Surface trap creation in polyvinylidene fluoride and poly(vinylidene fluoride/trifluoroethylene) on peeling from a silicon substrate

1992 ◽  
Vol 71 (2) ◽  
pp. 753-755
Author(s):  
P. Andry ◽  
A. Y. Filion ◽  
M. M. Perlman
Keyword(s):  
Silicon Substrate ◽  
Polyvinylidene Fluoride ◽  
Vinylidene Fluoride ◽  
Surface Trap ◽  
Poly Vinylidene Fluoride

scholarly journals Preparation and Electrochemical Characterization of Organic–Inorganic Hybrid Poly(Vinylidene Fluoride)-SiO2 Cation-Exchange Membranes by the Sol-Gel Method Using 3-Mercapto-Propyl-Triethoxyl-Silane

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3265 ◽  
Author(s):  
Li ◽  
Li ◽  
Li ◽  
Guan ◽  
Zheng ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Oxidative Stability ◽  
Water Uptake ◽  
Polyvinylidene Fluoride ◽  
Vinylidene Fluoride ◽  
Sol Gel ◽  
Synthesis Method ◽  
Co2 Production ◽  
Inorganic Hybrid ◽  
Poly Vinylidene Fluoride

A new synthesis method for organic–inorganic hybrid Poly(vinylidene fluoride)-SiO2 cation-change membranes (CEMs) is proposed. This method involves mixing tetraethyl orthosilicate (TEOS) and 3-mercapto-propyl-triethoxy-silane (MPTES) into a polyvinylidene fluoride (PVDF) sol-gel solution. The resulting slurry was used to prepare films, which were immersed in 0.01 M HCl, which caused hydrolysis and polycondensation between the MPTES and TEOS. The resulting Si-O-Si polymers chains intertwined and/or penetrated the PVDF skeleton, significantly improving the mechanical strength of the resulting hybrid PVDF-SiO2 CEMs. The -SH functional groups of MPTES oxidized to-SO3H, which contributed to the excellent permeability of these CEMs. The surface morphology, hybrid structure, oxidative stability, and physicochemical properties (IEC, water uptake, membrane resistance, membrane potential, transport number, and selective permittivity) of the CEMs obtained in this work were characterized using scanning electron microscope and Fourier transform infrared spectroscopy, as well as electrochemical testing. Tests to analyze the oxidative stability, water uptake, membrane potential, and selective permeability were also performed. Our organic–inorganic hybrid PVDF-SiO2 CEMs demonstrated higher oxidative stability and lower resistance than commercial Ionsep-HC-C membranes with a hydrocarbon structure. Thus, the synthesis method described in this work is very promising for the production of very efficient CEMs. In addition, the physical and electrochemical properties of the PVDF-SiO2 CEMs are comparable to the Ionsep-HC-C membranes. The electrolysis of the concentrated CoCl2 solution performed using PVDF-SiO2-6 and Ionsep-HC-C CEMs showed that at the same current density, Co2+ production, and current efficiency of the PVDF-SiO2-6 CEM membrane were slightly higher than those obtained using the Ionsep-HC-C membrane. Therefore, our novel membrane might be suitable for the recovery of cobalt from concentrated CoCl2 solutions.

Fabrication and Characterization of Polyvinylidene Fluoride Microfilms for Microfluidic Applications

2016 ◽  
Vol 15 (05n06) ◽  
pp. 1660013
Author(s):  
Yammani Venkat Subba Rao ◽  
Aravinda Narayanan Raghavan ◽  
Meenakshi Viswanathan
Keyword(s):  
Spin Coating ◽  
Polyvinylidene Fluoride ◽  
Vinylidene Fluoride ◽  
Microstructural Properties ◽  
Average Roughness ◽  
Microfluidic Mixer ◽  
Poly Vinylidene Fluoride ◽  
Fabrication And Characterization ◽  
Microfluidic Mixers

The ability to create patterns of piezo responsive material on smooth substrate is an important method to develop efficient microfluidic mixers. This paper reports the fabrication of Poly vinylidene fluoride microfilms using spin-coating on smooth glass surface. The suitable crystalline phases, surface morphology and microstructural properties of the PVDF films have been investigated. We found that films of average thickness 10[Formula: see text][Formula: see text]m, had average roughness of 0.13[Formula: see text][Formula: see text]m. These PVDF films are useful in microfluidic mixer applications.

scholarly journals Influence of dopant on the specific features of formation and properties of nanocomposites of poly(3-methylthiophene) with polyvinylidene fluoride

2021 ◽  
pp. 159-174
Author(s):  
Alexander A. Pud ◽  
◽  
Nikolay A. Ogurtsov ◽  
Olga S. Kruglyak ◽  
◽  
...  
Keyword(s):  
Thermal Stability ◽  
Polyvinylidene Fluoride ◽  
Vinylidene Fluoride ◽  
Thermal Studies ◽  
Shell Morphology ◽  
Inhomogeneous Layer ◽  
Transmission Electron ◽  
Oxidant Concentration ◽  
Poly Vinylidene Fluoride ◽  
Thermal Stability Of

The work is devoted to the development and study of conducting nanocomposites of poly(3-methylthiophene) (P3MT) and poly(vinylidene fluoride) (PVDF), suitable for changing properties when interaction with of the environment components, and to find factors of influence on properties of such materials. The kinetic aspects of P3MT formation in the process of 3-methylthiophene (3MT) polymerization in PVDF dispersions in the presence of dopants of different nature, in particular, chloride (Cl-), as well as surface-active dodecylbenzenesulfonate (DBS-) and perfluorooctanoate (PFO-) anions are studied. It is found that DBS- and PFO- anions inhibit 3MT oxidation and decrease P3MT yield in comparison with those of chloride anions. It is shown that P3MT is formed through two consecutive kinetically different reactions of pseudo-first order in terms of the oxidant concentration. Transmission electron microscopy revealed that as a result of such polymerization nanoparticles of doped P3MT formed a surface inhomogeneous layer on PVDF particles, thus forming nanocomposite particles with core-shell morphology. Thermal studies showed higher thermal stability of the doped P3MT phase in the nanocomposite compared to the pure polymer. It is found that thermal stability of the P3MT phase in the PVDF/P3MT-DBS nanocomposites is higher than in the PVDF/P3MT-Cl. The influence of the dopant nature and content of doped P3MT on conductivity and sensitivity of the nanocomposites to vapors of harmful volatile organic compounds (acetone and isopropanol) is characterized. The strongest responses to acetone are shown by the nanocomposite with PFO- dopant. In the DBS- dopant case medium intensity responses are found and the lowest ones are observed for Cl- dopant. It is shown that the sensitivity of nanocomposites extremely depends on the conducting polymer content.

Integrated Pyroelectric Infrared Sensor Using Pvdf thin Film Deposited by Electro-Spray Method

1993 ◽  
Vol 310 ◽  
Author(s):  
Ryouji Asahi ◽  
Jiro Sakata ◽  
Osamu Tabata ◽  
Midori Mochizuki ◽  
Susumu Sugiyama ◽  
...  
Keyword(s):  
Thin Film ◽  
Silicon Substrate ◽  
Thermal Conduction ◽  
Vinylidene Fluoride ◽  
Sacrificial Layer ◽  
Pyroelectric Coefficient ◽  
Infrared Sensor ◽  
Etching Technique ◽  
Spray Method ◽  
Poly Vinylidene Fluoride

AbstractA pyroelectric infrared sensor using a poly(vinylidene fluoride) (PVDF) thin film has been integrated with a read-out circuit on a silicon substrate. The PVDF thin film with a thickness of 1-2 µm was deposited on the sensing area by an electro-spray (ESP) method. A form I crystal and a large pyroelectric coefficient of 4 nCcm−2K−1 were observed just after the deposition without any poling treatments. The fabrication process of the sensor was based on a standard MOS LSI process and a polysilicon sacrificial layer etching technique. In order to reduce the heat capacitance and the thermal conduction, the PVDF thin film was supported on a thin Si3N4 membrane structure formed by etching a part of the silicon substrate under the sensing area. The sensor with a sensing area of 400x400 µm2 had a responsivity of 98 V/W, a detectivity of l.4× 107 cmHz1/2W−1, an NEP of 2.9× 10−99 Hz1/2W at a frequency of 100 Hz and a time constant of 1.3 msec.

scholarly journals Static-Aligned Piezoelectric Poly (Vinylidene Fluoride) Electrospun Nanofibers/MWCNT Composite Membrane: Facile Method

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 965 ◽  
Author(s):  
Nader Shehata ◽  
Eman Elnabawy ◽  
Mohamed Abdelkader ◽  
Ahmed Hassanin ◽  
Mohamed Salah ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
High Speed ◽  
Vinylidene Fluoride ◽  
Electrospun Nanofibers ◽  
Piezoelectric Response ◽  
Rotating Drum ◽  
Β Phase ◽  
Aligned Nanofibers ◽  
Poly Vinylidene Fluoride ◽  
Nanofiber Mats

Polyvinylidene Fluoride (PVDF) piezoelectric electrospun nanofibers have been intensively used for sensing and actuation applications in the last decade. However, in most cases, random PVDF piezoelectric nanofiber mats have moderate piezoelectric response compared to aligned PVDF nanofibers. In this work, we demonstrate the effect of alignment conducted by a collector setup composed of two-metal bars with gab inside where the aligned fiber can be formed. That is what we called static aligned nanofibers, which is distinct from the dynamic traditional technique using a high speed rotating drum. The two-bar system shows a superior alignment degree for the PVDF nanofibers. Also, the effect of added carbon nanotubes (CNTs) of different concentrations to PVDF nanofibers is studied to observe the enhancement of piezoelectric response of PVDF nanofibers. Improvement of β-phase content of aligned (PVDF) nanofibers, as compared to randomly orientated fibers, is achieved. Significant change in the piezoelectricity of PVDF fiber is produced with added CNTs with saturation response in the case of 0.3 wt % doping of CNTs, and piezoelectric sensitivity of 73.8 mV/g with applied masses down to 100 g.

scholarly journals Computer Aided Molecular Modeling of the Piezoelectric Properties of Ferroelectric Composites on the Base of Polyvinylidene Fluoride with Graphene and Graphene Oxide

2017 ◽  
Vol 12 (2) ◽  
pp. 466-486
Author(s):  
А.В. Быстрова ◽  
A.V. Bystrova
Keyword(s):  
Graphene Oxide ◽  
Molecular Modeling ◽  
Polyvinylidene Fluoride ◽  
Piezoelectric Coefficient ◽  
Vinylidene Fluoride ◽  
Piezoelectric Properties ◽  
A Value ◽  
Poly Vinylidene Fluoride ◽  
Pure Pvdf ◽  
Sandwich Model

Molecular modeling of ferroelectric composites containing polyvinylidene fluoride (PVDF), graphene (G) and/or graphene oxide (GO), was performed using the semi-empirical quantum approximation PM3 in the HyperChem software package. The piezoelectric properties of the composites were analyzed and compared with the experimental data obtained for thin films containing poly(vinylidene-fluoride-trifluoroethylene) with graphene oxide (P (VDF-TrFE)/GO). A qualitative agreement was obtained between the simulation results and the experimental measurements of the piezoelectric coefficient, its decrease in the presence of G or GO was revealed. When models containing one or more layers of graphene with 54 carbon atoms were investigated, it was found that the average piezoelectric coefficient was reduced to -9.8 pm/V for the one-sided PVDF/G model and to -18.98 pm/V for the two-sided sandwich model G/PVDF/G in compare with the calculated piezoelectric coefficient for pure PVDF (-42.2 pm/V). After computer modeling for models incorporating one or more layers of 96 carbon atoms in the oxide graphene, it was found that the piezoelectric coefficient was reduced to a value of -14.6 pm/V for a one-sided PVDF / GO model and to a value of -29.8 pm/V for a two-sided sandwich model GO/ PVDF/GO compared to the piezoelectric coefficient for pure PVDF.

scholarly journals Poly(vinylidene fluoride)/poly(acrylonitrile) – based superior hydrophobic piezoelectric solid derived by aligned carbon nanotubes in electrospinning: fabrication, phase conversion and surface energy

RSC Advances ◽  
2015 ◽  
Vol 5 (93) ◽  
pp. 76383-76391 ◽  
Author(s):  
Salem M. Aqeel ◽  
Zhe Wang ◽  
Lisa Than ◽  
Gollapudi Sreenivasulu ◽  
Xiangqun Zeng
Keyword(s):  
Carbon Nanotubes ◽  
Surface Energy ◽  
Polyvinylidene Fluoride ◽  
Vinylidene Fluoride ◽  
Phase Conversion ◽  
Functionalized Carbon Nanotubes ◽  
Aligned Carbon Nanotubes ◽  
Poly Vinylidene Fluoride ◽  
Piezoelectric Solid ◽  
Poly Acrylonitrile

A superior hydrophobic piezoelectric solid based on the polyvinylidene fluoride (PVDF)–polyacrilonitrile (PAN) blend was fabricated. The phase conversion was derived by functionalized carbon nanotubes under a modified electrospinning field.

Structure and electrophysical properties of polyvinylidene fluoride (PVDF)/magnetite nanocomposites

2018 ◽  
Vol 33 (1) ◽  
pp. 138-149 ◽  
Author(s):  
MA Ramazanov ◽  
AM Maharramov ◽  
HA Shirinova ◽  
Luca Di Palma
Keyword(s):  
Dielectric Permittivity ◽  
Polyvinylidene Fluoride ◽  
Vinylidene Fluoride ◽  
Theoretical Calculations ◽  
Threshold Value ◽  
Electrophysical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Subsequent Decrease ◽  
Poly Vinylidene Fluoride

In the present study, the effect of magnetite (Fe3O4) nanoparticles on the structural and dielectric properties of poly(vinylidene fluoride) (PVDF) matrix was investigated. Distribution of Fe3O4 nanoparticles in the polymer matrix has been studied by scanning electron microscopy (JEOL JSM-7600 F). The structure of the nanocomposite samples was investigated by the X-ray diffraction and Fourier-transform infrared spectroscopy. It was shown that the dielectric permittivity of PVDF + Fe3O4 nanocomposite samples was gradually increased up to 7 wt% of Fe3O4 content. Further increase in the concentration of the filler leads to decrease in the dielectric permittivity. The subsequent decrease in dielectric permittivity at higher Fe3O4 content can be explained by the increase in defects in the structure of the nanocomposite. The comparison of experimental data and the results of theoretical calculations show that the reduction in the empirical value of dielectric permittivity of the nanocomposite is obviously linked with the threshold value of filler. While calculating the theoretical value of the dielectric permittivity for the higher content of the filler, defects in the nanocomposite structure should be considered.

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