State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics , Chinese Academy of Sciences , Lanzhou 730000 , P. R. China.
University of Chinese Academy of Sciences , Beijing 100049 , P. R. China.
ACS Appl Mater Interfaces. 2018 Mar 7;10(9):8180-8189. doi: 10.1021/acsami.7b17018. Epub 2018 Feb 20.
The bulk materials of three-dimensional graphene (3DG) with high network structure and excellent electrical conductivity have many potential applications in flexible electronics, but the network structure is not very stable due to weak bonding between graphene nanosheets. Here, a polyimide (PI) layer was introduced on the as-prepared 3DG sponge by vacuum infiltration-curing method. The resulting 3DG/PI composite sponges with robust 3D network structure exhibited an excellent electrical conductivity (3.7 S/cm), compression strength (175 kPa), elasticity, and flexibility, as well as outstanding compression sensitivity to resistance and stable piezoresistance effect; namely, they possess a large change in resistance in response to application of small strain and low density, and the resistance change remains favorably stable after performing 300 compress-release cycles, which means that the prepared composite sponges can find wide applications in pressure-sensing or stimulus-responsive graphene system.
三维石墨烯（3DG）具有高网络结构和优异导电性的块状材料在柔性电子产品中有许多潜在的应用，但由于石墨烯纳米片之间的结合较弱，其网络结构不是非常稳定。在这里，通过真空渗透-固化法在制备的 3DG 海绵上引入了聚酰亚胺（PI）层。所得的具有坚固 3D 网络结构的 3DG/PI 复合海绵表现出优异的导电性（3.7 S/cm）、压缩强度（175 kPa）、弹性和柔韧性，以及对电阻的出色压缩灵敏度和稳定的压阻效应；也就是说，它们在响应小应变和低密度时表现出较大的电阻变化，并且在进行 300 次压缩-释放循环后，电阻变化仍然保持良好的稳定性，这意味着所制备的复合海绵在压力感应或刺激响应的石墨烯系统中有广泛的应用。
