刺激响应型石墨烯材料的研究新进展

Recent Research Progress in Stimuli-Responsive Graphene Materials

石墨烯是一种具有六角型蜂巢状晶格的二维碳纳米材料,它由碳原子以sp2电子轨道杂化形成,它的高比表面积以及优良的力学、电学、光学和热学性能使它成为智能材料的基本构筑单元。利用具备特定功能的聚合物、小分子或者纳米粒子对石墨烯进行修饰或者杂化,得到具备相应刺激响应性能的石墨烯材料,与传统的刺激响应型高分子材料相比,它具备更佳的力学性能以及更好的环境稳定性,有望在致动器、传感器、自愈合材料、光热治疗以及可控药物输送等方面得到应用。本文简要概述了近年来利用对温度、pH、电、光以及有机分子等刺激响应的聚合物和小分子化合物对石墨烯进行修饰,并赋予其智能响应特性的方法以及相关应用研究,分析了现有智能响应石墨烯材料的不足,展望了其未来的应用前景以及发展方向。

Graphene is a kind of two-dimensional carbon nano-material with hexagonal honeycomb lattice,which is formed by the hybridization of carbon atoms in sp2 electron orbit.The atoms in graphene layer are connected together byσbond,and the free electrons form a large area of conjugatedπbond.This structural feature endows graphene with excellent electrical properties,mechanical properties,optical properties and thermal conductivity,making graphene be a“rising star”material which has attracted enormous attentions.With the rapid development of this field,the research focus has been shifting to controlled fabrication of graphene materials by chemical or physical modifications aiming to achieve specific applications in different advanced systems.Stimuli-responsive systems are of great theoretical and practical interests because of their spontaneously response to environmental changes.Polymer-based stimuli-responsive materials have the disadvantages of poor mechanical strength and insufficient environment stability.In contrast,graphene-based materials are stable,mechanically strong,electrically and thermally conductive,making them be attractive building discrete for the fabrication of stimuli-responsive materials.Stimuli-responsive graphene materials can be obtained by modifying graphene with specific polymers,small molecules or nano-particles through covalent or non-covalent interactions.These polymers or small molecules are typically able to response to external stimulus.Therefore,the functionalized graphene-based materials are sensitive to a series of stimulus,including temperature,pH,electrical field,light,gas molecule,solvent molecule,magnetic field or even multiple signals.In this review,the fabrication methods and related applications of stimuli-responsive graphene materials functionalized by the corresponding polymers,small molecules or nano-particles are outlined.These stimuliresponsive graphene systems present great theoretical and practical interests in a wide range of fields,such as actuators,switches,chemical or strain sensors,self-healing materials,photothermal therapy and controlled drug/gene delivery,etc.Moreover,the deficiencies of the existing stimuli-responsive graphene materials are summarized as well.The future application and development directions of the stimuli-responsive graphene materials are proposed.