  Interface constitutes a significant volume fraction in nanocomposites, and it
requires the ability to tune and tailor interfaces to tap the full potential of
nanocomposites. However, the development and optimization of nanocomposites is
currently restricted by the limited exploration and utilization of interfaces
at different length scales. In this research, we have designed and introduced a
relatively large-scale vertical interphase into carbon nanocomposites, in which
the dielectric response and dispersion features in microwave frequency range
are successfully adjusted. A remarkable relaxation process has been observed in
vertical-interphase nanocomposites, showing sensitivity to both filler loading
and the discrepancy in polarization ability across the interphase. Together
with our analyses on dielectric spectra and relaxation processes, it is
suggested that the intrinsic effect of vertical interphase lies in its ability
to constrain and localize heterogeneous charges under external fields.
Following this logic, systematic research is presented in this article
affording to realize tunable frequency-dependent dielectric functionality by
means of vertical interphase engineering. Overall, this study provides a novel
method to utilize interfacial effects rationally. The research approach
demonstrated here has great potential in developing microwave dielectric
nanocomposites and devices with targeted or unique performance such as tunable
broadband absorbers.
