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.

scholarly journals Preparation and Microstructure of Electrospun BaTiO3 Fibers

2015 ◽  
Vol 62 ◽  
pp. 5-9
Author(s):  
Tasuku Kawashima ◽  
Ryosuke S.S. Maki ◽  
Yoshikazu Suzuki
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fiber Diameter ◽  
Weight Ratio ◽  
Ferroelectric Ceramics ◽  
Poly Vinyl Alcohol ◽  
Electrospinning Method ◽  
Before And After ◽  
New Applications ◽  
Scanning Electron

Barium titanate (BaTiO3: BT) is widely used in various shapes depending on specific applications. Recently, 1-D ferroelectric ceramics are eagerly studied to innovate on new applications. Electrospinning is a versatile method to prepare 1-D nanomaterials. Here, we have prepared BaTiO3/poly (vinyl alcohol) (BT/PVA) composite fibers via the electrospinning method. Suspensions of BT/PVA aq. were prepared with weight ratio of BT:PVA:H2O = x:0.1:0.9-x (x = 0.2 and 0.3). Dried electrospun BT/PVA fibers were sintered at 900-1000°C for 2 h in air. Morphological change of the 1-D BT fibers before and after sintering was investigated by using scanning electron microscopy (SEM) observation. Distribution of the fiber diameter before and after sintering was characterized; average diameters of the 1-D BT fibers before and after sintering were 720 nm and 640 nm, respectively.

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.

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.

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.

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.

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.

Study of fossil bones by synchrotron radiation micro-spectroscopic techniques and scanning electron microscopy

2013 ◽  
Vol 21 (1) ◽  
pp. 149-160 ◽  
Author(s):  
I. M. Zougrou ◽  
M. Katsikini ◽  
F. Pinakidou ◽  
E. C. Paloura ◽  
L. Papadopoulou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cross Sections ◽  
Weight Ratio ◽  
Spectroscopic Techniques ◽  
X Ray ◽  
Osteocyte Lacunae ◽  
Fossil Bones ◽  
Bone Apatite ◽  
Scanning Electron

Earlymost Villafranchian fossil bones of an artiodactyl and a perissodactyl from the Milia excavation site in Grevena, Greece, were studied in order to evaluate diagenetic effects. Optical microscopy revealed the different bone types (fibro-lamellar and Haversian, respectively) of the two fragments and their good preservation state. The spatial distribution of bone apatite and soil-originating elements was studied using micro-X-ray fluorescence (µ-XRF) mapping and scanning electron microscopy. The approximate value of the Ca/P ratio was 2.2, as determined from scanning electron microscopy measurements. Bacterial boring was detected close to the periosteal region and Fe bearing oxides were found to fill bone cavities,e.g.Haversian canals and osteocyte lacunae. In the perissodactyl bone considerable amounts of Mn were detected close to cracks (the Mn/Fe weight ratio takes values up to 3.5). Goethite and pyrite were detected in both samples by means of metallographic microscopy. The local Ca/P ratio determined with µ-XRF varied significantly in metal-poor spots indicating spatial inhomogeneities in the ionic substitutions. XRF line scans that span the bone cross sections revealed that Fe and Mn contaminate the bones from both the periosteum and medullar cavity and aggregate around local maxima. The formation of goethite, irrespective of the local Fe concentration, was verified by the FeK-edge X-ray absorption fine structure (XAFS) spectra. Finally, SrK-edge extended XAFS (EXAFS) revealed that Sr substitutes for Ca in bone apatite without obvious preference to the Ca1or Ca2unit-cell site occupation.

Effect of Anthracite on Preparation of Ceramsite Using Red Mud

2013 ◽  
Vol 467 ◽  
pp. 3-7
Author(s):  
Hui Fen Yang ◽  
Lin Fei Lu ◽  
Bei Ping Jiang ◽  
Jin Long Zhang
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Bulk Density ◽  
Red Mud ◽  
Absorption Rate ◽  
Weight Ratio ◽  
Foaming Agent ◽  
Thermal Stability Of ◽  
Scanning Electron

Based on analyzing of chemical composition, mineral composition and thermal stability of red mud, preparation of ceramisite, using anthracite added as foaming agent, was investigated. Internal structure was observed by scanning electron microscopy (SEM). The results showed the bulk density of ceramisite was obviously reduced by anthracite added. The ceramisite with bulk density of 1.30g/cm3, water absorption rate£ ̈WAR£©of 2.98% and cylinder compressive strength £ ̈CCS£©of 9.48 MPa was obtained when weight ratio of red mud/waste glass/bentonites/anthracite was at 73:15:11:1. Majority of porosity in ceramisite was closed based on SEM. The porosity of ceramisite was much higher when anthracite was added as foaming agent than only calcite in red mud was used as foaming agent. The bulk density of the former was lower than that of the latter.

Sign in / Sign up

Export Citation Format

Share Document