Journal of Nanomaterials http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2017 , Hindawi Publishing Corporation . All rights reserved. Surface Modification of nTiO2/Ag Hybrid Nanoparticles Using Microwave-Assisted Polymerization in the Presence of Bis(2-hydroxyethyl) Terephthalate Thu, 19 Jan 2017 13:29:41 +0000 http://www.hindawi.com/journals/jnm/2017/7079497/ Titanium dioxide doped silver (nTiO2/Ag) nanoparticles were surface-modified by microwave-assisted polymerization of 2-bis-(hydroxyethyl) terephthalate (BHET). The modified and unmodified nanoparticles were analyzed by FTIR, XRD, TGA, and TEM. A thin layer of grafted PET on the surface of the nanoparticles was observed and quantified by TGA giving a value of 40 wt-%. XRD and electron diffraction analyses showed traces of AgO2 after the modification. The bactericide activity of modified and unmodified nanoparticles was evaluated; the presence of the thin layer of grafted-PET on the nTiO2/Ag did not change significantly the bactericide activity, showing an excellent performance similar to unmodified nanoparticles. P. A. De León-Martínez, F. Soriano-Corral, C. A. Ávila-Orta, P. González-Morones, E. Hernández-Hernández, A. S. Ledezma-Pérez, C. A. Covarrubias-Gordillo, A. C. Espinosa-López, and R. E. Díaz de León Gómez Copyright © 2017 P. A. De León-Martínez et al. All rights reserved. Functional Surface Coating on Cellulosic Flexible Substrates with Improved Water-Resistant and Antimicrobial Properties by Use of ZnO Nanoparticles Thu, 19 Jan 2017 00:00:00 +0000 http://www.hindawi.com/journals/jnm/2017/9689035/ It is of significant interest to create functional flexible surfaces that simultaneously exhibit high water-resistance and antimicrobial performances for medical or packaging applications. This study reported a synthesis of functional surface coating on flexible cellulose materials (filter papers) with ZnO nanoparticles and binds of renewable soybean oil-based polymers. Self-aggregation of ZnO nanoparticles could form ZnO particles with two regular morphological patterns. Rather than a rod-like morphology, a flower-like ZnO benefited a promotion of surface hydrophobicity. Moreover, surface with the flower-like ZnO showed a 51.6% promotion on antimicrobial activities against Gram-negative bacteria (E. coli) than the rod-like ZnO. A low binder/ZnO ratio of 0.2 led to a remarkable improvement on water repelling performances without negative effects on a coating adhesion of ZnO. Under this condition, a hydrophobic surface was achieved with a large static contact angle of 138° when applying ZnO nanoparticles at a dosage of 3 g m−2. Xiaofei Tian, Yaping Li, Sikang Wan, Zhenqiang Wu, and Zhiwei Wang Copyright © 2017 Xiaofei Tian et al. All rights reserved. Enhancement of the Pitting Corrosion Resistance of AISI 316LVM Steel with Ta-Hf-C/Au Bilayers for Biomedical Applications Tue, 17 Jan 2017 06:37:44 +0000 http://www.hindawi.com/journals/jnm/2017/6825250/ Tantalum carbide (TaC), hafnium carbide (HfC), and Ta-Hf-C mixed coatings with and without a gold (Au) interlayer were deposited on 316LVM steel substrates by the magnetron cosputtering technique in order to improve the corrosion resistance of steel substrates in a simulated biological fluid. To study the effect of the gold interlayer on pitting corrosion, the different systems were placed in contact with Ringer’s solution at pH 7.4 and a temperature of 37°C. The electrochemical properties of the coatings were determined using polarization curves. Subsequently, the surface morphologies were observed using scanning electron microscopy (SEM) in order to analyze the corrosion processes on the different surfaces. The gold interlayer was found to significantly improve the electrochemical properties of the system, showing a decrease in the pitting corrosion and deterioration rate, while it is expected that the binary and ternary carbides provide mechanical stability to the bilayers protecting the gold. Pablo Guzmán, Willian Aperador, and Luis Yate Copyright © 2017 Pablo Guzmán et al. All rights reserved. Performance of NiFe2O4-SiO2-TiO2 Magnetic Photocatalyst for the Effective Photocatalytic Reduction of Cr(VI) in Aqueous Solutions Mon, 16 Jan 2017 00:00:00 +0000 http://www.hindawi.com/journals/jnm/2017/5264910/ Investigation into the reduction of Cr(VI) in aqueous solution was carried out through some batch photocatalytic studies. The photocatalysts used were silica coated nickel ferrite nanoparticles (NiFe2O4-SiO2), nickel ferrite titanium dioxide (NiFe2O4-TiO2), nickel ferrite silica titanium dioxide (NiFe2O4-SiO2-TiO2), and titanium dioxide (TiO2). The characterization of the materials prepared via stepwise synthesis using coprecipitation and sol-gel methods were carried out with the aid of X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, thermal gravimetric analysis (TGA), and vibrating sample magnetometry (VSM). The reduction efficiency was studied as a function of pH, photocatalyst dose, and contact time. The effects of silica interlayer between the magnetic photocatalyst materials reveal that reduction efficiency of NiFe2O4-SiO2-TiO2 towards Cr(VI) was higher than that of NiFe2O4-TiO2. However, TiO2 was observed to have the highest reduction efficiency at all batch photocatalytic experiments. Kinetics study shows that photocatalytic reduction of Cr(VI) obeyed Langmuir-Hinshelwood model and first-order rate kinetics. Regenerability study also suggested that the photocatalyst materials can be reused. Mike O. Ojemaye, Omobola O. Okoh, and Anthony I. Okoh Copyright © 2017 Mike O. Ojemaye et al. All rights reserved. Synthesis, Characterization, and Magnetic Properties of Pure and EDTA-Capped NiO Nanosized Particles Sun, 15 Jan 2017 09:09:45 +0000 http://www.hindawi.com/journals/jnm/2017/7460323/ The effect of ethylenediaminetetraacetic acid (EDTA) as a capping agent on the structure, morphology, optical, and magnetic properties of nickel oxide (NiO) nanosized particles, synthesized by coprecipitation method, was investigated. Nickel chloride hexahydrate and sodium hydroxide (NaOH) were used as precursors. The resultant nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). XRD patterns showed that NiO have a face-centered cubic (FCC) structure. The crystallite size, estimated by Scherrer formula, has been found in the range of 28–33 nm. It is noticed that EDTA-capped NiO nanoparticles have a smaller size than pure nanoparticles. Thus, the addition of 0.1 M capping agent EDTA can form a nucleation point for nanoparticles growth. The optical and magnetic properties were investigated by Fourier transform infrared spectroscopy (FTIR) and UV-vis absorption spectroscopy (UV) as well as electron paramagnetic resonance (EPR) and magnetization measurements. FTIR spectra indicated the presence of absorption bands in the range of 402–425 cm−1, which is a common feature of NiO. EPR for NiO nanosized particles was measured at room temperature. An EPR line with factor ≈1.9–2 is detected for NiO nanoparticles, corresponding to Ni2+ ions. The magnetic hysteresis of NiO nanoparticles showed that EDTA capping recovers the surface magnetization of the nanoparticles. H. T. Rahal, R. Awad, A. M. Abdel-Gaber, and D. El-Said Bakeer Copyright © 2017 H. T. Rahal et al. All rights reserved. Biotechnological Production Process and Life Cycle Assessment of Graphene Thu, 12 Jan 2017 08:41:15 +0000 http://www.hindawi.com/journals/jnm/2017/5671584/ The aim of this study is to compare the graphene produced using a biotechnological method (Escherichia coli) with the graphene produced by Hummers’ method (a chemical method) and to study the effect on the energy consumption and environment. The results indicated that the chemical reduction process has higher energy consumption, approximately 1642 Wh, than the energy consumption of the biotechnological reduction process, which is 5 Wh. The potential of global warming (GWP 100) improved by 71% using the biotechnological route for the production of graphene. Abiotic depletion, the photochemical ozone creation potential, and marine aquatic ecotoxicity potential were improved when the biological route was employed, compared with the chemical route. The eutrophication potential, terrestrial ecotoxicity, and ozone depletion layer changed very little since the main variables involved in the production of graphene oxide and waste management are the same. The biotechnological method can be considered a green technique for the production of graphene, especially given the reduction in the negative effects on global warming, abiotic depletion, the photochemical ozone creation potential, and the marine aquatic ecotoxicity potential. P. Noorunnisa Khanam, Anton Popelka, Maryam Alejji, and M. A. AlMaadeed Copyright © 2017 P. Noorunnisa Khanam et al. All rights reserved. Effect of Calcination Temperatures and Mo Modification on Nanocrystalline (γ-χ)-Al2O3 Catalysts for Catalytic Ethanol Dehydration Thu, 12 Jan 2017 00:00:00 +0000 http://www.hindawi.com/journals/jnm/2017/5018384/ The mixed gamma and chi crystalline phase alumina (M-Al) catalysts prepared by the solvothermal method were investigated for catalytic ethanol dehydration. The effects of calcination temperatures and Mo modification were elucidated. The catalysts were characterized by X-ray diffraction (XRD), N2 physisorption, transmission electron microscopy (TEM), and NH3-temperature programmed desorption (NH3-TPD). The catalytic activity was tested for ethylene production by dehydration reaction of ethanol in gas phase at atmospheric pressure and temperature between 200°C and 400°C. It was found that the calcination temperatures and Mo modification have effects on acidity of the catalysts. The increase in calcination temperature resulted in decreased acidity, while the Mo modification on the mixed phase alumina catalyst yielded increased acidity, especially in medium to strong acids. In this study, the catalytic activity of ethanol dehydration to ethylene apparently depends on the medium to strong acid. The mixed phase alumina catalyst calcined at 600°C (M-Al-600) exhibits the complete ethanol conversion having ethylene yield of 98.8% (at 350°C) and the Mo-modified catalysts promoted dehydrogenation reaction to acetaldehyde. This can be attributed to the enhancement of medium to strong acid with metal sites of catalyst. Tharmmanoon Inmanee, Piriya Pinthong, and Bunjerd Jongsomjit Copyright © 2017 Tharmmanoon Inmanee et al. All rights reserved. Effects of Aromatic Ammoniums on Methyl Ammonium Lead Iodide Hybrid Perovskite Materials Thu, 12 Jan 2017 00:00:00 +0000 http://www.hindawi.com/journals/jnm/2017/1640965/ The introduction of bulky ammoniums into methyl ammonium lead iodide hybrid perovskites (MAPbI3) has emerged as a promising strategy to improve the properties of these materials. In the present work, we studied the effects of several aromatic ammoniums onto the structural, electronic, and optical properties of MAPbI3. Although powder XRD data suggest that the bulky cations are not involved in the bulk phase of the MAPbI3, a surprisingly large effect of the bulky cations onto the photoluminescence properties was observed. Jianli Yang, Yan Yu, Liyang Zeng, Yiting Li, Yaoqi Pang, Fuqiang Huang, and Bo-Lin Lin Copyright © 2017 Jianli Yang et al. All rights reserved. Origin of Ferromagnetism in Ru and N Codoped TiO2 Nanotubes: Experiments and Theory Investigations Thu, 12 Jan 2017 00:00:00 +0000 http://www.hindawi.com/journals/jnm/2017/2316745/ The room temperature ferromagnetism (RTFM) of the undoped, N doped, Ru doped ,and Ru-N codoped anatase TiO2 nanotubes (TNTs) films are investigated combined with experiments and first principles approaches. The experiments are highly consistent with the theory calculations. All samples display anatase structures and ferromagnetism at room temperature. The values of the saturation magnetization (Ms) of undoped TiO2, N doped TiO2, Ru doped TiO2, and Ru-N codoped TiO2, respectively, are 0.065 emu/g, 0.015 emu/g, 0.155 emu/g, and 0.073 emu/g. The calculated net moment is in the order of Ru doped > Ru-N codoped > undoped > N doped. The oxygen vacancies play an important role in RTFM of TNTs. Moreover, the hybridization of Ru 4d, N 2p, and O 2p led to the spin-spilt of Ru 4d, N 2p, and O 2p which is devoted to the system magnetism. Jing Xu, Zhongpo Zhou, and Haiying Wang Copyright © 2017 Jing Xu et al. All rights reserved. An Injectable Composite Gelatin Hydrogel with pH Response Properties Wed, 11 Jan 2017 00:00:00 +0000 http://www.hindawi.com/journals/jnm/2017/5139609/ On account of minimally invasive procedure and of filling irregular defects of tissues, injectable hydrogels are increasingly attractive in biomedical fields. However, traditional hydrogel formed by simple physical interaction or in situ crosslinking had inevitably some drawbacks such as low mechanical strength and lack of multifunctional properties. Though many investigations had successfully modified traditional injectable hydrogel to obtain both mechanical and functional properties, an acetalated β-cyclodextrin (Ac-β-CD) nanoparticle composite injectable hydrogel designed in the research was another effective and efficient choice to solve the drawbacks. First of all, gelatin derivative (G-AA) and Ac-β-CD were synthesized to prepare hydrogel and nanoparticle, respectively. In order to ensure good compatibility between nanoparticle and macromonomer and provide crosslink points between nanoparticle and macromonomer, G-AA was simultaneously functionalized onto the surface of Ac-β-CD nanoparticle during the fabrication of Ac-β-CD nanoparticle using one-step method. Finally, injectable composite hydrogel was obtained by photoinitiated polymerization in situ. Hydrogel properties like gelation time and swelling ratio were investigated. The viscoelastic behavior of hydrogels confirmed that typical characteristics of crosslinked elastomer for all hydrogel and nanoparticle in hydrogel could improve the mechanical property of hydrogel. Moreover, the transparency with time had verified obvious acid-response properties of hydrogels. Baoguo Chen and Xiaohong Hu Copyright © 2017 Baoguo Chen and Xiaohong Hu. All rights reserved. Properties of Hydrogenated Nanoporous SiC: An Ab Initio Study Tue, 10 Jan 2017 10:28:45 +0000 http://www.hindawi.com/journals/jnm/2017/4705734/ Nanoporous silicon carbide is part of the important organosilicate class of low dielectric constant alloys. We report first-principles microscopic calculations of the properties of crystalline nanoporous SiCH systems. Properties examined include the density, pore size, dielectric constant, and strain moduli. We examined the relationship between the various properties and the amount of hydrogen in the material. In addition, the bonding topology is examined. The present results are compared with a variety of experiments. Blair R. Tuttle, Nathan J. Held, Lai Hin Lam, Yu-Yang Zhang, and Sokrates T. Pantelides Copyright © 2017 Blair R. Tuttle et al. All rights reserved. Metal-Carbon Interactions on Reduced Graphene Oxide under Facile Thermal Treatment: Microbiological and Cell Assay Mon, 09 Jan 2017 08:31:03 +0000 http://www.hindawi.com/journals/jnm/2017/6059540/ Silver-functionalized reduced graphene oxide (Ag-rGO) nanosheets were prepared by single chemical and thermal processes, with very low concentration of silver. The resulting carbon framework consists of reduced graphene oxide (rGO) sheets or 3D networks, decorated with anchored silver nanoparticles. The Ag-rGO nanosheets were dispersed into a polymer matrix and the composites evaluated for use as biological scaffolds. The rGO material in poly(dimethylsiloxane) (PDMS) has been tested for antimicrobial activity against Gram-positive Staphylococcus aureus (S. Aureus) bacteria, after exposure times of 24 and 120 hours, as well as in the determination of cell viability on cultures of fibroblast cells (NIH/3T3). Using 1 mL of Ag-rGO in PDMS the antibacterial effectiveness against Staphylococcus aureus was limited, showing an increased amount of Colony Forming Units (CFU), after 24 hours of contact. In the cell viability assay, after 48 hours of contact, the group of 1 mL of Ag-rGO with PDMS was the only group that increased cell viability when compared to the control group. In this context, it is believed these behaviors are due to the increase in cell adhesion capacity promoted by the rGO. Thus, the Ag-rGO/PDMS hybrid nanocomposite films can be used as scaffolds for tissue engineering, as they limit antimicrobial activity. N. L. V. Carreño, A. M. Barbosa, V. C. Duarte, C. F. Correa, C. Ferrúa, F. Nedel, S. Peralta, C. A. Mills, R. Rhodes, F. L. M. Sam, and S. R. P. Silva Copyright © 2017 N. L. V. Carreño et al. All rights reserved. The Conjugated Phenylene Polymer-Modified Photoanodes for Quantum Dot-Sensitized Solar Cells Mon, 09 Jan 2017 06:27:43 +0000 http://www.hindawi.com/journals/jnm/2017/9048279/ Five types of conjugated phenylene polymer-modified photoanodes for quantum dot-sensitized solar cells (QDSSCs) were prepared by immobilization of CdSe QDs after electrochemical polymerization of functionalized phenyldiazonium salts onto ITO glass electrodes. The successful preparation of the conjugated phenylene polymer-modified photoanodes for QDSSCs was confirmed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), FT-IR spectroscopy, UV-visible spectroscopy, contact angles, and electrochemical impedance spectroscopy. The open-circuit voltage and fill factor in QDSSCs with the conjugated phenylene polymer with -COOH photoanodes were achieved at 0.52 V and 76.8%, respectively, and the energy conversion efficiency was improved to 2.73% using the conjugated phenylene polymer with -COOH photoanodes. So-Ra Lee, Da-Seul Kim, and Seong-Ho Choi Copyright © 2017 So-Ra Lee et al. All rights reserved. Effect of Annealing Temperature and Spin Coating Speed on Mn-Doped ZnS Nanocrystals Thin Film by Spin Coating Wed, 04 Jan 2017 14:39:17 +0000 http://www.hindawi.com/journals/jnm/2017/2560436/ ZnS:Mn nanocrystals thin film was fabricated at 300°C and 500°C via the spin coating method. Its sol-gel was spin coated for 20 s at 3000 rpm and 4000 rpm with metal tape being used to mold the shape of the thin film. A different combination of these parameters was used to investigate their influences on the fabrication of the film. Optical and structural characterizations have been performed. Optical characterization was analyzed using UV-visible spectroscopy and photoluminescence spectrophotometer while the structural and compositional analysis of films was measured via field emission scanning electron microscopy and energy dispersive X-ray. From UV-vis spectra, the wavelength of the ZnS:Mn was 250 nm and the band gap was within the range 4.43 eV–4.60 eV. In room temperature PL spectra, there were two emission peaks centered at 460 nm and 590 nm. Under higher annealing temperature and higher speed used in spin coating, an increase of 0.05 eV was observed. It was concluded that the spin coating process is able to synthesize high quality spherical ZnS:Mn nanocrystals. This conventional process can replace other high technology methods due to its synthesis cost. Noor Azie Azura Mohd Arif, Chong Chee Jiun, and Sahbudin Shaari Copyright © 2017 Noor Azie Azura Mohd Arif et al. All rights reserved. Nanostructured Semiconductor Materials for Dye-Sensitized Solar Cells Wed, 04 Jan 2017 12:14:47 +0000 http://www.hindawi.com/journals/jnm/2017/5323164/ Since O’Regan and Grätzel’s first report in 1991, dye-sensitized solar cells (DSSCs) appeared immediately as a promising low-cost photovoltaic technology. In fact, though being far less efficient than conventional silicon-based photovoltaics (being the maximum, lab scale prototype reported efficiency around 13%), the simple design of the device and the absence of the strict and expensive manufacturing processes needed for conventional photovoltaics make them attractive in small-power applications especially in low-light conditions, where they outperform their silicon counterparts. Nanomaterials are at the very heart of DSSC, as the success of its design is due to the use of nanostructures at both the anode and the cathode. In this review, we present the state of the art for both -type and -type semiconductors used in the photoelectrodes of DSSCs, showing the evolution of the materials during the 25 years of history of this kind of devices. In the case of -type semiconductors, also some other energy conversion applications are touched upon. Carmen Cavallo, Francesco Di Pascasio, Alessandro Latini, Matteo Bonomo, and Danilo Dini Copyright © 2017 Carmen Cavallo et al. All rights reserved. Water Soluble Fluorescent Carbon Nanodots from Biosource for Cells Imaging Wed, 04 Jan 2017 08:11:27 +0000 http://www.hindawi.com/journals/jnm/2017/7029731/ Carbon nanodots (CNDs) derived from a green precursor, kidney beans, was synthesized with high yield via a facile pyrolysis technique. The CND material was easily modified through simple oxidative treatment with nitric acid, leading to a high density “self-passivated” water soluble form (wsCNDs). The synthesized wsCNDs have been extensively characterized by using various microscopic and spectroscopic techniques and were crystalline in nature. The highly carboxylated wsCNDs possessed tunable-photoluminescence emission behavior throughout the visible region of the spectrum, demonstrating their application for multicolor cellular imaging of HeLa cells. The tunable-photoluminescence properties of “self-passivated” wsCNDs make them a promising candidate as a probe in biological cell-imaging applications. Kumud Malika Tripathi, Tuan Sang Tran, Tran Thanh Tung, Dusan Losic, and TaeYoung Kim Copyright © 2017 Kumud Malika Tripathi et al. All rights reserved. Star Polymer-Drug Conjugates with pH-Controlled Drug Release and Carrier Degradation Tue, 03 Jan 2017 12:48:32 +0000 http://www.hindawi.com/journals/jnm/2017/8675435/ In this study, we describe the design, synthesis, and physicochemical and preliminary biological characteristics of new biodegradable, high-molecular-weight (HMW) drug delivery systems with star-like architectures bearing the cytotoxic drug doxorubicin (DOX) attached by a hydrazone bond-containing spacer. The star polymers were synthesized by grafting semitelechelic N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers on a 2,2-bis(hydroxymethyl)propionic acid- (bis-MPA-) based polyester dendritic core. The molecular weight of the star polymers ranged from 280 to 450 000 g/mol and could be adjusted by proper selection of the bis-MPA dendrimer generation and by considering the polymer to dendrimer molar ratio. The biodegradation of the polymer conjugates is based on the spontaneous slow hydrolysis of the dendritic core in neutral physiological conditions. Hydrazone spacers in the conjugates were fairly stable at neutral pH (7.4) mimicking blood stream conditions, and DOX was released from the conjugates under mild acidic conditions simulating the tumor cell microenvironment in endosomes and lysosomes (pH 5). Finally, we have shown the significant in vitro cytotoxicity of the star polymer-DOX conjugate on selected cancer cell lines with IC50 values almost comparable with that of the free drug and higher than that observed for a linear polymer-DOX conjugate with much lower molecular weight. H. Kostková, L. Schindler, L. Kotrchová, M. Kovář, M. Šírová, L. Kostka, and T. Etrych Copyright © 2017 H. Kostková et al. All rights reserved. Simple Microwave-Assisted Synthesis of Carbon Nanotubes Using Polyethylene as Carbon Precursor Mon, 02 Jan 2017 12:03:51 +0000 http://www.hindawi.com/journals/jnm/2017/2474267/ In this work, a quick and effective method to synthesize carbon nanotubes (CNTs) is reported; a commercial microwave oven of 600 W at 2.45 GHz was utilized to synthesize CNTs from plasma catalytic decomposition of polyethylene. Polyethylene and silicon substrate coated with iron (III) nitrate were placed in the reaction chamber to form the synthesis stock. The CNTs were synthesized at 750°C under atmospheric pressure of 0.81 mbar. Raman spectroscopy and field emission scanning electron microscope revealed the quality and entangled bundles of mixed CNTs from which the diameters of the CNTs were calculated to be between 1.03 and 25.00 nm. High resolution transmission electron microscope further showed that the CNTs obtained by this method are graphitized. Energy dispersive X-ray analysis and thermogravimetric analysis revealed above 98% carbon purity. N. Kure, M. N. Hamidon, S. Azhari, N. S. Mamat, H. M. Yusoff, B. M. Isa, and Z. Yunusa Copyright © 2017 N. Kure et al. All rights reserved. Sample Size Effect of Magnetomechanical Response for Magnetic Elastomers by Using Permanent Magnets Mon, 02 Jan 2017 09:51:29 +0000 http://www.hindawi.com/journals/jnm/2017/8605413/ The size effect of magnetomechanical response of chemically cross-linked disk shaped magnetic elastomers placed on a permanent magnet has been investigated by unidirectional compression tests. A cylindrical permanent magnet with a size of 35 mm in diameter and 15 mm in height was used to create the magnetic field. The magnetic field strength was approximately 420 mT at the center of the upper surface of the magnet. The diameter of the magnetoelastic polymer disks was varied from 14 mm to 35 mm, whereas the height was kept constant (5 mm) in the undeformed state. We have studied the influence of the disk diameter on the stress-strain behavior of the magnetoelastic in the presence and in the lack of magnetic field. It was found that the smallest magnetic elastomer with 14 mm diameter did not exhibit measurable magnetomechanical response due to magnetic field. On the opposite, the magnetic elastomers with diameters larger than 30 mm contracted in the direction parallel to the mechanical stress and largely elongated in the perpendicular direction. An explanation is put forward to interpret this size-dependent behavior by taking into account the nonuniform field distribution of magnetic field produced by the permanent magnet. Tsubasa Oguro, Shuhei Sasaki, Yuri Tsujiei, Mika Kawai, Tetsu Mitsumata, Tatsuo Kaneko, and Miklós Zrínyi Copyright © 2017 Tsubasa Oguro et al. All rights reserved. Morphology, Aggregation Properties, Cytocompatibility, and Anti-Inflammatory Potential of Citrate-Stabilized AuNPs Prepared by Modular Ultrasonic Spray Pyrolysis Mon, 02 Jan 2017 08:52:20 +0000 http://www.hindawi.com/journals/jnm/2017/9365012/ Ultrasonic Spray Pyrolysis (USP) possesses a great potential for production of higher quantities of gold nanoparticles (AuNPs), thus overcoming the problem of batch-to-batch variations in their properties. Recently, we demonstrated that USP with an additional evaporation chamber (modular USP) led to a better size control of AuNPs. However, their morphology, stability, toxicity, and immunomodulatory properties have not been investigated completely. Here, two types of spherical AuNPs were produced by using different USP parameters, followed by their stabilization in Na-citrate solution. No significant changes in their size, agglomeration, and -potential occurred 3 months after their initial production in citrate solution. However, the conditioning of AuNPs in serum-containing cell culture media for 24 h induced an increase in the AuNPs’ hydrodynamic size and a red shift in their Surface Plasmon Resonance, pointing to their instability in biological media. Cytocompatibility tests showed that the produced AuNPs were internalized by L929 cells and primary human monocytes and were not cytotoxic at the concentrations lower than 200 μg/mL, but they exhibited antiproliferative and anti-inflammatory effects, respectively. AuNPs reduced the percentage of CD14+CD16+ but not CD14lowCD16+ monocytes in vitro and reduced the expression of CD86, HLA-DR, TNF-α, and IL-12/IL-23 by these cells. These results indicate that the anti-inflammatory effects of citrate-capped AuNPs produced by modular USP could be beneficial for their application in the treatment of inflammatory conditions. Rebeka Rudolf, Peter Majerič, Sergej Tomić, Mohammed Shariq, Urban Ferčec, Bojan Budič, Bernd Friedrich, Dragana Vučević, and Miodrag Čolić Copyright © 2017 Rebeka Rudolf et al. All rights reserved. Functional Nanofibers: Production and Applications Thu, 29 Dec 2016 09:31:14 +0000 http://www.hindawi.com/journals/jnm/2016/2195787/ Zeeshan Khatri, Ick-Soo Kim, and Seong Hun Kim Copyright © 2016 Zeeshan Khatri et al. All rights reserved. In Vitro Evaluation of Colloidal Silver on Immune Function: Antilymphoproliferative Activity Wed, 28 Dec 2016 14:59:18 +0000 http://www.hindawi.com/journals/jnm/2016/4176212/ Colloidal silver (AgC) is currently used by humans and it can be internalized through inhalation, injection, ingestion, and dermal contact. However, there is limited information about immunological activity; more investigations using colloidal silver are needed. In the present study, the effects of AgC (17.5 ng/mL) on immunological parameters (proliferation and immunophenotyping) using human peripheral blood mononuclear cells (PBMC) and macrophages (phagocytosis) and cytotoxicity on leukemia and lymphoma cancer cell lines (1.75 to 17.5 ng/mL) were investigated. AgC was observed to significantly () decrease interleukin-2 (IL-2) production and proliferation induced by phytohemagglutinin or concanavalin A in PBMC without affecting its cell viability but with cytotoxic effect on cancer cells. IL-2, IL-4, IL-6, IL-10, INF-γ, and IL-17A cytokines production and CD3+, CD3−CD19+, CD3+CD4+, CD3+CD8+, and CD16+CD56+ PBMC phenotypes were not affected by AgC. The present study demonstrates that colloidal silver is harmless and nontoxic to the immune system cells and its ability to interfere with the immune response by decreasing cell proliferation when stimulated with mitogens demonstrated the antilymphoproliferative potential of AgC. M. A. Franco-Molina, E. Mendoza-Gamboa, D. G. Zarate-Triviño, E. E. Coronado-Cerda, J. M. Alcocer-González, D. Resendez-Pérez, M. C. Rodríguez-Salazar, L. G. Rivera-Morales, R. Tamez-Guerra, and C. Rodríguez-Padilla Copyright © 2016 M. A. Franco-Molina et al. All rights reserved. Nanostructured Fe2O3 Based Composites Prepared through Arc Plasma Method as Anode Materials in the Lithium-Ion Battery Wed, 28 Dec 2016 12:28:51 +0000 http://www.hindawi.com/journals/jnm/2016/1207907/ In the present work, a method combining arc plasma evaporation of a metal followed by oxidation in air was developed to produce nanosized metal oxide based composites in large scale. As an example, Fe2O3 based nanocomposites were prepared through such a method. With increasing the oxidation temperature, α-Fe2O3 content in the composites increases, while γ-Fe2O3 and residual α-Fe contents decrease. As anode materials for lithium batteries, the electrochemical properties of nanosized Fe2O3 composites were tested. It was found that the anode materials changed to tiny crystallites and then followed by grain growth during the galvanostatic charge/discharge cycles. A capacity rising was observed for the composites obtained at 400°C and 450°C, which was more prominent with increasing the oxidation temperature. Among these composites, the one obtained at 450°C showed the best performance: a specific capacity of 507.6 mAh/g remained after 150 cycles at a current density of 200 mA/g, much higher than that of the commercial nano-Fe2O3 powder (~180 mAh/g after 30 cycles). Minpeng Liang, Jianxin Zou, Xiaoqin Zeng, and Wenjiang Ding Copyright © 2016 Minpeng Liang et al. All rights reserved. Characterization and Growth Mechanism of Nickel Nanowires Resulting from Reduction of Nickel Formate in Polyol Medium Wed, 28 Dec 2016 12:08:32 +0000 http://www.hindawi.com/journals/jnm/2016/9058686/ Nickel linear nanostructures were synthesized by reduction of nickel formate with hydrazine hydrate in ethylene glycol medium in the absence of any surfactants or capping agents for direction of the particles growth. The effect of the synthesis conditions such as temperature, reduction time, type of polyol, and nickel formate concentration on the reduction products was studied. The size and morphology of the nickel nanowires were characterized by X-ray diffraction, scanning, and transmission electron microscopy. It was shown that the nickel nanocrystallites were wire-shaped with a face-center-cubic phase. Ethylene glycol was found to play a crucial role in the formation of the nickel nanowires. The possible growth processes of the wire-shaped particles taking place at 110 and 130°C are discussed. It was shown that, under certain synthesis conditions, nickel nanowires grow on the surface of the crystals of the solid intermediate of nickel with hydrazine hydrate. Olga A. Logutenko, Alexander I. Titkov, Alexander M. Vorob’yov, Yriy M. Yukhin, and Nikolay Z. Lyakhov Copyright © 2016 Olga A. Logutenko et al. All rights reserved. A Three-Dimensional Porous Conducting Polymer Composite with Ultralow Density and Highly Sensitive Pressure Sensing Properties Tue, 27 Dec 2016 13:05:04 +0000 http://www.hindawi.com/journals/jnm/2016/5164012/ An ultralight conducting polyaniline/SiC/polyacrylonitrile (PANI/SiC/PAN) composite was fabricated by in situ polymerization of aniline monomer on the surface of fibers in SiC/PAN aerogel. The SiC/PAN aerogel was obtained by electrospinning, freeze-drying, and heat treatment. The ingredient, morphology, structure, and electrical properties of the aerogel before and after in situ polymerization were investigated by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and voltage-current characteristic measurement. The thermostability of PANI/SiC/PAN composite was investigated by thermogravimetric analysis (TGA) and electrical resistance measured at different temperatures. The density of the PANI/SiC/PAN composite was approximately 0.211 g cm−3, the porosity was 76.44%, and the conductivity was 0.013 S m−1. The pressure sensing properties were evaluated at room temperature. The electrical resistance of as-prepared sample decreased gradually with the increase of pressure. Furthermore, the pressure sensing process was reversible and the response time was short (about 1 s). This composite may have application in pressure sensor field. Jin-Dong Su, Xian-Sheng Jia, Jin-Tao Li, Tao Lou, Xu Yan, Jia-Lin Sun, Jun-Hong Chen, and Yun-Ze Long Copyright © 2016 Jin-Dong Su et al. All rights reserved. Microbial-Physical Synthesis of Fe and Fe3O4 Magnetic Nanoparticles Using Aspergillus niger YESM1 and Supercritical Condition of Ethanol Tue, 27 Dec 2016 11:46:38 +0000 http://www.hindawi.com/journals/jnm/2016/9174891/ Magnetic Fe and Fe3O4 (magnetite) nanoparticles are successfully synthesized using Aspergillus niger YESM 1 and supercritical condition of liquids. Aspergillus niger is used for decomposition of FeSO4 and FeCl3 to FeS and Fe2O3, respectively. The produced particles are exposed to supercritical condition of ethanol for 1 hour at 300°C and pressure of 850 psi. The phase structure and the morphology measurements yield pure iron and major Fe3O4 spherical nanoparticles with average size of 18 and 50 nm, respectively. The crystal size amounts to 9 nm for Fe and 8 nm for Fe3O4. The magnetic properties are measured to exhibit superparamagnetic- and ferromagnetic-like behaviors for Fe and Fe3O4 nanoparticles, respectively. The saturation magnetization amounts to 112 and 68 emu/g for Fe and Fe3O4, respectively. The obtained results open new route for using the biophysical method for large-scale production of highly magnetic nanoparticles to be used for biomedical applications. Mai Abdeen, Soraya Sabry, Hanan Ghozlan, Ahmed A. El-Gendy, and Everett E. Carpenter Copyright © 2016 Mai Abdeen et al. All rights reserved. One-Step Synthesis of Copper and Cupric Oxide Particles from the Liquid Phase by X-Ray Radiolysis Using Synchrotron Radiation Tue, 27 Dec 2016 08:04:15 +0000 http://www.hindawi.com/journals/jnm/2016/8584304/ The deposition of copper (Cu) and cupric oxide (Cu4O3, Cu2O, and CuO) particles in an aqueous copper sulfate (CuSO4) solution with additive alcohol such as methanol, ethanol, 2-propanol, and ethylene glycol has been studied by X-ray exposure from synchrotron radiation. An attenuated X-ray radiation time of 5 min allows for the synthesis of Cu, Cu4O3, Cu2O, and CuO nano/microscale particles and their aggregation into clusters. The morphology and composition of the synthesized Cu/cupric oxide particle clusters were characterized by scanning electron microscopy, scanning transmission electron microscopy, and high-resolution transmission electron microscopy with energy dispersive X-ray spectroscopy. Micro-Raman spectroscopy revealed that the clusters comprised cupric oxide core particles covered with Cu particles. Neither Cu/cupric oxide particles nor their clusters were formed without any alcohol additives. The effect of alcohol additives is attributed to the following sequential steps: photochemical reaction due to X-ray irradiation induces nucleation of the particles accompanying redox reaction and forms a cluster or aggregates by LaMer process and DLVO interactions. The procedure offers a novel route to synthesize the Cu/cupric oxide particles and aggregates. It also provides a novel additive manufacturing process or lithography of composite materials such as metal, oxide, and resin. Akinobu Yamaguchi, Ikuo Okada, Takao Fukuoka, Mari Ishihara, Ikuya Sakurai, and Yuichi Utsumi Copyright © 2016 Akinobu Yamaguchi et al. All rights reserved. Corrigendum to “Development of a Doxycycline Hydrochloride-Loaded Electrospun Nanofibrous Membrane for GTR/GBR Applications” Tue, 27 Dec 2016 06:07:07 +0000 http://www.hindawi.com/journals/jnm/2016/6721806/ Lie-ni Jia, Xin Zhang, Hong-yu Xu, Fei Hua, Xiang-gang Hu, Qiao Xie, Wei Wang, and Jun Jia Copyright © 2016 Lie-ni Jia et al. All rights reserved. Protonic Conduction of Nanostructured Y-Doped BaZrO3 Mon, 26 Dec 2016 12:03:52 +0000 http://www.hindawi.com/journals/jnm/2016/8757305/ Nanostructured ionic conductors have recently attracted our attention due to the expectation that they may lead to new functionalities absent in microcrystalline conductors. In this study, nanostructured barium zirconate with perovskite crystal structure was prepared and its grain and grain boundary protonic conduction was investigated using ac impedance measurements as a function of temperature (RT ~ 400°C) and water partial pressure. The grain was highly conductive of protons, which is governed by the concentration of protonic defects at all temperatures. On the other hand, the grain boundary was not the preferred route for protonic conduction due to high resistance. However, enhanced protonic transport was observed at certain temperatures (<100°C). The protonic resistivity below that temperature decreased with decreasing temperature, showing positive activation energy in relation to temperature. The conduction route for the enhanced transport was the serial grain boundary. In addition, the route was compared with that of nanostructured zirconia with fluorite crystal-structure. Hee Jung Park and Jong Wook Roh Copyright © 2016 Hee Jung Park and Jong Wook Roh. All rights reserved. RGD Peptide-Grafted Graphene Oxide as a New Biomimetic Nanointerface for Impedance-Monitoring Cell Behaviors Sun, 25 Dec 2016 14:16:45 +0000 http://www.hindawi.com/journals/jnm/2016/2828512/ A new biomimetic nanointerface was constructed by facile grafting the bioactive arginylglycylaspartic acid (RGD) peptide on the graphene oxide (GO) surface through carbodiimide and N-hydroxysuccinimide coupling amidation reaction. The formed RGD-GO nanocomposites own unique two-dimensional structure and desirable electrochemical performance. The linked RGD peptides could improve GO’s biocompatibility and support the adhesion and proliferation of human periodontal ligament fibroblasts (HPLFs) on RGD-GO biofilm surface. Furthermore the biologically active RGD-GO nanocomposites were demonstrated as a potential biomimetic nanointerface for monitoring cell biobehaviors by electrochemical impedance spectroscopy (EIS). By analysis of the data obtained from equivalent circuit-fitting impedance spectroscopy, the information related to cell membrane capacitance, cell-cell gap resistance, and cell-electrode interface gap resistance in the process of cell adhesion and proliferation could be obtained. Besides, this proposed impedance-based cell sensor could be used to assess the inhibition effect of the lipopolysaccharide (LPS) on the HPLFs proliferation. Findings from this work suggested that RGD peptide functionalized GO nanomaterials may be not only applied in dental tissue engineering but also used as a sensor interface for electrochemical detection and analysis of cell behaviors in vitro. Jianxia Li, Leilei Zheng, Lin Zeng, Yan Zhang, Lin Jiang, and Jinlin Song Copyright © 2016 Jianxia Li et al. All rights reserved.