He Zhongjie, Li Xiaoqian, Wang Hongni, Su Fangfang, Wang Dechao, Yao Dongdong, Zheng Yaping
School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710129, P. R. China.
ACS Appl Mater Interfaces. 2022 May 18;14(19):22544-22553. doi: 10.1021/acsami.2c00525. Epub 2022 May 5.
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 m/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 cm/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.
石墨烯气凝胶（GAs）的性能基于其微观结构。然而，GAs面临着一项挑战，即要策略性地同时控制孔隙的尺寸和排列。在此，我们首次提出了一种基于乳液和冰双模板法构建结构可调节的GAs的简单策略。具体而言，通过常规冷冻制备的具有蜂窝结构的GAs（CGAs）表现出176 m²/g的高比表面积、95%压缩应变的超弹性、各向同性压缩和隔热性能，以及150 - 550 g/g的优异吸收能力。相反，通过单向冷冻形成竹状网络的GAs（UGAs）在压缩和隔热行为上表现出各向异性。此外，UGAs沿轴向的特殊应力（7.9 kPa·cm/mg）比径向的特殊应力大两倍。同时，当沿径向放置在120°C的热台上时，UGAs的表观温度仅为45.6°C。值得注意的是，随着微观结构的调整，CGAs和UGAs的性能得到了显著改善。
