S) of 2,5-polybenzimidazole (PBI) were synthesized by adding inorganic heteropoly acids (IHA-D and IHA-S). IHA-D and IHA-S were synthesized by condensation reaction of silicotungstic acid with tetraethyl orthosilicate (TEOS) in the absence and presence of mesoporous silica (SiO2), respectively. The synthesized composites were structurally and morphologically characterized and further investigated the functional relationships between the materials structure and proton conductivity. The proton conductivity as well as thermal stability was found to be higher for composite membranes which suggest that both properties are highly contingent on mesoporous silica. The composite membrane with mesoporous silica shows high thermal properties and proton conductivity. IHA-D shows proton conductivity of almost  Scm−1 while IHA-S exhibited  Scm−1 in nonhumidity imposing condition (150°C) which is higher than pure PBI. Thus introduction of inorganic heteropoly acid to PBI is functionally preferable as it results in increase of ion conductivity of PBI and can be better candidates for high temperature PEMFC. Jin-Woo Lee, Kwangin Kim, Sher Bahadar Khan, Patrick Han, Jongchul Seo, Wonbong Jang, and Haksoo Han Copyright © 2014 Jin-Woo Lee et al. All rights reserved. The Effect of Ultrafine Magnesium Hydroxide on the Tensile Properties and Flame Retardancy of Wood Plastic Composites Tue, 28 Oct 2014 06:04:09 +0000 The effect of ultrafine magnesium hydroxide (UMH) and ordinary magnesium hydroxide (OMH) on the tensile properties and flame retardancy of wood plastic composites (WPC) were investigated by tensile test, oxygen index tester, cone calorimeter test, and thermogravimetric analysis. The results showed that ultrafine magnesium hydroxide possesses strengthening and toughening effect of WPC. Scanning electron micrograph (SEM) of fracture section of samples provided the positive evidence that the tensile properties of UMH/WPC are superior to that of WPC and OMH/WPC. The limited oxygen index (LOI) and cone calorimeter test illustrated that ultrafine magnesium hydroxide has stronger flame retardancy and smoke suppression effect of WPC compared to that of ordinary magnesium hydroxide. The results of thermogravimetric analysis implied that ultrafine magnesium hydroxide can improve the char structure which plays an important role in reducing the degradation speed of the inner matrix during combustion process and increases the char residue at high temperature. Zhiping Wu, Na Hu, Yiqiang Wu, Shuyun Wu, and Zu Qin Copyright © 2014 Zhiping Wu et al. All rights reserved.