ZrO2 nanotube arrays were prepared by anodization method in aqueous electrolyte containing (NH4)2SO4 and NH4F. The morphology and structure of nanotube arrays were characterized through scanning electron microscope, X-ray diffraction, and infrared spectra analysis. The zirconia nanotube arrays were used as catalyst in esterification reaction. The effects of calcination temperature and electrolyte concentration on catalytic esterification activity have been investigated in detail. Experiments indicate that nanotube arrays have highest catalytic activity when the concentration of (NH4)2SO4 is 1 mol/L, the concentration of NH4F is 1 wt%, and the calcination temperature is 400°C. Esterification reaction yield of as much as 97% could be obtained under optimal conditions.

Xixin Wang

Jianling Zhao

Xiaorui Hou

Qi He

Chengchun Tang

Catalytic Activity of ZrO2 Nanotube Arrays Prepared by Anodization
Method

<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>Er</mml:mtext></mml:mrow><mml:mi>x</mml:mi></mml:msub><mml:msub><mml:mtext>Y</mml:mtext><mml:mrow><mml:mn>3</mml:mn><mml:mo>-</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mtext>Fe</mml:mtext></mml:mrow><mml:mn>5</mml:mn></mml:msub><mml:msub><mml:mtext>O</mml:mtext><mml:mrow><mml:mn>12</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math> nanoparticle films (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>x</mml:mi><mml:mo>=</mml:mo><mml:mn>0.0</mml:mn></mml:math>, 0.6, 1.2, 2.0, and 2.5) have been synthesized by a sol-gel technique. All of the samples were annealed at 1000°C. The nanostructures were characterized by an X-ray diffractometer (XRD), the magnetic properties and the grain size were studied using a vibrating sample magnetometer (VSM), and a field emission scanning electron microscope (FE-SEM), respectively. The XRD patterns of the films show single phase structure. The sizes of the particles are in the range of 78 to 89 nm. The VSM result shows that the saturation magnetization of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mrow><mml:mtext>Er</mml:mtext></mml:mrow><mml:mi>x</mml:mi></mml:msub><mml:msub><mml:mtext>Y</mml:mtext><mml:mrow><mml:mn>3</mml:mn><mml:mo>-</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mtext>Fe</mml:mtext></mml:mrow><mml:mn>5</mml:mn></mml:msub><mml:msub><mml:mtext>O</mml:mtext><mml:mrow><mml:mn>12</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math> films decreased with the increment of Er concentration (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>x</mml:mi></mml:math>).

Ramadan Shaiboub

Noor Baa'yah Ibrahim

Mustafa Abdullah

Ftema Abdulhade

The Physical Properties of Erbium-Doped Yttrium Iron Garnet Films Prepared by Sol-Gel Method

We visually identify pork adulteration in beef and chicken meatball preparations using 20 nm gold nanoparticles (GNPs) as colorimetric sensors. Meatball is a popular food in certain Asian and European countries. Verification of pork adulteration in meatball is necessary to meet the Halal and Kosher food standards. Twenty nm GNPs change color from pinkish-red to gray-purple, and their absorption peak at 525 nm is red-shifted by 30–50 nm in 3 mM phosphate buffer saline (PBS). Adsorption of single-stranded DNA protects the particles against salt-induced aggregation. Mixing and annealing of a 25-nucleotide (nt) single-stranded (ss) DNA probe with denatured DNA of different meatballs differentiated well between perfectly matched and mismatch hybridization at a critical annealing temperature. The probes become available in nonpork DNA containing vials due to mismatches and interact with GNPs to protect them from salt-induced aggregation. Whereas, all the pork containing vials, either in pure and mixed forms, consumed the probes totally by perfect hybridization and turned into grey, indicating aggregation. This is clearly reflected by a well-defined red-shift of the absorption peak and significantly increased absorbance in 550–800 nm regimes. This label-free low-cost assay should find applications in food analysis, genetic screening, and homology studies.

M. E. Ali

U. Hashim

S. Mustafa

Y. B. Che Man

Kh. N. Islam

Gold Nanoparticle Sensor for the Visual Detection of Pork Adulteration in Meatball Formulation

A novel strategy, herein, is demonstrated for improving comprehensive properties of poly (methyl methacrylate)(PMMA)-based gel polymer electrolyte (GPE) with a core-shell PMMA-grafted ordered mesoporous silica (OMS-g-PMMA). The OMS-g-PMMA was synthesized by surface-initiated atom transfer radical polymerization of methyl methacrylate from the exterior surface of OMS particle. A series of PMMA-based GPE membrances, filled with the OMS-g-PMMA of different contents, were further prepared by solution casting technique. The OMS-g-PMMA was confirmed to possess regular core-shell structure, in which a PMMA shell is chemically grafted to the exterior surface of silica core remaining intact mesoporous characteristics. Compared to the bare OMS, the OMS-g-PMMA is found to more effectively improve the comprehensive properties of PMMA-based GPE including ionic conductivity, thermal stability, and mechanical properties as well. For the PMMA-based GPE filled with 15 phr OMS-g-PMMA, the ionic conductivity at 25°C reaches 1.59 × 10−4 S⋅cm−1, which is higher by nearly two orders than that of the corresponding filler-free parent GPE. Meanwhile, the tensile strength and Young's modulus increase by 2.39 and 2.41 times, respectively, with an improvement in glass-transition temperature (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi>T</mml:mi></mml:mrow><mml:mrow><mml:mi>g</mml:mi></mml:mrow></mml:msub></mml:math>) about 10°C. The excellent comprehensive properties make the PMMA-based GPE filled with OMS-g-PMMA as potential candidate for electrochemical devices.

Lixin Xu

Feng Xu

Feng Chen

Jintao Yang

Mingqiang Zhong

Improvement in Comprehensive Properties of Poly(Methyl Methacrylate)-Based Gel Polymer Electrolyte by a Core-Shell Poly(Methyl Methacrylate)-Grafted Ordered Mesoporous Silica

ZnO nanorods with mean diameter 200 nm on different substrates were fabricated by hydrothermal method. Fluorescent properties of fabricated ZnO nanorods were researched by both linear and nonlinear excitation using femtosecond lasers. The damage threshold of productions on Si substrate irradiated under intense femtosecond pulses was found much higher than that on Zn plate. Raman spectrum was also applied to investigate relative optical properties. The A1L optical mode was found to be important to the fluorescent properties of ZnO materials.

Zhiwei Dong

Bing Han

Shixiong Qian

Deying Chen

Fluorescent Properties of ZnO Nanostructures Fabricated by Hydrothermal Method

This work is devoted to synthesize different semiconductor nanoparticles and their metal-hybrid nanocomposites such as TiO2, Au/TiO2, ZnO, and Au/ZnO. The morphology and crystal structure of the prepared nanomaterials are characterized by the TEM and XRD, respectively. These materials are used as catalysts for the photodegradation of Malathion which is one of the most commonly used pesticides in the developing countries. The degradation of 10&#x2009;ppm Malathion under ultraviolet (UV) and visible light in the presence of the different synthesized nanocomposites was analyzed with high-performance liquid chromatography (HPLC) and UV-Visible Spectra. A comprehensive study is carried out for the catalytic efficiency of the prepared nanoparticles. Different factors influencing the catalytic photodegradation are investigated, as different light source, surface coverage, and nature of the organic contaminants. The results indicate that hybrid nanocomposite of the semiconductor-metal hybrid serves as a better catalytic system compared with semiconductor nanoparticles themselves.

Dina Mamdouh Fouad

Mona Bakr Mohamed

Comparative Study of the Photocatalytic Activity of Semiconductor Nanostructures and Their Hybrid Metal Nanocomposites on the Photodegradation of Malathion

We have investigated morphological and optical properties of zinc oxide rods. Highly structured ZnO layers comprising with well-shaped hexagonal rods were prepared by spray pyrolysis deposition of zinc chloride aqueous solutions at ~550&#x2218;C. The rods were characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, photoluminescence, and ultraviolet and visible absorption spectroscopy measurements. The deposition of the 0.1&#x2009;mol/L solution at ~550&#x2218;C resulted in crystals with a diameter of 400&#8211;1000&#x2009;nm and length of 500&#8211;2000&#x2009;nm. Sharp near-band edge emission peaks, centered at 3844 and 3680&#x2009;&#197;, dominated the PL spectra of ZnO at 300&#x2009;K and 6.2&#x2009;K, respectively. In addition to this, absorption coefficient was determined by absorption measurement. X-ray diffraction, scanning electron microscopy and atomic force microscopy, results suggest that ZnO rods, prepared by spray pyrolysis, have high crystalline quality. This is desirable in nanotechnology applications.

Erdal Sonmez

Serdar Aydin

Mehmet Yilmaz

Mustafa Tolga Yurtcan

Tevhit Karacali

Mehmet Ertugrul

Study of Structural and Optical Properties of Zinc Oxide Rods Grown on Glasses by Chemical Spray Pyrolysis

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Journal of Nanomaterials publishes research on nanoscale and nanostructured materials with an emphasis on synthesis, processing, characterization, and the applications of nanomaterials.

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Chief Editor Stefano Bellucci is Professor of Theoretical Physics at the National Institute for Nuclear Physics in Frascati, Italy. His research interests include&nbsp;nanoscience and nanotechnology, nanocarbon-based composites, and the biomedical applications of nanomaterials.

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Journal of Nanomaterials - Table of contents 2012

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Journal of Nanomaterials publishes research on nanoscale and nanostructured materials with an emphasis on synthesis, processing, characterization, and the applications of nanomaterials.

Journal of Nanomaterials