Adsorption of different types of surfactants on graphene oxide

Abstract The aim of this study was to improve the dispersibility of graphene oxide (GO) and pave the way for future research of proteins and nanosheets in our laboratory. The interactions of GO (with a concentration fixed at 0.10 g/L) with typical cationic, anionic, and neutral surfactants, dodecyl trimethylammonium bromide (DTAB), sodium dodecyl sulfate (SDS), and Triton X-100 (TX-100) were explored using several methods, including surface tension (ST), conductivity, ζ-potential, hydrogen nuclear magnetic resonance ( 1 H NMR), and isothermal titration microcalorimetry (ITC). Several approaches were adopted to confirm the different adsorption behaviors between three surfactants with different charged head groups and the negatively charged GO in different aspects. After comprehensive consideration, it was deduced that the interaction between DTAB and GO was strongest mainly because of electrostatic attraction supplemented by hydrophobic interaction; this was followed the SDS-GO and TX-100-GO interactions for which the hydrophobic interaction played the main role in the adsorption process. The probable adsorption patterns of each surfactant-GO pair were proposed and are presented at the end of the paper.