▎ 摘　　要

As an advanced upgrade form of green buildings, passive ultra-low energy consumption building is an inevitable trend of future building development. Therefore, it is of great significance to develop new fireretardant and ultra-thin thermal insulation materials for exterior wall. In this paper, we focus on graphene foams with excellent thermal insulation, and the microstructure of graphene hydrogel was studied as an intermediate to prepare graphene foam. The microstructure of graphene hydrogel as an intermediate to prepare graphene foam was studied. This study was proposed based on two problems: (1) Graphene hydrogels change from hydrophilic/lipophobic to hydrophobic/lipophilic after freeze-drying. (2) Compared with the poor mechanical properties of graphene hydrogels, graphene-based nanocomposite hydrogels have highly extensiIP: 182 75.148 10 On: Fri 04 Feb 2022 08:21:17 ble and resilient properties. We studied Copyright: the American microstructures Scien of ificboth Publisrsgraphene and graphene hydrogel. Notably, many stomatas were distributed in graphene hydrogl, and the proportion could be adjusted by changing the quantity and type of reducing agent. This property can be applied to adjust the microstructure and properties of graphene foams. Based on the practice of passive ultra-low energy consumption buildings, the heat insulation mechanism of graphene foam insulation material and the preparation process of graphene foam were studied through theoretical analysis and experimental research. The results of this study provide a theoretical basis and scientific basis for the development and application of graphene foam insulation materials, and promote the industrial production of graphene foam insulation materials, with important research value and application prospect to solve the problems of high quality and large-scale development of passive ultra-low energy consumption building restricted by conventional exterior wall insulation materials.