Journal of Nanomaterials http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Mechanisms of Hydrogen Transport in Flexible-Wall Narrow Carbon Nanotubes Thu, 23 Apr 2015 14:29:20 +0000 http://www.hindawi.com/journals/jnm/2015/959402/ Understanding the interaction between hydrogen and carbon nanotubes is crucial to enhancing the performance of hydrogen storage and nanofluidic carbon-adsorbent systems. Accordingly, this study performs a series of molecular dynamics simulations to investigate the transport properties of hydrogen molecules confined within a flexible narrow carbon nanotube. The tube’s diameter is 10.8 Å at temperatures in the range of 100~800 K. The particle loadings inside carbon nanotubes are ranging from 0.01∼1 No/Å. The results show that the hydrogen molecules exhibit three distinct diffusion regimes, namely, single-file, Fickian, and ballistic, depending on the value of the Knudsen number. In addition, it is shown that with the Knudsen number of less than 1, the tube-wall long wavelength acoustic phonons induced Rayleigh traveling wave prompts a longitudinal wave slip and compression-expansion of the hydrogen molecule crowds within the CNT, which leads to a significant increase in the mean square displacement of the molecules. Bin-Hao Chen, Chieh Kung, and I-Peng Chu Copyright © 2015 Bin-Hao Chen et al. All rights reserved. Preparation and Characterization of Novel Electrospinnable PBT/POSS Hybrid Systems Starting from c-PBT Thu, 23 Apr 2015 13:42:39 +0000 http://www.hindawi.com/journals/jnm/2015/101674/ Novel hybrid systems based on poly(butyleneterephthalate) (PBT) and polyhedral oligomeric silsesquioxanes (POSS) have been prepared by applying the ring-opening polymerization of cyclic poly(butyleneterephthalate) oligomers. Two types of POSS have been used: one characterized by hydroxyl functionalities (named POSS-OH) and another without specific reactive groups (named oib-POSS). It was demonstrated that POSS-OH acts as an initiator for the polymerization reaction, leading to the direct insertion of the silsesquioxane into the polymer backbone. Among the possible applications of the PBT/POSS hybrid system, the possibility to obtain nanofibers has been assessed in this work. Lorenza Gardella, Alberto Fina, and Orietta Monticelli Copyright © 2015 Lorenza Gardella et al. All rights reserved. Temperature Dependent Variations of Phonon Interactions in Nanocrystalline Cerium Oxide Thu, 23 Apr 2015 12:56:43 +0000 http://www.hindawi.com/journals/jnm/2015/492967/ The temperature dependent anharmonic behavior of the phonon modes of nanocrystalline CeO2 was investigated in the temperature range of 80–440 K. The anharmonic constants have been derived from the shift in phonon modes fitted to account for the anharmonic contributions as well as the thermal expansion contribution using the high pressure parameters derived from our own high pressure experimental data reported previously. The total anharmonicity has also been estimated from the true anharmonicity as well as quasiharmonic component. In the line-width variation analysis, the cubic anharmonic term was found to dominate the quartic term. Finally, the phonon lifetime also reflected the trend so observed. Sugandha Dogra Pandey, Jasveer Singh, K. Samanta, Nita Dilawar Sharma, and A. K. Bandyopadhyay Copyright © 2015 Sugandha Dogra Pandey et al. All rights reserved. Dioscorea bulbifera Mediated Synthesis of Novel AucoreAgshell Nanoparticles with Potent Antibiofilm and Antileishmanial Activity Wed, 22 Apr 2015 14:27:55 +0000 http://www.hindawi.com/journals/jnm/2015/562938/ Dioscorea bulbifera is a potent medicinal plant used in both Indian and Chinese traditional medicine owing to its rich phytochemical diversity. Herein, we report the rapid synthesis of novel nanoparticles by D. bulbifera tuber extract (DBTE). NPs synthesis was completed within 5 h showing a prominent peak at 540 nm. HRTEM analysis revealed 9 nm inner core of elemental gold covered by a silver shell giving a total particle diameter upto 15 nm. NPs were comprised of % gold and % silver of the total mass. NPs showed highest biofilm inhibition upto % against A. baumannii. Biofilms of P. aeruginosa, E. coli, and S. aureus were inhibited up to %, %, and %, respectively. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) confirmed unregulated cellular efflux through pore formation leading to cell death. Potent antileishmanial activity of NPs ( µg/mL) was confirmed by MTT assay. Further SEM micrographs showed pronounced deformity in the spindle shaped cellular morphology changing to spherical. This is the first report of synthesis, characterization, antibiofilm, and antileishmanial activity of NPs synthesized by D. bulbifera. Sougata Ghosh, Soham Jagtap, Piyush More, Usha J. Shete, Neeraj O. Maheshwari, Shilpa J. Rao, Rohini Kitture, Sangeeta Kale, Jayesh Bellare, Shivprasad Patil, Jayanta K. Pal, and Balu A. Chopade Copyright © 2015 Sougata Ghosh et al. All rights reserved. Investigation on Nano-Self-Lubricant Coating Synthesized by Laser Cladding and Ion Sulfurization Wed, 22 Apr 2015 09:52:55 +0000 http://www.hindawi.com/journals/jnm/2015/814038/ The composite processing between laser cladding and low temperature (300°C) ion sulfurization was applied to prepare wear resistant and self-lubricating coating. The microstructure, morphology, phase composition, valence states, and wear resistance of the composite coating were investigated by scanning electron microscopy (SEM), atomic force microscope (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscope (XPS), and friction and wear apparatus. The results indicate that the laser cladding Ni-based coatings and the maximum hardness of 46.5 HRC were obtained when the percent of pure W powder was 10%, composed of columnar dendrites crystals and ultrafine dendritic structure. After ion sulfurization at 300°C for 4 h, the loose and porous composite coating is formed with nanograins and the granularity of all grains is less than 100 nm, which consists of γ-(Fe, Ni), M23C6 carbides, FeS, FeS2, and WS2. Furthermore, the wear resistance of the composite coating is better than the laser cladding Ni55 + 10%W coating, and the friction coefficient and mass losses under the conditions of dry and oil lubrication are lower than those of laser cladding Ni55 + 10%W coating. Meiyan Li, Bin Han, Conghua Qi, Yong Wang, and Lixin Song Copyright © 2015 Meiyan Li et al. All rights reserved. Fibers and Conductive Films Using Silver Nanoparticles and Nanowires by Near-Field Electrospinning Process Wed, 22 Apr 2015 09:06:11 +0000 http://www.hindawi.com/journals/jnm/2015/494052/ The silver nanowires (AgNWs) and silver nanoparticles (AgNPs) were synthesized. With near-field electrospinning (NFES) process, fibers and thin films with AgNPs and AgNWs were fabricated. In the NFES process, 10 k voltage was applied and the AgNPs and AgNWs fibers can be directly orderly collected without breaking and bending. Then, the characteristics of the fibers were analyzed by four-point probe and EDS. The conductive film was analyzed. When the thickness of films with AgNWs and AgNPs was 1.6 µm, the sheet resistance of films was 0.032 Ω/sq which was superior to that of the commercial ITO. The transmissivity of films was analyzed. The transmissivity was inversely proportional to sheet resistance of the films. In the future, the fibers and films can be used as transparent conductive electrodes. Cheng-Tang Pan, Tsung-Lin Yang, Yi-Chian Chen, Cherng-Yuh Su, Shin-Pon Ju, Kun-Hao Hung, I-Chou Wu, Ci-Chang Hsieh, and Sheng-Chih Shen Copyright © 2015 Cheng-Tang Pan et al. All rights reserved. High Performance Electrocatalysts Based on Pt Nanoarchitecture for Fuel Cell Applications Tue, 21 Apr 2015 13:09:35 +0000 http://www.hindawi.com/journals/jnm/2015/273720/ Fuel cells, converting chemical energy from fuels into electricity directly without the need for combustion, are promising energy conversion devices for their potential applications as environmentally friendly, energy efficient power sources. However, to take fuel cell technology forward towards commercialization, we need to achieve further improvements in electrocatalyst technology, which can play an extremely important role in essentially determining cost-effectiveness, performance, and durability. In particular, platinum- (Pt-) based electrocatalyst approaches have been extensively investigated and actively pursued to meet those demands as an ideal fuel cell catalyst due to their most outstanding activity for both cathode oxygen reduction reactions and anode fuel oxidation reactions. In this review, we will address important issues and recent progress in the development of Pt-based catalysts, their synthesis, and characterization. We will also review snapshots of research that are focused on essential dynamics aspects of electrocatalytic reactions, such as the shape effects on the catalytic activity of Pt-based nanostructures, the relationships between structural morphology of Pt-based nanostructures and electrochemical reactions on both cathode and anode electrodes, and the effects of composition and electronic structure of Pt-based catalysts on electrochemical reaction properties of fuel cells. Young-Woo Lee, SeungNam Cha, Kyung-Won Park, Jung Inn Sohn, and Jong Min Kim Copyright © 2015 Young-Woo Lee et al. All rights reserved. Palladium-Gold Nanoalloy Surface Modified LiMn2O4 Cathode for Enhanced Li-Ion Battery Mon, 20 Apr 2015 12:55:55 +0000 http://www.hindawi.com/journals/jnm/2015/613124/ Au with Pd nanoparticles were synthesized and coated onto the spinel LiMn2O4 via a coprecipitation calcination method with the objective to improve the microstructure, conductivity, and electrochemical activities of pristine LiMn2O4. The novel composite cathode had high phase purity, well crystallized particles, and more regular morphological structures with narrow size distributions. At enlarged cycling potential ranges the sample delivered 90 mAh g−1 discharge capacity compared to LiMn2O4 (45 mAh g−1). It was concluded that even a small amount of the Pd and Au enhanced both the lithium diffusivity and electrochemical conductivity of the host sample due to the beneficial properties of their synergy. Natasha Ross, Myra Nzaba, Wonderboy Ntuthuko, Chinwe Ikpo, Priscilla Baker, and Emmanuel Iwuoha Copyright © 2015 Natasha Ross et al. All rights reserved. Design and Performance Analysis of 1-Bit FinFET Full Adder Cells for Subthreshold Region at 16 nm Process Technology Mon, 20 Apr 2015 12:12:38 +0000 http://www.hindawi.com/journals/jnm/2015/726175/ The scaling process of the conventional 2D-planar metal-oxide semiconductor field-effect transistor (MOSFET) is now approaching its limit as technology has reached below 20 nm process technology. A new nonplanar device architecture called FinFET was invented to overcome the problem by allowing transistors to be scaled down into sub-20 nm region. In this work, the FinFET structure is implemented in 1-bit full adder transistors to investigate its performance and energy efficiency in the subthreshold region for cell designs of Complementary MOS (CMOS), Complementary Pass-Transistor Logic (CPL), Transmission Gate (TG), and Hybrid CMOS (HCMOS). The performance of 1-bit FinFET-based full adder in 16-nm technology is benchmarked against conventional MOSFET-based full adder. The Predictive Technology Model (PTM) and Berkeley Shortchannel IGFET Model-Common Multi-Gate (BSIM-CMG) 16 nm low power libraries are used. Propagation delay, average power dissipation, power-delay-product (PDP), and energy-delay-product (EDP) are analysed based on all four types of full adder cell designs of both FETs. The 1-bit FinFET-based full adder shows a great reduction in all four metric performances. A reduction in propagation delay, PDP, and EDP is evident in the 1-bit FinFET-based full adder of CPL, giving the best overall performance due to its high-speed performance and good current driving capabilities. ‘Aqilah binti Abdul Tahrim, Huei Chaeng Chin, Cheng Siong Lim, and Michael Loong Peng Tan Copyright © 2015 ‘Aqilah binti Abdul Tahrim et al. All rights reserved. The Electrical and Mechanical Properties of Porous Anodic 6061-T6 Aluminum Alloy Oxide Film Sun, 19 Apr 2015 09:48:17 +0000 http://www.hindawi.com/journals/jnm/2015/371405/ The properties of the growth of the 6061-T6 aluminum alloy oxide were studied using sulfuric acid anodization. The parameters for the manufacturing process include electrolyte categories, electrolyte concentration, and operating voltages. The results showed that the aluminum oxides obtained by anodization process are mainly amorphous structure and the anodic current density is an important factor affecting the rate of response for oxygen and aluminum ions in barrier. In this experiment, polish process is very important to stable the anodic aluminum oxide film and then it will get the better properties of anodic film. Besides, when using sulfuric acid as the electrolyte, the increase of anodic voltage also increases the rate of reaction which increases the mechanical and electrical properties of anodic oxide film, but too large applied anodic voltage will reduce the mechanical and electrical properties of film because of the crack of the anodic oxide film. Tsung-Chieh Cheng and Chu-Chiang Chou Copyright © 2015 Tsung-Chieh Cheng and Chu-Chiang Chou. All rights reserved. Nanomaterial Synthesis, Characterization, and Application Thu, 16 Apr 2015 14:11:44 +0000 http://www.hindawi.com/journals/jnm/2015/892542/ Mahmood Ghoranneviss, Ajay Soni, Alireza Talebitaher, and Necdet Aslan Copyright © 2015 Mahmood Ghoranneviss et al. All rights reserved. The Effect of Interfacial Transition Zone Properties on the Elastic Properties of Cementitious Nanocomposite Materials Thu, 16 Apr 2015 09:54:31 +0000 http://www.hindawi.com/journals/jnm/2015/258384/ A parametric study was conducted to explore the effect of the interfacial transition zone (ITZ or interphase) on the overall elastic modulus of the CNT-reinforced cement. The effect of the ITZ properties on the elastic modulus of the CNT-reinforced cement was investigated using a four-phase axisymmetric model consisting of a single CNT aligned at the center of composite unit cell, an interface, an ITZ (or interphase), and a cement matrix. The CNT and cement matrix were assumed fully elastic while the interface was modeled using a cohesive surface framework. The width and mechanical properties of the ITZ and the interface were found to affect significantly the elastic modulus and the behavior of the composite material. Ala G. Abu Taqa, Rashid K. Abu Al-Rub, Ahmed Senouci, Nasser Al-Nuaimi, and Khaldoon A. Bani-Hani Copyright © 2015 Ala G. Abu Taqa et al. All rights reserved. Preparation, Characterization, and Dissolution Rate In Vitro Evaluation of Total Panax Notoginsenoside Nanoparticles, Typical Multicomponent Extracts from Traditional Chinese Medicine, Using Supercritical Antisolvent Process Tue, 14 Apr 2015 14:27:09 +0000 http://www.hindawi.com/journals/jnm/2015/439540/ Total Panax notoginsenosides nanoparticles, typical multicomponent extracts from traditional Chinese medicine, were prepared with a supercritical antisolvent (SAS) process using ethanol as solvent and carbon dioxide as antisolvent. The optimum conditions were determined to be as follows: TPNS solution concentration of 2.5 mg/mL, TPNS solution flow rate of 6.6 mL/min, precipitation temperature of 40°C, and precipitation pressure of 20 MPa. Under the optimum conditions, TPNS nanoparticles with a MPS of 141.5 ± 18.2 nm and total saponins amounts (TSA) of 78.9% were obtained. The TPNS nanoparticles obtained were characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimeters (DSC), and high performance liquid chromatography (HPLC). The results showed that the chemical and crystal structure of the obtained TPNS nanoparticles has not changed. Dissolution in vitro studies showed that the solubility and dissolution rate of notoginsenosides R1 and ginsenoside Rb1 in TPNS nanoparticles are higher than these in raw TPNS, with no obvious difference in Rg1. These results suggest that TPNS nanoparticles can be helpful to the improvement of its bioavailability for the treatment of cardiovascular diseases. Ying Zhang, Xiuhua Zhao, Wengang Li, Yuangang Zu, Yong Li, and Kunlun Wang Copyright © 2015 Ying Zhang et al. All rights reserved. Formation and Photocatalytic Activity of BaTiO3 Nanocubes via Hydrothermal Process Tue, 14 Apr 2015 08:58:58 +0000 http://www.hindawi.com/journals/jnm/2015/692182/ We reported a facile hydrothermal approach to synthesize BaTiO3 nanocubes with controlled sizes for degradation of methylene blue (MB). The nanocubes with reaction time of 48 hours exhibited the highest photocatalytic efficiency, owing to their narrower size distribution and better crystallinity compared to those of 24 hours and, at the meantime, smaller particle size than those of 72 hours. This work also demonstrated the degradation of methylene orange (MO) using BaTiO3 nanocubes synthesized for 48 hours. Compared with the removal of MB, BaTiO3 had lower photocatalytic activity on MO, mainly due to the poorer absorption behavior of MO on the surface of BaTiO3 nanocubes. The degradation efficiency for each photocatalytic reaction was calculated. The possible mechanism of the photocatalytic decomposition on MB has been addressed as well. Xinrun Xiong, Ruoming Tian, Xi Lin, Dewei Chu, and Sean Li Copyright © 2015 Xinrun Xiong et al. All rights reserved. Enhancement of Power Efficiency and Stability of P3HT-Based Organic Solar Cells under Elevated Operating-Temperatures by Using a Nanocomposite Photoactive Layer Tue, 14 Apr 2015 08:41:52 +0000 http://www.hindawi.com/journals/jnm/2015/463565/ With the aim to find out an enhanced operating-temperature range for photovoltaic device parameters, two types of the photoactive layer were prepared: poly(3-hexylthiophene) (P3HT) and P3HT+nc-TiO2 (PTC) thin films. The enhancement obtained for the photoelectrical conversion efficiency of the composite based OSCs is attributed to the presence of nanoheterojunctions of TiO2/P3HT. For the temperature range of 30–70°C, the decrease of the open-circuit potential was compensated by an increase of the fill factor; and the increase in the short-circuit current resulted in an overall increase of the energy conversion efficiency. At elevated temperatures of 60–80°C the efficiency of the P3HT- and PTC-based cells reached a maximum value of 1.6% and 2.1%, respectively. Over this temperature range the efficiency of P3HT-based OSC decreased strongly to zero, whereas for the PTC cells it maintained a value as large as 1.2% at the temperature range of 110–140°C. The improved thermal stability of the composite-based device was attributed to the lowered thermal expansion coefficient of the nanocomposite photoactive layer. Tran Thi Thao, Tran Quang Trung, Vo-Van Truong, and Nguyen Nang Dinh Copyright © 2015 Tran Thi Thao et al. All rights reserved. Ferroelectric Polymer Thin Films for Organic Electronics Sun, 12 Apr 2015 09:00:45 +0000 http://www.hindawi.com/journals/jnm/2015/812538/ The considerable investigations of ferroelectric polymer thin films have explored new functional devices for flexible electronics industry. Polyvinylidene fluoride (PVDF) and its copolymer with trifluoroethylene (TrFE) are the most commonly used polymer ferroelectric due to their well-defined ferroelectric properties and ease of fabrication into thin films. In this study, we review the recent advances of thin ferroelectric polymer films for organic electronic applications. Initially the properties of ferroelectric polymer and fabrication methods of thin films are briefly described. Then the theoretical polarization switching models for ferroelectric polymer films are summarized and the switching mechanisms are discussed. Lastly the emerging ferroelectric devices based on P(VDF-TrFE) films are addressed. Conclusions are drawn regarding future work on materials and devices. Manfang Mai, Shanming Ke, Peng Lin, and Xierong Zeng Copyright © 2015 Manfang Mai et al. All rights reserved. Effect of MXene (Nano-Ti3C2) on Early-Age Hydration of Cement Paste Thu, 09 Apr 2015 12:11:43 +0000 http://www.hindawi.com/journals/jnm/2015/430578/ As a new two-dimensional material, MXene (nano-Ti3C2) has been widely applied in many fields, especially for reinforced composite materials. In this paper, mechanical testing, X-ray diffraction (XRD), hydration heat, scanning electron microscope (SEM), and EDS analysis were used to analyze the impact of MXene on cement hydration properties. The obtained results revealed that (a) MXene could greatly improve the early compressive strength of cement paste with 0.04 wt% concentration, (b) the phase type of early-age hydration products has not been changed after the addition of MXene, (c) hydration exothermic rate within 72 h has small difference at different amount of MXene, and (d) morphologies of hydration products were varied with the dosage of MXene, a lot of tufted ettringites appeared in 3 d hydration products when the content of MXene was 0.04 wt%, which will have a positive effect on improving the early mechanical properties of cement paste. MXene has inhibited the Portland cement hydration process; the main role of MXene in the cement hydration process is to promote the messy ettringite becoming regular distribution at a node and form network connection structure in the crystals growth process, making the mechanics performance of cement paste significantly improved. Haibin Yin, Jianping Zhu, Xuemao Guan, Zhengpeng Yang, Yu Zhu, Hongyi Zhao, Zhanying Zhang, Aiguo Zhou, Xing Zhang, Chunhua Feng, and Dongxu Li Copyright © 2015 Haibin Yin et al. All rights reserved. Induction of Heat Shock Protein-72 by Magnetic Nanofluid Hyperthermia in Cultured Retinal Ganglion Cells for Neuroprotective Treatment in Glaucoma Wed, 08 Apr 2015 14:57:23 +0000 http://www.hindawi.com/journals/jnm/2015/142387/ Background. Magnetic hyperthermia using superparamagnetic nanoparticle (SPNP) agents is considered a promising biotechnological approach to induce heat shock proteins (HSPs) in a target tissue because it can generate accurately controllable localized heating. Objectives. The main objective of this study is to demonstrate induction of HSPs in cultured retinal ganglion cells (RGCs) by using engineered Mn0.5Zn0.5Fe2O4 SPNP agents coated with polyethylene glycol (PEG) 500. Methods. The Mn0.5Zn0.5Fe2O4 nanoparticles were synthesized using a high temperature thermal decomposition method. The AC heating characteristics of PEG 500-coated Mn0.5Zn0.5Fe2O4 nanoparticles were investigated using an AC solenoid coil-capacitor system. Results. PEG 500-coated SPNPs efficiently penetrated into the cytoplasm of RGCs without causing obvious cytological changes and showed stable and well-saturated self-heating temperature rise characteristics. Immunofluorescent staining images showed that AC magnetic hyperthermia successfully induced HSP72 in RGCs incubated with Mn0.5Zn0.5Fe2O4 nanoparticles. In Western blot analysis, a significant increase in immunoreactivity was observed for RGCs incubated with SPNPs in a fixed AC magnetic field ( kHz and  Oe). Conclusion. Our results demonstrate that the induction of HSP72 with a magnetic nanofluid hyperthermia could potentially be used as a neuroprotective treatment modality by way of enhancing a natural cytoprotective response. Jin Wook Jeoung, Minhong Jeun, Joo Hyun Park, Yu Jeong Kim, Seongtae Bae, and Ki Ho Park Copyright © 2015 Jin Wook Jeoung et al. All rights reserved. Catalytic Reductive Degradation of Methyl Orange Using Air Resilient Copper Nanostructures Wed, 08 Apr 2015 09:23:29 +0000 http://www.hindawi.com/journals/jnm/2015/136164/ The study describes the application of oxidation resistant copper nanostructures as an efficient heterogeneous catalyst for the treatment of organic dye containing waste waters. Copper nanostructures were synthesized in an aqueous environment using modified surfactant assisted chemical reduction route. The synthesized nanostructures have been characterized by UV-Vis, Fourier transform infrared spectroscopy FTIR spectroscopy, Atomic force microscopy (AFM), Scanning Electron Microscopy (SEM), and X-ray diffractometry (XRD). These surfactant capped Cu nanostructures have been used as a heterogeneous catalyst for the comparative reductive degradation of methyl orange (MO) in the presence of sodium borohydride (NaBH4) used as a potential reductant. Copper nanoparticles (Cu NPs) were found to be more efficient compared to copper nanorods (Cu NRds) with the degradation reaction obeying pseudofirst order reaction kinetics. Shape dependent catalytic efficiency was further evaluated from activation energy () of reductive degradation reaction. The more efficient Cu NPs were further employed for reductive degradation of real waste water samples containing dyes collected from the drain of different local textile industries situated in Hyderabad region, Pakistan. Razium Ali Soomro, Ayman Nafady, Sirajuddin, Syed Tufail Hussain Sherazi, Nazar Hussain Kalwar, Mohammad Raza Shah, and Keith Richard Hallam Copyright © 2015 Razium Ali Soomro et al. All rights reserved. Lipoamino Acid Coated Superparamagnetic Iron Oxide Nanoparticles Concentration and Time Dependently Enhanced Growth of Human Hepatocarcinoma Cell Line (Hep-G2) Wed, 08 Apr 2015 09:00:39 +0000 http://www.hindawi.com/journals/jnm/2015/451405/ Superparamagnetic iron oxide nanoparticles (SPION) have been widely used in medicine for magnetic resonance imaging, hyperthermia, and drug delivery applications. The effect of SPION on animal cells has been a controversial issue on which there are many contradictions. This study focused on preparation of SPION with novel biocompatible coatings, their characterization, and cytotoxicity evaluation. An amino acid (glycine) and two novel lipo-amino acids (2 amino-hexanoic acid and 2 amino-hexadecanoic acid) coated magnetic nanoparticles were characterized by various physicochemical means such as X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), differential scanning calorimetry (DSC), and infrared spectroscopy (FT-IR). The cytotoxicity profile of the synthesized nanoparticles on Hep-G2 cells as measured by MTT assay showed the nanoparticles are nontoxic and the cell growth is promoted by SPION. Moreover, lipoamino acid coating SPION appear more beneficial than the other ones. By increasing concentration of SPION, growth enhancing impact will attenuate and toxicity will appear. Although the aggregation of SPION can affect the results, the gradual delivery of ferric/ferrous ions into cells is the main cause of this growth promotion effect. Conclusively, this study shows that lipoamino acid coating SPION can be used for various biomedical purposes. Ahmad Gholami, Sara Rasoul-amini, Alireza Ebrahiminezhad, Seyed Hassan Seradj, and Younes Ghasemi Copyright © 2015 Ahmad Gholami et al. All rights reserved. The Effect of Fiber Geometry and Interfacial Properties on the Elastic Properties of Cementitious Nanocomposite Material Tue, 07 Apr 2015 06:53:12 +0000 http://www.hindawi.com/journals/jnm/2015/283579/ This paper investigates the elastic (Young’s) modulus of carbon Nanotube- (CNT-) reinforced cement paste using 3D and axisymmetric models using Abaqus software. The behavior of the CNT and the cement matrix was assumed to be fully elastic while the cohesive surface framework was used to model the interface. To investigate the effect of fiber waviness on the value of the elastic modulus, 3D models were developed assuming different distributions of fibers. The results obtained using the 3D model were compared to those obtained using the simplified three-phase axisymmetric model which consists of one single CNT aligned in the center of composite unit cell, an interface, and cement matrix. A parametric study was then carried out using the axisymmetric model to study the role of the interface in the composite elastic modulus without accounting for the presence of the interfacial transition zone (ITZ or interphase). The results showed that the CNTs waviness significantly reduced their reinforcing capability in the cement paste. On the other hand, the results obtained using the axisymmetric model were found to be in good agreement with those obtained using the 3D model. Moreover, the results of the parametric study showed that the interface properties significantly affect the composite elastic modulus and alter its behavior. Ala G. Abu Taqa, Rashid K. Abu Al-Rub, Ahmed Senouci, Nasser Al-Nuaimi, and Khaldoon A. Bani-Hani Copyright © 2015 Ala G. Abu Taqa et al. All rights reserved. Functionalization of Carbon Nanofibres Obtained by Floating Catalyst Method Mon, 06 Apr 2015 12:12:33 +0000 http://www.hindawi.com/journals/jnm/2015/395014/ The excellent physicochemical and electrical properties of carbon nanofibres (CNF) combined with the possibility of being produced at industrial scale at reasonable costs have promoted the interest in their use in very diverse areas. However, there are still some drawbacks that must be solved in order to optimize their set of properties such as the presence of impurities or the imperfections in the crystalline structure. In this work, different modification treatments of CNFs produced by the floating catalyst method have been studied. Three types of modification processes have been explored that can be grouped as mechanical, thermal, and chemical functionalization processes. Mechanical processing has allowed solving the agglomeration problem related to CNFs produced by floating catalyst method and the resulting modified product ensures the secure handling of carbon nanofibres. Thermal and chemical treatments lead to purer and more crystalline products by removing catalyst impurities and amorphous carbon. Functionalization processes explored in this work open the possibility of customized posttreatment of carbon nanofibres according to the desired requirements. Adolfo Fernández, Pavel Peretyagin, Washington Solís, Ramón Torrecillas, and Amparo Borrell Copyright © 2015 Adolfo Fernández et al. All rights reserved. Nanostructured Multilayer Composite Films of Manganese Dioxide/Nickel/Copper Sulfide Deposited on Polyethylene Terephthalate Supporting Substrate Mon, 06 Apr 2015 10:01:00 +0000 http://www.hindawi.com/journals/jnm/2015/270635/ Nanostructured multilayer manganese dioxide/nickel/copper sulfide (MnO2/Ni/CuS) composite films were successfully deposited onto supporting polyethylene terephthalate (PET) substrate through the sequential deposition of CuS, Ni, and MnO2 thin films by chemical bath deposition, electrodeposition, and horizontal submersion deposition techniques, respectively. Deposition of each thin-film layer was optimized by varying deposition parameters and conditions associated with specific deposition technique. Both CuS and Ni thin films were optimized for their electrical conductivity whereas MnO2 thin film was optimized for its microstructure and charge capacity. The electrochemical properties of nanostructured multilayer MnO2/Ni/CuS composite films were evaluated by cyclic voltammetry as electrode materials of an electrochemical capacitor prototype in a dual-planar device configuration. Cyclic voltammogram in mild Na2SO4 aqueous electrolyte exhibited a featureless and almost rectangular shape which was indicative of the ideal capacitive behavior and high cycling reversibility of the electrochemical capacitor prototype. Nanostructured multilayer MnO2/Ni/CuS composite films on supporting polyethylene terephthalate (PET) substrate could potentially be utilized as electrode materials for the fabrication of high performance electrochemical capacitors. Awangku Nabil Syafiq Bin Awangku Metosen, Suh Cem Pang, and Suk Fun Chin Copyright © 2015 Awangku Nabil Syafiq Bin Awangku Metosen et al. All rights reserved. Modification of PLGA Nanofibrous Mats by Electron Beam Irradiation for Soft Tissue Regeneration Mon, 06 Apr 2015 08:40:33 +0000 http://www.hindawi.com/journals/jnm/2015/295807/ Biodegradable poly(lactide-co-glycolide) (PLGA) has found widespread use in modern medical practice. However, the degradation rate of PLGA should be adjusted for specific biomedical applications such as tissue engineering, drug delivery, and surgical implantation. This study focused on the effect of electron beam radiation on nanofibrous PLGA mats in terms of physical properties and degradation behavior with cell proliferation. PLGA nanofiber mats were prepared by electrospinning, and electron beam was irradiated at doses of 50, 100, 150, 200, 250, and 300 kGy. PLGA mats showed dimensional integrity after electron beam irradiation without change of fiber diameter. The degradation behavior of a control PLGA nanofiber (0 kGy) and electron beam-irradiated PLGA nanofibers was analyzed by measuring the molecular weight, weight loss, change of chemical structure, and fibrous morphology. The molecular weight of the PLGA nanofibers decreased with increasing electron beam radiation dose. The mechanical properties of the PLGA nanofibrous mats were decreased with increasing electron beam irradiation dose. Cell proliferation behavior on all electron beam irradiated PLGA mats was similar to the control PLGA mats. Electron beam irradiation of PLGA nanofibrous mats is a potentially useful approach for modulating the biodegradation rate of tissue-specific nonwoven nanofibrous scaffolds, specifically for soft tissue engineering applications. Jae Baek Lee, Young-Gwang Ko, Donghwan Cho, Won Ho Park, Byeong Nam Kim, Byeong Cheol Lee, Inn-Kyu Kang, and Oh Hyeong Kwon Copyright © 2015 Jae Baek Lee et al. All rights reserved. Low-Temperature Synthesis and Thermodynamic and Electrical Properties of Barium Titanate Nanorods Sun, 05 Apr 2015 16:02:47 +0000 http://www.hindawi.com/journals/jnm/2015/827641/ Studies regarding the morphology dependence of the perovskite-type oxides functional materials properties are of recent interest. With this aim, nanorods (NRs) and nanocubes (NCs) of barium titanate (BaTiO3) have been successfully synthesized via a hydrothermal route at temperature as low as 408 K, employing barium acetate, titanium isopropoxide, and sodium hydroxide as reagents without any surfactant or template. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray powder diffraction (XRD), used for the morphology and structure analyses, showed that the NRs were formed by an oriented attachment of the NCs building-blocks with 20 nm average crystallites size. The thermodynamic properties represented by the relative partial molar free energies, enthalpies, and entropies of the oxygen dissolution in the perovskite phase, as well as the equilibrium partial pressure of oxygen, indicated that NRs powders have lower oxygen vacancies concentration than the NCs. This NRs characteristic, together with higher tetragonallity of the structure, leads to the enhancement of the dielectric properties of BaTiO3 ceramics. The results presented in this work show indubitably the importance of the nanopowders morphology on the material properties. Florentina Maxim, Daniela Berger, Florina Teodorescu, Cristian Hornoiu, Cecilia Lete, and Speranta Tanasescu Copyright © 2015 Florentina Maxim et al. All rights reserved. Development of Drug Loaded Nanoparticles Binding to Hydroxyapatite Based on a Bisphosphonate Modified Nonionic Surfactant Sun, 05 Apr 2015 15:59:52 +0000 http://www.hindawi.com/journals/jnm/2015/393968/ This study aimed at development of drug loaded nanoparticles which could bind to hydroxyapatite (HA) to construct drug or growth factor releasing bone graft substitutes. To this end, the terminal hydroxyl group of a nonionic surfactant Brij 78 (polyoxyethylene (20) stearyl ether) was first modified with pamidronate (Pa). Using Pa-Brij 78 as both a surfactant and an affinity ligand to HA, three different Pa surface functionalized nanoparticles were prepared, named as solid lipid nanoparticles (Pa-SNPs), nanoemulsions (Pa-NEMs), and PLGA nanoparticles (Pa-PNPs). A model drug curcumin was successfully encapsulated in the three nanoparticles. The sizes of Pa-NEM and Pa-PNP were around 150 nm and the size of Pa-SNP was around 90 nm with polydispersity indexes (PDIs) less than 0.20. Drug encapsulation efficiencies of the three nanoparticles were all greater than 85%. Furthermore, the order of binding affinity of the nanoparticles to HA was . After lyophilization, the sizes of the three nanoparticles were increased about 0.5–2.0-fold but their binding affinities to HA were almost the same as the fresh prepared nanoparticles. In conclusion, a Pa-modified Brij 78 was synthesized and used for fabrication of a series of drug loaded nanoparticles to construct drug-eluting HA-based bone graft substitutes. Jiabin Zhang, Xinrong Liu, Tongming Deng, Peng Yao, Heliang Song, Shaobing Zhou, and Weili Yan Copyright © 2015 Jiabin Zhang et al. All rights reserved. Synthesis of Metal Oxide Decorated Polycarboxyphenyl Polymer-Grafted Multiwalled Carbon Nanotube Composites by a Chemical Grafting Approach for Supercapacitor Application Sun, 05 Apr 2015 14:05:51 +0000 http://www.hindawi.com/journals/jnm/2015/535319/ We present grafting of polycarboxyphenyl polymer on the surface of multiwalled carbon nanotube (MWCNT) via a free radical polymerization and subsequent anchoring of the metal oxide nanoparticles for the evaluation of their potential applicability to supercapacitor electrodes. Here, metal oxide nanoparticles, Fe3O4 and Sm2O3, were created after the oxidation of metal precursors Sm(NO3)3 and FeCl2, respectively, and attached on the surface of polycarboxyphenyl-grafted MWCNT (P-CNT) in aqueous medium. This approach shows a potential for enhancing the dispersion of Fe3O4 and Sm2O3 nanoparticles on the wall of P-CNT. The structure and morphological characteristics of the purified MWCNT, P-CNT, and metal oxide-anchored polycarboxyphenyl-grafted MWCNT (MP-CNT) nanocomposites were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The electrochemical performance of the purified MWCNT electrode, P-CNT electrode, and MP-CNT electrodes was tested by cyclic voltammetry (CV) and galvanostatic charge discharge in a 1.0 M H2SO4 aqueous electrolyte. The results showed that the specific capacitance of the purified MWCNT was 45.3 F/g at the scan rate of 5 mV/s and increased to 54.1 F/g after the modification with polycarboxyphenyl polymer. Further modification of P-CNT with Sm2O3 and Fe3O4 improved the specific capacitance of 65.84 F/g and 173.38 F/g, respectively, at the same scan rate. Do-Yeon Kang, Pashupati Pokharel, Yeong-Seok Kim, Sunwoong Choi, and Seong-Ho Choi Copyright © 2015 Do-Yeon Kang et al. All rights reserved. Performance of the Chemical and Electrochemical Composites of PPy/CNT as Electrodes in Type I Supercapacitors Sun, 05 Apr 2015 07:00:37 +0000 http://www.hindawi.com/journals/jnm/2015/560164/ Polypyrrole (PPy) is one of the most studied conducting polymers and a very promising material for various applications such as lithium-ion secondary batteries, light-emitting devices, capacitors, and supercapacitors, owing to its many advantages, including good processability, easy handling, and high electronic conductivity. In this work, PPy films were chemically and electrochemically synthesized, both in and around carbon nanotubes (CNTs). The cyclic voltammograms of the device, composed of the electrochemically synthesized PPy/CNT composites as working and counter electrodes (Type I supercapacitor with p-type doping), showed a predominantly capacitive profile with low impedance values and good electrochemical stability, with the anodic charge remaining almost constant (11.38 mC), a specific capacitance value of 530 F g−1 after 50 charge and discharge cycles, and a coulombic efficiency of 99.2%. The electrochemically synthesized PPy/CNT composite exhibited better electrochemical properties compared to those obtained for the chemically synthesized composite. Thus, the electrochemically synthesized PPy/CNT composite is a promising material to be used as electrodes in Type I supercapacitors. S. C. Canobre, F. F. S. Xavier, W. S. Fagundes, A. C. de Freitas, and F. A. Amaral Copyright © 2015 S. C. Canobre et al. All rights reserved. A Biomimic Reconstituted High Density Lipoprotein Nanosystem for Enhanced VEGF Gene Therapy of Myocardial Ischemia Thu, 02 Apr 2015 18:20:53 +0000 http://www.hindawi.com/journals/jnm/2015/693234/ A biomimic reconstituted high density lipoprotein (rHDL) based system, rHDL/Stearic-PEI/VEGF complexes, was fabricated as an advanced nanovector for delivering VEGF plasmid. Here, Stearic-PEI was utilized to effectively condense VEGF plasmid and to incorporate the plasmid into rHDL. The rHDL/Stearic-PEI/VEGF complexes with diameter under 100 nm and neutral surface charge demonstrated enhanced stability under the presence of bovine serum albumin. Moreover, in vitro cytotoxicity and transfection assays on H9C2 cells further revealed their superiority, as they displayed lower cytotoxicity with much higher transfection efficiency when compared to PEI 10K/VEGF and Lipos/Stearic-PEI/VEGF complexes. In addition, in vivo investigation on ischemia/reperfusion rat model implied that rHDL/Stearic-PEI/VEGF complexes possessed high transgene capacity and strong therapeutic activity. These findings indicated that rHDL/Stearic-PEI/VEGF complexes could be an ideal gene delivery system for enhanced VEGF gene therapy of myocardial ischemia, which might be a new promising strategy for effective myocardial ischemia treatment. Xiaotian Sun, Wenshuo Wang, Jiechun Huang, Hao Lai, Changfa Guo, and Chunsheng Wang Copyright © 2015 Xiaotian Sun et al. All rights reserved. Preparation and Photocatalytic Activity of TiO2/Fine Char for Removal of Rhodamine B Thu, 02 Apr 2015 14:11:12 +0000 http://www.hindawi.com/journals/jnm/2015/538275/ TiO2/fine char (FC) photocatalyst was prepared via sol-gel method with tetrabutyl titanate as the precursor and FC as the carrier. The structural property of TiO2/FC photocatalyst was investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the photocatalytic activity of TiO2/FC was evaluated by photocatalytic degradation of rhodamine B (RhB) aqueous solution under UV light irradiation. The results showed that TiO2 was successfully coated on the surface of FC, and the TiO2/FC photocatalyst had better photocatalytic efficiency and stability for degradation of RhB under UV light illumination as compared to that of the pure TiO2 and FC. The study provided a novel way for the application of FC to the photocatalytic degradation of organic wastes. Mingjie Ma, Weijie Guo, Zhengpeng Yang, Shanxiu Huang, and Guanyu Wang Copyright © 2015 Mingjie Ma et al. All rights reserved.