Preparation and Dielectric Behavior of Polyvinylidene Fluoride Composite Filled with Modified Graphite Nanoplatelet

摘要

Graphite nanoplatelet (GNP) was modified by polyvinylpyrrolidone (PVP), Cetyltrimethyl ammonium bromide (CTAB), γ-aminopropyltriethoxysilane (KH-550), and Stearic acid (SA), respectively. The polyvinylidene fluoride (PVDF)/modified GNP (m-GNP) nanocomposites were fabricated via solution mixing method. SEM, TEM, XRD, FTIR, and impendence analyzer were used to characterize the morphology, structure, and their electrical properties. Results showed that PVP and CTAB modified-GNP enables a better homogeneous dispersion of GNP in N,N-dimethylformamide (DMF) solvent than that of KH-550 and SA, which leads to a decreased conductivity in PVDF/m-GNP system. The permittivities of these nanocomposites were found to decrease with increasing frequencies. The SA modified-GNP filled PVDF nanocomposite has the largest dielectric constant and lowest dielectric loss. Such electrical behavior can be well interpreted in terms of the percolation theory.