The effect of temperature on the electrical and thermal conductivity of graphene‐based polymer composite films

Abstract

In this work, we studied the effect of temperature on the electrical, thermal, and mechanical properties of graphene-based poly(vinylidene fluoride-cohexafluoropropylene) composites. Graphene-based polymer composites (PC-Gn) with various graphene content were prepared using solution mixing and molding process. The physical, chemical, and mechanical properties of the PC-Gn composites were investigated using different characterization techniques including differential scanning calorimetry, scanning electron microscopy, potentiostatic electrochemical impedance spectroscopy, and dynamic mechanical analysis (DMA). DMA results showed that the strength of obtained PC-Gn composites increased with higher graphene wt%. The in-plane electrical and thermal conductivity values were measured over a temperature range from 25 to 125 C using a four-point probe electrical conductivity system and optothermal Raman technique, respectively. Our results showed that temperature had a noticeable effect on the in-plane electrical and thermal conductivity values for PC-Gn where both values gradually decreased by the increment of temperature.We believe that by increasing temperature, the vibration of composite particles became more severe, which increased the system's anharmonicity and strongly reduced the lifetimes of electrons and phonons in the composite. Further analysis, including electrochemical analysis, was also done on all composite films showing that our process produced highly conductive films that potentially can be used in many electrochemical applications in the future.applications, conducting polymers, thermal properties | INTRODUCTIONGraphene, a one-atom-thick two-dimensional honeycomb network of carbon atoms, has a very large specific surface area of 2600 m 2 /g and very high mechanical, thermal, and electrical properties. 1 The in-plane thermal conductivity of a single layer of graphene is very high and is around 3080-5150 W/mK at room temperature. 2

Numerical Investigation and Response Surface Optimization of the Effective Modulus and Electrical and Thermal Conductivities of the Borophene Nanoplatelet-Reinforced PEDOT:PSS Nanocomposite for Energy Storage Application

“…According to the Wiedermann–Franz law (eq ), the poor electrical conductivity of the BNP causes a low thermal conductivity generated by electron movement. As a result, as illustrated in Figure , the temperature gradient is consistently spread over all point nodes in these composites, with phonon transport serving as the primary heat carriers, which originated from the BNP inclusion. k normale = L 0 σ normale T where L 0 is the Lorentz constant ( 2.44 × 10 − 8 W Ω K 2 ) , k e is the thermal conductivity due to electrons, σ e is the electrical conductivity, and T is the temperature …”

“… where L 0 is the Lorentz constant , k e is the thermal conductivity due to electrons, σ e is the electrical conductivity, and T is the temperature. 59 …”

“…, k e is the thermal conductivity due to electrons, σ e is the electrical conductivity, and T is the temperature. 59 Figure 14 displays the maximum magnitude of the nodal point temperatures, NT11, and the heat flux vector, HFL, for the RVE of BNP inclusions, the PEDOT:PSS matrix, and their nanocomposite under uniaxial macroscopic temperature gradient loading in the 1-, 2-, and 3-direction. Meanwhile, Figures S12− S14 show the distribution of the heat flow vector's magnitude, nodal point temperatures, and reaction flux for the inclusions, matrix, and nanocomposite along directions 1, 2, and 3.…”

Catalytic Reaction Intensification by a Novel Cryogenic Auxiliary Synthesized Fe-PAN Membrane

“…During electrospinning, the low temperature can reduce the intensity of molecular motion and reduce the disorderly collision between molecules, thus enhancing the magnetic property of the nanometal. , The increase in magnetic property leads to increased repulsion between nanometals and is conducive to more uniform metal dispersion inside the fiber. , Additionally, low temperature also improves the conductivity of polymers and thus improves the entrapment rate of nanometals . To confirm the NZVI dispersion in Fe-PAN, the average crystallite sizes D (nm) of NZVI were calculated by the Scherrer formula D = K γ B .25em cos ⁡ θ where K is the Scherrer constant (0.89), γ is the X-ray wavelength (0.154056 nm), B is the half-peak width (in radians form), and θ (°) is the diffraction angle.…”

“…38,39 Additionally, low temperature also improves the conductivity of polymers 40 and thus improves the entrapment rate of nanometals. 41 To confirm the NZVI dispersion in Fe-PAN, the average crystallite sizes D (nm) of NZVI were calculated by the Scherrer formula 15…”