▎ 摘　　要

In this work we identify the molecular properties responsible for intercalation in multilayer (ML-) graphene oxide (GO) through in situ monitoring of probe molecule delivery via Fourier transform infrared spectroscopy (FTIR), focusing on the probe molecules ability to displace the naturally intercalated species in ML-GO. By monitoring changes occurring in the FTIR spectra in real time, we show that small molecules with the ability to form hydrogen bonds are strongly retained in ML-GO. These molecules can easily replace the intercalated CO2, while molecules incapable of hydrogen bonding are unable to do so, even if their size should allow them to intercalate between the ML-GO layers. These results provide direct evidence of the importance of hydrogen bonding, molecule size, and functional group orientation on the intercalation process and introduce in situ FTIR spectroscopy with probe molecules as a valuable technique to characterize ML-GO.