Properties of PVDF films stretched in machine direction

2020 ◽  
pp. 096739112091059
Author(s):  
TS Roopa ◽  
HN Narasimha Murthy ◽  
DVN Harish ◽  
Anjana Jain ◽  
Gangadhar Angadi
Keyword(s):  
Electron Microscopy ◽  
Polyvinylidene Fluoride ◽  
Piezoelectric Properties ◽  
Gray Relational Analysis ◽  
X Ray Diffraction ◽  
Polar Solvents ◽  
Β Phase ◽  
Transmission Electron ◽  
Diffraction Peaks ◽  
Mechanical Stretching

Polyvinylidene fluoride (PVDF) films possess superior piezoelectric properties due to the β-phase obtained by methods, such as addition of nanofillers, application of high electric field, use of polar solvents and mechanical stretching. Simultaneous stretching and heating of the films can reduce porosity, increase transformation from α-phase to β-phase, and hence, improve their piezoelectric properties. This article presents the effects of stretching PVDF films on the β-phase formation and the resulting mechanical properties. A custom-designed stretching unit with roller mechanism and heating provision was employed for the purpose. The 200% stretched films at 100°C showed 86.79% β-phase, which is in correlation with X-ray diffraction peaks at 2 θ = 20.3–20.6°. Transmission electron microscopy and scanning electron microscopy of the stretched films revealed spherulitic to lamellar transformation and decrease in porosity. Stretching increased crystallinity from 32.99% to 44.84%. Nanoindentation results showed increase in hardness and Young’s modulus from 23.33 MPa to 93.3 MPa and 0.483 GPa to 1.816 GPa, respectively. Tensile strength increased from 4.72 MPa to 21.02 MPa. The experiments were conducted using L9 orthogonal array and the results were analyzed using analysis of variance and gray relational analysis.

Effects of Surface Energy on the Microstructures of Thin Sb Films

1990 ◽  
Vol 202 ◽  
Author(s):  
L. H. Chou ◽  
M. C. Kuo
Keyword(s):  
Electron Microscopy ◽  
Surface Energy ◽  
Grain Growth ◽  
Grain Orientation ◽  
Thermal Evaporation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Transmission Electron ◽  
Diffraction Peaks

ABSTRACTThin Sb films have been prepared on glass substrates by rapid thermal evaporation. Films with thicknesses varied from 260 Å to 1300Å were used for the study. X-ray diffraction data showed that for films deposited at room substrate temperature, an almost random grain orientation was observed for films of 1300 Å thick and a tendency for preferred grain orientation was observed as films got thinner. For films of 260 Å thick, only two x-ray diffraction peaks--(003) and (006) were observed. After thermal annealing, secondary grains grew to show preferred orientation in all the films. This phenomenon was explained by surface-energy-driven secondary grain growth. This paper reports the effects of annealing time and film thickness on the secondary grain growth and the evolution of thin Sb film microstmctures. Transmission electron microscopy (TEM) and x-ray diffraction were used to characterize the films.

scholarly journals Fixation of BiOI/BiOBr/MoS2 Powders on Fiber Cloths for Photocatalytic Degradation of Ammonia Nitrogen from Aqueous Solution

2020 ◽  
Vol 9 (1) ◽  
pp. 14
Author(s):  
Yi Wei ◽  
Peiwei Tang ◽  
Minfeng Huang ◽  
Yongzhang Pan
Keyword(s):  
Electron Microscopy ◽  
Carbon Fiber ◽  
Glass Fiber ◽  
Polyvinylidene Fluoride ◽  
Photocatalytic Performance ◽  
Solvothermal Method ◽  
Ammonia Nitrogen ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

A novel photocatalyst powder, BiOI/BiOBr/MoS2, was synthesized by a simple solvothermal method. X-ray diffraction (XRD), specific surface area and pore size analyses, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray energy spectrometry (EDS) were utilized to characterize the prepared samples. After evaluating the photocatalytic performance of the catalyst, it was loaded on the glass fiber and carbon fiber by polyvinylidene fluoride (PVDF) and N-methylpyrrolidone, respectively. The photocatalytic activity of the composite was investigated by the degradation of ammonia nitrogen wastewater. The fiber cloth solved the problem of separation of powder from solution after reaction, and the presence of the binder reduces the agglomeration of the nanoparticles in the water. After four times repeated experiments, the degradation of simulate ammonia nitrogen wastewater by loaded glass fiber and loaded carbon fiber are 74.1% and 60.58%. Fixation of BiOI/BiOBr/MoS2 powders on fiber cloth solve the problem of difficult recovery of powder photocatalytic materials and it can be recycled, which has economic valuable.

Preparation of Al-doped ZnO Nanoparticulate Film for Optoelectronic Applications

2010 ◽  
Vol 1247 ◽  
Author(s):  
Thu V. Tran ◽  
Shinya Maenosono
Keyword(s):  
Electron Microscopy ◽  
Optical Transmittance ◽  
X Ray Diffraction ◽  
High Concentration ◽  
Polar Solvents ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Doped Zno ◽  
Optoelectronic Applications

AbstractAl-doped ZnO (AZO) nanoparticles (NPs) were synthesized by the solvothermal decomposition. The as-synthesized AZO NPs were characterized by X-ray diffraction and transmission electron microscopy. These NPs were well dispersible in non-polar solvents at high concentration to produce AZO nanoink. The AZO nanoparticulate films were prepared from AZO nanoink by spin coating technique. Thickness, surface morphology, optical transparency and conductivity of the films were characterized by surface profilometer, scanning electron microscopy, UV-Vis spectroscopy and Hall measurements. The AZO nanoparticlulate films had highly optical transmittance and well electrical conductivity, which are potential for optoelectronic applications.

Phase Transformation in Binary Titanium-Base Alloys with Metals of the I, IV−VIII Groups

2007 ◽  
Vol 546-549 ◽  
pp. 1349-1354 ◽  
Author(s):  
A.V. Dobromyslov
Keyword(s):  
Electron Microscopy ◽  
Structural Information ◽  
Eutectoid Decomposition ◽  
X Ray Diffraction ◽  
Minimum Concentration ◽  
X Ray ◽  
Β Phase ◽  
Ω Phase ◽  
Α Phase ◽  
Transmission Electron

Martensitic β→α′(α″) transformation, β→ω transformation and eutectoid decomposition in a series of Ti-base alloys with d transition metals of Groups I, IV-VIII have been investigated using the techniques of X-ray diffraction, optical and transmission electron microscopy. Phase and structural information is given on the non-equilibrium and metastable modifications occurring in these alloys after quenching from high-temperature β-field and aging. The conditions of the orthorhombic α″-phase, ω-phase and metastable β-phase formation in binary titanium–base alloys with d-metals of V-VIII groups were investigated. It was established that the position of the alloying metal in the Periodic Table defines the presence or absence of the α″-phase in the alloy after quenching and the minimum concentration of the alloying metal necessary for formation of the α″-phase, ω-phase and metastable β-phase.

Influences of Hydrogenation on Microstructure and Microhardness of Ti6Al4V Alloy

2007 ◽  
Vol 561-565 ◽  
pp. 295-298
Author(s):  
J.W. Zhao ◽  
Hua Ding ◽  
Wen Juan Zhao ◽  
X.F. Tian ◽  
H.W. Xiao ◽  
...  
Keyword(s):  
Ti6al4v Alloy ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Microstructure Observation ◽  
Β Phase ◽  
Transmission Electron ◽  
Microhardness Testing ◽  
Diffraction Peaks ◽  
Major Factors ◽  
Fcc Structure

The microstructures of Ti6Al4V alloy after hydrogenation have been investigated and analysed by optical microscopy (OM), X-ray diffraction (XRD) and transmission electron microscopy (TEM), and the influence of hydrogenation on the hardness of α and β phases has been analysed by microhardness testing. The microstructure observation revealed that δ hydride (fcc structure) precipitated in the specimens with 0.278 wt.% and 0.514 wt.% hydrogen, and a lot of dislocations and twins have been found simultaneously. The diffraction peaks moved to the lower angles because of the lattice expansion of β phase with the solution of hydrogen atoms. The result of microhardness testing shows that the hardness of α and β phases increases synchronously with increasing of hydrogen and the increment of β is larger than that of α. It is considered that the formation of δ hydrides, lattice defects and alloying element diffusion are the major factors leading to the microhardness change.

Effect of MnFe2O4 and the Heat Treatment Temperature on the Bioactive Glass Properties

2016 ◽  
Vol 690 ◽  
pp. 137-142
Author(s):  
Thanaporn Boonchoo ◽  
Pratthana Intawin ◽  
Wilaiwan Leenakul
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Magnetic Properties ◽  
Bioactive Glass ◽  
Glass Ceramics ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Peaks

In this study, the effects of heat treatment temperatures on structural and magnetic properties in MnFe2O4(MF)/SiO2-Na2O-CaO-P2O5 (bioglass) bioactive glass ceramics were investigated. The MF/SiO2-Na2O-CaO-P2O5 bioactive glass ceramics were fabricated under various heat treatment temperatures in a range of 600-1000 °C. X-ray diffraction (XRD) technique, the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are used to characterize phase and microstructure. The magnetic properties were determined from Vibrating Sample Magnetometer (VSM). The X-ray diffraction peaks presented two major crystalline phases: MnFe2O4 and Na2Ca2Si3O9. It was found that the heat treatment temperatures are the most influential parameter on microstructure and magnetic properties of the bioactive glass ceramics. The highest magnetic properties of studied ceramics were found in the sample heated at 1000 °C with adding 20 wt%. MF. The microstructural properties of the studies samples were investigated and the results were then correlated with the characteristics of heat treatment temperatures as well as the microstructure of the bioactive glass ceramic.

Characterisation of β Phase in WE54 Magnesium Alloy

2007 ◽  
Vol 130 ◽  
pp. 155-158 ◽  
Author(s):  
Tomasz Rzychoń ◽  
Andrzej Kiełbus ◽  
Bożena Bierska-Piech
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Volume Fraction ◽  
Ageing Time ◽  
Lattice Parameter ◽  
Rare Earth Alloys ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Transmission Electron

Precipitation hardened magnesium-rare earth alloys offer attractive properties for the aerospace and racing automotive industries. The most successful magnesium alloys developed to date have been those based on the Mg-Y-Nd system identified as WE54 (Mg-5.0wt%Y-4.1wt%RE-0.5wt%Zr) and WE43 (Mg-4.0wt%Y-3.3wt%RE-0.5wt%Zr), where RE represents neodymium-rich rare earth elements. Precipitations sequence in WE-system alloys involved the formation of phases designated β”, β’, β1 and β depending on the ageing temperature. WE54 alloy with the equilibrium β-phase exhibits good ductility and medium tensile strength. The β phase precipitated in Mg-Y-Nd alloy during ageing at 300 °C was studied using X-ray diffraction analysis and transmission electron microscopy. Precipitation at 300 °C for one hour causes formation of the equilibrium β phase. This phase has an f.c.c. structure (a = 2.2 nm), which makes it isomorphous with Mg5Gd. With the prolonged ageing time at 300 °C, the volume fraction of the β phase increases and lattice parameter of the solid solution of α-magnesium decreases.

Piezoelectric PVDF Nanofibrous Membrane Electrospinning Optimization Parameters

2021 ◽  
Vol 897 ◽  
pp. 71-76
Author(s):  
Aliaa Essam ◽  
Ahmed H. El-Shazly ◽  
Hassan Shokry
Keyword(s):  
Flow Rate ◽  
Efficient Method ◽  
Polyvinylidene Fluoride ◽  
Piezoelectric Properties ◽  
Solution Concentration ◽  
Phase Content ◽  
Optimum Conditions ◽  
Β Phase ◽  
Optimization Parameters ◽  
Mechanical Stretching

The application of piezoelectric polyvinylidene fluoride (PVDF) has become of a great interest. Due to its piezoelectric properties, PVDF is used in various applications, namely, microdevices and sensors. Electrospinning was found to be the most suitable and efficient method to synthesis PVDF nanofibers. It is used to obtain PVDF nanofibers without additional mechanical stretching and with high β phase content. For these reasons, it is considered to be an economic technique. In the present paper, the parameters affecting the synthesis of PVDF nanofibers such as solution concentration, flow rate, voltage and Tip to Collector Distance (TCD), have been investigated. The optimum conditions were found to be 18% concentration, 15 cm TCD, 1 mL/h flowrate and 19 kV voltages. The fabricated nanofiber has been characterized using SEM, FTIR, XRD and a conductivity test.

Preparation of a Novel Carbon Nano-Material Studded Iron Granules from Needle Coke by Arc Method

2007 ◽  
Vol 336-338 ◽  
pp. 2186-2188
Author(s):  
Xue Fei Zhao ◽  
Ye Xin Sun ◽  
Tian Jun Sun ◽  
Jie Shan Qiu
Keyword(s):  
Electron Microscopy ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Needle Coke ◽  
Sem Images ◽  
Transmission Electron ◽  
Nano Material ◽  
Graphite Structure ◽  
Diffraction Peaks ◽  
Analytical Result

A novel nano-material of carbon rod studded iron granules on its surface was prepared from needle coke with iron as catalyst by arc method in the vacuum condition. Its structure and composition was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). In the SEM images the carbon material showed cotton-like. The TEM results showed that the nano-material was bar-like with diameter of 20nm to 50nm and there were lots of iron particles studded on its surface. The analytical result of EDS showed that the chemical composition of materials mainly consisted of carbon and iron elements. The XRD analysis revealed that there were two sharp diffraction peaks, one was at 26.2° which corresponded to the (002) plane of graphite structure and the other was at 43.2° which corresponded to the (fcc) γ-Fe structure. The nano-material might be used as catalyst in the chemical reaction.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

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