As shown in Figure , the interlayer space increases with the hydrated diameter of the intercalated cations. As previously reported, both methods allow controlling the swelling of GO to a certain degree . In particular, K + -M/S-GO show a smaller interlayer space compared to pristine GOM as well as Na + -M/S-GO. Intercalation of divalent cations (Ca 2+ and Mg 2+ ) increases the wet interlayer spaces in GOMs regardless of the preparation method. In the dry state, X-S-GO show a reduced interlayer space, whereas X-M-GO show an increased interlayer space except for K + . The slight differences in the interlayer spaces resulting from different preparation methods are discussed in SI section 1 and Figure .