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R. Chandra - One of the best experts on this subject based on the ideXlab platform.

  • Charge storage mechanism in vacuum deposited PVF films
    Journal of Materials Science, 2005
    Co-Authors: S. Chand, G. D. Sharma, S. Dwivedi, S. S. Bawa, R. Chandra
    Abstract:

    Thermally stimulated discharge current (TSD) behavior of vacuum deposited Polyvinyl Fluoride (PVF) films has been studied as a function of various polarization parameters such as field (1.0 × 10^3–14.0 × 10^3 V/cm), temperature (313–453 K), time (3.6 × 10^3–6.0 × 10^3 sec), electrode work function (copper, silver, aluminum and indium) and thickness (2000–10000 Å). In a field dependent case the TSD spectra of PVF films show a single relaxation peak centered around 430 ± 1 K. The peak current, charge, peak position and activation energy associated with the peak depend strongly on the polarization parameters. The mechanism of origin of the relaxation peak has been attributed to the space charge polarization where the charge carriers injected at the electrode-polymer interface barrier are displaced at macroscopic distances and get subsequently trapped at trapping levels that are distributed in their activation energies and relaxation times.

  • Effect of injecting electrodes on TSD behaviour of vacuum deposited PVF films
    Ionics, 2004
    Co-Authors: S. Chand, G. D. Sharma, S. Dwivedi, R. Chandra
    Abstract:

    Depolarization behaviour of vacuum deposited Polyvinyl Fluoride (PVF) films has been studied as a function of nature of the electrode materials used during polarization such as copper, silver, aluminium and indium using the thermally stimulated discharge current (TSD) technique. TSD spectra of these films show a single relaxation peak centered around 430 ± 1 K with activation energies of ∼ 0.65 eV. The peak current and the charge associated with the relaxation peak depend strongly on the electrode material used. This has been attributed to the electrode-polymer interface barrier controlling the injection of the charge carriers into PVF films that results into space charge effects by subsequent trapping of the injected charge carriers at macroscopic distances.

  • Electrical conduction in vacuum deposited Polyvinyl Fluoride (PVF) films
    Journal of Materials Science, 2003
    Co-Authors: S. Chand, G. D. Sharma, S. Dwivedi, A. Agarwal, R. Chandra
    Abstract:

    I-V characteristics of vacuum deposited Polyvinyl Fluoride (PVF) films have been investigated as a function of temperature in the range of 303 K to 403 K and as a function of thickness in the range of 2500 Å to 10000 Å, respectively. The I-V curves of these films show two distinct regions of conduction, viz., ohmic region at low-fields with slope ∼1 and non-ohmic region at high-fields with slope ∼2. Space charge limited conduction (SCLC) has been suggested as the dominant mechanism of conduction at high-fields.

  • Effect of PVF interface barrier layer on TSD behaviour of a-Se films
    Journal of Physics D: Applied Physics, 2001
    Co-Authors: Suresh Chand, G. D. Sharma, S. Dwivedi, Ashutosh Agarwal, R. Chandra
    Abstract:

    Thermally stimulated discharge (TSD) current behaviour of amorphous selenium (a-Se) films (~100 µm thick) has been studied as a function of Polyvinyl Fluoride (PVF) interface barrier layer thickness in the range of 2000-8000 A (temperature range of 295-385 K). TSD spectra of these films show that charge storage in a-Se reduces considerably on incorporation of a PVF interface barrier layer. These effects have been attributed to the blocking and field enhanced mobility role of the PVF interface layer.

  • Space-charge distributed relaxations in vacuum-deposited Polyvinyl Fluoride films
    Journal of Physics D: Applied Physics, 1997
    Co-Authors: Suresh Chand, G. D. Sharma, Subhas Chandra, R. Chandra
    Abstract:

    The thermally stimulated discharge behaviour of vacuum-deposited Polyvinyl Fluoride films (about thick) studied as a function of polarization temperature (313 - 453 K) and polarization field (1 - ) shows a single relaxation peak whose peak temperature, charge, activation energy and so on depend strongly on the polarization parameters. The peak has been attributed to space-charge distributed polarization due to the migration of the charge carriers, injected from the electrodes or present inherently, over macroscopic distances and their subsequent trapping; the trapping levels being distributed in the range of energies 0.55 - 0.69 eV.

G. D. Sharma - One of the best experts on this subject based on the ideXlab platform.

  • Charge storage mechanism in vacuum deposited PVF films
    Journal of Materials Science, 2005
    Co-Authors: S. Chand, G. D. Sharma, S. Dwivedi, S. S. Bawa, R. Chandra
    Abstract:

    Thermally stimulated discharge current (TSD) behavior of vacuum deposited Polyvinyl Fluoride (PVF) films has been studied as a function of various polarization parameters such as field (1.0 × 10^3–14.0 × 10^3 V/cm), temperature (313–453 K), time (3.6 × 10^3–6.0 × 10^3 sec), electrode work function (copper, silver, aluminum and indium) and thickness (2000–10000 Å). In a field dependent case the TSD spectra of PVF films show a single relaxation peak centered around 430 ± 1 K. The peak current, charge, peak position and activation energy associated with the peak depend strongly on the polarization parameters. The mechanism of origin of the relaxation peak has been attributed to the space charge polarization where the charge carriers injected at the electrode-polymer interface barrier are displaced at macroscopic distances and get subsequently trapped at trapping levels that are distributed in their activation energies and relaxation times.

  • Effect of injecting electrodes on TSD behaviour of vacuum deposited PVF films
    Ionics, 2004
    Co-Authors: S. Chand, G. D. Sharma, S. Dwivedi, R. Chandra
    Abstract:

    Depolarization behaviour of vacuum deposited Polyvinyl Fluoride (PVF) films has been studied as a function of nature of the electrode materials used during polarization such as copper, silver, aluminium and indium using the thermally stimulated discharge current (TSD) technique. TSD spectra of these films show a single relaxation peak centered around 430 ± 1 K with activation energies of ∼ 0.65 eV. The peak current and the charge associated with the relaxation peak depend strongly on the electrode material used. This has been attributed to the electrode-polymer interface barrier controlling the injection of the charge carriers into PVF films that results into space charge effects by subsequent trapping of the injected charge carriers at macroscopic distances.

  • Electrical conduction in vacuum deposited Polyvinyl Fluoride (PVF) films
    Journal of Materials Science, 2003
    Co-Authors: S. Chand, G. D. Sharma, S. Dwivedi, A. Agarwal, R. Chandra
    Abstract:

    I-V characteristics of vacuum deposited Polyvinyl Fluoride (PVF) films have been investigated as a function of temperature in the range of 303 K to 403 K and as a function of thickness in the range of 2500 Å to 10000 Å, respectively. The I-V curves of these films show two distinct regions of conduction, viz., ohmic region at low-fields with slope ∼1 and non-ohmic region at high-fields with slope ∼2. Space charge limited conduction (SCLC) has been suggested as the dominant mechanism of conduction at high-fields.

  • Effect of PVF interface barrier layer on TSD behaviour of a-Se films
    Journal of Physics D: Applied Physics, 2001
    Co-Authors: Suresh Chand, G. D. Sharma, S. Dwivedi, Ashutosh Agarwal, R. Chandra
    Abstract:

    Thermally stimulated discharge (TSD) current behaviour of amorphous selenium (a-Se) films (~100 µm thick) has been studied as a function of Polyvinyl Fluoride (PVF) interface barrier layer thickness in the range of 2000-8000 A (temperature range of 295-385 K). TSD spectra of these films show that charge storage in a-Se reduces considerably on incorporation of a PVF interface barrier layer. These effects have been attributed to the blocking and field enhanced mobility role of the PVF interface layer.

  • Space-charge distributed relaxations in vacuum-deposited Polyvinyl Fluoride films
    Journal of Physics D: Applied Physics, 1997
    Co-Authors: Suresh Chand, G. D. Sharma, Subhas Chandra, R. Chandra
    Abstract:

    The thermally stimulated discharge behaviour of vacuum-deposited Polyvinyl Fluoride films (about thick) studied as a function of polarization temperature (313 - 453 K) and polarization field (1 - ) shows a single relaxation peak whose peak temperature, charge, activation energy and so on depend strongly on the polarization parameters. The peak has been attributed to space-charge distributed polarization due to the migration of the charge carriers, injected from the electrodes or present inherently, over macroscopic distances and their subsequent trapping; the trapping levels being distributed in the range of energies 0.55 - 0.69 eV.

S. Dwivedi - One of the best experts on this subject based on the ideXlab platform.

  • Charge storage mechanism in vacuum deposited PVF films
    Journal of Materials Science, 2005
    Co-Authors: S. Chand, G. D. Sharma, S. Dwivedi, S. S. Bawa, R. Chandra
    Abstract:

    Thermally stimulated discharge current (TSD) behavior of vacuum deposited Polyvinyl Fluoride (PVF) films has been studied as a function of various polarization parameters such as field (1.0 × 10^3–14.0 × 10^3 V/cm), temperature (313–453 K), time (3.6 × 10^3–6.0 × 10^3 sec), electrode work function (copper, silver, aluminum and indium) and thickness (2000–10000 Å). In a field dependent case the TSD spectra of PVF films show a single relaxation peak centered around 430 ± 1 K. The peak current, charge, peak position and activation energy associated with the peak depend strongly on the polarization parameters. The mechanism of origin of the relaxation peak has been attributed to the space charge polarization where the charge carriers injected at the electrode-polymer interface barrier are displaced at macroscopic distances and get subsequently trapped at trapping levels that are distributed in their activation energies and relaxation times.

  • Effect of injecting electrodes on TSD behaviour of vacuum deposited PVF films
    Ionics, 2004
    Co-Authors: S. Chand, G. D. Sharma, S. Dwivedi, R. Chandra
    Abstract:

    Depolarization behaviour of vacuum deposited Polyvinyl Fluoride (PVF) films has been studied as a function of nature of the electrode materials used during polarization such as copper, silver, aluminium and indium using the thermally stimulated discharge current (TSD) technique. TSD spectra of these films show a single relaxation peak centered around 430 ± 1 K with activation energies of ∼ 0.65 eV. The peak current and the charge associated with the relaxation peak depend strongly on the electrode material used. This has been attributed to the electrode-polymer interface barrier controlling the injection of the charge carriers into PVF films that results into space charge effects by subsequent trapping of the injected charge carriers at macroscopic distances.

  • Electrical conduction in vacuum deposited Polyvinyl Fluoride (PVF) films
    Journal of Materials Science, 2003
    Co-Authors: S. Chand, G. D. Sharma, S. Dwivedi, A. Agarwal, R. Chandra
    Abstract:

    I-V characteristics of vacuum deposited Polyvinyl Fluoride (PVF) films have been investigated as a function of temperature in the range of 303 K to 403 K and as a function of thickness in the range of 2500 Å to 10000 Å, respectively. The I-V curves of these films show two distinct regions of conduction, viz., ohmic region at low-fields with slope ∼1 and non-ohmic region at high-fields with slope ∼2. Space charge limited conduction (SCLC) has been suggested as the dominant mechanism of conduction at high-fields.

  • Effect of PVF interface barrier layer on TSD behaviour of a-Se films
    Journal of Physics D: Applied Physics, 2001
    Co-Authors: Suresh Chand, G. D. Sharma, S. Dwivedi, Ashutosh Agarwal, R. Chandra
    Abstract:

    Thermally stimulated discharge (TSD) current behaviour of amorphous selenium (a-Se) films (~100 µm thick) has been studied as a function of Polyvinyl Fluoride (PVF) interface barrier layer thickness in the range of 2000-8000 A (temperature range of 295-385 K). TSD spectra of these films show that charge storage in a-Se reduces considerably on incorporation of a PVF interface barrier layer. These effects have been attributed to the blocking and field enhanced mobility role of the PVF interface layer.

S. Chand - One of the best experts on this subject based on the ideXlab platform.

  • Charge storage mechanism in vacuum deposited PVF films
    Journal of Materials Science, 2005
    Co-Authors: S. Chand, G. D. Sharma, S. Dwivedi, S. S. Bawa, R. Chandra
    Abstract:

    Thermally stimulated discharge current (TSD) behavior of vacuum deposited Polyvinyl Fluoride (PVF) films has been studied as a function of various polarization parameters such as field (1.0 × 10^3–14.0 × 10^3 V/cm), temperature (313–453 K), time (3.6 × 10^3–6.0 × 10^3 sec), electrode work function (copper, silver, aluminum and indium) and thickness (2000–10000 Å). In a field dependent case the TSD spectra of PVF films show a single relaxation peak centered around 430 ± 1 K. The peak current, charge, peak position and activation energy associated with the peak depend strongly on the polarization parameters. The mechanism of origin of the relaxation peak has been attributed to the space charge polarization where the charge carriers injected at the electrode-polymer interface barrier are displaced at macroscopic distances and get subsequently trapped at trapping levels that are distributed in their activation energies and relaxation times.

  • Effect of injecting electrodes on TSD behaviour of vacuum deposited PVF films
    Ionics, 2004
    Co-Authors: S. Chand, G. D. Sharma, S. Dwivedi, R. Chandra
    Abstract:

    Depolarization behaviour of vacuum deposited Polyvinyl Fluoride (PVF) films has been studied as a function of nature of the electrode materials used during polarization such as copper, silver, aluminium and indium using the thermally stimulated discharge current (TSD) technique. TSD spectra of these films show a single relaxation peak centered around 430 ± 1 K with activation energies of ∼ 0.65 eV. The peak current and the charge associated with the relaxation peak depend strongly on the electrode material used. This has been attributed to the electrode-polymer interface barrier controlling the injection of the charge carriers into PVF films that results into space charge effects by subsequent trapping of the injected charge carriers at macroscopic distances.

  • Electrical conduction in vacuum deposited Polyvinyl Fluoride (PVF) films
    Journal of Materials Science, 2003
    Co-Authors: S. Chand, G. D. Sharma, S. Dwivedi, A. Agarwal, R. Chandra
    Abstract:

    I-V characteristics of vacuum deposited Polyvinyl Fluoride (PVF) films have been investigated as a function of temperature in the range of 303 K to 403 K and as a function of thickness in the range of 2500 Å to 10000 Å, respectively. The I-V curves of these films show two distinct regions of conduction, viz., ohmic region at low-fields with slope ∼1 and non-ohmic region at high-fields with slope ∼2. Space charge limited conduction (SCLC) has been suggested as the dominant mechanism of conduction at high-fields.

Sina Ebnesajjad - One of the best experts on this subject based on the ideXlab platform.

  • 3 – Introduction to Fluoropolymers
    Applied Plastics Engineering Handbook, 2017
    Co-Authors: Sina Ebnesajjad
    Abstract:

    The important fluoropolymers include polytetrafluoroethylene (PTFE), perfluoroalkoxy polymer (PFA), fluorinated ethylene propylene polymer (FEP), ethylene-tetrafluoroethylene copolymer (ETFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), polychlorotrifluoroethylene (PCTFE), Polyvinylidene Fluoride (PVDF), and Polyvinyl Fluoride (PVF). This chapter describes the classification, preparation, properties, fabrication, applications, safety considerations, and economics of fluoropolymers. Monomer synthesis and properties are discussed as well.

  • Surface Treatment of Polyvinyl Fluoride Films and Coatings
    Polyvinyl Fluoride, 2013
    Co-Authors: Sina Ebnesajjad
    Abstract:

    The chapter focuses on the surface treatment of Polyvinyl Fluoride (PVF) films. It provides a description of choices of the technique for surface treatment of PVF including chemical, corona, flame, plasma and atmospheric plasma treatment. Table representing surface energy of PVF compared to a number of other polymers is presented. Application of surface treatment methods to PVF alters the surface by cleaning, ablation, cross-linking, and surface chemical modification. It reports the results of sodium etch treatment on bond strength and surface composition of PVF film. It discusses the configurations of corona treatment equipment including conventional and bare-roll configuration. The chapter also provides information on fuel equivalence ratio, oxygen ratio and fluorine-to-carbon ratio.

  • Manufacturing of Unoriented Polyvinyl Fluoride Films and Coatings
    Polyvinyl Fluoride, 2013
    Co-Authors: Sina Ebnesajjad
    Abstract:

    The chapter focuses on the manufacturing of unoriented Polyvinyl Fluoride (PVF) films and coatings. Unoriented PVF film is cast onto a carrier web to achieve negligible stretching. Unoriented films are more compliant, have lower tensile strength, and have higher elongation at break than oriented ones. A comparison of oriented and unoriented clear PVF film is presented in a tabular form. A number of techniques for the application of polymer solution to the web including gravure coating, reverse roll coating, doctor-blade roller coating, Meyer rod coating and reverse gravure roll coating are mentioned. It provides a detailed discussion on the preparation of unoriented PVF films. Finally, the chapter shows a schematic diagram of the manufacturing process for unoriented PVF film.

  • Manufacturing of Oriented Polyvinyl Fluoride Film
    Polyvinyl Fluoride, 2013
    Co-Authors: Sina Ebnesajjad
    Abstract:

    The chapter reviews the technology developed for extrusion and orientation of Polyvinyl Fluoride (PVF) films. PVF does not dissolve in most solvents at room temperature and pressure because of the large number of hydrogen bonds and high degree of crystallinity. PVF is converted to thin films and coatings by melt extrusion of a plastisol of the resin in a polar solvent. The chapter provides information related to PVF dispersion in latent solvent and film extrusion including brief overview on casting die and biaxial orientation. Data showing range of inherent viscosity values, polymer concentrations, and extrusion temperatures is presented. Finally, the chapter provides a schematic diagram of the commercial oriented PVF film manufacturing process.

  • Polymerization and Finishing Polyvinyl Fluoride
    Polyvinyl Fluoride, 2013
    Co-Authors: Sina Ebnesajjad
    Abstract:

    The chapter focuses on the polymerization of vinyl Fluoride (VF). The polymerization reaction is dominated by the high energy and reactivity of the propagating vinyl Fluoride radical. VF undergoes free-radical polymerization in which a thermal free radical initiator is used to start the polymerization reaction. VF polymerizes in both head-to-head and head-to-tail configurations. The chapter provides the numerous techniques used including suspension, bulk, and emulsion polymerizations in batch and continuous modes. Graft and radiation-induced polymerizations are discussed. The chapter also discusses procedures used to measure properties of the polymer including melt viscosity, haze measurements, film surface tension and dispersion viscosities. Tables related to melting point and degree of crystallinity of Polyvinyl Fluoride, reactivity ratios of VF with alkylboron and Ziegler–Natta catalysts are provided. It also presents information on region-irregularity or regiosequence defects.