Journal of Nanoparticles The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Influence of Gas Sort on the Nucleation Region Width of Si Nanocrystal Grains Prepared by Pulsed Laser Ablation Sun, 30 Mar 2014 11:23:08 +0000 We have calculated the nucleation region (NR) location of Si nanocrystal grains prepared by pulsed laser ablation (PLA) with fluence of 4 J/cm2 in 10 Pa gas at room temperature, and ambient gases were He, Ne, and Ar, respectively. Results of calculation indicated that NR width in Ne gas was narrowest, while it was widest in He gas. Maximum mean size of grains deposited on substrates under ablated spot, which were placed horizontally, was the smallest in Ne gas. It would be attribute to more effective energy transfer during the process of collision when atomic mass of Si and ambient gas Ne are more close to each other. In this work, an additional gas flow with the same element as ambient gas was introduced, which is vertical to the plume axis at different lateral positions above ablated spot. Zechao Deng, Lizhi Chu, Xuecheng Ding, Aili Qin, Guangsheng Fu, and Yinglong Wang Copyright © 2014 Zechao Deng et al. All rights reserved. Green Chemistry Based Benign Routes for Nanoparticle Synthesis Mon, 24 Mar 2014 07:41:33 +0000 Green chemistry has been an eye catching area of interest since the past few years. With the problem of energy crisis looming high and its constraint being particularly vulnerable on the developing economies, the need for giving alternative traditional chemistry a serious consideration as well as adequate room for development has received significant boost through the coveted efforts of multidisciplinary and interdisciplinary scientific fields. Nanoscience has been the right field in this dimension as it opens up the door to multiple opportunities through enabling a number of chemical, biochemical, and biophysical transformations in a significantly easier and reliable manner. The use of nanoparticles has made the fields of catalysis, synthesis, and enzyme immobilizations as well as molecular interactions a lot much easier, rapid and easily controllable. This review article sheds light on the popular alternative synthesis routes being employed for the synthesis of nanoparticles, the pivotal being from microbes, plants, and chemical routes via sonication, microwaving, and many others. Parth Malik, Ravi Shankar, Vibhuti Malik, Nitin Sharma, and Tapan Kumar Mukherjee Copyright © 2014 Parth Malik et al. All rights reserved. Performance of Water-Based Zinc Oxide Nanoparticle Coolant during Abrasive Grinding of Ductile Cast Iron Wed, 05 Mar 2014 09:49:27 +0000 This paper presents the performance of ductile cast iron grinding machining using water-based zinc oxide nanoparticles as a coolant. The experimental data was utilized to develop the mathematical model for first- and second-order models. The second order gives worthy performance of the grinding. The results indicate that the optimum parameters for the grinding model are 20 m/min table speed and 42.43 μm depth of cut for single-pass grinding. For multiple-pass grinding, optimization is at a table speed equal to 35.11 m/min and a depth of cut equal to 29.78 μm. The model fit was adequate and acceptable for sustainable grinding using a 0.15% volume concentration of zinc oxide nanocoolant. This paper quantifies the impact of water-based ZnO nanoparticle coolant on the achieved surface quality. It is concluded that the surface quality is the most influenced by the depth of cut(s) and table speed. M. M. Rahman and K. Kadirgama Copyright © 2014 M. M. Rahman and K. Kadirgama. All rights reserved. The Mode of Action of Silver and Silver Halides Nanoparticles against Saccharomyces cerevisiae Cells Thu, 13 Feb 2014 16:12:34 +0000 Silver and silver halides nanoparticles (NPs) (Ag, AgCl, AgBr, and AgI) capped with two different stabilizers (sodium citrate and nonionic surfactant Tween 80) were obtained via sodium borohydride reduction of silver nitrate in an aqueous solution. The effect of the biocidal action of as-prepared synthesized materials against yeast cells Saccharomyces cerevisiae was compared to the effect produced by silver nitrate and studied through the measurement of cell loss and kinetics of K+ efflux from the cells depending on concentration of silver. The results clearly indicate that the silver ions either remained in the dispersion of silver NPs and silver halides NPs after their synthesis or were generated afterwards by dissolving silver and silver halides particles playing a major part in the cytotoxic activity of NPs against yeast cells. It was also supposed that this activity most likely does not relate to the damage of cell membrane. A. A. Kudrinskiy, A. Yu. Ivanov, E. V. Kulakovskaya, A. I. Klimov, P. M. Zherebin, D. V. Khodarev, Anh-Tuan Le, Le Thi Tam, G. V. Lisichkin, and Yu. A. Krutyakov Copyright © 2014 A. A. Kudrinskiy et al. All rights reserved. Small Angle X-Ray Scattering Technique for the Particle Size Distribution of Nonporous Nanoparticles Sun, 22 Dec 2013 09:44:57 +0000 Nanoparticles are small particles whose sizes are less than 100 nm. They have many industrial applications due to their unique properties. Their properties are often size-dependent; thus the accurate determination of nanoparticle sizes is important for quality assurance of nanoparticle production processes. A small angle X-ray scattering technique is a promising method used for characterizing nanoparticle sizes. It has distinctive advantages over other techniques such as electron microscope techniques. In this paper, we review the state-of-the-art methods for determining the sizes of nanoparticles with small angle X-ray experiments and discuss the advantages and limitations of the state-of-the-art methods. A. Agbabiaka, M. Wiltfong, and C. Park Copyright © 2013 A. Agbabiaka et al. All rights reserved. Magnetization and Specific Absorption Rate Studies of Ball-Milled Iron Oxide Nanoparticles for Biomedicine Sat, 28 Sep 2013 14:48:37 +0000 Comparative studies are presented of iron oxide nanoparticles in the 7–15 nm average diameter range ball milled in hexane in the presence of oleic acid. Transmission electron microscopy identified spherical particles of decreasing size as milling time and/or surfactant concentration increased. Micromagnetic characterization via Mössbauer spectroscopy at room temperature yielded broadened magnetic spectroscopic signatures, while macromagnetic characterization via vibrating sample magnetometry of 7-8 nm diameter particles showed largely superparamagnetic behavior at room temperature and hysteretic at 2 K. Zero-field and field-cooled magnetization curves exhibited a broad maximum at ~215 K indicating the presence of strong interparticle magnetic interactions. The specific absorption rates of ferrofluids based on these nanoparticle preparations were measured in order to test their efficacies as hyperthermia agents. P. Burnham, N. Dollahon, C. H. Li, A. J. Viescas, and G. C. Papaefthymiou Copyright © 2013 P. Burnham et al. All rights reserved. Characterization and Modification of Mesoporous Silica Nanoparticles Prepared by Sol-Gel Wed, 25 Sep 2013 15:50:22 +0000 Mesoporous silica nanoparticles (MSNs) were synthesized by sol-gel reaction at normal pressure by using TEOS as a silica source and CTAB as a directing agent in ammonia solution at 323 K subsequently calcined at 823 K. Then inorganic pores were modified with metal-supported MSN with attention to the acidity, surface area, pore size, and ability of ion exchange. Crystalline size was shown to decrease up to 20 molar ratios of Si/Al followed by increasing while further adding nanoparticles-aluminium. Moreover, the XRD patterns revealed the mesostructured material for all with 2D hexagonal structure. The obtained results from the XRD patterns were confirmed by using BET and EDX. The BET surface areas revealed the spherical shape for all samples with a decrease in the pore volume and surface area for various AlMSNs which emphasized that the loading of Al and was compatible with XRD results. MSN was prepared by sol-gel methods followed by loading of Al in order to prepare AlMSN which possess strong Lewis acidic sites. This modification occurred by using various molar ratios of 0, 5, 10, 20, 50, and 100 Si/Al, respectively. The XRD patterns of various ratios of Si/Al were interpreted in terms of strain, nanocrystalline size, and distribution of the particle size by deriving Wiliamson Hall equation. Meysam Keshavarz and Norhayati Ahmad Copyright © 2013 Meysam Keshavarz and Norhayati Ahmad. All rights reserved. Dependence Properties of Sol-Gel Derived CuO@SiO2 Nanostructure to Diverse Concentrations of Copper Oxide Thu, 19 Sep 2013 10:34:09 +0000 Various concentrations of copper oxide were embedded into silica matrix of xerogel forms using copper source Cu(NO3)2·3H2O. The xerogel samples were prepared by hydrolysis and condensation of tetraethyl orthosilicate (TEOS) with determination of new molar ratios of the components by the sol-gel method. In this paper, three samples of copper oxide were doped into silica matrices using different concentrations. We obtained 10, 20, and 30 wt.% of copper oxide in silica matrices labeled as A, B, and C, respectively. The absorption and transmittance spectra of the gel matrices were treated at different concentrations by Uv-vis spectrophotometer. Quantities of water and transparency in the silica network change the spectral characteristics of Cu2+ ions in the host silica. Absorption spectra of the samples heated to higher concentration complete the conversion of Cu2+ ions to Cu+ ions. The effects of concentration of copper oxide were characterized by X-ray diffraction (XRD) patterns, and the transmission electron microscope (TEM) micrographs. Also, textural properties of samples were studied by surface area analysis (BET method) at different concentrations. V. Homaunmir, S. H. Tohidi, G. Grigorya, and M. Ayatollah Zada Shirazi Copyright © 2013 V. Homaunmir et al. All rights reserved. Condensation Energy for a Two-Gap Superconducting State in Nanoparticles Wed, 04 Sep 2013 13:30:17 +0000 Recent technology and experiments have fabricated high-quality superconducting MgB2 nanoparticles. We investigate properties of two-gap superconductivity in nanosized systems by using a two-sublevel model. In the present work, we analyze the results obtained for superconducting granules in the case of multiband superconductivity. We discuss the finite size effect in multiband superconductors. A definition of the critical level spacing of two-gap superconductivity is also presented, and we discuss the condensation energy and the parity gap of two-gap superconductivity in relation to the size dependence of those properties with two bulk gaps and the effective pair scattering process between two sublevels. Sergei P. Kruchinin, Hiroyuki Kawabe, Hidemi Nagao, and Yasuhiro Nakazawa Copyright © 2013 Sergei P. Kruchinin et al. All rights reserved. Nano/Microstructured Materials: Rapid, Low-Cost, and Eco-Friendly Synthesis Methods Wed, 24 Jul 2013 11:30:44 +0000 Amir Kajbafvala, Minghang Li, Hamed Bahmanpour, Mohammad H. Maneshian, and Alexander Kauffmann Copyright © 2013 Amir Kajbafvala et al. All rights reserved. Green Synthesis of Nanocrystalline Cu2ZnSnS4 Powder Using Hydrothermal Route Thu, 27 Jun 2013 16:05:12 +0000 Nanocrystalline Cu2ZnSnS4 (CZTS) powder was synthesized by a hydrothermal process, using thiourea as sulfur precursor. The powder was qualitatively analyzed using X-ray to identify the phase, and the size of the particles was determined using transmission electron microscopy (TEM). Raman peak at 337.5 cm−1 confirms the formation of pure CZTS particles. The powder was also synthesized solvothermally using ethylenediamine as solvent. The hydrothermally synthesized powder indicated the presence of the kesterite phase Cu2ZnSnS4 and particle size of about 4-5 nm. This environmentally green synthesis by hydrothermal route can produce gram scale synthesis of material with a chemical yield in excess of ~ 90%. UV Vis absorption spectra measurements indicated the band gap of as-synthesized CZTS nanoparticles to be 1.7 eV, which is near the optimum value for photovoltaic solar cell, showing its possible use in photovoltaics. Shri kant Verma, Vikash Agrawal, Kiran Jain, Renu Pasricha, and Suresh Chand Copyright © 2013 Shri kant Verma et al. All rights reserved. Charge Transfer in Nanocrystalline Semiconductor Electrodes Sat, 25 May 2013 15:58:47 +0000 Nanocrystalline electrodes in liquid junction devices possess a number of unique properties arising from their convoluted structure and the dimensions of their building units. The light-induced charge separation and transport in photoelectrochemical systems using nanocrystalline/nanoporous semiconductor electrodes is discussed here in connection with the basic principles of the (Schottky) barrier theory. Recent models for charge transfer kinetics in normal and unipolar (dye-sensitized) cells are reviewed, and novel concepts and materials are considered. M. Bouroushian Copyright © 2013 M. Bouroushian. All rights reserved. Effect of Nanoalumina on the Electrochemical and Mechanical Properties of Waterborne Polyurethane Composite Coatings Mon, 20 May 2013 16:56:25 +0000 A nanocomposite coating was formed by incorporating nanoalumina pigment in a waterborne polyurethane dispersion (WPUD) to different loading levels (0.1% and 1.0% by weight). Electrochemical performance of the nanocomposite coating was evaluated by applying these nanomodified coatings on mild steel substrate and exposing them to salt-spray, humidity, and accelerated UV weathering. The surface morphology of the composite coating was evaluated using various analytical techniques. SEM and AFM were used to investigate the dispersion of nanoalumina pigment and surface morphological changes of the nanomodified coating, before and after exposure to the test environment. Mechanical properties like scratch resistance were studied by using nanoscratch technique (Nanoindenter TI-900, Hysitron Inc, USA) and hardness using pencil hardness test method. The results showed an improvement in the corrosion, UV weathering, and mechanical properties of the coatings at lower concentration (0.1% by wt), indicating the positive effect of addition of nanoalumina pigment to the coating. Shailesh K. Dhoke, Narayani Rajgopalan, and A. S. Khanna Copyright © 2013 Shailesh K. Dhoke et al. All rights reserved. The Impact of Nanochloroquine on Restoration of Hepatic and Splenic Mitochondrial Damage against Rodent Malaria Thu, 16 May 2013 15:32:34 +0000 The applications of nanotechnology to pharmacology are the potential appliance of biodegradable polymers and convection-enhanced drug delivery in the diagnostics and treatment of diseases. Chitosan is a natural polysaccharide that has attracted significant scientific interest during the last two decades. The present study was to evaluate the possible effects of chitosan tripolyphosphate conjugated nanochloroquine against Plasmodium berghei infection on select makers of oxidative damage and antioxidant status in mitochondria of liver and spleen. P. berghei infection was developed in Swiss mice by intraperitoneal injection of 200 µL of infected blood. Parasite-infected mice were treated with chloroquine and nanoconjugated chloroquine. Superoxide radical generation, nitrate level, and oxidized glutathione were increased significantly () in the mitochondria of infected group as compared to control group, and reduced glutathione level, activity of SOD, GPx, GR, and GST, and mitochondrial transmembrane potential were decreased significantly (), which were increased or decreased significantly () near to normal in nanoconjugated chloroquine treated group than chloroquine treated group. So, the findings may suggest the advantageous role of nanoconjugated chloroquine against the P. berghei induced oxidative damage in hepatic and splenic mitochondria. Satyajit Tripathy, Sabyasachi Das, Sandeep Kumar Dash, Sourav Chattopadhyay, and Somenath Roy Copyright © 2013 Satyajit Tripathy et al. All rights reserved. Adiantum philippense L. Frond Assisted Rapid Green Synthesis of Gold and Silver Nanoparticles Thu, 16 May 2013 11:12:34 +0000 Development of an ecofriendly, reliable, and rapid process for synthesis of nanoparticles using biological system is an important bulge in nanotechnology. Antioxidant potential and medicinal value of Adiantum philippense L. fascinated us to utilize it for biosynthesis of gold and silver nanoparticles (AuNPs and AgNPs). The current paper reports utility of aqueous extract of A. philippense L. fronds for the green synthesis of AuNPs and AgNPs. Effect of various parameters on synthesis of nanoparticles was monitored by UV-Vis spectrometry. Optimum conditions for AuNPs synthesis were 1 : 1 proportion of original extract at pH 11 and 5 mM tetrachloroauric acid, whereas optimum conditions for AgNPs synthesis were 1 : 1 proportion of original extract at pH 12 and 9 mM silver nitrate. Characterization of nanoparticles was done by TEM, SAED, XRD, EDS, FTIR, and DLS analyses. The results revealed that AuNPs and AgNPs were anisotropic. Monocrystalline AuNPs and polycrystalline AgNPs measured 10 to 18 nm in size. EDS and XRD analyses confirmed the presence of elemental gold and silver. FTIR analysis revealed a possible binding of extract to AuNPs through –NH2 group and to AgNPs through C=C group. These nanoparticles stabilized by a biological capping agent could further be utilized for biomedical applications. Duhita G. Sant, Tejal R. Gujarathi, Shrikant R. Harne, Sougata Ghosh, Rohini Kitture, Sangeeta Kale, Balu A. Chopade, and Karishma R. Pardesi Copyright © 2013 Duhita G. Sant et al. All rights reserved. Antibacterial Activity of Silver Nanoparticles Synthesized by Bark Extract of Syzygium cumini Tue, 30 Apr 2013 14:38:25 +0000 The unique property of the silver nanoparticles having the antimicrobial activity drags the major attention towards the present nanotechnology. The environmentally nontoxic, ecofriendly, and cost-effective method that has been developed for the synthesis of silver nanoparticles using plant extracts creates the major research interest in the field of nanobiotechnology. The synthesized silver nanoparticles have been characterized by the UV-visible spectroscopy, atomic force microscopy (AFM), and scanning electron microscopy (SEM). Further, the antibacterial activity of silver nanoparticles was evaluated by well diffusion method, and it was found that the biogenic silver nanoparticles have antibacterial activity against Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 29213), Pseudomonas aeruginosa (ATCC 27853), Azotobacter chroococcum WR 9, and Bacillus licheniformis (MTCC 9555). Ram Prasad and Vyshnava Satyanarayana Swamy Copyright © 2013 Ram Prasad and Vyshnava Satyanarayana Swamy. All rights reserved. Metal Oxide Sol-Gels (, AlO(OH), and ) to Improve the Mechanical Performance of Wood Substrates Mon, 29 Apr 2013 09:06:47 +0000 Wood is a renewable material widely used in many applications due to its unique properties and distinctive look. However, as wood is organically constituted, it is slowly destroyed by the long-term impact of oxygen, UV radiations, water, and biological attacks (Mahltig et al., 2008). Therefore, protective treatments are necessary to improve the mechanical, thermal, and chemical properties of wood. In order to improve the mechanical properties of sugar maple (Acer saccharum Marsh.), as this species is widely used in the wood products industry, samples of sugar maple were impregnated with sols of metal oxides (AlO(OH), SiO2, and ZrO2). The weight gain and two different techniques of microscopy were used to evaluate the efficiency of the impregnation in the wood samples. The mechanical properties were evaluated using hardness test, scratch test, and impact test. It was shown that the maple samples impregnated with ZrO2 led to the greatest improvement of the mechanical properties. Véronic Landry, Pierre Blanchet, and Gabrielle Boivin Copyright © 2013 Véronic Landry et al. All rights reserved. Sol-Gel Synthesis of TiO2/SiO2 and ZnO/SiO2 Composite Films and Evaluation of Their Photocatalytic Activity towards Methyl Green Sun, 28 Apr 2013 14:28:03 +0000 The TiO2/SiO2 and ZnO/SiO2 composite films were prepared by sol-gel dip coating method. The surface morphology and crystal structure of thin films were characterized by means of scanning electron microscopy (SEM) with elementary dispersive X-ray analysis (EDX) and X-ray diffractometer (XRD). Optical properties of films have been investigated using ultraviolet and visible spectroscopy (UV-visible spectroscopy). The photocatalytic activity was established by testing the degradation and decolorization of methyl green (MG) from aqueous solution with artificial UV-light. V. L. Chandraboss, B. Karthikeyan, J. Kamalakkannan, S. Prabha, and S. Senthilvelan Copyright © 2013 V. L. Chandraboss et al. All rights reserved. Aqueous Medium Synthesis Route for Randomly Stacked Molybdenum Disulfide Thu, 18 Apr 2013 10:46:28 +0000 Synthesis of poorly crystalline, randomly oriented rag-like structures of molybdenum disulfide has been reported starting from aqueous solutions of ammonium molybdate, and thioacetamide in presence of sodium dodecyl sulfate via calcination of the amorphous precipitates, obtained through acidification of the in situ generated intermediate of ammonium tetrathiomolybdate. X-ray photoelectron spectroscopy, UV-visible spectroscopy, and X-ray diffraction of the calcined samples reveal the formation of single-phase MoS2, while the amorphous precipitates have been found to be a mixture of Mo2S5, MoS3, and a trace amount of H2MoS4. Highly folded and disordered layers of rag-like MoS2 have been confirmed through high-resolution transmission electron microscopy. The electrical conductivity for the cold pressed pellet of the MoS2 sample is found to be significantly higher than that of 2H-MoS2 and increases further on annealing. Pravas Kumar Panigrahi and Amita Pathak Copyright © 2013 Pravas Kumar Panigrahi and Amita Pathak. All rights reserved. Conductometry and Size Characterization of Polypyrrole Nanoparticles Produced by Ball Milling Mon, 15 Apr 2013 10:58:52 +0000 Polypyrrole (PPy), one of the most extensively investigated conducting polymers, has attracted a great deal of interest because of its good electrical conductivity, environmental stability, and easy synthesis. PPy films were produced by polymerization of pyrrole and tosylate (TsO−) as dopants in the presence of oxidant FeCl3 and polyethylene glycol ( 8000) at −5°C for 48 h. High energy milling was carried out at 850 rpm in the dry media with the balls of 10 mm. Particles were then characterized by Scanning Electron Microscope and Dynamic Light Scattering techniques for size distribution, and it was found that the size of PPy particles is a decreasing function of time of milling. Electrical conductivity was measured by preparing a homogenous aqueous dispersion of PPy particles and found as exponential decreasing function of time of milling. The changes occurred in PPy after milling was analyzed by Differential Scanning Calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). Abdul Malik Rehan Abbasi, Miroslava Marsalkova, and Jiri Militky Copyright © 2013 Abdul Malik Rehan Abbasi et al. All rights reserved. Ecofriendly and Facile One-Pot Multicomponent Synthesis of Thiopyrimidines under Microwave Irradiation Mon, 08 Apr 2013 10:51:21 +0000 A rapid, improved, and ecofriendly synthesis of thiopyrimidines is carried out via one-pot multicomponent reaction of ethylcyanoacetate, substituted benzaldehydes, and thiourea in presence of ethanolic K2CO3 using microwave irradiation heating method. Excellent yields, shorter reaction time, and easy workup are the major advantageous features of this green protocol. So the application of multicomponent reactions involves the combination of multiple starting materials with different functional groups leading to the highly efficient and environmentally friendly construction of multifunctional drug molecules. The structures of the newly synthesized products were assigned on the basis of IR and 1HNMR spectral data. Biswa Mohan Sahoo, B. V. V. Ravi Kumar, Jnyanaranjan Panda, and S. C. Dinda Copyright © 2013 Biswa Mohan Sahoo et al. All rights reserved. Electrochemical Method for Ag-PEG Nanoparticles Synthesis Thu, 04 Apr 2013 16:48:29 +0000 In this work we present an electrochemical method to successfully prepare silver nanoparticles using only polyethylene glycol as stabilizer and without any other reactive. Here we study the use of the polymeric stabilizer to allow the introduction of a potential tool to reinforce the control of the size and shape of the nanoparticles throughout the synthesis process. The evolution of the reactions was followed by UV-Vis spectroscopy. The electrode processes were characterized by cyclic voltammetric measurements and the final product was studied by Atomic Force Microscopy, Transmission Electron Microscopy, and X-Ray Diffraction. The influences of the current density, polymer length, and concentration media were analyzed. M. Virginia Roldán, Nora Pellegri, and Oscar de Sanctis Copyright © 2013 M. Virginia Roldán et al. All rights reserved. Studying the Enrichment of Ice Cream with Alginate Nanoparticles Including Fe and Zn Salts Thu, 04 Apr 2013 16:47:46 +0000 The aim of this research was developing alginate nanoparticles as a carrier for food enrichment. In this research, Fe/Zn-loaded alginate nanoparticles were prepared and characterized as point size, morphology, FTIR, loading efficacy (LE), and release properties and used in ice cream structure. After this stage, absorption of the salts was measured and sensory and rheological evaluations were taken for samples. Results showed that alginate nanoparticles have average size between 90 and 135 nm. Also, the shape of the nanoparticles is regular and smooth without aggregation phenomena. FTIR certified that Zn/Fe loaded into alginate nanoparticles. Also, loading efficacy of Zn/Fe was 70–85% and release profile of nanoparticles showed a steady state. Alginate nanoparticles could decrease the loss of Fe/Zn in comparison control. Furthermore, these nanoparticles have no side effects on sensory and rheological properties. Hence, this nanoparticle can be suggestive for the enrichment of ice cream and probably other foods. Armoon Sharifi, Leila Golestan, and Mazyar Sharifzadeh Baei Copyright © 2013 Armoon Sharifi et al. All rights reserved. Synthesis of Gold Nanoparticles Using Whole Cells of Geotrichum candidum Sun, 31 Mar 2013 15:22:06 +0000 The synthesis of nanoparticles with desired size and shape is an important area of research in nanotechnology. Use of biological system is an alternative approach to chemical and physical procedures for the synthesis of metal nanoparticles. An efficient environment-friendly approach for the biosynthesis of rapid and stable Gold nanoparticles (AuNPs) using whole cells of Geotrichum candidum is discussed in this paper. The enzymes/proteins present in the microorganism might be responsible for the reduction of metal salts to nanoparticles. Various reaction parameters such as culture age, temperature, pH, metal salt, and cell mass concentrations were optimized. The AuNPs were characterized by UV-visible spectroscopy, dynamic light scattering (DLS), energy dispersive spectroscopy (EDS), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR). Nanoparticles were isolated by sonicating the whole cells after treatment with Tween 80. The whole cell mediated process showed the simplistic, feasible, easy to scale up, and low-cost approach for the synthesis of AuNPs. Amit Kumar Mittal, Abhishek Kaler, Aparna Vasant Mulay, and Uttam Chand Banerjee Copyright © 2013 Amit Kumar Mittal et al. All rights reserved. Experimental Investigation into the Forced Convective Heat Transfer of Aqueous Fe3O4 Nanofluids under Transition Region Wed, 27 Mar 2013 14:53:03 +0000 The forced convective heat transfer (FCHT) properties of nanofluids, made of Fe3O4 nanomaterials and deionized water, are firstly measured by a self-made forced convective heat transfer apparatus. The nanofluid flows through a horizontal copper tube in the transition region with Reynolds numbers in the range of 2500–5000. Some parameters including Reynolds number, axial distance, and mass concentration are also investigated. The preliminary results are firstly presented that the heat transfer coefficients of Fe3O4 nanofluids systematically decrease with increasing concentration of nanoparticles under transition region which contradicts the initial expectation. Jie Ma, Yinchen Xu, Wenlie Li, Jiantao Zhao, Shuping Zhang, and Sergey Basov Copyright © 2013 Jie Ma et al. All rights reserved. Electroless Deposited Gold Nanoparticles on Glass Plates as Sensors for Measuring the Dielectric Constant of Solutions Tue, 26 Mar 2013 16:53:44 +0000 This work describes a method for the deposition of Au nanoparticles on glass plates (Au-glass). An electroless metal plating technique was extended to the Au nanoparticle deposition. The technique consisted of three steps that took place on the glass plate: (1) adsorption of Sn2+ ions, (2) deposition of metallic Ag nuclei generated by reducing Ag+ ions with Sn2+ ions on the Sn-adsorbed sites, and (3) deposition of Au nanoparticles by reducing Au+ ions on the Ag surface. TEM observation revealed that metallic Au nanoparticles with a size of  nm were formed on the glass surface. A surface plasmon resonance absorption peak was observed, and its peak wavelength redshifted by immersing the Au-glass into a solution with a large dielectric constant. The redshift corresponded qualitatively to the calculation by the Mie theory accompanying the Drude expression, which was based on the change of the dielectric constant of the solution. The obtained results indicated that the Au-glass functioned as a sensor for measuring the dielectric constant of the solution. Y. Kobayashi and Y. Ishii Copyright © 2013 Y. Kobayashi and Y. Ishii. All rights reserved. Influence of Various Surfactants on Size, Morphology, and Optical Properties of CeO2 Nanostructures via Facile Hydrothermal Route Tue, 26 Mar 2013 14:34:21 +0000 Different surfactants such as sodium dodecyl sulfate (SDS), polyethylene glycol (PEG), and cetyltrimethyl ammonium bromide (CTAB,) assisted cerium oxide (CeO2) nanoparticles were synthesized by using cerium chloride and potassium hydroxide as the starting materials via facile hydrothermal route. The powder X-ray diffraction (XRD) shows that cubic fluorite-type structure of pure CeO2 and the average crystallite sizes were calculated to be ~12–16 nm. Raman spectra of various surfactants assisted CeO2 consist of a single triply degenerated F2g mode characteristic of the fluorite structure. The elongated spherical-like morphology of SDS assisted CeO2 samples was observed from the SEM and TEM studies. Optical absorption spectra showed a blue shift by the capped CeO2 due to the quantum confinement effect. Photoluminescence (PL) emission studies shows that there is a change in the intensity of emission peaks by the capping agents, which indicates that the capping layers did result in size changes or increased surface defect. S. Gnanam and V. Rajendran Copyright © 2013 S. Gnanam and V. Rajendran. All rights reserved. CuO- Nanocomposite: An Efficient Recyclable Catalyst for the Synthesis of Aryl-14H-dibenzo[a-j]xanthenes Mon, 25 Mar 2013 11:46:23 +0000 CuO-CeO2 nanocomposite is reported as a highly efficient recyclable catalyst that is applied for the synthesis of Aryl-14H-dibenzo[a-j]xanthenes under solvent-free conditions. The catalyst was synthesized by coprecipitation method and characterized by X-ray powder diffraction (XRD), BET specific surface area, field emission scanning electron microscopy (FESEM), and energy dispersive spectroscopy (EDS) analysis. The copper nanoparticles are dispersed as fine and amorphous phases on the surface of ceria and made nanoclusters with average size of about 33 nm. This catalyst can be recovered by simple filtration and recycled up to 8 consecutive runs without any losing of its efficiency. This procedure provides several advantages such as simple workup, mild reaction conditions, short reaction times, and high yields of the products. Jalal Albadi, Abdolhossein Razeghi, Hossein Abbaszadeh, and Azam Mansournezhad Copyright © 2013 Jalal Albadi et al. All rights reserved. Recent Advancement in Functional Core-Shell Nanoparticles of Polymers: Synthesis, Physical Properties, and Applications in Medical Biotechnology Mon, 25 Mar 2013 10:51:32 +0000 This paper covers the core-shell nanomaterials, mainly, polymer-core polymer shell, polymer-core metal shell, and polymer-core nonmetal shells. Herein, various synthesis techniques, properties, and applications of these materials have been discussed. The detailed discussion of the properties with experimental parameters has been carried out. The various characterization techniques for the core-shell nanostructure have also been discussed. Their physical and chemical properties have been addressed. The future aspects of such core-shell nanostructures for biomedical and various other applications have been discussed with a special emphasis on their properties. K. Santhosh Kumar, Vijay Bhooshan Kumar, and Pradip Paik Copyright © 2013 K. Santhosh Kumar et al. All rights reserved. Rapid, Low-Cost, and Ecofriendly Approach for Iron Nanoparticle Synthesis Using Aspergillus oryzae TFR9 Sun, 24 Mar 2013 13:31:52 +0000 Development of reliable and ecofriendly green approach for synthesis of metallic nanoparticles biologically is an important step in the field of application of nanoscience and nanotechnology. The present paper reports the green approach for iron nanoparticle synthesis using Aspergillus oryzae TFR9 using FeCl3 as a precursor metal salt. Valid characterization techniques employed for biosynthesized iron nanoparticles including dynamic light scattering (DLS), transmission electron microscopy (TEM), and high resolution-transmission electron microscopy (HR-TEM) for morphological study. X-ray energy dispersive spectroscopy (EDS) spectrum confirmed the presence of elemental iron signal in high percentage. Apart from ecofriendliness and easy availability, low-cost biomass production will be more advantageous when compared to other chemical methods. Biosynthesis of iron nanoparticles using fungus has greater commercial viability that it may be used in agriculture, biomedicals and engineering sector. Jagadish Chandra Tarafdar and Ramesh Raliya Copyright © 2013 Jagadish Chandra Tarafdar and Ramesh Raliya. All rights reserved.