posted on 2022-05-05, 16:07authored byZhongjie He, Xiaoqian Li, Hongni Wang, Fangfang Su, Dechao Wang, Dongdong Yao, Yaping Zheng
The
performance of graphene aerogels (GAs) is based on the microstructure.
However, GAs face a challenge of simultaneously controlling the size
and alignment of pores strategically. Herein, we initially proposed
a simple strategy to construct GAs with an adjustable structure based
on the emulsion and ice dual template methods. Specifically, GAs with
a honeycomb structure prepared by conventional freezing (CGAs) exhibited
a high specific surface of 176 m2/g, superelasticity with
a compressive strain of 95%, isotropic compression and thermal insulation
performances, as well as an excellent absorption capacity of 150–550
g/g. Instead, the GAs with a bamboo-like network frozen by unidirectional
freezing (UGAs) showed anisotropy in compression and thermal insulation
behavior. Furthermore, UGAs exhibited incredible special stress (7.9
kPa cm3/mg) along the axial direction twice than that of
the radial direction. Meanwhile, the apparent temperature of UGAs
was only 45.6 °C when placed on a 120 °C hot stage along
the radial direction. Remarkably, the properties of CGAs and UGAs
were significantly improved with the adjustment of the microstructure.