Journal of Nanotechnology The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Metal Oxide Nanostructures: Synthesis, Properties, and Applications Mon, 05 Oct 2015 13:06:39 +0000 Lin-Hua Xu, Dnyaneshwar S. Patil, Jiazhi Yang, and Jingzhong Xiao Copyright © 2015 Lin-Hua Xu et al. All rights reserved. Preparation of ZnO/CdS/BC Photocatalyst Hybrid Fiber and Research of Its Photocatalytic Properties Thu, 01 Oct 2015 12:14:00 +0000 An environment-friendly biomaterial bacterial cellulose (BC) is introduced to substitute general organic polymers to assist the preparation of ZnO/CdS/BC photocatalyst hybrid nanofiber through coprecipitation method under the low-temperature condition. The XRD, XPS, and SEM results show that high load of ZnO/CdS/BC ternary hybrid fiber can be produced. TGA curves scan shows that ZnO/CdS/BC hybrid fiber has better thermal properties than bacterial cellulose. The UV-Vis spectra of the ZnO/CdS/BC hybrid nanofiber (0, 10, 20, and 50 wt%, resp.) show that photocatalytic activities of ZnO/CdS/BC are influenced by the added amount of CdS. The degradation curve of methyl shows that ZnO/CdS/BC nanohybrid fibers exhibit excellent photocatalytic efficiency. Beibei Dai, Cheng Chao, Xiaoyu Lu, Qingcheng Xia, Jing Han, Fei Mao, Jiazhi Yang, and Dongping Sun Copyright © 2015 Beibei Dai et al. All rights reserved. Comparing and Optimizing Nitrate Adsorption from Aqueous Solution Using Fe/Pt Bimetallic Nanoparticles and Anion Exchange Resins Thu, 01 Oct 2015 12:13:05 +0000 This research work was carried out for the removal of nitrate from raw water for a drinking water supply. Nitrate is a widespread ground water contaminant. Methodology employed in this study included adsorption on metal based nanoparticles and ion exchange using anionic resins. Fe/Pt bimetallic nanoparticles were prepared in the laboratory, by the reduction of their respective salts using sodium borohydride. Scanning electron microscope, X-ray diffraction, energy dispersive spectrometry, and X-ray florescence techniques were utilized for characterization of bimetallic Fe/Pt nanoparticles. Optimum dose, pH, temperature, and contact time were determined for removal through batch tests, both for metal based nanoparticles and anionic exchange resin. Adsorption data fitted well the Langmuir isotherm and conformed to the pseudofirst-order kinetic model. Results indicated 97% reduction in nitrate by 0.25 mg/L of Fe/Pt nanoparticles at pH 7 and 83% reduction in nitrate was observed using 0.50 mg/L anionic exchange resins at pH 4 and contact time of one hour. Overall, Fe/Pt bimetallic nanoparticles demonstrated greater removal efficiency due to the small particle size, extremely large surface area (627 m2/g), and high adsorption capacity. Muhammad Daud, Zahiruddin Khan, Aisha Ashgar, M. Ihsan Danish, and Ishtiaq A. Qazi Copyright © 2015 Muhammad Daud et al. All rights reserved. Analysis of Thermal Properties on Backward Feed Multieffect Distillation Dealing with High-Salinity Wastewater Thu, 01 Oct 2015 12:12:16 +0000 Theoretical investigations on thermal properties of multieffect distillation (MED) are presented to approach lower capital costs and more distillated products. A mathematical model, based on the energy and mass balance, is developed to (i) evaluate the influences of variations in key parameters (effect numbers, evaporation temperature in last effect, and feed salinity) on steam consumption, gained output ratio (GOR), and total heat transfer areas of MED and (ii) compare two operation modes (backward feed (BF) and forward feed (FF) systems). The result in the first part indicated that GOR and total heat transfer areas increased with the effect numbers. Also, higher effect numbers result in the fact that the evaporation temperature in last effect has slight influence on GOR, while it influences the total heat transfer areas remarkably. In addition, an increase of feed salinity promotes the total heat transfer areas but reduces GOR. The analyses in the second part indicate that GOR and total heat transfer areas of BF system are higher than those in FF system. One thing to be aware of is that the changes of steam consumption can be omitted, considering that it shows an opposite trend to GOR. Jianliang Xue, Qinqin Cui, Jie Ming, Yu Bai, and Lin Li Copyright © 2015 Jianliang Xue et al. All rights reserved. Iron Contamination Mechanism and Reaction Performance Research on FCC Catalyst Thu, 01 Oct 2015 12:11:28 +0000 FCC (Fluid Catalytic Cracking) catalyst iron poisoning would not only influence units’ product slate; when the poisoning is serious, it could also jeopardize FCC catalysts’ fluidization in reaction-regeneration system and further cause bad influences on units’ stable operation. Under catalytic cracking reaction conditions, large amount of iron nanonodules is formed on the seriously iron contaminated catalyst due to exothermic reaction. These nodules intensify the attrition between catalyst particles and generate plenty of fines which severely influence units’ smooth running. A dense layer could be formed on the catalysts’ surface after iron contamination and the dense layer stops reactants to diffuse to inner structures of catalyst. This causes extremely negative effects on catalyst’s heavy oil conversion ability and could greatly cut down gasoline yield while increasing yields of dry gas, coke, and slurry largely. Research shows that catalyst’s reaction performance would be severely deteriorated when iron content in E-cat (equilibrium catalyst) exceeds 8000 μg/g. Zhaoyong Liu, Zhongdong Zhang, Pusheng Liu, Jianing Zhai, and Chaohe Yang Copyright © 2015 Zhaoyong Liu et al. All rights reserved. Growth Mechanisms of Nanostructured Titania in Turbulent Reacting Flows Thu, 01 Oct 2015 11:52:35 +0000 Titanium dioxide (titania) is used in chemical sensors, pigments, and paints and holds promise as an antimicrobial agent. This is due to its photoinduced activity and, in nanostructured form, its high specific surface area. Particle size and surface area result from the interplay of fluid, chemical, and thermal dynamics as well as nucleation, condensation and coagulation. After nucleation, condensation, and coagulation are the dominant phenomena affecting the particle size distribution. Manufacture of nanostructured titania via gas-phase synthesis often occurs under turbulent flow conditions. This study examines the competition between coagulation and condensation in the growth of nanostructured titania. Direct numerical simulation is utilized in simulating the hydrolysis of titanium tetrachloride to produce titania in a turbulent, planar jet. The fluid, chemical, and particle fields are resolved as a function of space and time. As a result, knowledge of titania is available as a function of space, time, and phase (vapor or particle), facilitating the analysis of the particle dynamics by mechanism. Results show that in the proximal region of the jet nucleation and condensation are the dominant mechanisms. However once the jet potential core collapses and turbulent mixing begins, coagulation is the dominant mechanism. The data also shows that the coagulation growth-rate is as much as twice the condensation growth-rate. Sean C. Garrick Copyright © 2015 Sean C. Garrick. All rights reserved. Experimental Assessment of Water Sprays Utilization for Controlling Hydrogen Sulfide Releases in Confined Space Thu, 01 Oct 2015 08:41:22 +0000 This paper reported the utilization of water spray for controlling H2S release in a confined space, which is especially important in industry. A typical spray tower was modified to simulate the confined space for people's enterable routine operation (e.g., pump room), in which the dilution capacity of water sprays can also be evaluated. This work consists of two parts: the first part focuses on the influences of different operating conditions on chemical dilution capacities of water sprays in mechanisms; the second one is comparison between two nozzle configurations for evaluating their feasibilities of practical application. Water sprays express eligible performance for H2S release control even though their dilution capacity was weakened at high gaseous concentrations and rates of releases. The presence of Na2CO3 can significantly improve absorption effectiveness of H2S in water and the optimal Na2CO3 additive was found to be 1.0 g·L−1 in this test. Compared with Na2CO3, adjusting water flow rate may be an effective strategy in enhancing dilution capacity of water sprays due to the fact that larger flow rate led to both less dilution time (TD) and dilution concentration (CD). Furthermore, multinozzle configuration is more efficient than single-nozzle configuration under the same water consumption. Dongfeng Zhao, Chao Li, Jun Liu, Guoying Zhou, Qingdong Zhang, and Chunshuang Liu Copyright © 2015 Dongfeng Zhao et al. All rights reserved. Synthesis and Application of Magnetic Photocatalyst of Ni-Zn Ferrite/TiO2 from IC Lead Frame Scraps Thu, 01 Oct 2015 08:38:46 +0000 IC lead frame scraps with about 18.01% tin, 34.33% nickel, and 47.66% iron in composition are industrial wastes of IC lead frame production. The amount of thousand tons of frame scraps in Taiwan each year is treated as scrap irons. Ni-Zn ferrites used in high frequent inductors and filters are produced from Ni-Zn ferrite powders by pressing and sintering. The amount of several ten thousand tons of ferrites of in compositions is consumed annually in the whole world. Therefore, these IC lead frame scraps will be used in this research as raw materials to fabricate magnetic ferrite powders and combined subsequently with titanium sulfate and urea to produce magnetic photocatalysts by coprecipitation for effective waste utilization. The prepared Ni-Zn ferrite powder and magnetic photocatalyst (Ni-Zn ferrite/TiO2) were characterized by ICP, XRF, XRD, EDX, SEM, SQUID, and BET. The photocatalytic activity of synthesized magnetic photocatalysts was tested by FBL dye wastewater degradation. TOC and ADMI measurement for degradation studies were carried out, respectively. Langmuir-Hinshelwood kinetic model of the prepared magnetic TiO2 proved available for the treatments. Wastes are transformed to valuable magnetic photocatalysts in this research to solve the separation problem of wastewater and TiO2 photocatalysts by magnetic field. Robert Liu and H. T. Ou Copyright © 2015 Robert Liu and H. T. Ou. All rights reserved. Influence of OH− Ion Concentration on the Surface Morphology of ZnO-SiO2 Nanostructure Thu, 01 Oct 2015 08:37:37 +0000 The influence of varying OH− ion concentration on the surface morphology of chemically deposited ZnO-SiO2 nanostructures on glass substrate was investigated. The morphological features, phase structure, and infrared characteristics were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR), respectively. Results revealed that silica significantly changes the hexagonal morphology of bare ZnO rod to “pointed tips” when using low initial OH− precursor concentration. Increasing OH− ion concentration resulted in a “flower-like” formation of ZnO-SiO2 and a remarkable change from “pointed tips” to “hemispherical tips” at the top surface of the rods. The surface capping of SiO2 to ZnO leads to the formation of these “hemispherical tips.” The infrared spectroscopic analysis showed the characteristics peaks of ZnO and SiO2 as well as the Si-O-Zn band which confirms the formation of ZnO-SiO2. Phase analysis manifested that the formed ZnO-SiO2 is of wurtzite structure. Furthermore, a possible growth mechanism is proposed based on the obtained results. Jessica Ven G. Tinio, Key T. Simfroso, Amber Dea Marie V. Peguit, and Rolando T. Candidato Jr. Copyright © 2015 Jessica Ven G. Tinio et al. All rights reserved. Silica Sol-Gel Entrapment of the Enzyme Chloroperoxidase Thu, 01 Oct 2015 08:33:22 +0000 The enzyme chloroperoxidase (CPO) was immobilized in silica sol-gel beads prepared from tetramethoxysilane. The average pore diameter of the silica host structure (~3 nm) was smaller than the globular CPO diameter (~6 nm) and the enzyme remained entrapped after sol-gel maturation. The catalytic performance of the entrapped enzyme was assessed via the pyrogallol peroxidation reaction. Sol-gel beads loaded with 4 μg CPO per mL sol solution reached 9–12% relative activity compared to free CPO in solution. Enzyme kinetic analysis revealed a decrease in but no changes in or . Product release or enzyme damage might thus limit catalytic performance. Yet circular dichroism and visible absorption spectra of transparent CPO sol-gel sheets did not indicate enzyme damage. Activity decline due to methanol exposure was shown to be reversible in solution. To improve catalytic performance the sol-gel protocol was modified. The incorporation of 5, 20, or 40% methyltrimethoxysilane resulted in more brittle sol-gel beads but the catalytic performance increased to 14% relative to free CPO in solution. The use of more acidic casting buffers (pH 4.5 or 5.5 instead of 6.5) resulted in a more porous silica host reaching up to 18% relative activity. Tuan Le, Selina Chan, Bassem Ebaid, and Monika Sommerhalter Copyright © 2015 Tuan Le et al. All rights reserved. TiO2 Nanocatalysts Supported on a Hybrid Carbon-Covered Alumina Support: Comparison between Visible Light and UV Light Degradation of Rhodamine B Thu, 01 Oct 2015 07:03:22 +0000 Titania nanoparticles were successfully supported on carbon-covered alumina (CCA) supports via the impregnation method to form carbon-covered alumna titania (CCA/TiO2). The CCA supports were synthesised through an equilibrium adsorption of toluene 2,4-diisocyante where the N=C=O irreversibly adsorbs on the alumina and pyrolysis at 700°C affords CCA supports. These CCA/TiO2 nanocatalysts were tested for their photocatalytic activity both under UV and visible light using Rhodamine B as a model pollutant. The reaction rate constant of the CCA/TiO2 was found to be higher than that of unsupported titania and the reaction kinetics were found to follow an apparent first-order rate law. The CCA/TiO2 nanocatalysts had a much larger surface area than the unsupported titania and they exhibited overall higher photodegradation efficiency under both UV and visible light than unsupported TiO2. Mphilisi M. Mahlambi, Ajay K. Mishra, Shivani B. Mishra, Rui W. Krause, Bhekie B. Mamba, and Ashok M. Raichur Copyright © 2015 Mphilisi M. Mahlambi et al. All rights reserved. Influence of Parameters of a Printing Plate on Photoluminescence of Nanophotonic Printed Elements of Novel Packaging Tue, 25 Aug 2015 12:26:38 +0000 In order to produce nanophotonic elements for smart packaging, we investigated the influence of the parameters of screen and offset gravure printing plates on features of printed application of coatings with nanophotonic components and on parameters of their photoluminescence. To determine the dependence of luminescence intensity on the thickness of solid coating, we carried out the formation of nanophotonic solid surfaces by means of screen printing with different layer thickness on polypropylene film. The obtained analytical dependencies were used to confirm the explanation of the processes that occur during the fabrication of nanophotonic coverings with offset gravure printing plates. As a result of experimental studies, it was determined that the different character of the dependency of total luminescence intensity of nanophotonic elements from the percentage of a pad is explained by the use of different types of offset gravure printing plates, where the size of raster points remains constant in one case and changes in the other case, while the depth of the printing elements accordingly changes or remains constant. To obtain nanophotonic areas with predetermined photoluminescent properties, the influence of investigated factors on changes of photoluminescent properties of nanophotonic printed surfaces should be taken into consideration. Olha Sarapulova and Valentyn Sherstiuk Copyright © 2015 Olha Sarapulova and Valentyn Sherstiuk. All rights reserved. Fabrication of Patterned Integrated Electrochemical Sensors Wed, 05 Aug 2015 09:41:58 +0000 Fabrication of integrated electrochemical sensors is an important step towards realizing fully integrated and truly wireless platforms for many local, real-time sensing applications. Micro/nanoscale patterning of small area electrochemical sensor surfaces enhances the sensor performance to overcome the limitations resulting from their small surface area and thus is the key to the successful miniaturization of integrated platforms. We have demonstrated the microfabrication of electrochemical sensors utilizing top-down lithography and etching techniques on silicon and CMOS substrates. This choice of fabrication avoids the need of bottom-up techniques that are not compatible with established methods for fabricating electronics (e.g., CMOS) which form the industrial basis of most integrated microsystems. We present the results of applying microfabricated sensors to various measurement problems, with special attention to their use for continuous DNA and glucose sensing. Our results demonstrate the advantages of using micro- and nanofabrication techniques for the miniaturization and optimization of modern sensing platforms that employ well-established electronic measurement techniques. Muhammad Mujeeb-U-Rahman, Dvin Adalian, and Axel Scherer Copyright © 2015 Muhammad Mujeeb-U-Rahman et al. All rights reserved. Solvent-Free MgO-Functionalized Mesoporous Catalysts for Jatropha Oil Transesterification Sun, 07 Jun 2015 06:58:12 +0000 A convenient solvent-free technique was employed in the functionalization of Micelle-Templated Silica using Cashew Nut Shell Liquid (MTS-CNSL) as a template and magnesium nitrate as a precursor salt. Magnesium oxide species was highly dispersed in MTS-CNSL by manually grinding the precursor salt and the as-synthesized mesoporous silica followed by calcination. The resultant modified mesoporous silicas MgO/MTS-CNSL were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR, N2 adsorption/desorption), and scanning electron microscopy/energy dispersive X-ray (SEM/EDX). MgO/MTS-CNSL (30) having small specific surface area of 16.7 m2/g and larger pore volume of 0.02 cm3/g, presented higher activity of 81.45% for jatropha oil under optimized conditions (200°C, 4 h, 36 : 1 methanol : oil ratio, 500 rpm, and 6% wt of catalyst). This method of catalyst development has an advantage of being highly energy- and time-efficient. Anamagreth Andrew, Jamidu Katima, Keat Teong Lee, and James Epiphan Gabriel Mdoe Copyright © 2015 Anamagreth Andrew et al. All rights reserved. Particle Size Affects Concentration-Dependent Cytotoxicity of Chitosan Nanoparticles towards Mouse Hematopoietic Stem Cells Wed, 15 Apr 2015 13:05:19 +0000 Chitosan nanoparticles (CSNPs) have been extensively applied in medical and pharmaceutical fields as promising drug delivery systems. Despite that, the safety of CSNPs remains inadequate and needs further investigation, particularly on hematopoietic stem cells (HSCs). CSNPs were prepared by ionic gelation method and later were characterized for their physical characteristics (particle size and zeta potential). Cytotoxicity of CSNPs was assessed by MTT assay. Particle size was highly influenced by chitosan concentration and molecular weight (medium and high molecular weight (MMW and HMW)). Higher chitosan concentration and molecular weight produced larger nanoparticles. Zeta potential of CSNPs was not significantly affected by chitosan concentrations and molecular weights used in the present study. MMW had a better stability than HMW CSNPs as their particle size and zeta potential were not significantly altered after autoclaving. Cytotoxicity of CSNPs was influenced by zeta potential and particle size. On the other hand, chitosan concentration and molecular weight indirectly influenced cytotoxicity by affecting particle size and zeta potential of CSNPs. In conclusion, cytotoxicity of CSNPs was mainly attributed to their physical characteristics and this opens a strategy to ensure the safety of CSNPs applications in stem cell technology. Siti Sarah Omar Zaki, Mohd Nazmi Ibrahim, and Haliza Katas Copyright © 2015 Siti Sarah Omar Zaki et al. All rights reserved. and Relaxivities of Dendrons Based on a OEG-DTPA Architecture: Effect of Gd3+ Placement and Dendron Functionalization Sun, 22 Mar 2015 12:38:48 +0000 In magnetic resonance imaging, contrast agents are employed to enhance the signal intensity. However, current commercial contrast agents are hindered by a low relaxivity constant. Dendrimers can be employed to create higher molecular weight contrast agents which have an increased relaxivity due to a lower molecular rotation. In this study, dendrimers containing DTPA derivatives as cores and/or branching units were used to chelate gadolinium ions. Locating the gadolinium ions inside the dendrimers results in higher relaxivity constants, possibly because the paramagnetic center is closer to the rotational axis of the macromolecule. The highest gain in relaxivity was produced by decorating the dendron surface with peptide sequences, which could be explained by the presence of more second-sphere water molecules attracted by the peptides. These findings could contribute to the development of more effective contrast agents, either by placing the paramagnetic gadolinium ion in a strategic position or through functionalization of the dendron surface. Peter Fransen, Daniel Pulido, Lorena Simón-Gracia, Ana Paula Candiota, Carles Arús, Fernando Albericio, and Miriam Royo Copyright © 2015 Peter Fransen et al. All rights reserved. Enhanced Photocatalytic Performance of NiO-Decorated ZnO Nanowhiskers for Methylene Blue Degradation Tue, 25 Nov 2014 16:32:24 +0000 ZnO nanowhiskers were used for photodecomposition of methylene blue in aqueous solution under UV irradiation. The rate of methylene blue degradation increased linearly with time of UV irradiation. 54% of degradation rate was observed when the ZnO nanowhiskers were used as photocatalysts for methylene blue degradation for 80 min under UV irradiation. The decoration of p-type NiO nanoparticles on n-type ZnO nanowhiskers significantly enhanced photocatalytic activity and reached 72% degradation rate of methylene blue by using the same method. NiO-decorated ZnO was recycled for second test and shows 66% degradation from maximal peak of methylene blue within the same period. The increment of photocatalytic activity of NiO-decorated ZnO nanowhiskers was explained by the extension of the electron depletion layer due to the formation of nanoscale p-n junctions between p-type NiO and n-type ZnO. Hence, these products provide new alternative proficient photocatalysts for wastewater treatment. I. Abdul Rahman, M. T. M. Ayob, and S. Radiman Copyright © 2014 I. Abdul Rahman et al. All rights reserved. Visible Discrimination of Broadband Infrared Light by Dye-Enhanced Upconversion in Lanthanide-Doped Nanocrystals Sun, 23 Nov 2014 07:20:26 +0000 Optical upconversion of near infrared light to visible light is an attractive way to capture the optical energy or optical information contained in low-energy photons that is otherwise lost to the human eye or to certain photodetectors and solar cells. Until the recent application of broadband absorbing optical antennas, upconversion efficiency in lanthanide-doped nanocrystals was limited by the weak, narrow atomic absorption of a handful of sensitizer elements. In this work, we extend the role of the optical antenna to provide false-color, visible discrimination between bands of infrared radiation. By pairing different optical antenna dyes to specific nanoparticle compositions, unique visible emission is associated with different bands of infrared excitation. In one material set, the peak emission was increased 10-fold, and the width of the spectral response was increased more than 10-fold. Charles G. Dupuy, Thomas L. Allen, George M. Williams, and David Schut Copyright © 2014 Charles G. Dupuy et al. All rights reserved. Organic Nanovesicular Cargoes for Sustained Drug Delivery: Synthesis, Vesicle Formation, Controlling “Pearling” States, and Terfenadine Loading/Release Studies Tue, 12 Aug 2014 13:14:34 +0000 “Sustained drug delivery systems” which are designed to accomplish long-lasting therapeutic effect are one of the challenging topics in the area of nanomedicine. We developed an innovative strategy to prepare nontoxic and polymer stabilized organic nanovesicles (diameter: 200 nm) from a novel bolaamphiphile, where two hydrogen bonding acetyl cytosine molecules connected to 4,4′′-positions of the 2,6-bispyrazolylpyridine through two flexible octyne chains. The nanovesicles behave like biological membrane by spontaneously self-assembling into “pearl-like” chains and subsequently forming long nanotubes (diameter: 150 nm), which further develop into various types of network-junctions through self-organization. For drug loading and delivery applications, the nanovesicles were externally protected with biocompatible poly(ethyleneglycol)-2000 to prevent them from fusion and ensuing tube formation. Nontoxic nature of the nanovesicles was demonstrated by zebrafish teratogenicity assay. Biocompatible nanovesicles were loaded with “terfenadine” drug and successfully utilized to transport and release drug in sustained manner (up to 72 h) in zebrafish larvae, which is recognized as an emerging in vivo model system. Ajay Kumar Botcha, Balakrishna Dulla, E. Ramanjaneya Reddy, Keerthana S. Chennubhotla, Pushkar Kulkarni, Rajadurai Chandrasekar, and Marina S. Rajadurai Copyright © 2014 Ajay Kumar Botcha et al. All rights reserved. Study of the Thermal Decomposition of PFPEs Lubricants on a Thin DLC Film Using Finitely Extensible Nonlinear Elastic Potential Based Molecular Dynamics Simulation Sun, 06 Jul 2014 10:07:33 +0000 Perfluoropolyethers (PFPEs) are widely used as hard disk lubricants for protecting carbon overcoat reducing friction between the hard disk interface and the head during the movement of head during reading and writing data in the hard disk. Due to temperature rise of PFPE Zdol lubricant molecules on a DLC surface, how polar end groups are detached from lubricant molecules during coating is described considering the effect of temperatures on the bond/break density of PFPE Zdol using the coarse-grained bead spring model based on finitely extensible nonlinear elastic potential. As PFPE Z contains no polar end groups, effects of temperature on the bond/break density (number of broken bonds/total number of bonds) are not so significant like PFPE Zdol. Effects of temperature on the bond/break density of PFPE Z on DLC surface are also discussed with the help of graphical results. How bond/break phenomenonaffects the end bead density of PFPE Z and PFPE Zdol on DLC surface is discussed elaborately. How the overall bond length of PFPE Zdol increases with the increase of temperature which is responsible for its decomposition is discussed with the help of graphical results. At HAMR condition, as PFPE Z and PFPE Zdol are not suitable lubricant on a hard disk surface, it needs more investigations to obtain suitable lubricant. We study the effect of breaking of bonds of nonfunctional lubricant PFPE Z, functional lubricants such as PFPE Zdol and PFPE Ztetrao, and multidented functional lubricants such as ARJ-DS, ARJ-DD, and OHJ-DS on a DLC substrate with the increase of temperature when heating of all of the lubricants on a DLC substrate is carried out isothermally using the coarse-grained bead spring model by molecular dynamics simulations and suitable lubricant is selected which is suitable on a DLC substrate at high temperature. S. K. Deb Nath and C. H. Wong Copyright © 2014 S. K. Deb Nath and C. H. Wong. All rights reserved. Impact of Bundle Structure on Performance of on-Chip CNT Interconnects Thu, 05 Jun 2014 08:46:41 +0000 CNTs are proposed as a promising candidate against copper in deep submicron IC interconnects. Still this technology is in its infancy. Most available literatures on performance predictions of CNT interconnects, have focused only on interconnect geometries using segregated CNTs. Yet during the manufacturing phase, CNTs are obtained usually as a mixture of single-walled and multi-walled CNTs (SWCNTs and MWCNTs). Especially in case of SWCNTs; it is usually available as a mixture of both Semi conducting CNTs and metallic CNTs. This paper attempts to answer whether segregation is inevitable before using them to construct interconnects. This paper attempt to compare the performance variations of bundled CNT interconnects, where bundles are made of segregated CNTs versus mixed CNTs, for future technology nodes using electrical model based analysis. Also a proportionate mixing of different CNTs has been introduced so as to yield a set of criteria to aid the industry in selection of an appropriate bundle structure for use in a specific application with optimum performance. It was found that even the worst case performance of geometries using a mixture of SWCNTs and MWCNTs was better than copper. These results also reveal that, for extracting optimum performance vide cost matrix, the focus should be more on diameter controlled synthesis than on segregation. Nisha Kuruvilla and J. P. Raina Copyright © 2014 Nisha Kuruvilla and J. P. Raina. All rights reserved. Catalytic Chemical Vapor Deposition of Methane to Carbon Nanotubes: Copper Promoted Effect of Ni/MgO Catalysts Wed, 04 Jun 2014 13:10:25 +0000 The Ni/MgO and Ni-Cu/MgO catalysts were prepared by sol-gel method and used as the catalysts for synthesis of carbon nanotubes by thermal chemical vapor deposition. The effect of Cu on the carbon yield and structure was investigated, and the effects of calcination temperature and reaction temperature were also investigated. The catalysts and synthesized carbon materials were characterized by temperature programmed reduction (TPR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Results showed that the addition of Cu promoted the reduction of nickel species, subsequently improving the growth and yield of CNTs. Meanwhile, CNTs were synthesized by the Ni/MgO and Ni-Cu/MgO catalysts with various calcination temperatures and reaction temperatures, and results suggested that the obtained CNTs on Ni-Cu/MgO catalyst with the calcination temperature of 500°C and the reaction temperature of 650°C were of the greatest yield and quantity of 927%. Wen Yang, Yanyan Feng, and Wei Chu Copyright © 2014 Wen Yang et al. All rights reserved. Properties of Electrospun TiO2 Nanofibers Tue, 03 Jun 2014 12:47:37 +0000 Titanium oxide filled polyvinylpyrrolidone (PVP) composite nanofibers have been prepared via a simple electrospinning technique. The combination of good TiO2 properties with its high surface area leads these nanofibers into having a vast applicability such as cosmetics, scaffolds for tissue engineering, catalytic devices, sensors, solar cells, and optoelectronic devices. The structural and chemical properties of the prepared samples have been studied. The presence of the TiO2 phase on the nanofibers was confirmed. An anatase to rutile transformation was observed at 600°C. Regarding the thermogravimetric and differential thermal analysis (TGA/DTA), the TIP decomposition and the PVP evaporation at 225°C were verified. Bianca Caratão, Edgar Carneiro, Pedro Sá, Bernardo Almeida, and Sandra Carvalho Copyright © 2014 Bianca Caratão et al. All rights reserved. Synthesis of Nanocrystalline MgO Particles by Combustion Followed by Annealing Method Using Hexamine as a Fuel Tue, 03 Jun 2014 12:02:29 +0000 In this work, nanocrystalline MgO particles were prepared through combustion method using magnesium nitrate as oxidizer and hexamine as a fuel. The materials obtained by combustion method were subsequently annealed at for 3 h to improve the crystallinity and phase purity. The obtained MgO nanomaterials were characterized by powder X-ray diffraction analysis (XRD), infrared (IR) spectroscopy, photoluminescence (PL), near-infrared (NIR) spectroscopy, and scanning electron microscopy (SEM). The cubic crystal structure with lattice parameter, a = 0.4210(4) nm with average crystalline size of 22 nm, is obtained for the nano-MgO particles. The PL emission spectrum of nanocrystalline MgO materials exhibits three emission peaks at 432, 465, and 495 nm which are due to various structural defects. The SEM results expose the fact that the MgO nanomaterials are seemingly porous and highly agglomerated with fine particles. Owing to the higher reflectance of prepared nanocrystalline MgO, it can be used as NIR reflective pigments. The present results prove that the combustion technique using hexamine can produce the materials with high crystallinity. To the best of our knowledge, this is the first report on the synthesis of nanocrystalline MgO materials by combustion method using hexamine as a fuel. S. Balamurugan, L. Ashna, and P. Parthiban Copyright © 2014 S. Balamurugan et al. All rights reserved. Graphene-Multiwalled Carbon Nanotube Hybrids Synthesized by Gamma Radiations: Application as a Glucose Sensor Sun, 01 Jun 2014 11:24:58 +0000 Three-dimensional hybrid nanomaterial of graphene-multiwalled carbon nanotubes (G-MWCNTs) was synthesized using gamma rays emitted by a 60Co source with a dose rate of 3.95 Gy min−1. The products were characterized by fourier transform infrared (FTIR), ultraviolet-visible (UV-Vis), photoluminescence (PL), and micro-Raman spectroscopy, X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). FTIR and UV-Vis analysis reveals the formation of hybrid nanomaterial which is confirmed by XRD, micro-Raman analysis, and PL. SEM micrograph depicts the composite structure of graphene layers and MWCNTs, while the TEM micrograph exhibits graphene layers covered by MWCNTs. The G-MWCNTs hybrid used as electrode for electrochemical studies in K3Fe(CN)6 shows enhancement in electrocatalytic behavior, compared to each individual starting material, therefore, has been applied for amperometric sensing of glucose in alkaline solution and exhibits sensitivity of 12.5 AmM-1 cm−2 and low detection limit 1.45 M () in a linear range of 0.1 to 14 mM (). Leila Shahriary, Hedayatollah Ghourchian, and Anjali A. Athawale Copyright © 2014 Leila Shahriary et al. All rights reserved. Controlled Synthesis of Gold Nanoparticles Using Aspergillus terreus IF0 and Its Antibacterial Potential against Gram Negative Pathogenic Bacteria Thu, 29 May 2014 00:00:00 +0000 Biosynthesis of monodispersed nanoparticles, along with determination of potential responsible biomolecules, is the major bottleneck in the area of bionanotechnology research. The present study focuses on an ecofriendly, ambient temperature protocol for size controlled synthesis of gold nanoparticles, using the fungus Aspergillus terreus IF0. Gold nanoparticles were formed immediately, with the addition of chloroauric acid to the aqueous fungal extract. Synthesized nanoparticles were characterized by UV-Vis spectroscopy, TEM-EDX, and XRD analysis. Particle diameter and dispersity of nanoparticles were controlled by varying the pH of the fungal extract. At pH 10, the average size of the synthesized particles was in the range of 10–19 nm. Dialysis to obtain high and low molecular weight fraction followed by FTIR analysis revealed that biomolecules larger than 12 kDa and having –CH, –NH, and –SH functional groups were responsible for bioreduction and stabilization. In addition, the synthesized gold nanoparticles were found to be selectively bactericidal against the pathogenic gram negative bacteria, Escherichia coli. Eepsita Priyadarshini, Nilotpala Pradhan, Lala B. Sukla, and Prasanna K. Panda Copyright © 2014 Eepsita Priyadarshini et al. All rights reserved. Binder Free SnO2-CNT Composite as Anode Material for Li-Ion Battery Sun, 25 May 2014 11:09:23 +0000 Tin dioxide-carbon nanotube (SnO2-CNT) composite films were synthesized on copper substrates by a one-step process using hot filament chemical vapor deposition (HFCVD) with methane gas (CH4) as the carbon source. The composite structural properties enhance the surface-to-volume ratio of SnO2 demonstrating a desirable electrochemical performance for a lithium-ion battery anode. The SnO2 and CNT interactions were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared-attenuated total reflectance (ATR-FTIR) spectroscopy. Comprehensive analysis of the structural, chemical, and electrochemical properties reveals that the material consists of self-assembled and highly dispersed SnO2 nanoparticles in CNT matrix. The process employed to develop this SnO2-CNT composite film presents a cost effective and facile way to develop anode materials for Li-ion battery technology. Dionne Hernandez, Frank Mendoza, Emmanuel Febus, Brad R. Weiner, and Gerardo Morell Copyright © 2014 Dionne Hernandez et al. All rights reserved. Biosynthesis of Metal Nanoparticles: A Review Thu, 15 May 2014 00:00:00 +0000 The synthesis of nanostructured materials, especially metallic nanoparticles, has accrued utmost interest over the past decade owing to their unique properties that make them applicable in different fields of science and technology. The limitation to the use of these nanoparticles is the paucity of an effective method of synthesis that will produce homogeneous size and shape nanoparticles as well as particles with limited or no toxicity to the human health and the environment. The biological method of nanoparticle synthesis is a relatively simple, cheap, and environmentally friendly method than the conventional chemical method of synthesis and thus gains an upper hand. The biomineralization of nanoparticles in protein cages is one of such biological approaches used in the generation of nanoparticles. This method of synthesis apart from being a safer method in the production of nanoparticles is also able to control particle morphology. Narendra Kulkarni and Uday Muddapur Copyright © 2014 Narendra Kulkarni and Uday Muddapur. All rights reserved. Silicon Nanofabrication by Atomic Force Microscopy-Based Mechanical Processing Sun, 11 May 2014 13:38:54 +0000 This paper reviews silicon nanofabrication processes using atomic force microscopy (AFM). In particular, it summarizes recent results obtained in our research group regarding AFM-based silicon nanofabrication through mechanochemical local oxidation by diamond tip sliding, as well as mechanical, electrical, and electromechanical processing using an electrically conductive diamond tip. Microscopic three-dimensional manufacturing mainly relies on etching, deposition, and lithography. Therefore, a special emphasis was placed on nanomechanical processes, mechanochemical reaction by potassium hydroxide solution etching, and mechanical and electrical approaches. Several important surface characterization techniques consisting of scanning tunneling microscopy and related techniques, such as scanning probe microscopy and AFM, were also discussed. Shojiro Miyake, Mei Wang, and Jongduk Kim Copyright © 2014 Shojiro Miyake et al. All rights reserved. Synthesis, XRD, TEM, EPR, and Optical Absorption Spectral Studies of CuZnO2 Nanocompound Sun, 11 May 2014 12:54:53 +0000 Synthesis of nano CuZnO2 compound is carried out by thermal decomposition method. The crystalline phase of the material is characterized by XRD. The calculated unit cell constants are   and   and are of tetragonal structure. The unit cell constants are different from wurtzite (hexagonal) which indicate that a nanocompound is formed. Further TEM images reveal that the metal ion is in tetragonal structure with oxygen ligands. The prepared CuZnO2 is then characterized for crystallite size analysis by employing transmission electron microscopy (TEM). The size is found to be 100 nm. Uniform bright rings are noticed in the TEM picture suggesting that the nanocrystals have preferential instead of random orientations. The selected-area electron diffraction (SAED) pattern clearly indicates the formation of CuO-ZnO nanocompound. The nature of bonding is studied by electron paramagnetic resonance (EPR). The covalency character is about 0.74 and thus the compound is electrically less conductive. Optical absorption spectral studies suggest that Cu(II) is placed in tetragonal elongation crystal field. The spin-orbit coupling constant, , is calculated using the EPR and optical absorption spectral results suggest some covalent bond between metal and ligand. Near infrared (NIR) spectra are due to hydroxyl and water fundamentals. T. Ravindra Reddy, K. Thyagarajan, S. Lakshmi Reddy, and Tamio Endo Copyright © 2014 T. Ravindra Reddy et al. All rights reserved.