Journal of Nanoparticles http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Biosynthesis of Silver Nanoparticles by Marine Invertebrate (Polychaete) and Assessment of Its Efficacy against Human Pathogens Thu, 21 Aug 2014 00:00:00 +0000 http://www.hindawi.com/journals/jnp/2014/718240/ Synthesis of metallic nanoparticles by chemical and physical method makes the process often cumbersome due the usage of toxic and expensive chemicals. The present study reports the biosynthesis of silver nanoparticles using marine invertebrate (polychaete) extract at room temperature. The ultraviolet-visible (UV-Vis) spectroscopy revealed the formation of silver nanoparticles (AgNPs) by exhibiting the typical surface plasmon absorption maximum at 418–420 nm. Structure and composition of AgNPs were analyzed by atomic force microscopy (AFM). Average particle size of AgNPs ranged from 40 to 90 nm, confirmed by scanning electron microscopy (SEM) analysis. The energy-dispersive X-ray spectroscopy (EDX) of the nanoparticles dispersion confirmed the presence of elemental silver signal, whereas X-ray diffraction (XRD) substantiated the crystalline nature of synthesized nanoparticle. Fourier transform infrared spectroscopy (FTIR) spectral analysis showed the presence of amides phenols, ethers, and fatty acids as major biomolecules responsible for the reduction of silver ions. The possible mechanism responsible for the synthesis of AgNPs by these biomolecules was also illustrated by chemical reactions. The synthesized AgNPs showed comparatively good antibacterial activity against the tested human pathogens. This study advocates that not only plants and microbes but also marine invertebrates do have potential for synthesizing nanoparticles by a cost-effective and eco-friendly approach. Reena Singh, Sunil Kumar Sahu, and Muthusamy Thangaraj Copyright © 2014 Reena Singh et al. All rights reserved. Magnetic Fluid Hyperthermia of Rodent Tumors Using Manganese Perovskite Nanoparticles Thu, 14 Aug 2014 11:33:37 +0000 http://www.hindawi.com/journals/jnp/2014/278761/ Purpose. To test the antitumor activity of magnetic fluid (MF) on the basis of substituted lanthanum-strontium manganite nanoparticles combined with alternating magnetic field (AMF) in experiments with transplanted tumors. Materials and Methods. MF with a size of nanoparticles of 30–40 nm in aqueous agarose solution was investigated. The ability of MF to heat tumor under AMF (300 kHz, 7.7 kA/m) was tested in vivo with rodent tumors (Guerin carcinoma, Walker-256 carcinosarcoma, and Lewis lung carcinoma (3LL)). Results. Single administration of MF into the tumor at a dose of 150 mg/kg (rats) or 200 mg/kg (mice) followed by AMF within 20–30 min (treatment was repeated 3-4-fold) has resulted in the complete regression of tumor in the 35% of rats and 57% of mice. Administration of MF alone or action of AMF alone has not resulted in tumor growth inhibition. The chemomodifying effect of nanohyperthermia was determined, in particular for cisplatinum: thermal enhancement ratio was 2.0. It was also observed that nanohyperthermia has resulted in the absence of 3LL metastases in 43% of mice. Conclusions. MF on the basis of lanthanum-strontium manganite may be considered as an effective inductor of tumor local hyperthermia. Larissa Bubnovskaya, Anatolij Belous, Sergej Solopan, Antonina Kovelskaya, Lyudmila Bovkun, Alexander Podoltsev, Igor Kondtratenko, and Sergej Osinsky Copyright © 2014 Larissa Bubnovskaya et al. All rights reserved. Response Surface Modelling of Electrosprayed Polyacrylonitrile Nanoparticle Size Sun, 10 Aug 2014 11:30:48 +0000 http://www.hindawi.com/journals/jnp/2014/146218/ Electrospraying (electrohydrodynamic spraying) is a method of liquid atomization by electrical forces. Spraying solutions or suspensions allow production of fine particles, down to nanometer size. These particles are interesting for a wide variety of applications, thanks to their unprecedented chemical and physical behaviour in comparison to their bulk form. Knowledge of the particle size in powders is important in many studies employing nanoparticles. In this paper, the effect of some process parameters on the size of electrosprayed polyacrylonitrile particles is presented in the form of response surface model. The model is achieved by employing a factorial design to evaluate the influence of parameters on the polyacrylonitrile nanoparticle size and response surface methodology. Four electrospraying parameters, namely, applied voltage, electrospraying solution concentration, flow rate, and syringe needle diameter were considered. Sanaz Khademolqorani, Ali Zeinal Hamadani, and Hossein Tavanai Copyright © 2014 Sanaz Khademolqorani et al. All rights reserved. Synthesis and the Structural Transformation of fcc to hcp in Ni-Graphene Nanocomposite by Simple Chemical Route via Sonication Mon, 23 Jun 2014 11:38:55 +0000 http://www.hindawi.com/journals/jnp/2014/305637/ We report the synthesis and structural transformation of fcc to hcp in Ni-graphene (Ni-Gr) composite by simple chemical route via sonication. The syntheses of Ni-Gr composite by simultaneous reduction method, and the effect of different composition ratio on morphology and crystal structure were examined in our present study. The results indicated that the graphene ratio played an important role in crystal structure and d-spacing in nickel crystals. Different compositions have shown different behavior. The nanonickel clusters of various shapes with coated graphene and decorated as nickel on graphene sheets are observed. The synthesized composites were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and transmission electron microscope (TEM). The XRD patterns indicated crystal lattice modifications in some composites while composites with a higher graphene ratio produced very small crystals with uniform lattice parameter and d-spacing. FE-SEM images indicated the growth of Datura fruit like shapes of nickel clusters in higher composition of nickel while the composites with least concentration of nickel were composed of cubical nanoparticles grown on graphene sheets. TEM analysis revealed many Ni nanoparticles surrounding the smooth petals like surface of graphene, with average diameters of spiky nickel nanoparticles being about 50 nm and 124 nm, respectively, on 200 nm of scale. N. K. Mahale, R. D. Ladhe, S. B. Attarde, and S. T. Ingle Copyright © 2014 N. K. Mahale et al. All rights reserved. Optical and Structural Properties of ZnO Nanoparticles Synthesized by CO2 Microwave Plasma at Atmospheric Pressure Mon, 23 Jun 2014 11:17:41 +0000 http://www.hindawi.com/journals/jnp/2014/734256/ The results of carbon-doped zinc oxide nanoparticles synthesized by CO2 microwave plasma at atmospheric pressure are presented. The 2.45-GHz microwave plasma torch and feeder for injecting Zn granules are used in the synthesis of zinc oxide nanoparticles. The Zn granules (13.5 g/min) were introduced into the microwave plasma by CO2 (5 l/min) swirl gas. The microwave power delivered to the CO2 microwave plasma was 1 kW. The synthesis of carbon-doped zinc oxide nanoparticles was carried out in accordance with CO2 + Zn → carbon-doped ZnO + CO. The synthesized carbon-doped zinc oxide nanoparticles have a high purity hexagonal phase. The absorption edge of carbon-doped zinc oxide nanoparticles exhibited a red shift from a high-energy wavelength to lower in the UV-visible spectrum, due to band gap narrowing. A UV-NIR spectrometer, X-ray diffraction, emission scanning electron-microscopy, energy dispersive X-ray microanalysis, Fourier transform infrared spectroscopy, and a UV-Vis-NIR spectrophotometer were used for the characterization of the as-produced products. Se Min Chun, Dae Hyun Choi, Jong Bae Park, and Yong Cheol Hong Copyright © 2014 Se Min Chun et al. All rights reserved. Ecofriendly Application of Nanomaterials: Nanobioremediation Thu, 19 Jun 2014 11:03:20 +0000 http://www.hindawi.com/journals/jnp/2014/431787/ Nanomaterials exhibit unique physical and chemical properties and, hence, they have received much attention from scientists and researchers in different areas of environmental sciences, specifically in bioremediation. Bioremediation provides a good clean-up strategy for some types of waste, but as it is expected, it will not be useful for all. For example, bioremediation may not provide a feasible strategy at sites with high concentrations of chemicals that are toxic to most microorganisms. These include heavy metals and salt. Further, the advancement in science and technology has increased standard of living which directly or indirectly contributes to the increase in waste and toxic material. Therefore, the remediation of contaminants by use of existing technology is not effective and efficient in cleaning up the environment. Hence, nanomaterials may be applied for bioremediation, which will not only have less toxic effect on microorganisms, but will also improve the microbial activity of the specific waste and toxic material which will reduce the overall time consumption as well as reduce the overall cost. In this paper we have briefly summarized the major types of nanomaterials that have been used so far in bioremediation of waste and toxic materials. Md. Rizwan, Man Singh, Chanchal K. Mitra, and Roshan K. Morve Copyright © 2014 Md. Rizwan et al. All rights reserved. Studies on the Iron Nanoparticles Catalyzed Reduction of Substituted Aromatic Ketones to Alcohols Wed, 11 Jun 2014 09:31:49 +0000 http://www.hindawi.com/journals/jnp/2014/156868/ Iron nanoparticles are synthesized and size characterized using HRTEM, FESEM, and XRD. Polyethylene glycol(PEG), carboxymethyl cellulose (CMC), and poly N-vinyl pyrrolidone (PVP) are used as nanoparticle stabilizers. The sizes of Fe nps are found to be 9 nm, 14 nm, and 17 nm ± 1 nm corresponding to PEG, CMC, and PVP stabilizers, respectively. The three different iron nanoparticles (Fe nps) prepared are used as catalysts in the hydrogenation reaction of various substituted aromatic ketones to alcohols with NaBH4. The progress of the reaction was monitored using time variance UV spectra. Kinetic plots are made from the absorbance values and the pseudo first order rate coefficient values are determined. Catalytic efficiency of the Fe nps is obtained by comparing the pseudo first order rate coefficient values, times of reaction, and % yield. Fe-PEG nps was found to act as better catalyst than Fe-CMC nps and Fe-PVP nps. Also, effects of substituents in the aromatic ring of ketones reveal that +I substituents are better catalysed than –I substituents. L. Parimala and J. Santhanalakshmi Copyright © 2014 L. Parimala and J. Santhanalakshmi. All rights reserved. Microwave Assisted Biosynthesis of Silver Nanoparticles Using the Rhizome Extract of Alpinia galanga and Evaluation of Their Catalytic and Antimicrobial Activities Tue, 13 May 2014 12:17:54 +0000 http://www.hindawi.com/journals/jnp/2014/967802/ Biomediated methods are considered to be a safer alternative to conventional physicochemical methods for the fabrication of nanomaterials due to their eco-friendly nature. In the present study, silver nanoparticles (AgNPs) were synthesized by microwave irradiation using aqueous rhizome extract of the medicinal plant Alpinia galanga. The nanoparticles were also synthesized under ambient condition without the assistance of microwave radiation and the former method was found to be much faster than the latter. The silver nanoparticles were characterized by UV-vis., FTIR, XRD, and HR-TEM analysis. UV-vis. spectroscopic studies provided ample evidences for the formation of nanoparticles. The FTIR spectrum confirmed the presence of plant phytochemicals as stabilizing agent around the AgNPs. XRD and HR-TEM analyses clearly proved the crystalline nature of the nanoparticles. From the TEM images, the nanoparticles were found to be roughly spherical in shape with an average diameter of 20.82 ± 1.8 nm. The nanoparticles showed outstanding catalytic activity for the reduction of methyl orange by NaBH4. The AgNPs were also evaluated for their antimicrobial activity by well diffusion method against S. aureus, B. subtilis, V. cholera, S. paratyphi, and A. niger. They were found to be highly toxic against all the tested pathogenic strains. Siby Joseph and Beena Mathew Copyright © 2014 Siby Joseph and Beena Mathew. All rights reserved. Copper Oxide Nanoparticles for Advanced Refrigerant Thermophysical Properties: Mathematical Modeling Wed, 30 Apr 2014 12:54:49 +0000 http://www.hindawi.com/journals/jnp/2014/890751/ In modern days, refrigeration systems are important for industrial and domestic applications. The systems consume more electricity as compared to other appliances. The refrigeration systems have been investigated thoroughly in many ways to reduce the energy consumption. Hence, nanorefrigerant which is one kind of nanofluids has been introduced as a superior properties refrigerant that increased the heat transfer rate in the refrigeration system. Many types of materials could be used as the nanoparticles to be suspended into the conventional refrigerants. In this study, the effect of the suspended copper oxide (CuO) nanoparticles into the 1,1,1,2-tetrafluoroethane, R-134a is investigated by using mathematical modeling. The investigation includes the thermal conductivity, dynamic viscosity, and heat transfer rate of the nanorefrigerant in a tube of evaporator. The results show enhanced thermophysical properties of nanorefrigerant compared to the conventional refrigerant. These advanced thermophysical properties increased the heat transfer rate in the tube. The nanorefrigerant could be a potential working fluid to be used in the refrigeration system to increase the heat transfer characteristics and save the energy usage. S. A. Fadhilah, R. S. Marhamah, and A. H. M. Izzat Copyright © 2014 S. A. Fadhilah et al. 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 http://www.hindawi.com/journals/jnp/2014/760712/ 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 http://www.hindawi.com/journals/jnp/2014/302429/ 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 http://www.hindawi.com/journals/jnp/2014/175896/ 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 http://www.hindawi.com/journals/jnp/2014/568635/ 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 http://www.hindawi.com/journals/jnp/2013/640436/ 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 http://www.hindawi.com/journals/jnp/2013/181820/ 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 http://www.hindawi.com/journals/jnp/2013/102823/ 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 http://www.hindawi.com/journals/jnp/2013/156813/ 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 http://www.hindawi.com/journals/jnp/2013/576232/ 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 http://www.hindawi.com/journals/jnp/2013/530170/ 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 http://www.hindawi.com/journals/jnp/2013/685836/ 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 http://www.hindawi.com/journals/jnp/2013/953153/ 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 http://www.hindawi.com/journals/jnp/2013/527432/ 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 http://www.hindawi.com/journals/jnp/2013/106152/ 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 http://www.hindawi.com/journals/jnp/2013/182320/ 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 http://www.hindawi.com/journals/jnp/2013/431218/ 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 http://www.hindawi.com/journals/jnp/2013/273204/ 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 http://www.hindawi.com/journals/jnp/2013/507161/ 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 http://www.hindawi.com/journals/jnp/2013/671214/ 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 http://www.hindawi.com/journals/jnp/2013/690407/ 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 http://www.hindawi.com/journals/jnp/2013/780786/ 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.