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Flexible Thermoelectric Polymers and Systems. Группа авторовЧитать онлайн книгу.

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charge‐transfer organic salts.

       1.1.5.3.3 Conducting Polymers

      The temperature dependence of the conductivity of conducting polymers is different because they are disordered systems. The charge transport is dominated by the interchain charge hopping. In general, the conductivity of conducting polymers follows the one‐dimensional variable range hopping model,

      (1.17)rho equals rho 0 exp left-parenthesis left-parenthesis StartFraction upper T 0 Over upper T EndFraction right-parenthesis Superscript 1 slash 2 Baseline right-parenthesis period

Schematic illustration of temperature dependence of the resistance of a PEDOT:PSS treated with H2SO4.

      Source: Xia et al. [21]. © John Wiley & Sons.

      1.1.5.4 Conductivity of Composites

Schematic illustration of structures of a composite with two phases of α and β (a) in series, (b) in parallel, and (c) one phase dispersed in another phase.

      (1.18)rho Subscript c Baseline equals chi Subscript alpha Baseline rho Subscript alpha Baseline plus chi Subscript beta Baseline rho Subscript beta Baseline comma

      where χ α and χ β are the volume fractions of the α and β phases, respectively, and ρ α and ρ β are the resisitivities of the two phases, respectively. The resistivity of the composite is dominated by the phase of higher resistivity.

      When the two phases of α and β are parallel, the conductivity (σ c) of the composites is related to the conductivities of the two phases by the following equation,

      (1.19)sigma Subscript c Baseline equals chi Subscript alpha Baseline sigma Subscript alpha Baseline plus chi Subscript beta Baseline sigma Subscript beta Baseline period

      The phase with higher conductivity will be the dominant one for the conductivity of the composite.

      If a composite has a structure of the α phase dispersed in the β phase, the α phase is the dispersed phase and the β phase is the matrix. The resistivity of the composite depends on the relative resistivities of the two phases. If the α phase is more resistive than the β phase, ρ α > 10 ρ β, the resistivity of the composite is given by

      (1.20)rho Subscript c Baseline equals rho Subscript beta Baseline StartFraction 1 plus one half chi Subscript alpha Baseline Over 1 minus chi Subscript alpha Baseline EndFraction comma

      If the α phase is less resistive than the β phase, ρ α < (1/10)ρ β, the resistivity of the composite is given by

      (1.21)rho Subscript c Baseline equals rho Subscript beta Baseline StartFraction 1 minus chi Subscript alpha Baseline Over 1 plus 2 chi Subscript alpha Baseline EndFraction period

      (1.22)upper S Subscript normal c Baseline equals StartStartFraction StartFraction chi Subscript beta Baseline upper S Subscript beta Baseline Over kappa Subscript beta Baseline EndFraction plus StartFraction chi Subscript alpha Baseline upper S Subscript alpha Baseline Over kappa Subscript alpha Baseline EndFraction OverOver StartFraction chi Subscript beta Baseline Over kappa Subscript beta Baseline EndFraction plus StartFraction chi Subscript alpha Baseline Over kappa Subscript alpha Baseline EndFraction EndEndFraction comma

      where S α and S β are the Seebeck coefficients of the α and β phases, respectively, and κ α and κ β are the thermal conductivities of the two phases, respectively. When the two phases are in parallel, the Seebeck coefficient of the composite is given by

      (1.23)upper S Subscript normal c Baseline equals StartFraction chi Subscript beta Baseline sigma Subscript beta Baseline upper S Subscript beta Baseline plus chi Subscript alpha Baseline sigma Subscript alpha Baseline upper S Subscript alpha Baseline Over chi Subscript beta Baseline sigma Subscript beta Baseline plus chi Subscript alpha Baseline sigma Subscript alpha Baseline EndFraction period

      1.1.6 Thermal Conductivity

      The thermal conductivity (κ) of an electronic material include the lattice thermal conductivity (κ L) and the electronic thermal conductivity (κ e),

      (1.24)kappa equals kappa Subscript upper L Baseline plus kappa Subscript <hr><noindex><a href=Скачать книгу

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