Journal of Nanomaterials http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Evaluation of Degradation in Nanofilled Adhesive Resins Using Quantitative Light-Induced Fluorescence Mon, 22 Sep 2014 00:00:00 +0000 http://www.hindawi.com/journals/jnm/2014/671205/ The aim of this study was to evaluate degradation in commercial dental nanofilled adhesive resins using quantitative light-induced fluorescence (QLF). Three adhesives were selected: D/E resin (DR), Single Bond Plus (SB), and G-Bond (GB). The adhesives were mixed with porphyrin for the QLF analysis. Specimens were prepared by dispensing blended adhesives into a flexible mold and polymerizing. Then, the QLF analysis of the specimens was done and the porphyrin values (Simple Plaque Score and ) were measured. After thermocycling of the specimens (5000 cycles, 5 to 55°C) for the degradation, the specimens were assayed by QLF again. The porphyrin values were analyzed using paired t-test at a 95% confidence level. A significant reduction in SPS was observed in all groups after thermocycling. The significantly decreased after thermocycling except area 30 of SB group. Overall, porphyrin values decreased after thermocycling which indicates that the degradation of the adhesive resins may be measured by the change of porphyrin value. The QLF method could be used to evaluate the degradation of adhesive resin. Tae-Young Park, Sun-Jae Kim, Hee-Jung Kim, Byoung-Jin Lee, Byung-Hoon Kim, Yeong-Mu Ko, and Jeong-Bum Min Copyright © 2014 Tae-Young Park et al. All rights reserved. Improvement of Short-Circuit Current Density in p-O:Li/n-Si Heterojunction Solar Cells by Wet Chemical Etching Sun, 21 Sep 2014 11:01:11 +0000 http://www.hindawi.com/journals/jnm/2014/104136/ This study confirms that the surface texturation of window layer (Al-Y codoped ZnO) etched by diluted HCl effectively increases conversion efficiency of p-O:Li/n-Si heterojunction solar cells. The results show that the short circuit current density ( ) of cell etched at 10 s increases about 8.5% compared to unetched cell, which also corresponds to the increase of efficient photoelectric conversion in NIR region as shown in external quantum efficiency spectra. It is attributed to the increase of light transmittance of AZOY thin films in the NIR region and the effective light path of the NIR wavelength, which results in increasing of light absorption in the base layer. Feng-Hao Hsu, Na-Fu Wang, Yu-Zen Tsai, Ming-Hao Chien, and Mau-Phon Houng Copyright © 2014 Feng-Hao Hsu et al. All rights reserved. Synthesis of Fe Nanoparticles Functionalized with Oleic Acid Synthesized by Inert Gas Condensation Thu, 18 Sep 2014 07:41:58 +0000 http://www.hindawi.com/journals/jnm/2014/643967/ In this work, we study the synthesis of monodispersed Fe nanoparticles (Fe-NPs) in situ functionalized with oleic acid. The nanoparticles were self-assembled by inert gas condensation (IGC) technique by using magnetron-sputtering process. Structural characterization of Fe-NPs was performed by transmission electron microscopy (TEM). Particle size control was carried out through the following parameters: (i) condensation zone length, (ii) magnetron power, and (iii) gas flow (Ar and He). Typically the nanoparticles generated by IGC showed diameters which ranged from ~0.7 to 20 nm. Mass spectroscopy of Fe-NPs in the deposition system allowed the study of in situ nanoparticle formation, through a quadrupole mass filter (QMF) that one can use together with a mass filter. When the deposition system works without quadrupole mass filter, the particle diameter distribution is around +/−20%. When the quadrupole is in line, then the distribution can be reduced to around +/−2%. L. G. Silva, F. Solis-Pomar, C. D. Gutiérrez-Lazos, Manuel F. Meléndrez, E. Martinez, A. Fundora, and E. Pérez-Tijerina Copyright © 2014 L. G. Silva et al. All rights reserved. Sustained Release and Cytotoxicity Evaluation of Carbon Nanotube-Mediated Drug Delivery System for Betulinic Acid Mon, 15 Sep 2014 11:15:34 +0000 http://www.hindawi.com/journals/jnm/2014/862148/ Carbon nanotubes (CNTs) have been widely utilized as a novel drug carrier with promising future applications in biomedical therapies due to their distinct characteristics. In the present work, carboxylic acid-functionalized single-walled carbon nanotubes (f-SWCNTs) were used as the starting material to react with anticancer drug, BA to produce f-SWCNTs-BA conjugate via stacking interaction. The conjugate was extensively characterized for drug loading capacity, physicochemical properties, surface morphology, drug releasing characteristics, and cytotoxicity evaluation. The results indicated that the drug loading capacity was determined to be around 20 wt% and this value has been verified by thermogravimetric analysis. The binding of BA onto the surface of f-SWCNTs was confirmed by FTIR and Raman spectroscopies. Powder XRD analysis showed that the structure of the conjugate was unaffected by the loading of BA. The developed conjugate was found to release the drug in a controlled manner with a prolonged release property. According to the preliminary in vitro cytotoxicity studies, the conjugate was not toxic in a standard fibroblast cell line, and anticancer activity was significantly higher in A549 than HepG2 cell line. This study suggests that f-SWCNTs could be developed as an efficient drug carrier to conjugate drugs for pharmaceutical applications in cancer chemotherapies. Julia M. Tan, Govindarajan Karthivashan, Palanisamy Arulselvan, Sharida Fakurazi, and Mohd Zobir Hussein Copyright © 2014 Julia M. Tan et al. All rights reserved. Characterization and Biocompatibility of Chitosan Gels with Silver and Gold Nanoparticles Mon, 15 Sep 2014 10:59:02 +0000 http://www.hindawi.com/journals/jnm/2014/543419/ The presence of bacterial resistance to antibiotics is a very important issue and the search of new alternatives is necessary. In this work, a combination of chitosan gel with silver or gold nanoparticles was prepared and characterized using thermal, rheology, bactericide, and biocompatibility analyses. ESEM images were also taken to visualize the incorporation of the nanoparticles into the gel matrix. Thermal analysis showed a better thermal stability in the chitosan-gold nanoparticles gels compared to the chitosan-silver nanoparticles gels. Rheology analyses showed that the viscosity of the gels decreased when velocity increased and there were differences in viscosity when silver and gold nanoparticles concentrations change. ESEM images showed the presence of agglomerates of silver and gold nanoparticles into the gel matrix with a good distribution; in some cases the formation of microstructures was found. Bactericide results show that these materials present an antibacterial activity against S. aureus, S. mutans, and E. coli. The biocompatibility test showed neither negative reaction nor wound healing delay after the application of the gels in an in vivo test. The gels with silver and gold nanoparticles could be used to treat wound infections in oral or skin applications. C. Sámano-Valencia, G. A. Martínez-Castañón, F. Martínez-Gutiérrez, F. Ruiz, J. F. Toro-Vázquez, J. A. Morales-Rueda, L. F. Espinosa-Cristóbal, N. V. Zavala Alonso, and N. Niño Martínez Copyright © 2014 C. Sámano-Valencia et al. All rights reserved. Deformation of Ordered Mesoporous Silica Structures on Exposure to High Temperatures Mon, 15 Sep 2014 09:32:38 +0000 http://www.hindawi.com/journals/jnm/2014/754076/ Ordered mesoporous silica materials are of interest for a wide range of applications. In many of these, elevated temperatures are used either in the preparation of the material or during its use. Therefore, an understanding of the effect of high temperature treatments on these materials is desirable. In this work, a detailed structural study is performed on silicas with three representative pore structures: a 2-D hexagonal pore arrangement (SBA-15), a continuous 3D cubic bimodal pore structure (KIT-6), and a 3D large cage pore structure (FDU-12). Each silica is studied as prepared and after treatment at a series of temperatures between 300 and 900°C. Pore structures are imaged using Transmission Electron Microscopy. This technique is used in conjunction with Small-Angle X-ray Diffraction, gas physisorption, and 29Si solid state Nuclear Magnetic Resonance. Using these techniques, the pore size distributions, the unit cell dimensions of the mesoporous structures, and the relative occupancy of the distinct chemical environments of Si within them are cross correlated for the three silicas and their evolution with treatment temperature is elucidated. The physical and chemical properties before, during, and after collapse of these structures at high temperatures are described as are the differences in behavior between the three silica structures. John B. Lowe and Richard T. Baker Copyright © 2014 John B. Lowe and Richard T. Baker. All rights reserved. Size-Controlled Synthesis of Fe3O4 Magnetic Nanoparticles in the Layers of Montmorillonite Mon, 15 Sep 2014 08:57:55 +0000 http://www.hindawi.com/journals/jnm/2014/739485/ Iron oxide nanoparticles (Fe3O4-NPs) were synthesized using chemical coprecipitation method. Fe3O4-NPs are located in interlamellar space and external surfaces of montmorillonite (MMT) as a solid supported at room temperature. The size of magnetite nanoparticles could be controlled by varying the amount of NaOH as reducing agent in the medium. The interlamellar space changed from 1.24 nm to 2.85 nm and average diameter of Fe3O4 nanoparticles was from 12.88 nm to 8.24 nm. The synthesized nanoparticles were characterized using some instruments such as transmission electron microscopy, powder X-ray diffraction, energy dispersive X-ray spectroscopy, field emission scanning electron microscopy, vibrating sample magnetometer, and Fourier transform infrared spectroscopy. Katayoon Kalantari, Mansor B. Ahmad, Kamyar Shameli, Mohd Zobir Bin Hussein, Roshanak Khandanlou, and Hajar Khanehzaei Copyright © 2014 Katayoon Kalantari et al. All rights reserved. Vibrational Order, Structural Properties, and Optical Gap of ZnO Nanostructures Sintered through Thermal Decomposition Mon, 15 Sep 2014 00:00:00 +0000 http://www.hindawi.com/journals/jnm/2014/340384/ The sintering of different ZnO nanostructures by the thermal decomposition of zinc acetate is reported. Morphological changes from nanorods to nanoparticles are exhibited with the increase of the decomposition temperature from 300 to 500°C. The material showed a loss in the crystalline order with the increase in the temperature, which is correlated to the loss of oxygen due to the low heating rate used. Nanoparticles have a greater vibrational freedom than nanorods which is demonstrated in the rise of the main Raman mode (high) during the transformation. The energy band gap of the nanostructured material is lower than the ZnO bulk material and decreases with the rise in the temperature. Alejandra Londono-Calderon, Fernando F. Jurado-Lasso, Juan D. Romero-Salazar, Nathaly Jurado-Lasso, and J. Fabian Jurado Copyright © 2014 Alejandra Londono-Calderon et al. All rights reserved. Mechanical, Thermal, and Morphological Properties of Nanocomposites Based on Polyvinyl Alcohol and Cellulose Nanofiber from Aloe vera Rind Sun, 14 Sep 2014 10:51:28 +0000 http://www.hindawi.com/journals/jnm/2014/903498/ This work was devoted to reinforcement of polyvinyl alcohol (PVA) using cellulose nanofibers from Aloe vera rind. Nanofibers were isolated from Aloe vera rind in the form of an aqueous suspension using chemimechanical technique. Mechanical characterizations showed that incorporation of even small amounts of nanofibers (as low as 2% by weight) had significant effects on both the modulus and strength of PVA. Tensile modulus and strength of PVA increased, 32 and 63%, respectively, after adding 2% of cellulose nanofiber from Aloe vera rind. Samples with higher concentrations of nanofibers also showed improved mechanical properties due to a high level of interfacial adhesion and also dispersion of fibers. The results showed that inclusion of nanofibers decreased deformability of PVA significantly. Dynamic mechanical analysis revealed that, at elevated temperatures, improvement of mechanical properties due to the presence of nanofibers was even more noticeable. Addition of nanofibers resulted in increased thermal stability of PVA in thermogravimetric analysis due to the reduction in mobility of matrix molecules. Morphological observations showed no signs of agglomeration of fibers even in composites with high cellulose nanofiber contents. Inclusion of nanofibers was shown to increase the density of composites. Adel Ramezani Kakroodi, Shuna Cheng, Mohini Sain, and Abdullah Asiri Copyright © 2014 Adel Ramezani Kakroodi et al. All rights reserved. Characterization of Carbon Nanofibers Treated with Thermal Nitrogen as a Catalyst Support Using Point-of-Zero Charge Analysis Sun, 14 Sep 2014 07:59:54 +0000 http://www.hindawi.com/journals/jnm/2014/631069/ The chemical and physical purification of carbon nanofiber exposes more anchoring sites between meal precursors and carbon surface but thermal N2 gas flow maintains the crystal’s structure as well as its defect and edge sites, referred to as active sites or anchoring sites. After calcination in nitrogen at 450°C, samples were characterized by Raman spectra X-ray diffraction, as well as thermogravimetric and nitrogen physisorption analyses. Results showed a relatively lower fraction of amorphous carbon to graphite, indicating a greater removal of amorphous carbon. Moreover, the disorder intensity of carbon nanofibers that were treated in N2 flow rate of 1 L/min and 3 hours, called 1Gcom-3h sample, achieved far more defect sites compared with unmodified carbon nanofiber. In addition, the surface areas of mesoporous carbon nanofibers decreased over prolonged residence time. The carbon nanofiber support-metal cation interaction therefore improved the deposition of iron when the point-of-zero charge reading was greater than four. Thien Duc Nguyen Van, Suriati Sufian, Nurlidia Mansor, and Noorhana Yahya Copyright © 2014 Thien Duc Nguyen Van et al. All rights reserved. Synthesis of a Cementitious Material Nanocement Using Bottom-Up Nanotechnology Concept: An Alternative Approach to Avoid CO2 Emission during Production of Cement Thu, 11 Sep 2014 13:32:38 +0000 http://www.hindawi.com/journals/jnm/2014/409380/ The world’s increasing need is to develop smart and sustainable construction material, which will generate minimal climate changing gas during their production. The bottom-up nanotechnology has established itself as a promising alternative technique for the production of the cementitious material. The present investigation deals with the chemical synthesis of cementitious material using nanosilica, sodium aluminate, sodium hydroxide, and calcium nitrate as reacting phases. The characteristic properties of the chemically synthesized nanocement were verified by the chemical composition analysis, setting time measurement, particle size distribution, fineness analysis, and SEM and XRD analyses. Finally, the performance of the nanocement was ensured by the fabrication and characterization of the nanocement based mortar. Comparing the results with the commercially available cement product, it is demonstrated that the chemically synthesized nanocement not only shows better physical and mechanical performance, but also brings several encouraging impacts to the society, including the reduction of CO2 emission and the development of sustainable construction material. A plausible reaction scheme has been proposed to explain the synthesis and the overall performances of the nanocement. Byung Wan Jo, Sumit Chakraborty, and Kwang Won Yoon Copyright © 2014 Byung Wan Jo et al. All rights reserved. Memory and Electrical Properties of (100)-Oriented AlN Thin Films Prepared by Radio Frequency Magnetron Sputtering Thu, 11 Sep 2014 08:08:33 +0000 http://www.hindawi.com/journals/jnm/2014/250439/ The (100)-oriented aluminum nitride (AlN) thin films were well deposited onto p-type Si substrate by radio frequency (RF) magnetron sputtering method. The optimal deposition parameters were the RF power of 350 W, chamber pressure of 9 mTorr, and nitrogen concentration of 50%. Regarding the physical properties, the microstructure of as-deposited (002)- and (100)-oriented AlN thin films were obtained and compared by XRD patterns and TEM images. For electrical properties analysis, we found that the memory windows of (100)-oriented AlN thin films are better than those of (002)-oriented thin films. Besides, the interface and interaction between the silicon and (100)-oriented AlN thin films was serious important problem. Finally, the current transport models of the as-deposited and annealed (100)-oriented AlN thin films were also discussed. From the results, we suggested and investigated that large memory window of the annealed (100)-oriented AlN thin films was induced by many dipoles and large electric field applied. Maw-Shung Lee, Sean Wu, Shih-Bin Jhong, Kai-Huang Chen, and Kuan-Ting Liu Copyright © 2014 Maw-Shung Lee et al. All rights reserved. Tribological Properties of Nanolamellar MoS2 Doped with Copper Nanoparticles Wed, 10 Sep 2014 06:33:14 +0000 http://www.hindawi.com/journals/jnm/2014/731073/ This study aimed at examining the tribological properties of nanolamellar molybdenum disulfide doped with copper nanoparticles. Nanolamellar molybdenum disulfide was produced using self-propagating high-temperature synthesis via the reaction between elementary sulfur and nanosized molybdenum powder prepared by electrical explosion of wires. Copper nanoparticles were also prepared by electrical explosion of copper wires. Comparative tribological tests were carried out for nanolamellar and commercial molybdenum disulfides doped with 7 wt.% of copper nanoparticles. It was demonstrated that doping copper nanoparticles additives reduce wear of the friction body when using both commercial and nanolamellar molybdenum disulfide. Vladimir An and Yuri Irtegov Copyright © 2014 Vladimir An and Yuri Irtegov. All rights reserved. Ostwald Ripening of the Platinum Nanoparticles in the Framework of the Modified LSW Theory Tue, 09 Sep 2014 10:02:13 +0000 http://www.hindawi.com/journals/jnm/2014/821584/ An analysis of the experimental data related to the mechanism of Pt particles sintering has been carried out using the modified LSW theory. The size distribution for the Pt nanoparticles at the stage of Ostwald ripening fits the generalized Lifshitz-Slyozov-Wagner model calculated with the assumption of two parallel mechanisms involved in the nanoparticles growth (dissolution): diffusion and Wagner’s (controlled by the chemical reaction rate). Comparison between the experimental histograms and the curves calculated theoretically proves the governing role of the Wagner’s mechanism (chemical reaction) in the Pt nanoparticles growth. R. D. Vengrenovich, B. V. Ivanskii, I. I. Panko, S. V. Yarema, V. I. Kryvetskyi, and M. O. Stasyk Copyright © 2014 R. D. Vengrenovich et al. All rights reserved. Fabrication of Silk Nanofibres with Needle and Roller Electrospinning Methods Mon, 08 Sep 2014 07:22:48 +0000 http://www.hindawi.com/journals/jnm/2014/947315/ In this study, silk nanofibres were prepared by electrospinning from silk fibroin in a mixture of formic acid and calcium chloride. A needle and a rotating cylinder were used as fibre generators in the spinning process. The influences of the spinning electrode and spinning parameters (silk concentration and applied voltage) on the spinning process, morphology of the obtained fibres, and the production rate of the spinning process were examined. The concentration of the spinning solution influenced the diameter of the silk electrospun fibres, with an increase in the concentration increasing the diameters of the fibres in both spinning systems. The diameters of the electrospun fibres produced by roller electrospinning were greater than those produced by needle electrospinning. Moreover, increasing the concentration of the silk solution and the applied voltage in the spinning process improved the production rate in roller electrospinning but had less influence on the production rate in needle electrospinning. Nongnut Sasithorn and Lenka Martinová Copyright © 2014 Nongnut Sasithorn and Lenka Martinová. All rights reserved. Macroscopic Ensembles of Aligned Carbon Nanotubes in Bubble Imprints Studied by Polarized Raman Microscopy Thu, 04 Sep 2014 00:00:00 +0000 http://www.hindawi.com/journals/jnm/2014/632501/ We study the alignment of single-wall carbon nanotubes (SWCNTs) in bubble imprints through polarized Raman microscopy. A hemispherical bubble containing SWCNTs is pressed against a glass substrate, resulting in an imprint of the bubble membrane with a coffee ring on the substrate. We find that macroscopic ensembles of aligned SWCNTs are obtained in the imprints, in which there are three patterns of orientations: (i) azimuthal alignment on the coffee ring, (ii) radial alignment at the edge of the membrane, and (iii) random orientation at the center of the membrane. We also find that the alignment of SWCNTs in the imprints can be manipulated by spinning bubbles. The orientation of SWCNTs on the coffee ring is directed radially, which is orthogonal to the case of unspun bubbles. This approach enables one to align SWCNTs in large quantities and in a short time, potentially opening up a wide range of CNT-based electronic and optical applications. Shota Ushiba, Jordan Hoyt, Kyoko Masui, Junichiro Kono, Satoshi Kawata, and Satoru Shoji Copyright © 2014 Shota Ushiba et al. All rights reserved. The Tissue Response and Degradation of Electrospun Poly(ε-caprolactone)/Poly(trimethylene-carbonate) Scaffold in Subcutaneous Space of Mice Wed, 03 Sep 2014 10:03:33 +0000 http://www.hindawi.com/journals/jnm/2014/837695/ Due to the advantage of controllability on the mechanical property and the degradation rates, electrospun PCL/PTMC nanofibrous scaffold could be appropriate for vascular tissue engineering. However, the tissue response and degradation of electrospun PCL/PTMC scaffold in vivo have never been evaluated in detail. So, electrospun PCL/PTMC scaffolds with different blend ratios were prepared in this study. Mice subcutaneous implantation showed that the continuous degradation of PCL/PTMC scaffolds induced a lasted macrophage-mediated foreign body reaction, which could be in favor of the tissue regeneration in graft. Tao Jiang, Guoquan Zhang, Wentong He, Hui Li, and Xun Jin Copyright © 2014 Tao Jiang et al. All rights reserved. Nanomaterials and the Environment Wed, 03 Sep 2014 08:13:35 +0000 http://www.hindawi.com/journals/jnm/2014/528606/ Prashant Kumar, Arun Kumar, Teresa Fernandes, and Godwin A. Ayoko Copyright © 2014 Prashant Kumar et al. All rights reserved. Generation of Porous Alumina Layers in a Polydimethylsiloxane/Hydrogen Peroxide Medium on Aluminum Substrate in Corona Discharges Wed, 03 Sep 2014 07:37:59 +0000 http://www.hindawi.com/journals/jnm/2014/578720/ The porous alumina (Al2O3) layer obtained at the interface between polydimethylsiloxane/hydrogen peroxide medium and aluminum substrate under charged and neutral species injection produced in negative corona discharges in air at atmospheric pressure is analyzed by different methods in this paper. The scanning electron microscopy investigations showed the uniform distribution of the pores formed in the alumina layer and their columnar structures. Both energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) measurements indicate that during the anodization process of the aluminum in the polydimethylsiloxane/hydrogen peroxide medium in corona discharge the incorporation of silicon in the structure of the alumina layer is possible. A. Groza, A. Surmeian, C. Diplasu, C. Luculescu, C. Negrila, and M. Ganciu Copyright © 2014 A. Groza et al. All rights reserved. Fabrication and Characterization of Electrospun Polycaprolactone Blended with Chitosan-Gelatin Complex Nanofibrous Mats Tue, 02 Sep 2014 12:33:53 +0000 http://www.hindawi.com/journals/jnm/2014/964621/ Design and fabrication of nanofibrous scaffolds should mimic the native extracellular matrix. This study is aimed at investigating electrospinning of polycaprolactone (PCL) blended with chitosan-gelatin complex. The morphologies were observed from scanning electron microscope. As-spun blended mats had thinner fibers than pure PCL. X-ray diffraction was used to analyze the degree of crystallinity. The intensity at two peaks at 2θ of 21° and 23.5° gradually decreased with the percentage of chitosan-gelatin complex increasing. Moreover, incorporation of the complex could obviously improve the hydrophilicity of as-spun blended mats. Mechanical properties of as-spun nanofibrous mats were also tested. The elongation at break of fibrous mats increased with the PCL content increasing and the ultimate tensile strength varied with different weight ratios. The as-spun mats had higher tensile strength when the weight ratio of PCL to CS-Gel was 75/25 compared to pure PCL. Both as-spun PCL scaffolds and PCL/CS-Gel scaffolds supported the proliferation of porcine iliac endothelial cells, and PCL/CS-Gel had better cell viability than pure PCL. Therefore, electrospun PCL/Chitosan-gelatin nanofibrous mats with weight ratio of 75/25 have better hydrophilicity mechanical properties, and cell proliferation and thus would be a promising candidate for tissue engineering scaffolds. Yongfang Qian, Zhen Zhang, Laijiu Zheng, Ruoyuan Song, and Yuping Zhao Copyright © 2014 Yongfang Qian et al. All rights reserved. Gold Nanoparticles: Synthesis, Stability Test, and Application for the Rice Growth Tue, 02 Sep 2014 10:55:05 +0000 http://www.hindawi.com/journals/jnm/2014/451232/ In today’s science, with the use of nanotechnology, nanomaterials, which behave very differently from the bulk solid, can be made. One of the capable uses of nanomaterials is bioapplications which make good use of the specific properties of nanoparticles. However, since the nanoparticles will be used both in-vivo and in-vitro, their stability is an important issue to the scientists, concern. In this dissertation, we are going to test the stability of gold nanoparticles in a number of media including the biocompatible medium and their behaviors will be illustrated in terms of optical properties change and aggregation degree. Herein, we report the synthesis of gold nanoparticles of different shapes and applications for the rice growth with significant difference. The gold nanoparticles can inhibit the elongation of rice root without inhibiting the germination of rice seeds. Aiwu Wang, Hoi Pong Ng, Yi Xu, Yuyu Li, Yuhong Zheng, Jingping Yu, Fugui Han, Feng Peng, and Li Fu Copyright © 2014 Aiwu Wang et al. All rights reserved. Morphological Investigation of Calcium Carbonate during Ammonification-Carbonization Process of Low Concentration Calcium Solution Tue, 02 Sep 2014 09:11:24 +0000 http://www.hindawi.com/journals/jnm/2014/503696/ Ultrafine calcium carbonate is a widely used cheap additive. The research is conducted in low degree supersaturation solution in order to study the polymorphic phases’ change and its factors of the calcium carbonate precipitate in the ammonification-carbonization process of the solution with calcium. Fine particles of calcium carbonate are made in the solution containing 0.015 mol/L of Ca2+. Over 98% of the calcium carbonate precipitate without ammonification resembles the morphology of calcite, while the introduction of ammonia can benefit the formation of vaterite. It was inferred that the main cause should be serious partial oversaturation or steric effects. Ammonia also helps to form the twin spherical calcium carbonate. However, particles formed in the process of ammonification-carbonization in solution with low concentration degree of calcium are not even with a scale of the particle diameter from 5 to 12 μm. Inorganic salts, alcohol, or organic acid salts have significant controlling effect on the particle diameter of calcium carbonate and can help to decrease the particle diameter to about 3 μm. Anionic surfactants can prevent the conglobation of calcium carbonate particles and shrink its diameter to 500 nm–1 μm. Huaigang Cheng, Xiaoxi Zhang, and Huiping Song Copyright © 2014 Huaigang Cheng et al. All rights reserved. Facile Synthesis of Graphene/ZnO Composite as an Anode with Enhanced Performance for Lithium Ion Batteries Tue, 02 Sep 2014 08:05:19 +0000 http://www.hindawi.com/journals/jnm/2014/964391/ Graphene/ZnO composites with different contents of ZnO have been successfully synthesized via a liquid phase route. The structure, morphology, and electrochemical performances of the composites are investigated by XRD, Raman, SEM, TEM, AFM, and electrochemical measurement. The results reveal that ZnO nanoparticles wedged on the surface of the graphene nanosheets. The initial capacity of graphene/ZnO (1 : 1) reached 1155.27 mAh g−1, which increased 162.87 mAh g−1 compared with the initial capacity of graphene. This could be attributed to the unique structure of the prepared composite and synergies of graphene and ZnO in the lithium ion storage. Yanhong Zhao, Gang Chen, and Yu Wang Copyright © 2014 Yanhong Zhao et al. All rights reserved. Carbon Nanomaterials and Related Nanostructures: Synthesis, Characterization, and Application Sun, 31 Aug 2014 07:48:42 +0000 http://www.hindawi.com/journals/jnm/2014/319165/ Jinlong Jiang, Jun Yang, Jian Lin, Zhenghong Huang, and S. C. Wang Copyright © 2014 Jinlong Jiang et al. All rights reserved. Microstructure and Properties of SCE-Al2O3/PES-MBAE Composite Thu, 28 Aug 2014 11:48:03 +0000 http://www.hindawi.com/journals/jnm/2014/356273/ SCE-Al2O3 was the nano-Al2O3 modified by supercritical ethanol and the surface of SCE-Al2O3 was coated with active group. 4,4′-diaminodiphenylmethane bismaleimide (MBMI) was used as matrix; 3,3′-diallyl bisphenol A (BBA) and bisphenol-A diallyl ether (BBE) were used as reactive diluent, polyethersulfone (PES) as toughening agent, and SCE-Al2O3 as modifier; SCE-Al2O3/PES-MBAE nanocomposite was prepared through in situ sol-gel method. The mechanism of composite toughened by PES was observed and analyzed. FTIR indicated that the reaction between MBMI and allyl compound occurred and SCE-Al2O3 had doped into the polymer matrix. SEM showed that PES particle was inlaid in matrix and presented as a two-phase structure in matrix. The heat resistance, dielectric properties, and mechanical properties of SCE-Al2O3/PES-MBAE nanocomposites were evaluated. The results showed that with the incorporation of PES, although the toughness of the material improved, the heat resistance and dielectric properties of material declined, meanwhile. The adulteration of SCE-Al2O3 could remedy the harmful effect caused by PES, while the content of SCE-Al2O3 was reasonable. The decomposition temperature, dielectric constant, and dielectric loss of composite were 441.23°C, 3.63 (100 Hz), and 1.52 × 10−3 (100 Hz); the bending strength and impact strength were 129.22 MPa and 13.19 kJ/mm2, respectively, when the content of SCE-Al2O3 was 3 wt% and PES was 5 wt%. Yufei Chen, Qiwang Dai, Xiwang Zhang, and Tao Feng Copyright © 2014 Yufei Chen et al. All rights reserved. Systematic Evaluation and Mechanistic Investigation of Antioxidant Activity of Fullerenols Using β-Carotene Bleaching Assay Thu, 28 Aug 2014 09:43:31 +0000 http://www.hindawi.com/journals/jnm/2014/802596/ Antioxidant activity of hydroxylated fullerenes, so-called fullerenols, against lipid peroxyl radical was evaluated by β-carotene bleaching assay. All samples showed moderate to high antioxidant activity (%AOA), especially for C60(OH)12 (70.1) and C60(OH)44 (66.0) as compared with 8, 24, 26, and 36 hydroxylated ones (31.7–62.8). The detection of the possible products was conducted in the model reaction of both fullerenols and C60 with methyl linoleate by MALDI-TOF-MS. These results suggested that the two possible mechanisms, such as C-addition to double bonds and H-abstraction from –OH groups, are involved in the present radical scavenging reaction. Hiroshi Ueno, Shizuka Yamakura, Riya S. Arastoo, Takumi Oshima, and Ken Kokubo Copyright © 2014 Hiroshi Ueno et al. All rights reserved. The Influence of Electrophoretic Deposition for Fabricating Dye-Sensitized Solar Cell Thu, 28 Aug 2014 00:00:00 +0000 http://www.hindawi.com/journals/jnm/2014/126053/ Titanium dioxide (TiO2) film was deposited on fluorine-doped tin oxide (FTO) glass substrate by electrophoretic deposition method (EPD). TiO2 films were prepared with different I2 dosages, electric field intensities and deposition time (D.T.), electrophotic deposition times. By different I2 dosages, electric field intensities, deposition time, electrophotic deposition times fabricated TiO2 films and compared photoelectric characteristics of TiO2 films to find optimal parameters which were the highest photovoltaic conversion efficiency. And use electrochemical impedance spectroscopy (EIS) to measure the Nyquist plots under different conditions and analyze the impendence of dye-sensitized solar cells at the internal heterojunction. According to the experimental results, the I2 dosage was 0.025 g which obtained the optimal characteristic parameters. Thickness of TiO2 film was 10.6 μm, the open-circuit voltage () was 0.77 V, the short-circuit current density () was 7.20 mA/cm2, the fill factor (F.F.) was 53.41%, and photovoltaic conversion efficiency (η) was 2.96%. Jung-Chuan Chou, Shen-Chang Lin, Yi-Hung Liao, Jui-En Hu, Shen-Wei Chuang, and Chin-Hui Huang Copyright © 2014 Jung-Chuan Chou et al. All rights reserved. Time-Evolution Contrast of Target MRI Using High-Stability Antibody Functionalized Magnetic Nanoparticles: An Animal Model Wed, 27 Aug 2014 12:29:19 +0000 http://www.hindawi.com/journals/jnm/2014/351848/ In this work, high-quality antibody functionalized Fe3O4 magnetic nanoparticles are synthesized. Such physical characterizations as particle morphology, particle size, stability, and relaxivity of magnetic particles are investigated. The immunoreactivity of biofunctionalized magnetic nanoparticles is examined by utilizing immunomagnetic reduction. The results show that the mean diameter of antibody functionalized magnetic nanoparticles is around 50 nm, and the relaxivity of the magnetic particles is 145 (mM·s)−1. In addition to characterizing the magnetic nanoparticles, the feasibility of using the antibody functionalized magnetic nanoparticles for the contrast medium of target magnetic resonance imaging is investigated. These antibody functionalized magnetic nanoparticles are injected into mice bearing with tumor. The tumor magnetic-resonance image becomes darker after the injection and then recovers 50 hours after the injection. The tumor magnetic-resonance image becomes the darkest at around 20 hours after the injection. Thus, the observing time window for the specific labeling of tumors with antibody functionalized magnetic nanoparticles was found to be 20 hours after injecting biofunctionalized magnetic nanoparticles into mice. The biopsy of tumor is stained after the injection to prove that the long-term darkness of tumor magnetic-resonance image is due to the specific anchoring of antibody functionalized magnetic nanoparticles at tumor. K. W. Huang, S. Y. Yang, H. E. Horng, J. J. Chieh, H. H. Chen, C. C. Wu, J. H. Chen, I.T. Lin, C. C. Yang, and H. C. Yang Copyright © 2014 K. W. Huang et al. All rights reserved. Size, Temperature, and Strain-Rate Dependence on Tensile Mechanical Behaviors of Ni3Sn4 Intermetallic Compound Using Molecular Dynamics Simulation Wed, 27 Aug 2014 08:36:11 +0000 http://www.hindawi.com/journals/jnm/2014/214510/ This study focuses on exploring the mechanical properties and nonlinear stress-strain behaviors of monoclinic Ni3Sn4 single crystals under uniaxial tensile test and also their size, temperature, and strain-rate dependence through constant temperature molecular dynamics (MD) simulation using Berendsen thermostat. The deformation evolution of the Ni3Sn4 atomic nanostructure during the tensile test is observed. In addition, the tensile yield strains of various Ni3Sn4 single crystals at different strain rates and temperatures are characterized through unloading process. At last, by way of linear regression analysis, the corresponding normal elastic stiffness constants are approximated and then compared with the literature theoretical data. The radial distribution function analysis shows that Ni3Sn4 single crystal in a one-dimensional nanowire configuration would become a highly disordered structure after thermal equilibration, thereby possessing amorphous-like mechanical behaviors and properties. The initial elastic deformation of Ni3Sn4 single crystal is governed by the reconfiguration of surface atoms, and its deformation evolution after further uniaxial tensile straining is characterized by Ni=Sn bond straightening, bond breakage, inner atomic distortion, cross-section shrinking, and rupture. The calculated normal elastic constants of Ni3Sn4 single crystal are found to be consistent with the literature theoretical data. Hsien-Chie Cheng, Ching-Feng Yu, and Wen-Hwa Chen Copyright © 2014 Hsien-Chie Cheng et al. All rights reserved. Oxidized Nano-Porous-Silicon Buffer Layers for Suppressing the Visible Photoresponsivity of ZnO Ultraviolet Photodetectors on Si Substrates Tue, 26 Aug 2014 12:42:07 +0000 http://www.hindawi.com/journals/jnm/2014/756527/ This paper demonstrated the fabrication and optoelectronic characteristics of ZnO ultraviolet (UV) photodetectors fabricated on Si substrates with oxidized nano-porous-Si (ONPS) buffer layers. ONPS layers were prepared on the surfaces of Si substrates by use of an electrochemical anodization technique following a rapid-thermal-oxidation process. Experimental results indicated that application of ONPS buffer layers not only improved the crystallinty of the deposited ZnO thin films but also greatly restricted the visible-to-infrared photoresponse that was generated from the light absorption of Si substrates. The developed ZnO-on-ONPS photodiodes achieved high photoresponsivity for the incident UV light of 300 ∼ 400 nm and got a large photo-to-dark current ratio up to 104 at wavelength of 375 nm under a bias of 5 V. Therefore, ZnO on ONPS provides a highly potential approach for the development of low-cost visible-blind UV photodetectors. Kuen-Hsien Wu Copyright © 2014 Kuen-Hsien Wu. All rights reserved.