Removed at authors request.

2014 ◽  
Vol 575 ◽  
pp. 191-194
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Solid State ◽  
Energy Dispersive Spectroscopy ◽  
Vinyl Alcohol ◽  
Mixed Matrix Membranes ◽  
Poly Vinyl Alcohol ◽  
Separation Performance ◽  
Mixed Matrix ◽  
Scanning Electron

In the present study, single-walled nanotubes-poly (vinyl alcohol) (SWNT-PVA) mixed-matrix-membranes (MMMs) are prepared and carefully characterized via various solid-state techniques, including scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). We investigate how the separation performance of SWNT-PVA MMM in an ethanol-water pervaporation system is improved with the loading of SWNTs in the membranes.

Radiation – induced preparation of polyaniline/poly vinyl alcohol nanocomposites and their properties

2019 ◽  
Vol 107 (8) ◽  
pp. 725-735
Author(s):  
Hoda H. Saleh ◽  
Rehab Sokary ◽  
Zakaria I. Ali
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Vinyl Alcohol ◽  
Oxidative Polymerization ◽  
Nanocomposite Films ◽  
Poly Vinyl Alcohol ◽  
Transmission Electron ◽  
Scanning Electron

Abstract Polyaniline (PANI) nanoparticles and PANI/poly vinyl alcohol (PVA) nanocomposite films were synthesized by the oxidative polymerization of aniline and ammonium peroxodisulfate (APS), as an oxidizing agent in aqueous medium. The PANI/PVA nanocomposite films were exposed to γ-irradiation after oxidative polymerization. Synthesized polyaniline (PANI) nanoparticles and PANI/PVA nanocomposite films were characterized by attenuated total reflectance infrared spectroscopy (FTIR-ATR), X-ray diffraction, high resolution scanning electron microscopy, (HRSEM) high resolution transmission electron microscopy, (HRTEM) and UV-VIS absorption spectroscopy. Energy band gap of PANI nanofibers was determined from Tauc’s plots which equal 4.2 eV. Scanning electron microscopy images show that chemically synthesized of polyaniline has nanofibers structure and irradiated PANI/PVA nanocomposite have a mixture of nanorod and nanosphere structures. The transmission electron microscopy show that chemically synthesized of polyaniline has average length in the range 34 ± 10 nm with less wide distribution, where as the irradiated PANI/PVA nanocomposite has coreshell structure.

Effect of Poly(vinyl alcohol)/Chitosan Ratio on Electrospun-Nanofiber Morphologies

2012 ◽  
Vol 463-464 ◽  
pp. 734-738 ◽  
Author(s):  
Tongsai Jamnongkan ◽  
Amnuay Wattanakornsiri ◽  
P. Pungboon Pansila ◽  
Claudio Migliaresi ◽  
Supranee Kaewpirom
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Vinyl Alcohol ◽  
Weight Ratio ◽  
Electrospun Nanofibers ◽  
Poly Vinyl Alcohol ◽  
Electrospun Nanofiber ◽  
Electrospinning Method ◽  
Chitosan Content ◽  
Scanning Electron

Series of poly (vinyl alcohol)/chitosan (PVA/CS) electrospun nanofibers with different weight ratio of PVA and CS were fabricated by electrospinning method. The surface morphology, diameter, and structure of electrospun nanofibers were investigated by scanning electron microscopy (SEM). As a result of PVA and CS composition measurements, the electrospun nanofibers morphologies were mainly affected by weight ratio of the polymer solution. When increasing the chitosan content in the blend solution, the electrospun nanofibers could hardly form. This result indicates that the electrospun nanofiber formation is enhanced by chitosan content.

Changes Induced by PVA in the Cement Microstructure Surrounding Aggregate

1994 ◽  
Vol 370 ◽  
Author(s):  
Un-Jen Chu ◽  
Jae-Ho Kim ◽  
Cheol Park ◽  
Richard E. Robertson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Cement Paste ◽  
Vinyl Alcohol ◽  
Secondary Electron ◽  
Poly Vinyl Alcohol ◽  
Backscattered Electron ◽  
And Behavior ◽  
Scanning Electron

AbstractThe presence of poly(vinyl alcohol) (PVA) in portland cement during its hydration was found to induce changes in the microstructure and behavior of the paste that forms around aggregate. The microstructure was studied with scanning electron microscopy in secondary electron, backscattered electron, and EDX mapping modes and with Fourier-transform infraredspectroscopy. The adhesion between cement paste and aggregate was examined with planar aggregate surfaces. With concentrations of the order of 1% by weight of PVA based onthe weight of the cement, the deposition of calcium hydroxide on the aggregate surface was found to be diminished and the porous layer that usually surrounds the aggregate to be reduced in thickness. Also, the bond between the aggregate and cement paste was increasedenough for the bond to approach the strength of the cement.

scholarly journals Influence of Blend Composition and Silica Nanoparticles on the Morphology and Gas Separation Performance of PU/PVA Blend Membranes

Membranes ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 82 ◽  
Author(s):  
Hemmat Shirvani ◽  
Saeid Maghami ◽  
Ali Pournaghshband Isfahani ◽  
Morteza Sadeghi
Keyword(s):  
Silica Nanoparticles ◽  
Gas Separation ◽  
Vinyl Alcohol ◽  
Silica Particles ◽  
Mixed Matrix Membranes ◽  
Poly Vinyl Alcohol ◽  
Separation Performance ◽  
Mixed Matrix ◽  
Blend Membranes ◽  
Gas Separation Performance

Polymer blending and mixed-matrix membranes are well-known modification techniques for tuning the gas separation properties of polymer membranes. Here, we studied the gas separation performance of mixed-matrix membranes (MMMs) based on the polyurethane/poly(vinyl alcohol) (PU/PVA) blend containing silica nanoparticles. Pure (CO2, CH4, N2, O2) and mixed-gas (CO2/N2 and CO2/CH4) permeability experiments were carried out at 10 bar and 35 °C. Poly(vinyl alcohol) (PVA) with a molecular weight of 200 kDa (PVA200) was blended with polyurethane (PU) to increase the CO2 solubility, while the addition of silica particles to the PU/PVA blend membranes augmented the CO2 separation performance. The SEM images of the membranes showed that the miscibility of the blend improved by increasing the PVA contents. The membrane containing 10 wt % of PVA200 (PU/PVA200–10) exhibited the highest CO2/N2~32.6 and CO2/CH4~9.5 selectivities among other blend compositions, which increased to 45.1 and 15.2 by incorporating 20 wt % nano-silica particles.

Effect of Ultrasonic Vibration on Electrospun Poly(vinyl Alcohol) (PVA) Nanofibers

2013 ◽  
Vol 843 ◽  
pp. 1-8 ◽  
Author(s):  
Na Si ◽  
Lan Xu ◽  
Mei Zhen Wang ◽  
Fu Juan Liu
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Scanning Electron Microscopy ◽  
Ultrasonic Vibration ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
The Novel ◽  
Novel Strategy ◽  
Radiation Time ◽  
Scanning Electron

Poly (vinyl alcohol) (PVA), a classical biodegradable polymer, is successfully fabricated into nanofibers via the vibration-electrospinning, and the obtained nanofibers are characterized by the scanning electron microscopy (SEM). The viscosity and electrical conductivity of PVA solution vary dramatically with the ultrasonic radiation time and intensity. The novel strategy can produce finer nanofibers than those obtained without ultrasonic vibration.

Pengaruh implantasi ion tin (Titanium Nitrida) terhadap sifat mekanis baja VCL 140

2010 ◽  
Vol 8 (1) ◽  
pp. 753
Author(s):  
Muhammad Muhammad
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Dispersive Spectroscopy ◽  
Energy Dispersive ◽  
Scanning Electron

Implantasi ion dapat meningkatkan sifat mekanik seperti kekerasan bahan yang akan digunakan untuk komponen dan peralatan proses manufaktur. Implantasi ion dipengaruhi oleh jenis ion dopan, waktu dan energi yang digunakan. Penelitian ini dilakukan untuk mengetahui pengaruh energi dan waktu implantasi ion titanium nitrida terhadap kekerasan dan struktur mikro pada baja VCL 140. Implantasi dilakukan pada arus berkas tetap 10 yA. Variasi waktu 60, 70, 80, 90, 100, 110, 120 menit, energi 75 keV dan variasi energi 15, 30, 45, 60, 75, 90 dan 100 keV dengan waktu implantasi 100 menit dilakukan untuk mendapatkan kekerasan optimum. Uji Kekerasan menggunakan metode Vickers dengan beban 10 gram dan waktu 10 detik. Topografi dari lapisan TIN diamati menggunakan scanning electron microscopy (SEM) dan komposisi kimia dari lapisan TIN dianalisa menggunakan energy dispersive spectroscopy (EDS).Kata kunci : Implantasi ion, VCL 140, kekerasan

scholarly journals Fabrication of Drug-Loaded Starch-based Nanofibers via Electrospinning Technique

2020 ◽  
Vol 11 (3) ◽  
pp. 10801-10811
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Poly Vinyl Alcohol ◽  
Loading Capacity ◽  
Sago Starch ◽  
Electrospinning Technique ◽  
Blending Process ◽  
Operation Parameters ◽  
Optimized Conditions ◽  
Scanning Electron

This paper reported the fabrication of starch-based nanofibers derived from various weight ratios (w:w) of native sago starch (SS) and poly (vinyl alcohol) (PVA) (0:100, 1:100, 3:100, and 5:100) using the electrospinning technique. The effects of electrospinning operation parameters on the surface morphology of SS/PVA nanofibers were observed by using Scanning Electron Microscopy (SEM). The smooth and bead-free SS/PVA nanofibers with fiber diameters within the range of 90 nm to 150 nm were produced under the optimized conditions. The paracetamol (PCM) was encapsulated into the SS/PVA nanofibers via the blending process. The SS/PVA nanofibers exhibited a maximum PCM loading capacity of 0.9573 mg.mg-1, and PCM was observed to release out from SS/PVA nanofibers slowly and steadily for 72 hours.

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