New preparation approach, electrical and mechanical properties of poly(vinyl alcohol)-loaded graphene films

2019 ◽  
pp. 089270571987394
Author(s):  
Osama Saber ◽  
Mohammed Abu-Abdeen ◽  
A Aljaafari ◽  
Javed Mazher ◽  
Mohamad M Ahmed ◽  
...  
Keyword(s):  
Polymer Matrix ◽  
Vinyl Alcohol ◽  
Graphene Nanosheets ◽  
Low Cost ◽  
High Mass ◽  
Poly Vinyl Alcohol ◽  
Graphene Sheets ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
One Step

Previous publications showed that graphene sheets polymer nanocomopsites were prepared by incorporating previously prepared graphene into the polymer matrix through two or more successive steps. In this work, graphene sheets were exfoliated from graphite inside the polymer matrix solution for certain period in one step. This approach was easy to perform, low cost, high mass production of graphene and, almost, produces effective results. In this respect, electrolytic solution from poly(vinyl alcohol) (PVA) and salt was prepared and exfoliation process took place inside it for different times. After that, solution was dried to get films of PVA loaded with different concentrations of graphene sheets. Scanning electron microscopic and transmission electron microscopic images of exfoliated graphene sheets were studied. Raman spectroscopy of graphite, graphene nanosheets, and PVA-loaded graphene was studied. The dielectric permittivity, dielectric loss, and alternating current electrical conductivity were studied and had maximum values at 10 min of exfoliation time. Cole–Cole impedance plots show semicircles behavior with lowest radius for samples prepared at 10 min. The elastic modulus was found to have a maximum value at exfoliation time of 30 min.

Nickel Nanoparticles Supported on Diphenylphosphinated Poly(Vinyl Alcohol-Co-ethylene) as a New Heterogeneous and Recyclable Catalyst for Mizoroki–Heck Reactions

2017 ◽  
Vol 41 (9) ◽  
pp. 541-546 ◽  
Author(s):  
Farzaneh Ebrahimzadeh
Keyword(s):  
Vinyl Alcohol ◽  
Nickel Nanoparticles ◽  
Supported Catalysts ◽  
Low Cost ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
Heck Reactions ◽  
Modified Polymer ◽  
Transmission Electron ◽  
High Metal

Nickel nanoparticles (NiNPs) supported on diphenylphosphinated poly(vinyl alcohol- co-ethylene) (DPP-PVA- co-PE) were synthesised by first reacting poly(vinyl alcohol- co-ethylene) with chlorodiphenylphosphine (ClPPh2) under basic conditions and then treating the product with Ni(OAc)2 followed by reduction with NaBH4. (DPP-PVA- co-PE)-NiNPs, a new metallised polymer, was then shown to efficiently catalyse Mizoroki–Heck reactions of aryl iodides, bromides or activated chlorides with olefins such as styrene and n-butyl acrylate in dimethylformamide. In contrast with other polymer-supported catalysts, the main advantage of this method is the low cost of the catalyst due to the simple synthetic route using easily obtained materials and good recoverability. Transmission electron microscopy and X-ray diffraction measurements were used to show the high metal dispersion and small sizes of Ni nanoparticle on the surface of the modified polymer. DPP-PVA- co-PE-NiNPs could be recycled several times.

A low-cost piezoresistive pressure sensor with a wide strain range – featuring polyurethane sponge@poly(vinyl alcohol)/sulfuric gel electrolyte

2021 ◽  
Author(s):  
Haonan Cheng ◽  
Bo Wang ◽  
Kun Yang ◽  
Chaoxia Wang
Keyword(s):  
Pressure Sensor ◽  
Vinyl Alcohol ◽  
Low Cost ◽  
Strain Range ◽  
Human Movement ◽  
Poly Vinyl Alcohol ◽  
Piezoresistive Pressure Sensor ◽  
One Step ◽  
Polyurethane Sponge ◽  
Movement Monitoring

A low-cost and high-compressibility PVA/H2SO4@PU composite was prepared by one-step dipping to realize human movement monitoring.

Preparation and Characterization of Hybrid Graphene-ZnS Nanoparticles

2010 ◽  
Vol 663-665 ◽  
pp. 894-897
Author(s):  
Hua Huang ◽  
Hai Hu Yu ◽  
Ling De Zhou ◽  
Er Dan Gu ◽  
De Sheng Jiang
Keyword(s):  
Coupling Effect ◽  
Zinc Acetate Dihydrate ◽  
Graphene Sheets ◽  
Acetate Dihydrate ◽  
Zns Nanoparticles ◽  
Transmission Electron ◽  
Infrared Spectrometer ◽  
One Step ◽  
Average Size

Hybrid Graphene-ZnS nanopaticles (G-ZnS NPs) were prepared by using a solvothermal method. A dispersion of graphite oxide (GO) and zinc acetate dihydrate (Zn(CH3COO)2.2H2O) in dimethl sulfoxide (DMSO) reacted at 180 °C for 12 h in a Telfon-lined stainless steel autoclave. In the reaction, DMSO serves as a sulphide source as well as a reducing agent, resulting formation of the hybrid G-ZnS NPs in one-step. Hybrid G-ZnS NPs were characterized by using a powder X-ray diffractometer, a Fourier-transform infrared spectrometer, a transmission electron microscope, a UV-vis spectrophotometer and a fluorescence spectrophotometer, respectively. In the FTIR spectra, the GO related stretching bands of C-O and carboxyl groups are not observed in the spectra of G-ZnS, suggesting that the GO sheets were reduced to graphene sheets. In the TEM images, it is observed that the ZnS nanoparticles with an average size of 23 nm are attached onto the graphene sheets. The UV-vis absorption spectrum of the G-ZnS NPs dispersed in ethanol has an absorption peak of G at 261 nm and a weak shoulder of ZnS NPs around 320 nm. The broadening and weakening of the peak of ZnS NPs at 320 nm arises from the interparticle coupling effect. Under excitation at 225 nm, a peak around 386 nm and other weaker bands appear in the fluorescence spectrum of the G-ZnS. The band at 386 nm is attributed to zinc vacancies.

scholarly journals A novel nano zero-valent iron@chitosan for effective removal of Microcystin-LR: Kinetics and adsorption mechanism

2018 ◽  
Vol 53 ◽  
pp. 04004 ◽  
Author(s):  
Xiaofan Yang ◽  
Xueyu Wei ◽  
Xiaoping Xu ◽  
Zhigang Liu
Keyword(s):  
Low Cost ◽  
Spherical Shape ◽  
Step Method ◽  
Variable Parameters ◽  
Transmission Electron ◽  
Effective Removal ◽  
Initial Ph ◽  
Nano Zero Valent Iron ◽  
One Step ◽  
Kinetics Of

Microcystin-LR (MC-LR) is one of the most notorious toxins liberated from cyanobacteria in drinking water sources. In this study, a skillful method access to new nanozero-valent iron @chitosan (nZVIMC) was synthesized by a facile one step method. The as-prepared nZVIMC was employed as an adsorbent for the effective removal MC-LR from aqueous solution. Transmission electron microscopy (TEM) demonstrates that nZVIMC is in quasi-spherical shape with size of around 50 nm, effect of variable parameters such as pH, contact time, initial concentration of MC-LR and adsorption properties of nZVIMC on MC-LR was further investigated. Scanning electron microscope (SEM) reveals that the particles are nearly spherical in shape with agglomeration. The results indicated that good adsorption performance was achieved at an initial pH of 5. The adsorption kinetics of nZVIMC was better fitted by pseudo-secondorder kinetics. The adsorption isotherm data was fitted well to Langmuir isotherm and then to Freundlich model, with an adsorption capacity of 68.9 mg/g at 300K. Thus, we believe that nZVIMC can be used as a low cost material for efficient removal of MC-LR from water.

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.

Growth and Characterization of Cobalt-filled Carbon Nanotubes Prepared by a Simple Catalytic Method

2003 ◽  
Vol 776 ◽  
Author(s):  
Xicheng Ma ◽  
Yuanhua Cai ◽  
Xia Li ◽  
Ning Lun ◽  
Shulin Wen
Keyword(s):  
Carbon Nanotubes ◽  
Metallic Nanoparticles ◽  
Low Cost ◽  
Catalytic Method ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
One Step

AbstractHigh-quality cobalt-filled carbon nanotubes (CNTs) were prepared in situ in the decomposition of benzene over Co/silica-gel nano-scale catalysts. Unlike the previous reports, the catalysts needn't be pre-reduced prior to the forming of Co-filled CNTs, thus the advantage of this method is that Co-filled CNTs can be produced in one step, at a relatively low cost. Transmission electron microscopy (TEM) investigation showed that the products contained abundance of CNTs and most of them were filled with metallic nanoparticles or nanorods. High-resolution TEM (HRTEM), selected area electron diffraction (SAED) patterns and energy dispersive X-ray spectroscopy (EDS) confirmed the presence of Co inside the nanotubes. The encapsulated Co was further identified always as high temperature alpha-Co phase with fcc structure, which frequently consists of twinned boundaries and stacking faults. Based on the experimental results, a possible growth mechanism of the Co-filled CNTs was proposed.

Microstructure and characterization of electrospun poly(vinyl alcohol) nanofiber scaffolds filled with graphene nanosheets

2015 ◽  
Vol 132 (17) ◽  
Author(s):  
Chien-Lin Huang ◽  
Sheng-Yin Peng ◽  
Yu-Jyun Wang ◽  
Wen-Cheng Chen ◽  
Jia-Horng Lin
Keyword(s):  
Vinyl Alcohol ◽  
Graphene Nanosheets ◽  
Poly Vinyl Alcohol ◽  
Nanofiber Scaffolds

Graphene-reinforced poly(vinyl alcohol) electrospun fibers as building blocks for high performance nanocomposites

RSC Advances ◽  
2015 ◽  
Vol 5 (103) ◽  
pp. 85009-85018 ◽  
Author(s):  
Sajjad Ghobadi ◽  
Sina Sadighikia ◽  
Melih Papila ◽  
Fevzi Çakmak Cebeci ◽  
Selmiye Alkan Gürsel
Keyword(s):  
Polymer Matrix ◽  
Vinyl Alcohol ◽  
High Performance ◽  
Building Blocks ◽  
Poly Vinyl Alcohol ◽  
Electrospun Fibers ◽  
Matrix Solution ◽  
High Level

Graphene-containing fibrous structures with a high level of affinity towards a polymer matrix solution have been proved to be promising for high performance macroscopic nanocomposite reinforcement purposes.

scholarly journals One-step fabrication and characterization of a poly(vinyl alcohol)/silver hybrid nanofiber mat by electrospinning for multifunctional applications

RSC Advances ◽  
2017 ◽  
Vol 7 (8) ◽  
pp. 4830-4839 ◽  
Author(s):  
Chun-Gang Yuan ◽  
Shiwei Guo ◽  
Jian Song ◽  
Can Huo ◽  
Yukai Li ◽  
...  
Keyword(s):  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
One Step ◽  
Fabrication And Characterization ◽  
Hybrid Nanofiber

Preparation and application of a poly(vinyl alcohol)/silver hybrid nanofiber mat by electrospinning.

One-Step Construction of Antifogging and Frost-Resisting Coatings on Flexible Substrates

2015 ◽  
Vol 14 (01n02) ◽  
pp. 1460015 ◽  
Author(s):  
Xiaojie Zhang ◽  
Junhui He
Keyword(s):  
Aqueous Solution ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Flexible Substrates ◽  
Average Transmittance ◽  
One Step

We here report a facile one-step approach to construction of antifogging and frost-resisting coatings on flexible substrates from poly(vinyl alcohol) (PVA). Excellent antifogging and frost-resisting properties were observed, and are derived from the hydrophilicity and hygroscopicity of coatings. The coatings are highly transparent, and the average transmittance of coatings increases with increase of the concentration of PVA aqueous solution.

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