scholarly journals ТЕХНОЛОГІЯ ОДЕРЖАННЯ УЛЬТРАТОНКИХ НЕТКАНИХ МАТЕРІАЛІВ НА ОСНОВІ ПОЛІМЕРНИХ КОМПОЗИЦІЙ З ХІТОЗАНОМ

2021 ◽  
Vol 148 (4) ◽  
pp. 107-116
Author(s):  
О. В. Іщенко ◽  
В. П. Плаван ◽  
І. О. Ляшок ◽  
Т. В. Шевчук ◽  
З. С. Патрихіна
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Scanning Electron Microscopy ◽  
Surface Tension ◽  
Polyvinyl Alcohol ◽  
Polyvinyl Acetate ◽  
Polymer Composition ◽  
Nonwoven Materials ◽  
Scanning Electron ◽  
Acetic Acids

The  aim  of  the  scientific  work  is  to  develop  a  technology  for  obtaining  of  ultrafine nonwoven  materials  based  on  a  polymer  composition  of  polyvinyl  alcohol  and  polyvinyl  acetate  with  the addition of chitosan, which was dissolved in lactic and acetic acids. Methodology. To assess the characteristics of the compositions, the viscosity and surface tension of working solutions were determined by capillary viscometry, and electrical conductivity - by conductometric method.  The  effect  of  thermal  stabilization  of  materials  based  on  chitosan  was  investigated  using  their sorption  properties.  The  morphological  composition  of  nonwovens  was  investigated  by  the  method  of scanning electron microscopy. Findings.  A  technology  has  been  developed  for  the  obtaining  of  ultrafine  materials  based  on chitosan dissolved in lactic and acetic acids by the method of electrospinning. The parameters for obtaining fibers from the studied compositions were determined. As a result of the analysis of the obtained ultrafine nonwoven  materials  by  the  method  of  scanning  electron  microscopy,  it  was  found  that  with  a  voltage between  the  electrodes  of  30  kV,  fibers  with  a  diameter  of  0.3  to  0.9  μm  are obtained.  According  to the statistical distribution of the diameters of polymer fibers in ultrafine nonwoven materials, it was determined that, depending on the components of the composition, 72-77% of the fibers have a diameter of 0.3 μm. Originality.  The  scientific  novelty  of  the  work  lies  in  the  determination  of  the  basic  laws  of  the electrospinning process using the natural polymer of chitosan and the peculiarities of the preparation of its solutions  in  lactic  and  acetic  acids.  The  effect  of  viscosity,  surface  tension  and  electrical  conductivity  of working solutions of the compositions on the process of electrospinning has been established. Practical value. Technological parameters for the obtaining of ultrafine nonwoven materials based on  the  composition  of  polyvinyl  alcohol  and  polyvinyl  acetate  with  the  addition  of  chitosan  have  been developed by the method of electrospinning; the possibility of adjusting the fiber diameter by choosing a chitosan solvent has been determined.

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.

USE OF NANOFLUIDS BASED ON CARBON NANOPARTICLES TO DISPLACE OIL FROM THE POROUS MEDIUM MODEL

2020 ◽  
Vol 6 (4) ◽  
pp. 141-157
Author(s):  
Yuri V. Pakharukov ◽  
Farid K. Shabiev ◽  
Ruslan F. Safargaliev ◽  
Boris S. Yezdin ◽  
Valery V. Kalyada
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Scanning Electron Microscopy ◽  
Porous Medium ◽  
Synergistic Effect ◽  
Transition Region ◽  
Dimensional Structure ◽  
Hybrid Nanofluids ◽  
Scanning Electron

Graphene, due to its two-dimensional structure, has some unique properties. For example, the thermal conductivity and electrical conductivity of graphene are an order of magnitude higher than the thermal conductivity and electrical conductivity of copper. For this reason, graphene-based nanofluids are now used in many industries. Due to the effect of self-organization of graphene nanoparticles with hydrocarbon molecules, the use of graphene has become possible in the oil industry. Graphene-based nanofluids are used as a displacement fluid to increase the oil recovery coefficient. The displacing ability of graphene-based nanofluids is concentration dependent. An increase in the concentration of nanoparticles entails an increase in viscosity, which negatively affects the performance characteristics of the nanofluid. This problem is partially solved due to the synergistic effect, hybrid nanofluids consisting of nanoparticles of graphene and metals or carbides enhance the displacing ability. Using atomic force microscopy, scanning electron microscopy and molecular modelling methods, this work has studied the formation of supramolecular structures that form a transition region at the oil-nanofluid interface with low surface tension as a result of a synergistic effect in the interaction of graphene planar nanoparticles and silicon carbide nanoparticles covered with graphene layers (Core-shell). The model experiments on a Hele-Shaw cell have shown that in a porous medium, such hybrid nanofluids have a high displacement ability of residual oil. At the same time, the oil — nanofluid interface remains stable, without the formation of viscous fingers. During the study by scanning electron microscopy, a transition region was observed, in the structuring of which the nanoparticles were directly involved. The displacement efficiency of a hybrid nonofluid depends on the concentration of nanoparticles and their interaction.

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.

Structural and electrical investigation of (Ag3AsS3)x(As2S3)1−x superionic glasses

Open Physics ◽  
2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Ihor Studenyak ◽  
Yuriy Neimet ◽  
Csaba Cserháti ◽  
Sándor Kökényesi ◽  
Edvardas Kazakevičius ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Activation Energy ◽  
Electrical Conductivity ◽  
Scanning Electron Microscopy ◽  
Transmission Coefficient ◽  
Structural Studies ◽  
Compositional Range ◽  
Electrical Investigation ◽  
Scanning Electron

AbstractStructural studies of (Ag3AsS3)x (As2S3)1−x chalcogenide superionic glasses in the compositional range x = 0.3–0.9 were performed by scanning electron microscopy. Temperature and compositional dependences of transmission coefficient, electrical conductivity, and activation energy were investigated

Effect of Al2O3 on the Electrical Conductivity and Structural Study in MgI2-Mg3(PO4)2 Based Solid Electrolyte

2013 ◽  
Vol 701 ◽  
pp. 150-153
Author(s):  
A. Aziz ◽  
M.M. Mahat ◽  
A.H. Ahmad
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Scanning Electron Microscopy ◽  
Impedance Spectroscopy ◽  
Field Emission ◽  
Weight Percent ◽  
Binary Compound ◽  
Maximum Conductivity ◽  
Enhanced Conductivity ◽  
Scanning Electron

The effect of filler to the binary compound of Magnesium Iodide ( MgI2) and Magnesium Phosphate (Mg3(PO4)2is investigated. A small amount Alumina (Al2O3) filler in the range of 2-10 weight percent is added to the optimum composition with maximum conductivity of binary compound 0.7 Mg3(PO4)2and 0.3 MgI2.The electrical conductivity of theMgI2- Mg3(PO4)2- Al2O3measured using the impedance spectroscopy (IS) method and result shows that the electrical conductivity of the compound has improved up to 9.84x10-4Scm-1. Field Emission Scanning Electron Microscopy (FESEM) images show some changes in the morphology after introduce the filler. The samples with filler showsnano flakes like structure with some space createdallowing the Mg2+cations to migrate that lead to enhanced conductivity.

Preparation of Polyaniline @ Polypyrrole Conductive Composite via In Situ Polymerization

2013 ◽  
Vol 562-565 ◽  
pp. 1137-1142
Author(s):  
Hui Xia Feng ◽  
Bing Wang ◽  
Lin Tan ◽  
Na Li Chen
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
In Situ Polymerization ◽  
Conductive Composite ◽  
The Core ◽  
Novel Method ◽  
Scanning Electron

We prepared the polyaniline@polypyrrole (PAn@PPy) conductive composite by a novel method. The struction like Pre-prepared PAn as the core and PPy as the shell for the composite has been prepared by in-situ polymerization. The PAn@PPy conductive composite presents an electrical conductivity of 12.5 S/cm, which is much higher than pure PAn. The synthesized polymer composites are characterized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Thermogravimetric analysis (TG). The results indicated that PPy successfully grafted on PAn and the heat resistance of nanocomposite is remarkably increased.

Multiwall Carbon Nanotube / Polyvinyl Alcohol Nanofibers Film, Electrical Conductivity Improvement

2020 ◽  
Vol 38 (3A) ◽  
pp. 431-439
Author(s):  
Akram R. Jabur
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Polyvinyl Alcohol ◽  
Maximum Stress ◽  
Conductive Polymer ◽  
Multiwall Carbon Nanotube ◽  
Multiwalled Carbon ◽  
Electrospinning Technique ◽  
Multiwall Carbon ◽  
Scanning Electron

Conductive polymer films were prepared of polyvinyl alcohol (PVA) with (0, 2, 4, 6, 8, and 10) wt. % multiwalled carbon nanotubes (MWCNTs) by electrospinning technique. The morphologies of the synthesized films were tested by scanning electron microscopy (SEM). Average fiber diameters gauged statically was (115nm) for (PVA/10 wt. % MWCNT film) while (170nm) for pure PVA electro spun film. Electrical conductivity (EC) of Polymeric nanofiber films improve by increasing MWCNT addition concentration from (3.69 × 10-7 S/ cm) for the pure (PVA) film to (1.24 ×10-2 S/cm) for the film with 10 wt. % MWCNT. The maximum stress of PVA film were increased by adding MWCNTs concentration, the modulus of elasticity was enhanced from 12.87 MPa for pure PVA to 49.89 MPa for PVA/8wt% MWCNT.

scholarly journals The effect of metalation processes on polymer morphology and conductivity properties

2021 ◽  
pp. 096739112110482
Author(s):  
Oğuz Yunus Sarıbıyık ◽  
İlyas Gönül ◽  
Burak Ay ◽  
Serkan Karaca
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Scanning Electron Microscopy ◽  
Three Dimensional ◽  
Spectroscopic Methods ◽  
Spectral Features ◽  
Photoluminescence Properties ◽  
Polymer Morphology ◽  
Polymeric Structures ◽  
Scanning Electron

In this work, an insoluble three dimensional (3D) porous polymeric structure and their metal complexes were synthesised by the condensation reactions of meta(m)-phenylenediamine, para(p)-phenylenediamine and glutaraldehyde. The morphological and spectral features of the porous polymeric structures were determined using different analytical and spectroscopic methods, including field emission scanning electron microscopy, four-point probe electrical conductivity, photoluminescence spectroscopy, Fourier-transform infrared spectroscopy, surface area Brunauer–Emmett–Teller and magnetic and thermal behaviours. According to the obtained data, the shape, size and photoluminescence properties of the compounds, especially the conductivity, were clearly changed after the metalation processes.

scholarly journals Synthesis, Crystal Structure Refinement, and Electrical Conductivity of Pb(8−x)Na2Smx(VO4)6O(x/2)

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Tatiana M. Savankova ◽  
Lev G. Akselrud ◽  
Lyudmyla I. Ardanova ◽  
Alexey V. Ignatov ◽  
Eugeni I. Get’man ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Scanning Electron Microscopy ◽  
Solid Solutions ◽  
Structure Refinement ◽  
Crystal Structure Refinement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Solid solutions of Pb(8−x)Na2Smx(VO4)6O(x/2)were studied using X-ray diffraction analysis including Rietveld refinement and scanning electron microscopy and by measuring their electrical conductivity. Crystal structure of the solid solutions was refined and the solubility region0≤x≤0.2was determined for samarium substitution for lead under the scheme2Pb2++□→2Sm3++O2-. The influence of degree of substitution on the electrical conductivity of solid solutions was established.

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.

Sign in / Sign up

Export Citation Format

Share Document