Comprehensive analysis of CNT/NS/GO composites: Dispersion effect of graphene oxide for environmental sensor application

Abstract

This study presents a comprehensive analysis of conductive and hygroscopic nanocomposites using graphene oxide (GO), carbon nanotubes (CNT), and nano-silica. Nanocomposite suspensions for vacuum filtration were prepared by dispersion via ultrasonication in water. The dispersed phase of each nanomaterial was evaluated through ultraviolet absorbance, extinction coefficient, and zeta potential. The dispersion was performed at a ratio of CNT to GO well over 0.4 without any surfactants or additives because of the rich functional groups on the GO surface. In addition, the morphology of the fabricated nanocomposite generated after vacuum filtration, verified through scanning electron microscopy and Raman spectroscopy, showed a lamellar structure of GO and was easily separated as a membrane at composite-to-GO ratios of over 0.4. The fabricated membrane exhibited an excellent moisture collection ability and good responsivity as an environmental (humidity) sensor. This study supports the use of GO for the formation of well-dispersed nanocomposites for various applications.