Abstract:Graphene is a two-dimensional carbon nano-material with hexagonal honeycomb lattice, which is formed by the hybridization of carbon atoms in sp2 electron orbital. The atoms in graphene layer are connected together by σ bond, and the free electrons form a large area of conjugated π bond. This structural feature gives graphene good electrical properties, mechanical properties, optical properties and thermal conductivity, making graphene a “rising star” material which has attracted enormous attentions. With the rapid development of this field, the research focus has moved to controlled construction of graphene materials by chemical or physical modification aiming to achieve specific applications in different advanced systems. Stimulus-responsive systems are of great theoretical and practical interests, for they can spontaneously respond to environmental changes. Polymer-based stimulus-responsive materials have the disadvantages of poor mechanical strength and unsatisfactory environmental stability. However, graphene-based materials are stable, mechanically strong, electrically and thermally conductive, making them attractive basic building units in stimulus-responsive materials. Stimulus-responsive graphene materials can be obtained by modifying graphene with specific polymers, small molecules or nano-particles through covalent or non-covalent interaction. These polymers or small molecules are typically responsive to external stimulus. Therefore, the functionalized graphene-based materials are sensitive to a range of stimuli, including temperature, pH, electrical, light, gas molecule, solvent molecule, magnetic field or even multiple signals. In this review article, the methods and related applications of stimulus-responsive graphene materials modified by the corresponding polymers, small molecules or nano-particles are outlined. These stimulus-responsive graphene systems are believed to have great theoretical and practical interests to a wide range of applications including actuators, switches, chemical or strain sensors, self-healing materials, photothermal therapy and controlled drug/gene delivery, etc. Besides, the shortcomings of existing stimulus-responsive graphene materials are analyzed. The future application and development directions of the stimulus-responsive graphene materials are prospected.