scholarly journals Facile Fabrication of Polyvinyl Alcohol/Edge-Selectively Oxidized Graphene Composite Fibers

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3525
Author(s):  
Taehoon Kim ◽  
Gayeong Han ◽  
Yeonsu Jung
Keyword(s):  
Tensile Strength ◽  
Polyvinyl Alcohol ◽  
Chemical Reduction ◽  
Composite Fibers ◽  
X Ray ◽  
Water Dispersible ◽  
Advantages And Disadvantages ◽  
Graphene Derivatives ◽  
The Matrix ◽  
Facile Fabrication

Graphene derivatives are effective nanofillers for the enhancement of the matrix mechanical properties; nonetheless, graphene oxide (GO), reduced GO, and exfoliated graphene all present distinct advantages and disadvantages. In this study, polyvinyl alcohol (PVA) composite fibers have been prepared using a recently reported graphene derivative, i.e., edge-selectively oxidized graphene (EOG). The PVA/EOG composite fibers were simply fabricated via conventional wet-spinning methods; thus, they can be produced at the commercial level. X-ray diffractometry, scanning electron microscopy, and two-dimensional wide-angle X-ray scattering analyses were conducted to evaluate the EOG dispersibility and alignment in the PVA matrix. The tensile strength of the PVA/EOG composite fibers was 631.4 MPa at an EOG concentration of 0.3 wt %, which is 31.4% higher compared with PVA-only fibers (480.6 MPa); compared with PVA composite fibers made with GO, which is the most famous water-dispersible graphene derivative, the proposed PVA/EOG ones exhibited about 10% higher tensile strength. Therefore, EOG can be considered an effective nanofiller to enhance the strength of PVA fibers without additional thermal or chemical reduction processes.

Preparation and Characterization of Alginate/Polyvinyl Alcohol Composite Fibers Containing Copper Ions

2013 ◽  
Vol 652-654 ◽  
pp. 1562-1565 ◽  
Author(s):  
Jing Guo ◽  
Qian He Chen ◽  
Yu Yan Zhang ◽  
Yu Mei Gong ◽  
Hong Zhang
Keyword(s):  
Tensile Strength ◽  
Polyvinyl Alcohol ◽  
Copper Ions ◽  
Fiber Surface ◽  
Coagulation Bath ◽  
Wet Spinning ◽  
Composite Fibers ◽  
Pseudoplastic Fluid ◽  
Cu Ions

Alginate/polyvinyl alcohol (PVA) composite fibers containing copper ions were prepared by wet spinning. The spinning solution and manufacturing process were researched. The composite fibers were characterized by Tensile Strength Tester, SEM and TGA. This report shows that the spinning solution is a typical kind of pseudoplastic fluid. Adding boric acid to coagulation bath and putting Cu ions into composite fibers can improve the strength. The structure of composite fibers with Cu ions is denser and there are grooves on the fiber surface. In addition, the thermal property of composite fibers is steady.

scholarly journals The Effect of Incorporating Silica Stone Waste on the Mechanical Properties of Sustainable Concretes

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3832 ◽  
Author(s):  
Saeid Abbasi ◽  
Mohammad Hemen Jannaty ◽  
Rabar H. Faraj ◽  
Shahriar Shahbazpanahi ◽  
Amir Mosavi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Sustainable Construction ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
Sem Images ◽  
X Ray ◽  
Fourier Transformed Infrared Spectroscopy ◽  
The Matrix ◽  
First Time

Incorporating various industrial waste materials into concrete has recently gained attention for sustainable construction. This paper, for the first time, studies the effects of silica stone waste (SSW) powder on concrete. The cement of concrete was replaced with 5, 10, 15, and 20% of the SSW powder. The mechanical properties of concrete, such as compressive and tensile strength, were studied. Furthermore, the microstructure of concrete was studied by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy analysis (EDX), Fourier transformed infrared spectroscopy (FTIR), and X-Ray diffraction (XRD) tests. Compressive and tensile strength of samples with 5% SSW powder was improved up to 18.8% and 10.46%, respectively. As can be observed in the SEM images, a reduced number of pores and higher density in the matrix can explain the better compressive strength of samples with 5% SSW powder.

scholarly journals Facile Fabrication of Polyaniline/Graphene Composite Fibers as Electrodes for Fiber-Shaped Supercapacitors

2021 ◽  
Vol 11 (18) ◽  
pp. 8690
Author(s):  
Xuefei Yang ◽  
Yihan Qiu ◽  
Mei Zhang ◽  
Liangjing Zhang ◽  
Hongwei Li
Keyword(s):  
Energy Density ◽  
Specific Capacitance ◽  
Flexible Electronics ◽  
Graphene Nanosheets ◽  
Chemical Reduction ◽  
Attractive Potential ◽  
Composite Fibers ◽  
Graphene Composite ◽  
Uniform Dispersion ◽  
Facile Fabrication

Graphene fiber-based supercapacitors are known as the potential energy resources for wearable/flexible electronics. However, increasing their specific capacitance and energy density remains a significant challenge. This paper indicates a double layer capacitance of the graphene nanosheets accompanied by pseudocapacitive behavior of the polyaniline to prepare composite fibers with high capacitive response. The polyaniline/graphene composite fibers (PANI/GFs) were synthesized by the self-assembled strategy and chemical reduction by HI. The wrinkle architecture of graphene nanosheets and uniform dispersion of the polyaniline are beneficial to increase the internal electroactive sites and provide a stable structure for the composite fibers. The constructed fiber-shaped supercapacitors with solid-state electrolyte deliver an excellent areal specific capacitance of 370.2 mF cm−2 and an outstanding areal energy density of 12.9 μW h cm−2. The current work reveals the attractive potential of the as-synthesized composite fibers for constructing fiber-shaped supercapacitors with distinguished electrochemical performance, which can be applied in future flexible electronics.

Lowering The Percolation Threshold In Carbon Blackfilled Polymer Composites

1999 ◽  
Vol 576 ◽  
Author(s):  
J. C. Grujnlan ◽  
W. W. Gerberich ◽  
L. F. Francis
Keyword(s):  
Carbon Black ◽  
Polyvinyl Alcohol ◽  
Percolation Threshold ◽  
Polymer Composites ◽  
Polyvinyl Acetate ◽  
Water Dispersible ◽  
Polymeric Particles ◽  
The Matrix ◽  
Polymer Microstructures ◽  
Prepared Composite

ABSTRACTIn an effort to lower the percolation threshold of carbon black-filled polymer composites, various polymer microstructures were examined. Composites prepared with a polyvinyl acetate (PVAc) latex and a poly(vinyl acetate – ethylene) water-dispersible powder showed a significantly lowered percolation threshold relative to an equivalently prepared composite that used a polyvinyl alcohol (PVA) solution to form the matrix phase. The percolation threshold of the dispersion-based composites occurred at 5 vol.% carbon black, while the equivalent solutionbased composite produced a threshold at 14 vol.%. By excluding the carbon black from regions occupied by polymeric particles, the dispersion-based composites lead to preferential aggregation of carbon black, as evidenced by SEM, and a lowered percolation threshold.

Mechanical Properties of TPNR-MWNTs-OMMT Hybrid Nanocomposites

2012 ◽  
Vol 501 ◽  
pp. 194-198 ◽  
Author(s):  
Mou'ad A. Tarawneh ◽  
Sahrim H. Ahmad ◽  
A.R. Shamsul Bahri ◽  
Yu Lih Jiun
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aspect Ratio ◽  
Interfacial Adhesion ◽  
Hybrid Nanocomposites ◽  
X Ray Diffraction ◽  
Elongation At Break ◽  
X Ray ◽  
Maximum Value ◽  
The Matrix

This paper discusses the processing of a hybrid of TPNR-MWNTs-OMMT nanocomposites with different percentages of filler to determine the optimum mechanical properties of the hybrid nanocomposites. Three types of hybrid nanocomposites with various MWNTs-OMMT compositions (1%wt MWNTs+3%wt OMMT), (2%wt MWNTs+2%wt OMMT) and (3%wt MWNTs+1%wt OMMT) were prepared. The OMMT layers were found to be separated further with higher nanotubes content as exhibited by X-ray diffraction. The result of tensile test showed that tensile strength and Young's modulus increase in the presence of nanotubes and maximum value were obtained for the nanocomposites with highest nanotubes (3%wt) which increased about 33% and 36%, respectively compared with pure TPNR matrix. On other hand, the elongation at break considerably decreased with increasing the percentage of MWNTs. TEM micrographs revealed aspect ratio and fillers orientation in the TPNR matrix also promoted strongly to interfacial adhesion between fillers and the matrix which contributed significantly to the improvement of the mechanical properties

Bonding Strength and Microstructure of Cermet/Cu-Based Alloy Composite Brazed Coatings

2005 ◽  
Vol 297-300 ◽  
pp. 154-159 ◽  
Author(s):  
Xin Hong Wang ◽  
Zeng Da Zou ◽  
Min Zhang ◽  
Si Li Song ◽  
Shi Yao Qu
Keyword(s):  
Electron Microscopy ◽  
Tensile Strength ◽  
Composite Coatings ◽  
Wear Property ◽  
Alloy Composite ◽  
X Ray Diffraction ◽  
Interfacial Diffusion ◽  
X Ray ◽  
Transmission Electron ◽  
The Matrix

WC-TiC-Co cermet and CuZnNi alloy composite coatings were produced on mild steel by a high temperature inside-furnace brazing technique. The microstructure, phase constituents and interfacial diffusion behavior of cermet and Cu-based alloy were investigated by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron probe microanalysis (EPMA) and X-ray diffraction. The tensile strength and wear property of composite coatings were also investigated. The results show that crème particles were not decomposed severely during the inside- furnace brazing process. The microstructure of the matrix is α and β phases. Diffusion occurred at the cermet/Cu-based alloy interface. The tensile strength of the composite coatings reached 240-300MPa, which depended on the brazing temperature and was far higher than that of the flame hardfacing layers. Cermet fracture was basically a brittle fracture in nature and matrix involves ductile fracture.

Ionic Liquid Assisted Dispersion of Reduced Graphene Oxide in Epoxy Composites with Improved Mechanical Properties

2013 ◽  
Vol 738 ◽  
pp. 56-60 ◽  
Author(s):  
Yue E Liu ◽  
Cheng En He ◽  
Ren Gui Peng ◽  
Wei Tang ◽  
Ying Kui Yang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ionic Liquids ◽  
Graphene Nanosheets ◽  
Chemical Reduction ◽  
Exfoliated Graphite ◽  
Epoxy Composites ◽  
Graphene Sheets ◽  
Reduced Graphene ◽  
The Matrix

Graphene nanosheets were prepared by chemical reduction of the exfoliated graphite oxide using sodium borohydride (NaBH4). The graphene/epoxy composites were separately fabricated in the absence or presence of imidazolium-based ionic liquids, and their dynamic thermomechanical and tensile properties were studied. TEM examinations show that graphene sheets are well dispersed in the epoxy resin and have strong interface adhesion with the matrix due to the π-π and/or cation-π interactions between graphene and imidazolium ions. The composite fabricated by assistance of ionic liquids shows larger increases in Youngs modulus, tensile strength, storage modulus and glass transition temperature compared to the composite without using ionic liquids. This work provides a method for the fabrication of multifunctional graphene-based polymer composites.

Research on Microstructure Evolution in Al-9.8Zn-2.0Mg-1.8Cu Alloy during Solution Treatment

2016 ◽  
Vol 879 ◽  
pp. 2336-2341
Author(s):  
Bai Qing Xiong ◽  
Kai Wen ◽  
Yong An Zhang ◽  
Xi Wu Li ◽  
Zhi Hui Li ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Solution Treatment ◽  
Electron Back Scatter Diffraction ◽  
Solution Time ◽  
Second Phase ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Solution Treated ◽  
The Matrix

The microstructure of as-extruded Al-9.8Zn-2.0Mg-1.8Cu aluminum alloy and its evolution during solution treatment were investigated by means of optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), differential scanning calorimetry (DSC) analysis and electron back-scatter diffraction (EBSD). The results indicated that second phase of the as-extruded alloy mainly consisted of Mg (Zn, Cu, Al)2 and Fe-rich phases. After solution treated at 475°C for 4h, Mg (Zn, Cu, Al)2 phases were dissolved into the matrix, while Fe-rich phases still existed. Fe-rich phases cannot dissolve by prolonging solution time. The room temperature tensile strength gradually increased by prolonging solution time at 475oC. The ultimate tensile strength of the alloy reached 700MPa after both single and two-step solution treatments.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

Lateral resolution of the electron microbeam analysis

1978 ◽  
Vol 36 (1) ◽  
pp. 542-543
Author(s):  
H.J. Dudek
Keyword(s):  
Quantitative Analysis ◽  
Depth Resolution ◽  
Lateral Resolution ◽  
Cylindrical Particle ◽  
Correction Procedure ◽  
X Ray ◽  
Element Concentrations ◽  
Microbeam Analysis ◽  
The Matrix

The chemical inhomogenities in modern materials such as fibers, phases and inclusions, often have diameters in the region of one micrometer. Using electron microbeam analysis for the determination of the element concentrations one has to know the smallest possible diameter of such regions for a given accuracy of the quantitative analysis.In th is paper the correction procedure for the quantitative electron microbeam analysis is extended to a spacial problem to determine the smallest possible measurements of a cylindrical particle P of high D (depth resolution) and diameter L (lateral resolution) embeded in a matrix M and which has to be analysed quantitative with the accuracy q. The mathematical accounts lead to the following form of the characteristic x-ray intens ity of the element i of a particle P embeded in the matrix M in relation to the intensity of a standard S

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