三维木头海绵-石墨烯/环氧树脂复合材料的制备及性能

Preparation and properties of epoxy composites reinforced by three-dimensional wood sponge-graphene

采用天然巴沙木作为原材料,进行选择性刻蚀,得到三维层状结构的木头海绵。以木头海绵为模板,在负载一定比例的还原氧化石墨烯(rGO)与石墨烯纳米片(GNP)后,通过真空浸渍的方法与环氧树脂复合并固化,制备得到石墨烯-木头海绵(G-WS)/环氧树脂复合材料。结果表明:采用真空浸渍的方法,能够成功使氧化石墨烯(GO)在水热还原的同时,带动GNP负载到木头海绵表面,同时GO被还原成为rGO,经过与环氧树脂复合后,在环氧树脂内部,G-WS仍然保持良好的三维结构,这种取向分层结构使复合材料具有导热的各向异性,三维连通的结构也为良好的热导率奠定了基础。当填料质量分数为1.45%时,沿取向结构方向的热导率能够达到1.59 W·m^(-1)·K^(-1),相比于纯环氧树脂而言,热导率提升率高达457%。同时由于木头海绵内部层状的结构,赋予了G-WS良好的压缩回弹性能,能够实现80%压缩以及40%形变压缩,循环100次但不发生明显形变。

The selectively etch nature balsa wood,leading to a wood sponge with three-dimensional(3D)lamellar structure.After loading a certain proportion of reduced graphene oxide(rGO)and graphene nanosheets(GNP),the graphene-wood sponge(G-WS)/epoxy resin composite was prepared by vacuum impregnation and curing with epoxy resin.After loading graphene via hydrothermal reduction,graphene oxide(GO)is reduced to rGO.During the self-assembly of rGO sheets,GNP are wrapped and connected by rGO sheets byπ-πinteractions.Meanwhile,G-WS can also maintain the good 3D structure after vacuum impregnation.The lamellar structure inherited from the wood stock that can lead to anisotropic conductivity G-WS with epoxy resin,at loading of 1.45%(mass fraction,the same below),represents a high through-plane thermal conductivity of 1.59 W·m^(-1)·K^(-1),compared to the neat epoxy matrix,which is equivalent to a significant enhancement 457%of per 1%loading.The lamellar structure made the G-WS can achieve 80%compression and 40%deformation and compression cycles for 100 times without significant deformation.