The Formation and Morphology of PVA Ferrogel Nanofibre by the Electrospinning Process

2010 ◽  
Vol 650 ◽  
pp. 361-366 ◽  
Author(s):  
Tao Yu Wan ◽  
Mohammad Chowdhury ◽  
George K. Stylios
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Polyvinyl Alcohol ◽  
Flow Rate ◽  
Electrospinning Process ◽  
Magnetic Sensors ◽  
Solution Flow Rate ◽  
Solution Flow ◽  
Fiber Mats ◽  
Scanning Electron

Aqueous solutions of polyvinyl alcohol (PVA) with FeCl3 were homogenously mixed and subsequently electrospun; and its characteristics were studied as a function of voltage, tip-target distance and solution flow rate. Fiber mats of (PVA)/FeCl3 composite, in the diameter of 700–1100 nm were prepared by electrospinning. Lower concentrations of solution tended to facilitate the formation of fibres with beads. With increasing concentration, the morphology was improved with smooth and uniform fibres and the increased fibre diameters in the nano range. Spinning voltage also had an important influence on the diameters of the nano fibres, while the collection distance affected fibre diameters. Nano fibres of smaller diameter were formed when lower voltages are applied. The morphology of the electrospun from PVA/FeCl3 nano fibres and their magnetic power was observed and analyzed by scanning electron microscopy (SEM).The fibres produced in this way could potentially be applied to manufacture magnetic sensors, flexible magnets.

scholarly journals Effects of Jet Path on Electrospun Polystyrene Fibers

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 842 ◽  
Author(s):  
Yuansheng Zheng ◽  
Na Meng ◽  
Binjie Xin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Morphology ◽  
High Speed ◽  
Solution Concentration ◽  
Electrospinning Process ◽  
High Speed Photography ◽  
Fiber Mats ◽  
Jet Length ◽  
Scanning Electron

In this study we investigated the effects of jet path on the morphology and mat size of synthetic polystyrene (PS) fibers during the electrospinning process. In addition, the mechanism of the fiber mats, which were prepared by varying the solution concentration, was evaluated. The straight jet length, envelope cone and whipping frequency of each electrospun jet were studied using images captured by a high-speed photography camera. The results showed that higher solution concentrations led to longer straight jet lengths, smaller envelope cones and lower whipping frequencies. The diameter and surface morphology of the PS fibers were also characterized by scanning electron microscopy (SEM). It was found that fibers spun with higher solution concentrations exhibited larger diameters and diameter distributions because of their jet path features. Furthermore, the electrospun jets with higher concentrations increased elongation and produced smaller fiber mats and higher breaking forces as a result of their different jet paths, which was a consequence of varying the solution concentration.

Morphology of Biodegradable Poly(hexamethylene Adipate)(PHMA) Nanofibers Prepared by Electrospinning

2009 ◽  
Vol 87-88 ◽  
pp. 555-560
Author(s):  
Wei Min Kang ◽  
Bo Wen Cheng ◽  
Quan Xiang Li ◽  
Xu Pin Zhuang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Flow Rate ◽  
Applied Voltage ◽  
Mixed Solvent ◽  
Solution Concentration ◽  
Electrospinning Process ◽  
Solvent Ratio ◽  
Biodegradable Poly ◽  
Scanning Electron

A kind of novel biodegradable poly(hexamethylene adipate) (PHMA) nanofibers with diameter of 100～700nm using a mixed solvent of 1,2-dichloroethane (DCE ) and trifluoroacetic acid (TFA) were obtained by electrospinning process in this paper. The morphology of electropun PHMA nanofibers were investigated by scanning electron microscopy (SEM). The results showed that the morphology, diameter and uniformity of the fibers were influenced by solvent ratio, solution concentration, applied voltage, capillary–screen distance and flow rate greatly. The finer and uniform nanofibers were electrospun from a mixed solvent of DCE and TFA with ratio of 70/30(w/w).

scholarly journals Research on morphologies of polyvinyl alcohol/milk nanofibers

2016 ◽  
Vol 20 (3) ◽  
pp. 961-966
Author(s):  
Yan Zhang ◽  
Chuan-Zheng Zhang ◽  
Fu-Juan Liu ◽  
Fei-Yan Wang ◽  
Ping Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Polyvinyl Alcohol ◽  
Polyvinyl Acetate ◽  
Electrospinning Process ◽  
Diameter Distribution ◽  
Electrospinning Technique ◽  
Weight Percentage ◽  
Surface Morphologies ◽  
Scanning Electron

In this paper, the surface morphologies of polyvinyl alcohol/milk nanofibers produced via electrospinning technique were investigated. The electrospinning process was performed at various processing parameters (flow rate, applied voltage) and different polyvinyl acetate to milk ratios (100/0, 90/10, 80/20, 70/30, and 60/40). The scanning electron microscopy and Image J software were used to characterize the surface morphologies, especially the diameter distribution of electro spun nanofibers. The results of scanning electron microscopy show that the diameter of polyvinyl acetate/milk nanofibers increases with the increase of the spinning speed and spinning voltage but decreases with the increase of the weight percentage of milk in the spinning solution. The potential applications of this bicomponent nanofibers are numerous and diverse. The research results in present paper can contribute to better control of the electrospinning process and thus expanding the applicabilities, such as dressings for wound healing in sports.

scholarly journals Surface and Morphological Investigation of Synthesized Nanostructured Ridges from Electrospun Polyvinyl Alcohol-Albumin Blend—A Taguchi Design of Experiment Approach

Fibers ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 29
Author(s):  
Jopeth Ramis ◽  
Bryan Pajarito ◽  
Crisneil Natividad ◽  
Mark Jared Van Ocampo ◽  
Crizaldy Tugade ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Flow Rate ◽  
Design Of Experiment ◽  
Surface Characterization ◽  
Taguchi Design ◽  
Root Mean Square Roughness ◽  
Solution Flow Rate ◽  
Radius Of Curvature ◽  
Solution Flow ◽  
Taguchi Design Of Experiment

We report the synthesis of presumably a “nanoridge” from the electrospinning of a hydrophilic polymer–protein blend. The material exhibits vertical elevation from the substrate, distinct from the morphologies seen in electrospinning. It is hypothesized that the formation of the nanostructured ridges is due to the migration of the charged protein to the apex through a highly polarized electric field in electrospinning conditions. In this study, we assessed the polyvinyl alcohol–egg albumin (PVA–EA) system in a solvent comprising of water, formic and acetic acid, together with the tip-to-collector distance (TCD) and solution flowrate. To quantify the factor effects in the surface properties of the material, a Taguchi design of experiment was used. The ridge heights observed ranged from 84.8–639.9 nm, and the material height is predominantly affected by the PVA–EA ratio and solution flow rate. The root mean square roughness was influenced by the TCD and flow rate, which has values ranging from 11.37–57.56 nm. In evaluating the sharpness of the ridge, we used the radius of curvature, where the TCD highly affects the apex sharpness. The work offers not just a likely new class of morphology, but a new perspective on the surface characterization of an electrospun material which could affect the performance of such a use in biological and physical systems.

Natural weather ageing of starch/polyvinyl alcohol blend: effect of glycerol content

2013 ◽  
Vol 33 (3) ◽  
pp. 257-263 ◽  
Author(s):  
Sreekumar Parambathmadhom Appu ◽  
Sadhan Kumar De ◽  
Massihullah J. Khan ◽  
Mamdouh A. Al-Harthi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hydrogen Bonding ◽  
Polyvinyl Alcohol ◽  
Weather Conditions ◽  
Intermolecular Hydrogen Bonding ◽  
Biodegradable Material ◽  
Glycerol Content ◽  
Fourier Transfer Infrared Spectroscopy ◽  
Scanning Electron

Abstract Starch plasticized with glycerol and blended with polyvinyl alcohol (PVA) is recommended for use as a biodegradable material. The present article reports the results of studies of the natural weather ageing of starch/PVA blends having various amounts of glycerol in natural weather conditions of Saudi Arabia, with special reference to morphology and thermal behavior. Neat PVA has been used as a control to understand its behavior in its blend with starch. Differential scanning calorimeter studies indicated that an increase in the exposure time of samples to natural environment increases the crystallinity of PVA due to the breakage of intermolecular hydrogen bonding, thus facilitating the removal of the amorphous portion of the polymers in the blend. Thermogravimetric analysis revealed that an increase in glycerol content enhanced the degradation of the polymer, which is corroborated with the findings from the surface morphology using scanning electron microscopy and Fourier transfer infrared spectroscopy analyses.

scholarly journals ANALISIS STRUKTUR NANO DARI LAPISAN TIPIS COBALT FERRITE YANG DIPREPARASI DENGAN METODE SPUTTERING

2017 ◽  
Vol 18 (01) ◽  
pp. 46-53 ◽  
Author(s):  
Ramli Ramli ◽  
Riri Jonuarti ◽  
Ambran Hartono
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Crystallite Size ◽  
Flow Rate ◽  
Cobalt Ferrite ◽  
Growth Parameter ◽  
Deposition Pressure ◽  
Scanning Electron

In this paper we report the results of studies relating to the synthesis of Cobalt Ferrite (CoFe2O4) thin films by a sputtering method. The CoFe2O4 thin film has been prepared onto silicon substrate from the sputtering targets, CoFe. Structural propertiesofthinfilms were characterized byx-ray diffraction and the morphology was characterized by scanning electron microscopy. The growth parameter are: base pressure 2,8 x 10-2 Torr, ratio of Argon:Oxygen flow rate are 100:50 sccm, deposition pressure 5.4 x10-1 Torr, growth temperature 100oC.Nanostructures of the thin film that have been analyzed are crystallite size and micro strain.We obtained the crystallite size of CoFe2O4 thin films for layer thickness of 40 and 48 nm, respectively are: 32 nm and 66 nm, while the micro strain is 8.0 x 10-4 and 10.2 x 10-4.

Study on PS-Molybdophosphoric Composite Fibers via Electrospinning Process

2013 ◽  
Vol 750-752 ◽  
pp. 311-314
Author(s):  
Zhi Ming Zhang ◽  
Ting Ting Li ◽  
Jie Cao ◽  
He Ti Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Morphology ◽  
Composite Membrane ◽  
Hot Pressing ◽  
Electrospinning Process ◽  
Molybdophosphoric Acid ◽  
Composite Fibers ◽  
Cold Pressing ◽  
Scanning Electron

Fine polystyrene fibers have been generated from electrospinning of PS/molybdophosphoric acid in THF and DMF solution. The fiber diameters ranged from 500 nm and increased by adjusting the volume of DMF, the amount of the PS/ molybdophosphoric acid and spinning voltage, the size of the distance. Surface morphology of the nanofibers was characterized by scanning electron microscopy (SEM). The fibers generated from the solutions were more homogeneous in sizes, especially when more THF was added. With the phosphomolybdate amount of increase in untreated, cold pressing, hot pressing modulus showed a trend to decrease. The infrared results show that the composite membrane contains four phosphomolybdate absorption peaks, which is consistent with the predicted results.

Immobilized Bio-Beads with Activated Carbon Fiber for Removal of Benzene

2010 ◽  
Vol 96 ◽  
pp. 93-98 ◽  
Author(s):  
Xiu Li Liu ◽  
Lin Zhao ◽  
She Jiang Liu ◽  
Lu Hua You
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Activated Carbon ◽  
Carbon Fiber ◽  
Polyvinyl Alcohol ◽  
Calcium Alginate ◽  
Activated Carbon Fiber ◽  
Carrier Material ◽  
Removal Process ◽  
Scanning Electron

Two kinds of new immobilized bio-beads in gel were produced with calcium alginate, polyvinyl alcohol and activated carbon fiber. Scanning electron microscopy was used to detect the microstructure and MB were applied to enhance degradation of benzene. It shows that activated carbon fiber was a excellent carrier material to increase MB stability and enhance the degradation of benzene by changing the microsructure. CA-MB in this study was characteristic of loose interface, intensely homogeneous holes and well-reusability. 80% of benzene could be reduced after120h and removal tallied with one-order knetics.Otherwise,for PVA-MB, it possed more compact ouside and irregular tunnles and poles inside.Benzene removal process was analysed to compose of absorption and biodegradation.The immobilization inoculum of 137.77mg/L was optimal with the most stabilities and the best degradation capability for both CA-MB and PVA-MB. Moreover, it is the addition of ACF as encapsulated carrier that made CA-MB superior to PVA-MB in benzene removal and reutilization.

scholarly journals Copper corrosion inhibitors based on polyvinyl alcohol and silver nanoparticles

2019 ◽  
Vol 25 (3) ◽  
pp. 267-275 ◽  
Author(s):  
Roxana Grecu ◽  
Adriana Samide ◽  
Gabriela Iacobescu ◽  
Nicoleta Cioateră ◽  
Alexandru Popescu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silver Nanoparticles ◽  
Hydrochloric Acid ◽  
Polyvinyl Alcohol ◽  
Acid Solution ◽  
Corrosion Inhibitors ◽  
Copper Surface ◽  
Copper Corrosion ◽  
Scanning Electron

Polyvinyl alcohol (PVA) and silver nanoparticles/poly(vinyl) alcohol system (nAg/PVA) were investigated as copper corrosion inhibitors in hydrochloric acid solution by electrochemical measurements, such as potentiodynamic polarization and cyclic voltammetry associated with the atomic force microscopy (AFM) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS) analysis. The potentiodynamic curves processed as a semilogarithmic diagram were employed for corrosion current density (icorr) computing that reached the highest value for copper corrosion in uninhibited hydrochloric acid solution and the lowest value in nAg/PVA inhibitor presence, resulting in a picked-up inhibition performance, greater than 95%. Recording ten cycles of CV, the initiation, development and stability of upper-layer formed on the copper surface in the presence of inhibitors was confirmed. It can be asserted that PVA acts by the adsorption of Cu(II)-PVA complexes or crosslinked PVA-copper aggregates and additionally, in the presence of nAg/PVA of some compounds involving silver attached to PVA. AFM 3D images showed completely different morphologies of the copper surface layers formed in the absence and presence of inhibitors. Just like AFM, a more regular and uniform arrangement of the surface layer, due to the silver interconnected to PVA macromolecular chain, was displayed by scanning electron microscopy (SEM) images.

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