Study of the combined carbonization of poly(vinylidene fluoride) by X-Ray photoelectron spectroscopy

A commercial ultrafiltration (UF) membrane (HFM-183 de Koch Membrane Systems) made of poly(vinylidene fluoride) (PVDF), was recovered with a negatively-charged polyelectrolyte (poly(sodium 4-styrenesulfonate)) (PSS), and the effects on its electric, chemical, and morphological properties were analyzed. Atomic force microscopy (AFM), liquid–liquid displacement porometry, Electrical Impedance Spectroscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy were used to investigate the modifications induced by the deposition of PSS on the PVDF positively-charged membrane and after its treatment by a radio frequency Ar-plasma. These techniques confirmed a real deposition and posterior compaction of PSS with increasing roughness and decreasing pore sizes. The evolution of the electric resistances of the membranes confirmed crosslinking and compaction with shielding of the sulfonated groups from PSS. In this way, a membrane with a negatively-charged active layer and a pore size which was 60% lower than the original membrane was obtained. The composition of the additive used by manufacturers to modify PVDF to make it positively charged was obtained by different procedures, all of which depended upon the results of X-ray photoelectron spectroscopy, leading to fairly consistent results. This polymer, carrying positive charges, contains quaternary nitrogen, as confirmed by XPS. Moreover, Raman spectroscopy confirmed that PVDF changes from mostly the to the α phase, which is more stable as a substrate for the deposited PSS. The aim of the tested modifications was to increase the retention of divalent anions without reducing permeability.

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An approach to durable poly(vinylidene fluoride) thin film loudspeaker

Journal of Materials Research ◽

10.1557/jmr.2003.0405 ◽

2003 ◽

Vol 18 (12) ◽

pp. 2904-2911 ◽

Cited By ~ 23

Author(s):

C.S. Lee ◽

J.Y. Kim ◽

D.E. Lee ◽

J. Joo ◽

S. Han ◽

...

Keyword(s):

Thin Film ◽

Indium Tin Oxide ◽

Photoelectron Spectroscopy ◽

Vinylidene Fluoride ◽

X Ray ◽

Force Microscopy ◽

Low Surface Energy ◽

Oxide Electrodes ◽

Atomic Force ◽

Poly Vinylidene Fluoride

The piezoelectric poly(vinylidene fluoride) (PVDF) surface possessing low surface energy was modified by the ion-assisted-reaction (IAR) method for the application of thin film speaker. The IAR-treated hydrophilic PVDF surface was investigated using atomic force microscopy and x-ray photoelectron spectroscopy. The adhesion strength between various types of electrodes and the film was dramatically improved due to the hydrophilic functional groups, such as –C–O–, –(C=O)–, –(C=O)–O–, and so forth. A durable loudspeaker film was fabricated by enhancing the adhesion between the screen-printed poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS) and the modified PVDF films. The PVDF speaker film with the PEDOT/PSS electrode showed higher durability, flatter sound pressure level characteristics, and easier processability compared to metals or indium tin oxide electrodes.

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Temperature-dependent small-angle x-ray scattering from poly(vinylidene fluoride)

Journal of Applied Physics ◽

10.1063/1.327468 ◽

1980 ◽

Vol 51 (10) ◽

pp. 5508 ◽

Cited By ~ 15

Author(s):

J. M. Schultz ◽

J. S. Lin ◽

R. W. Hendricks ◽

R. R. Lagasse ◽

R. G. Kepler

Keyword(s):

Small Angle ◽

Vinylidene Fluoride ◽

Temperature Dependent ◽

X Ray ◽

X Ray Scattering ◽

Poly Vinylidene Fluoride ◽

Ray Scattering

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Kinetic of poly(vinylidene fluoride) defluorination under X-ray irradiation

Journal of Surface Investigation X-ray Synchrotron and Neutron Techniques ◽

10.1134/s1027451010010180 ◽

2010 ◽

Vol 4 (1) ◽

pp. 122-127 ◽

Cited By ~ 6

Author(s):

A. M. Kuvshinov ◽

S. S. Chebotaryov ◽

L. A. Pesin ◽

I. V. Gribov ◽

N. A. Moskvina ◽

...

Keyword(s):

Vinylidene Fluoride ◽

X Ray ◽

Poly Vinylidene Fluoride

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Simulations of High-Strain Electrostrictive Chlorinated Terpolymers

MRS Proceedings ◽

10.1557/proc-785-d3.7 ◽

2003 ◽

Vol 785 ◽

Author(s):

George J. Kavarnos ◽

Thomas Ramotowski

Keyword(s):

Vinylidene Fluoride ◽

High Strain ◽

Polymer Chains ◽

X Ray Diffraction ◽

X Ray ◽

Lamellar Structures ◽

Annealing Conditions ◽

Poly Vinylidene Fluoride ◽

Electromechanical Responses ◽

Kinetics Of

ABSTRACTChlorinated poly(vinylidene fluoride/trifluoroethylene) terpolymers are remarkable examples of high strain electrostrictive materials. These polymers are synthesized by copolymerizing vinylidene fluoride and trifluoroethylene with small levels of a third chlorinated monomer. The electromechanical responses of these materials are believed to originate from the chlorine atom, which, by its presence in the polymer chains and by virtue of its large van der Waals radius, destroys the long-range crystalline polar macro-domains and transforms the polymer from a normal to a high-strain relaxor ferroelectric. To exploit the strain properties of the terpolymer, it is desirable to understand the structural implications resulting from the presence of the chlorinated monomer. To this end, computations have been performed on model superlattices of terpolymers using quantum-mechanical based force fields. The focus has been on determining the energetics and kinetics of crystallization of the various polymorphs that have been identified by x-ray diffraction and fourier transform infrared spectroscopy. The chlorinated monomer is shown to act as a defect that can be incorporated into the lamellar structures of annealed terpolymer without a high cost in energy. The degree of incorporation of the chlorinated monomer into the crystal lattice is controlled by annealing conditions and ultimately determines the ferroelectric behavior of the terpolymers.

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SURFACE PHOTODEGRADATION OF POLY(VINYLIDENE FLUORIDE) BY INNER-SHELL EXCITATION

Surface Review and Letters ◽

10.1142/s0218625x06008074 ◽

2006 ◽

Vol 13 (02n03) ◽

pp. 259-263 ◽

Cited By ~ 2

Author(s):

KOJI KAMIYA OKUDAIRA ◽

EIICHI KOBAYASHI ◽

KAZUHIKO MASE ◽

SATOSHI KERA ◽

NOBUO UENO

Keyword(s):

Vinylidene Fluoride ◽

Early Stage ◽

Pvdf Film ◽

Double Bonds ◽

X Ray ◽

Hybrid State ◽

Nexafs Spectrum ◽

Backbone Chain ◽

Bond Scission ◽

Poly Vinylidene Fluoride

Poly(vinylidene fluoride) (PVDF, –( CH 2– CF 2)n–) shows the effective H + desorption induced by the irradiation of photon corresponding to the transition from carbon ( C ) 1s to σ( C – H )*. In order to clarify the effect of the C – H bond scission by the irradiation, near-edge X-ray absorption fine structure (NEXAFS) spectra and the kinetic energy (Ek) distribution of desorbed ion were observed. By the irradiation of photon near C 1s region, a new peak appears in the C 1s NEXAFS spectra at photon energy of 285 eV, which is about 3 eV lower than that of the lowest peak in the NEXAFS spectrum of the pristine PVDF film. The appearance of the lowest NEXAFS peak of irradiated PVDF film is assigned to the transition to π*. It indicates that the irradiation of photons near C 1s region introduces carbon–carbon double bonds into the backbone chain of PVDF. At early stage of X-ray exposure the yield of desorbed ion with low Ek (~ 2 eV) decreases rapidly. The ion with low Ek is assigned to H + desorbed from the sp3-hybrid state, which is characteristics of the pristine PVDF. It indicates that formation of double bonds in PVDF backbone chain makes the number of sp3-hybrid state decrease. This variation occurs by irradiation of photons corresponding to the transition from C 1s to σ( C – H )* more rapidly than that to the transition to σ( C – F )*.

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Structures and Physical Properties of Multi-Walled Carbon Nanotube-Filled PVDF Thermoplastic Composites

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.124-126.1117 ◽

2007 ◽

Vol 124-126 ◽

pp. 1117-1120 ◽

Cited By ~ 1

Author(s):

Dong Wook Chae ◽

Young Wan Nam ◽

Seung Sangh Wang ◽

S.M. Hong

Keyword(s):

Carbon Nanotube ◽

Vinylidene Fluoride ◽

Thermoplastic Composites ◽

Wide Angle ◽

X Ray Diffraction ◽

X Ray ◽

Loading Level ◽

Multi Walled Carbon Nanotube ◽

Poly Vinylidene Fluoride ◽

Internal Mixer

Poly(vinylidene fluoride) (PVDF) / multi-walled carbon nanotube (MWNT) thermoplastic composites was melt compounded in an internal mixer. The percolation level for this system in electrical conductivity clearly occured between 2 and 2.5 wt%. PVDF/MWNT thermoplastic composites exhibited an increased crystallization temperature with the loading level, at 10 wt% loading by ca. 6. In addition, they presented a shoulder posterior to the main melting peak and an increased endpoint of the peak. In the Wide Angle X-ray Diffraction (WAXD) patterns, the incorporation of MWNT produced a larger shoulder at 2θ =20.7° with increasing the loading level, corresponding to the β-form crystal of PVDF.

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