Superparamagnetic Flexible Substrates based on Submicron Electrospun Estane Fibers Containing MnZnFe-Ni Nanoparticles

2005 ◽  
Vol 877 ◽  
Author(s):  
Pankaj Gupta ◽  
Ramazan Asmatulu ◽  
Rick Claus ◽  
Garth Wilkes
Keyword(s):  
Electron Microscopy ◽  
Ferrite Nanoparticles ◽  
Magnetic Saturation ◽  
Electrospun Fibers ◽  
Flexible Substrates ◽  
Ni Nanoparticles ◽  
Ambient Conditions ◽  
Fiber Morphology ◽  
Scattered Electron ◽  
Scanning Electron

AbstractFlexible field responsive superparamagnetic substrates were prepared by electrospinning a solution of elastomeric polyurethane containing ferrite nanoparticles (ca. 14 nm) of Mn-Zn-Ni. The flexible mats were characterized in terms of fiber morphology and magnetic properties. Field Emission Scanning Electron Microscopy (FESEM) indicated that the diameter of these composite fibers was ca. 300-500 nm. Furthermore, the back-scattered electron FESEM images indicated agglomeration of the nanoparticles at higher wt% (ca 17-26 wt%) loading in the electrospun fibers. The induced specific magnetic saturation and the relative permeability were found to increase linearly with increasing wt% loading of the ferrite nanoparticles on the submicron electrospun fibers. A specific magnetic saturation of 1.7 – 6.3 emu/g at ambient conditions indicated superparamagnetic behavior of these composite electrospun substrates. Additionally, dielectric constant values of the electrospun fibers were measured to be between 2.3 and 5.8.

Fabrication and Characterization of Fibrous Polycaprolactone Blended with Natural Green Tea Extracts Using Dual Solvent Systems

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ainatul Aqilah Binti Mohd Rashid ◽  
Saravana Kumar Jaganathan ◽  
Ahmad Zahran Mohd Khudzari ◽  
Ahmad Fauzi Ismail
Keyword(s):  
Electron Microscopy ◽  
Green Tea ◽  
Water Uptake ◽  
Wound Dressing ◽  
Electrospun Fibers ◽  
Fibrous Morphology ◽  
Solvent Systems ◽  
Fabrication And Characterization ◽  
Scanning Electron

AbstractNanofibrous dressings serve as an impeccable candidate in the management of wounds. Nanofibrous composites composed of polycaprolactone (PCL) and green tea using dual solvent systems at different ratios were fabricated through electrospinning. Pure PCL electrospun fibers along with composites were characterized by using scanning electron microscopy (SEM), wettability, water uptake analysis, and Fourier transform infrared spectroscopy (FTIR). SEM indicated that fibrous morphology and the diameter of PCL/green tea were smaller for chloroform/dimethylformamide (DMF) (601 nm) and acetone/DMF (896 nm) than the pure PCL (673 nm and 1,104 nm for chloroform/DMF and acetone/DMF, respectively). Wettability of the fabricated composites was increased, and pure PCL fibers were slightly more hydrophobic (100°) than PCL/green tea (94°). Water uptake of the composites was enhanced compared with PCL significantly in acetone/DMF. The PCL/green tea nanofibrous wound dressing with enhanced physicochemical properties serves as an indispensable candidate for wound healing applications.

scholarly journals Layer-by-Layer Self-Assembled Ferrite Multilayer Nanofilms for Microwave Absorption

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jiwoong Heo ◽  
Daheui Choi ◽  
Jinkee Hong
Keyword(s):  
Electron Microscopy ◽  
Self Assembly ◽  
Precursor Solution ◽  
Ferrite Nanoparticles ◽  
Energy Dispersive ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Simple Method ◽  
X Ray ◽  
Scanning Electron

We demonstrate a simple method for fabricating multilayer thin films containing ferrite (Co0.5Zn0.5Fe2O4) nanoparticles, using layer-by-layer (LbL) self-assembly. These films have microwave absorbing properties for possible radar absorbing and stealth applications. To demonstrate incorporation of inorganic ferrite nanoparticles into an electrostatic-interaction-based LbL self-assembly, we fabricated two types of films: (1) a blended three-component LbL film consisting of a sequential poly(acrylic acid)/oleic acid-ferrite blend layer and a poly(allylamine hydrochloride) layer and (2) a tetralayer LbL film consisting of sequential poly(diallyldimethylammonium chloride), poly(sodium-4-sulfonate), bPEI-ferrite, and poly(sodium-4-sulfonate) layers. We compared surface morphologies, thicknesses, and packing density of the two types of ferrite multilayer film. Ferrite nanoparticles (Co0.5Zn0.5Fe2O4) were prepared via a coprecipitation method from an aqueous precursor solution. The structure and composition of the ferrite nanoparticles were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy, and scanning electron microscopy. X-ray diffraction patterns of ferrite nanoparticles indicated a cubic spinel structure, and energy dispersive X-ray spectroscopy revealed their composition. Thickness growth and surface morphology were measured using a profilometer, atomic force microscope, and scanning electron microscope.

Improvement of Morphology, Structure, and Thermal Properties of Electrospun PVA/RSF Fiber Mats by SiO2

2012 ◽  
Vol 184-185 ◽  
pp. 1017-1020 ◽  
Author(s):  
Yan Hua Liu ◽  
Li Xing Dai
Keyword(s):  
Thermal Properties ◽  
Silicon Dioxide ◽  
Solution Viscosity ◽  
Electrospun Fibers ◽  
Fiber Morphology ◽  
Fiber Mats ◽  
Hydrogen Bonding Interactions ◽  
Regenerated Silk Fibroin ◽  
Solution Conductivity ◽  
Scanning Electron

Poly(viny1 alcohol) (PVA)/regenerated silk fibroin (RSF)/silicon dioxide (SiO2) fiber mats were prepared by electrospinning of composite solutions. Fiber morphology was observed under a scanning electron microscope and effects addition of SiO2 was evaluated. Results showed that the obtained fibers exhibited a smooth outer surface, and the continuity was improved because of the different solution conductivity, solution viscosity and compatibility of PVA and RSF by the addition of 1.0 wt. % SiO2. It was found that both Si-O-C linkage and hydrogen bonding interactions were existed among SiO2, PVA, and RSF by FTIR spectroscopy. The addition of SiO2 also resulted in the decrease of crystallinity and increase of thermal properties of electrospun fibers, which were suggested as a result of enhanced compatibility and physical properties of PVA and RSF composite.

Synthesis of Fe2O3/CNTs for the Fast Removal of Tetracycline from Aqueous Solutions

2014 ◽  
Vol 915-916 ◽  
pp. 933-941 ◽  
Author(s):  
Zhong Jie Zhang ◽  
Chang Yu Lu ◽  
Wei Huang ◽  
Wei Sheng Guan ◽  
Yue Xin Peng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Magnetic Measurements ◽  
Ferrite Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Wide Range ◽  
Fast Removal ◽  
Scanning Electron

The effective remove to tetracycline still remains a big challenge for scientists. In this work, we used a new method for preparing functional magnetic CNTS with ferrite nanoparticles. A wide range of techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and magnetic measurements were applied to characterize the obtained Fe2O3/CNTs. Moreover, we have also studied the properties of adsorbent to tetracycline. In addition, we have found that the Fe2O3/CNTs are better reusable adsorbent than other traditional adsorbents by magnetic separation recycling method.

Investigating the influence of temperature on electrospinning of polycaprolactone solutions

e-Polymers ◽  
2014 ◽  
Vol 14 (5) ◽  
pp. 323-333 ◽  
Author(s):  
Soghra Ramazani ◽  
Mohammad Karimi
Keyword(s):  
Electron Microscopy ◽  
Molecular Orientation ◽  
Fiber Diameter ◽  
Minimum Size ◽  
Effect Of Temperature ◽  
Electrospun Fibers ◽  
Influence Of Temperature ◽  
Set Point ◽  
Influence Of Temperature On ◽  
Scanning Electron

AbstractThe present work shows the effect of temperature on successfully obtained uniform electrospun poly-(ε-caprolactone) (PCL) fibers, with specific attention to the molecular orientation and diameter of nanofibers. Experiments were performed at temperatures (T) of 25°, 35°, and 45°C, and at PCL concentrations (w) of 12, 16, and 20 wt.%. Scanning electron microscopy provided the morphology of electrospun fibers and quantified their diameters. Elevated temperature for all PCL concentrations yielded a viscosity that allows for easier stretching of the jet to obtain a smaller diameter for fibers. A minimum size of the fiber diameter (close to 100 nm) was achieved for the set point T=45°C and w=12 and 16 wt.%. Due to the easy stretching of the jet by controlling the elastic property of the solution, a dichroic ratio of 1.62 was accessible for the set point T=35°C and w=12 wt.% from polarized Fourier transform infrared spectra as a factor for the orientation of PCL chains.

scholarly journals High-responsivity hybrid α-Ag2S/Si photodetector prepared by pulsed laser ablation in liquid

2020 ◽  
Vol 11 ◽  
pp. 1596-1607
Author(s):  
Raid A Ismail ◽  
Hanan A Rawdhan ◽  
Duha S Ahmed
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Laser Ablation ◽  
Energy Gap ◽  
Longitudinal Optical Phonon ◽  
Ambient Conditions ◽  
Optical Energy Gap ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Scanning Electron

We report the synthesis of α-Ag2S nanoparticles (NPs) by one-step laser ablation of a silver target in aqueous solution of thiourea (Tu, CH4N2S) mixed with cationic cetyltrimethylammonium bromide (CTAB) as surfactant. The effect of the CTAB surfactant on the structural, morphological, optical, and elemental composition of Ag2S NPs was evaluated using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and UV–vis spectroscopy. The optical absorption decreased and the optical energy gap of α-Ag2S increased from 1.5 to 2 eV after the CTAB surfactant was added to the Tu solution. XRD studies revealed that the synthesized Ag2S NPs were polycrystalline with a monoclinic structure and that crystallinity of the nanoparticles was improved after adding CTAB. Raman studies revealed the presence of peaks related to Ag–S bonds (Ag modes) and the longitudinal optical phonon 2LO mode. Scanning electron microscopy investigations confirmed the production of monodisperse Ag2S NPs when using the CTAB surfactant. The optoelectronic properties of α-Ag2S/p-Si photodetector, such as current–voltage characteristics and responsivity in the dark and under illumination, were also improved after using the CTAB surfactant. The responsivity of the photodetector increases from 0.64 to 1.85 A/W at 510 nm after adding CTAB. The energy band diagram of the α-Ag2S/p-Si photodetector under illumination was constructed. The fabricated photodetectors exhibited reasonable stability after three weeks of storage under ambient conditions with a responsivity of 70% of the initial value.

Dislocation density and oxidation behavior in mineral and coal pyrites

1990 ◽  
Vol 48 (4) ◽  
pp. 224-225 ◽  
Author(s):  
S. S. Pollack ◽  
D. V. Martello ◽  
J. P. Tamilia ◽  
H. B. Booher ◽  
R. A. Souza
Keyword(s):  
Electron Microscopy ◽  
Oxidation Behavior ◽  
Mine Drainage ◽  
Defect Density ◽  
Pyrite Oxidation ◽  
Line Defect ◽  
Ambient Conditions ◽  
Etch Pits ◽  
Iron Pyrites ◽  
Scanning Electron

Unstable iron pyrites known as ‘rotten’ pyrite, have been a problem for mineral collectors since these pyrites spontaneously react to form iron sulfates with subsequent fracturing of the specimens when they are stored under ambient conditions. Much of the pyrite found in coal is also highly reactive, and produces acid mine drainage, with associated environmental problems. Other iron pyrites are chemically stable under identical weathering conditions. The authors propose that the increased pyrite oxidation behavior of the coal and ‘rotten’ pyrites may be explained by differences in the crystal defect concentration.In the present study, stable and ‘rotten’ mineral pyrites, and coal pyrite crystals have been examined using light microscopy and scanning electron microscopy. Etch pits observed on the pyrite crystal faces are presumed to result from the intersection of dislocations with the free surface and hence provide a measure of crystal line defect density.

scholarly journals Phase inversion phenomena of EPDM/PP - based TPVs by Electronic Microscopy

2009 ◽  
Vol 15 (S3) ◽  
pp. 91-92
Author(s):  
C. F. Antunes ◽  
A. V. Machado ◽  
M. van Duin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Inversion ◽  
Electronic Microscopy ◽  
Scattered Electron ◽  
Electron Detector ◽  
Morphology Development ◽  
Microscopy Techniques ◽  
Scanning Electron

AbstractMorphology development during phase inversion is a very complex and not well understood process. EPDM/PP -based TPVs were prepared and characterize by different electronic microscopy techniques. Using a low Mw-EPDM, morphology development during phase inversion was successfully followed by scanning electron microscopy with a back scattered electron detector.

Measuring size-dependent mechanical properties of electrospun polystyrene fibers using in-situ AFM-SEM

2012 ◽  
Vol 1424 ◽  
Author(s):  
Russell J. Bailey ◽  
Beatriz Cortes-Ballesteros ◽  
Hao Zhang ◽  
Congwei Wang ◽  
Asa H. Barber
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Fiber Diameter ◽  
Electrospun Fibers ◽  
Force Microscopy ◽  
Size Dependent ◽  
Atomic Force ◽  
Scanning Electron

ABSTRACTThe mechanical properties of individual electrospun polystyrene fibers with sub-micron diameters were measured using a combination of atomic force microscopy (AFM) and scanning electron microscopy (SEM). The strain to failure of the electrospun fibers was observed to increase as the fiber diameter decreased. This size dependent mechanical behavior in individual electrospun polystyrene fibers indicates a suppression of localized failure and a shift away from crazing that is dominant in bulk samples.

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