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Field Emission Scanning Electron Microscope (field + emission_scanning_electron_microscope)

Distribution by Scientific Domains
Polymers and Materials Science80%

Selected Abstracts

Properties of InAs co-doped ZnO thin films prepared by pulsed laser deposition

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 12 2009
J. Elanchezhiyan
Abstract InAs co-doped ZnO films were grown on sapphire substrates by pulsed laser deposition. The grown films have been characterized using X-ray diffraction (XRD), Hall effect measurements, Atomic force microscope (AFM) and Field emission scanning electron microscope (FESEM) in order to investigate the structural, electrical, morphological and elemental properties of the films respectively. XRD analysis showed that all the films were highly orientated along the c-axis. It was observed from Hall effect measurements that InAs co-doped ZnO films were of n-type conductivity. In addition, the presence of In and As has been confirmed by Energy dispersive X-ray analysis. AFM images revealed that the surface roughness of the films was decreased upon the co-doping. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Preparation of Porous Tin Oxide Nanobelts Using the Electrospinning Technique

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2008
An Yang
The electrospinning method is adopted to prepare utralong PEO/stannic hydroxide composite nanofibers. Tin-oxide nanobelts can be obtained by calcination of the composite nanofibers in an open atmosphere. The nanobelts were characterized by a field emission scanning electron microscope, X-ray diffraction, a transmission electron microscope, a Raman spectromicroscope, and Fourier transform infrared spectroscopy. Microstructural analysis has shown that the nanobelts prepared consist of a continuous network of interconnected SnO2 grains. As a result, the SnO2 nanobelts possess a high surface area and continuous porosity, which may be applied for the fabrication of sensitive gas sensors. [source]

Structure and properties of multi-walled carbon nanotubes/polyethylene nanocomposites synthesized by in situ polymerization with supported Cp2ZrCl2 catalyst

POLYMER COMPOSITES, Issue 3 2010
Shiyun Li
Multi-walled carbon nanotubes (MWCNTs)/polyethylene (PE) nanocomposites were prepared via in situ polymerization with MWCNTs supported Bis- (cyclopentadienyl) zirconium dichloride (Cp2ZrCl2) catalyst. X-ray photoelectron spectroscopy (XPS) and field emission scanning electron microscope (FESEM) results implied that Cp2ZrCl2 catalyst was immobilized in the surface of the MWCNTs supports via a bridge of methylaluminoxane (MAO). The efficient dispersion of MWCNTs in PE matrix and the strong compressive forces associated with PE on the MWCNTs were demonstrated by means of transmission electron microscope (TEM), FESEM and Raman spectra. With introducing 0.2 wt% MWCNTs, both the tensile strength and elongation of MWCNTs/PE nanocomposite were improved by factors of 1.6 (from 29 to 45 MPa) and 1.5 (from 909% to 1360%) comparing with the pure PE, respectively. Morphology observation of fractured surface revealed that the PE firmly adhered to the nanotubes, which was responsible for the significant improvement of the mechanical properties of nanocomposites. Thermal stabilities of the nanocomposites were significantly improved. In addition, the MWCNTs/PE nanocomposites showed very high ultraviolet (UV) shielding property, which could increase photooxidative stability of the PE. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers [source]

Fabrication of protein-doped PLA composite nanofibrous scaffolds for tissue engineering

POLYMER INTERNATIONAL, Issue 10 2008
Jiang Yuan
Abstract BACKGROUND: Electrospinning is known as a novel fabrication method to form nanofibrous scaffolds for tissue-engineering application. Previously, many natural biopolymers of protein have been electrospun. However, keratin has not attracted enough attention. In this study, keratin and gelatin were co-electrospun with polylactide (PLA), respectively. RESULTS: The resulting nanofibers were characterized by a field emission scanning electron microscope (FE-SEM), an attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), and an electron spectroscopy for chemical analysis (ESCA). The biodegradation of mats in the presence of trypsin solution was studied. Cell attachment experiments showed that NIH 3T3 cells adhered more and spread better onto the PLA/keratin and PLA/gelatin nanofibrous mats than that onto the blank PLA mats. MTT and BrdU assay showed that PLA/keratin and PLA/gelatin nanofibrous mats could both accelerate the viability and proliferation of fibroblast cells as compared to PLA nanofibrous mats. CONCLUSION: The present study suggests that the introduction of gelatin and keratin can both improve cell-material interaction, especially, the former is more effective. Copyright © 2008 Society of Chemical Industry [source]

Characterization of gelatin nanofibers electrospun using ethanol/formic acid/water as a solvent

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 2 2009
Hsin-Chieh Chen
Abstract Gelatin nanofibers were prepared via electrospinning using aqueous solutions of formic acid and ethanol as the solvent instead of cytotoxic solvents. The resulting mat was further crosslinked with glutaraldehyde (GTA). The influence of the storing time on the viscosity and gel point of the solution was investigated. The gelatin nanofibers were examined using a field emission scanning electron microscope (FESEM) for the fiber size and morphology. The lowest diameter of gelatin fiber (85,nm, without beads) was achieved when the gelatin concentration was 20,wt% and electrospinning was conducted with a voltage of 20,kV over a distance of 10,cm at ambient temperature. The results from differential scanning calorimetry (DSC) showed that the softening temperature of gelatin nanofibers crosslinked with GTA was elevated. In addition, GTA-crosslinked gelatin nanofibers exhibited cell compatibility for mouse mesangial cells (CRL 1927). Copyright © 2008 John Wiley & Sons, Ltd. [source]