Highly Ordered and Multiple-Responsive Graphene Oxide/Azoimidazolium Surfactant Intercalation Hybrids: A Versatile Control Platform.

Abstract

To produce graphene materials with better controllability, a new graphene oxide (GO) intercalation hybrid is fabricated with the incorporation and functionalization with the azoimidazolium (AzoIm+) surfactant. The hybrid exhibits a highly uniform lamellar structure in which a few layers of GO are stacked with AzoIm+ alternatively. Simultaneous control of the mesoscopic structures, aggregation properties, and electrochemical behavior of the hybrid is achieved by inheriting the photo, thermal, and mechanical responsiveness of azoimidazolium. Ultraviolet (UV) treatment produces a well-dispersed GO/AzoIm+ suspension aggregate and a precipitate, whereas the specific capacitance of the final hybrid decreases. The lamellar stacking becomes anisotropic by uniaxial stretching on a soft polymer. With a liquid crystal unit inserted between the layers, the d spacing of the lamella passes through transformation, disordering, and finally recovery stages, associated with the increasing and decreasing temperature. The explosive release of heat generated by the thermal reduction of GO is reduced in the GO/AzoIm+ intercalation hybrid. The release of heat is tunable by varying the relative quantity and UV treatment of AzoIm+. The physical properties of the hybrid allow the controlled preparation of ultrasmall Au nanodots between the GO layers. This represents a major step toward multiple-responsive integrated graphene applications.