Journal of Nanotechnology The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . 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. Time-Domain Analysis of Coupled Carbon Nanotube Interconnects Sun, 04 May 2014 14:09:21 +0000 This paper describes a new method for the analysis of coupling effects including the crosstalk effects between two driven coupled single-walled carbon nanotubes (SWCNTs) and the intertalk effects between two neighboring shells in a multiwalled carbon nanotube (MWCNT), based on transmission line circuit modeling. Using rigorous calculations, a new parametric transfer function has been obtained for the analysis of the impact of aggressor line on the victim line, which depends on the various coupling parameters such as the mutual inductance, the coupling capacitance, and the tunneling resistance. The influences of various parameters such as the contact resistance and the switching factor on the time behavior of coupling effects between the two coupled CNTs and an important effect named “crosstalk-induced delay” are studied and analyzed. Davood Fathi Copyright © 2014 Davood Fathi. All rights reserved. Synthesis and Characterization of Cobalt Nanoparticles Using Hydrazine and Citric Acid Thu, 13 Mar 2014 11:36:48 +0000 Cobalt nanoparticles were produced by employing the liquid-phase reduction method and hydrazine. The effect of citric acid additives on the formation and growth mechanism of cobalt nanoparticles was investigated using polarization methods. The cobalt nanoparticles produced in 0.2 M cobalt sulfate and 5 M hydrazine at 298 K had a spherical shape with a diameter of 400 nm. The dendritic nanoparticles formed with the decreasing of hydrazine concentration at 298 K. On the other hand, dendritic large particles are confirmed at 353 K. It was confirmed that the reduction reaction progressed with the addition of citric acid, and a hexagonal close-packed (εCo) phase was formed. S. A. Salman, T. Usami, K. Kuroda, and M. Okido Copyright © 2014 S. A. Salman et al. All rights reserved. Magnetic Nanoparticles of Chitosan for Targeted Delivery System of Plasmids to the Lungs Wed, 12 Mar 2014 15:40:43 +0000 One of the major problems of gene therapy is the efficient, specific, and targeted delivery as well as the safety of the materials used in such systems. The specific targeted delivery of genes to the lung offers the possibility to treat a variety of specific diseases. We developed chitosan nanoparticles with the plasmid pCEM-Luc, which contains a promoter activated by magnetic field. Nanoparticles of 200–250 nm obtained by ionic gelation with a 99% retention rate were transfected in B16F10 cells and in vivo in the lungs of Balb/c mice by intratracheal administration. We observed that an external magnetic field increased the expression of the luciferase reporter gene in B16F10 cells transfected with magnetic nanoparticles and in homogenized lungs of mice which determined differences in levels of expression between different regions of the lungs (apical or distal and left or right). The highest levels of luciferase activity were observed in the apical left region. The magnetic nanoparticles prove an efficient delivery system to in vitro transfection of cells and lung tissue. Cynthia Aracely Alvizo Báez, Itza Eloisa Luna Cruz, Maria Cristina Rodríguez Padilla, and Juan Manuel Alcocer González Copyright © 2014 Cynthia Aracely Alvizo Báez et al. All rights reserved. Reviewing the Tannic Acid Mediated Synthesis of Metal Nanoparticles Tue, 11 Mar 2014 12:52:37 +0000 Metal nanoparticles harbour numerous exceptional physiochemical properties absolutely different from those of bulk metal as a function of their extremely small size and large superficial area to volume. Naked metal nanoparticles are synthesized by various physical and chemical methods. Chemical methods involving metal salt reduction in solution enjoy an extra edge over other protocols owing to their relative facileness and capability of controlling particle size along with the attribute of surface tailoring. Although chemical methods are the easiest, they are marred by the use of hazardous chemicals such as borohydrides. This has led to inclination of scientific community towards eco-friendly agents for the reduction of metal salts to form nanoparticles. Tannic acid, a plant derived polyphenolic compound, is one such agent which embodies characteristics of being harmless and environmentally friendly combined with being a good reducing and stabilizing agent. In this review, first various methods used to prepare metal nanoparticles are highlighted and further tannic acid mediated synthesis of metal nanoparticles is emphasized. This review brings forth the most recent findings on this issue. Tufail Ahmad Copyright © 2014 Tufail Ahmad. All rights reserved. Noncovalent Attachment of PbS Quantum Dots to Single- and Multiwalled Carbon Nanotubes Mon, 10 Mar 2014 15:59:40 +0000 Attachment of PbS quantum dots (QD) to single-walled carbon nanotubes (SWNT) and multiwalled carbon nanotubes (MWCNT) is described; wherein commercially obtained PbS-QD of size 2.7 nm, stabilized by oleic acid, are added to a suspension of single- or multiwalled carbon nanotubes (CNT) prefunctionalized noncovalently with 1,2-benzenedimethanethiol (1,2-BDMT) in ethanol. The aromatic part of 1,2-BDMT attaches to the CNT by π-π stacking interactions, noncovalently functionalizing the CNT. The thiol part of the 1,2-BDMT on the functionalized CNT replaces oleic acid on the surface of the QD facilitating the noncovalent attachment of the QD to the CNT. The composites were characterized by TEM and FTIR spectroscopy. Quenching of NIR fluorescence of the PbS-QD on attachment to the carbon nanotubes (CNT) was observed, indicating FRET from the QD to the CNT. Anirban Das, Eric Hall, and Chien M. Wai Copyright © 2014 Anirban Das et al. All rights reserved. Peeling of Long, Straight Carbon Nanotubes from Surfaces Sun, 23 Feb 2014 13:20:16 +0000 The adhesion of long, straight, single-walled carbon nanotubes to surfaces is examined using multidimensional force spectroscopy. We observed characteristic signatures in the deflection and frequency response of the cantilever indicative of nanotube buckling and slip-stick motion as a result of compression and subsequent adhesion and peeling of the nanotube from the surface. The spring constant and the elastic modulus of the SWNT were estimated from the frequency shifts under tension. Using elastica modeling for postbuckled columns, we have determined the static coefficient of friction for the SWNT on alkanethiol-modified gold surfaces and showed that it varies with the identity of the monolayer terminal group. Kane M. Barker, Mark A. Poggi, Leonardo Lizarraga, Peter T. Lillehei, Aldo A. Ferri, and Lawrence A. Bottomley Copyright © 2014 Kane M. Barker et al. All rights reserved. Pharmacokinetic and Tissue Distribution Study of Solid Lipid Nanoparticles of Zidovudine in Rats Wed, 19 Feb 2014 10:14:23 +0000 Zidovudine-loaded solid lipid nanoparticles (AZT-SLNs) and zidovudine in solution were prepared and administered in rats. The aim of this research was to study whether the bioavailability of zidovudine can be improved by AZT-SLNs perorally to rats as compared to oral administration of zidovudine. Zidovudine was determined in plasma and tissues by reverse phase high performance liquid chromatography. The pharmacokinetic parameters of zidovudine were determined after peroral administration: area under curve of concentration versus time (AUC) for AZT-SLNs was 31.25% greater than AZT solution; meanwhile mean resident time (MRT) was found to be 1.83 times higher for AZT-SLNs than AZT solution. Elimination half life of zidovudine was also increased for SLN formulation. Tissue distribution pattern of zidovudine was changed in case of AZT-SLNs. AUC of zidovudine in brain and liver was found to be approximately 2.73 and 1.77 times higher in AZT-SLNs than AZT solution, respectively, indicating that AZT-SLNs could cross blood brain barrier. Distribution of zidovudine was approximately 0.95 and 0.86 times lesser in heart and kidney, respectively. It can be concluded from the study that oral administration of AZT-SLNs modifies the plasma pharmacokinetic parameters and biodistribution of zidovudine. Shah Purvin, Parameswara Rao Vuddanda, Sanjay Kumar Singh, Achint Jain, and Sanjay Singh Copyright © 2014 Shah Purvin et al. All rights reserved. Application of Iron Oxide Nanomaterials for the Removal of Heavy Metals Wed, 19 Feb 2014 08:14:29 +0000 In the 21st century water polluted by heavy metal is one of the environment problems. Various methods for removal of the heavy metal ions from the water have extensively been studied. Application of iron oxide nanaparticles based nanomaterials for removal of heavy metals is well-known adsorbents for remediation of water. Due to its important physiochemical property, inexpensive method and easy regeneration in the presence of external magnetic field make them more attractive toward water purification. Surface modification strategy of iron oxide nanoparticles is also used for the remediation of water increases the efficiency of iron oxide for the removal of the heavy metal ions from the aqueous system. Pragnesh N. Dave and Lakhan V. Chopda Copyright © 2014 Pragnesh N. Dave and Lakhan V. Chopda. All rights reserved. Intestinal Lymphatic Delivery of Praziquantel by Solid Lipid Nanoparticles: Formulation Design, In Vitro and In Vivo Studies Wed, 19 Feb 2014 06:38:56 +0000 The aim of the present work was to design and develop Praziquantal (PZQ) loaded solid lipid nanoparticles (PZQ-SLN) to improve the oral bioavailability by targeting intestinal lymphatic system. PZQ is practically insoluble in water and exhibits extensive hepatic first-pass metabolism. PZQ SLN were composed of triglycerides, lecithin and various aqueous surfactants; were optimized using hot homogenization followed by ultrasonication method. The optimized SLN had particle size of  nm, EE of %. The drug release of PZQ-SLN showed initial burst release followed by the sustained release. Inspite of zeta potential being around −10 mV, the optimized SLN were stable at storage conditions (°C and °C/% RH) for six months. TEM study confirmed the almost spherical shape similar to the control formulations. Solid state characterization using differential scanning calorimeter (DSC) and powder X-ray diffraction (PXRD) analysis confirmed the homogeneous distribution of PZQ within the lipid matrix. The 5.81-fold increase in , after intraduodenal administration of PZQ-SLN in rats treated with saline in comparison to rats treated with cycloheximide (a blocker of intestinal lymphatic pathway), confirmed its intestinal lymphatic delivery. The experimental results indicate that SLN may offer a promising strategy for improving the therapeutic efficacy and reducing the dose. Amit Mishra, Parameswara Rao Vuddanda, and Sanjay Singh Copyright © 2014 Amit Mishra et al. All rights reserved. Nanocatalysis: Academic Discipline and Industrial Realities Mon, 17 Feb 2014 13:14:01 +0000 Nanotechnology plays a central role in both academic research and industrial applications. Nanoenabled products are not only found in consumer markets, but also importantly in business to business markets (B2B). One of the oldest application areas of nanotechnology is nanocatalysis—an excellent example for such a B2B market. Several existing reviews illustrate the scientific developments in the field of nanocatalysis. The goal of the present review is to provide an up-to-date picture of academic research and to extend this picture by an industrial and economic perspective. We therefore conducted an extensive search on several scientific databases and we further analyzed more than 1,500 nanocatalysis-related patents and numerous market studies. We found that scientists today are able to prepare nanocatalysts with superior characteristics regarding activity, selectivity, durability, and recoverability, which will contribute to solve current environmental, social, and industrial problems. In industry, the potential of nanocatalysis is recognized, clearly reflected by the increasing number of nanocatalysis-related patents and products on the market. The current nanocatalysis research in academic and industrial laboratories will therefore enable a wealth of future applications in the industry. Sandro Olveira, Simon P. Forster, and Stefan Seeger Copyright © 2014 Sandro Olveira et al. All rights reserved. Fabrication of Electrospun Polyamide-6/Chitosan Nanofibrous Membrane toward Anionic Dyes Removal Sun, 16 Feb 2014 12:01:29 +0000 Nanofibrous filter media of polyamide-6/chitosan were fabricated by electrospinning onto a satin fabric substrate and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and water contact angle (WCA). Anionic dye removal capability of the filter was investigated for Solophenyl Red 3BL and Polar Yellow GN, respectively, as acidic and direct dyes were investigated with respect to solution parameters (pH and initial dye concentration) and membrane parameters (electrospinning time and chitosan ratio) through filtration system. Experiments were designed using response surface methodology (RSM) based on five-level central composite design (CCD) with four parameters to maximize removal efficiency of the filter media. Moreover, the effect of parameters and their likely interactions on dye removal were investigated by mathematically developed models. The optimum values for solution pH, initial dye concentration, electrospinning time, and chitosan ratio were predicted to be 5, 50 mg/L, 4 hr, 30% and 5, 100 mg/L, 4 hr, 10%, respectively, for achieving 96% and 95% removal of Solophenyl Red 3BL and Polar Yellow GN. Evaluation of the estimation capability of applied models revealed that the models have a good agreement with experimental values. This study demonstrated that polyamide-6/chitosan nanofibrous membrane has an enormous applicable potential in dye removal from aqueous solutions. Mozhdeh Ghani, Ali Akbar Gharehaghaji, Mokhtar Arami, Negar Takhtkuse, and Babak Rezaei Copyright © 2014 Mozhdeh Ghani et al. 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