an0c01328_si_001.pdf (1.12 MB)
Flexible Reduced Graphene Oxide/Polyacrylonitrile Dielectric Nanocomposite Films for High-Temperature Electronics Applications
journal contribution
posted on 2020-07-03, 17:03 authored by Yaotian Su, Wenqing Zhang, Jinle Lan, Gang Sui, Hongtao Zhang, Xiaoping YangPolymer
dielectrics possess excellent flexibility compared with
inorganic ceramic materials. However, the relatively low dielectric
constant and working temperature significantly constrain their widespread
application. Here, we report a low-cost facile strategy to develop
flexible polymer-based composite films with high dielectric constant
over a broad temperature. Polyacrylonitrile (PAN) nanofiber mats containing
graphene oxide (GO) with core–shell microstructure were first
prepared via coaxial electrospinning and then hot-pressed into dense
composite films. It was revealed that hot-pressing assisted by a stretching
force under appropriate temperature and pressure can generate local
conformational changes of PAN, leading to the formation of an electroactive
phase with increased dielectric constant. Meanwhile, the GO transformed
into reduced graphene oxide (rGO) under heat reduction, serving as
conductive nanofillers to further promote the increase of dielectric
constant. Consequently, the optimized rGO/PAN composites displayed
thermally stable dielectric properties with a high dielectric constant
(ε′ = 23, 80 °C; ε′ = 40, 150 °C)
and low loss (tan δ = 0.13, 80 °C; tan δ = 0.55,
150 °C) over a broad temperature range. This work offers an efficient
method for the synthesis of flexible composite dielectric films that
hold great potential in high-temperature electronic applications.