From Figure we can conclude that the HB bridge of the random GO (panel (b)) is more stable than its analogue in the ordered GO (panel (a)). Specifically, the OH acc acceptor in the case of OGO1 is weaker than its counterpart in RGO1 (tendency for larger R 2 values). This difference can be traced to the spatial arrangement of the GO functional groups in OGO1, which are closer to each other compared to RGO1. As a result neighboring functional groups on the same GO layer compete with functional groups from the other GO layer to form a HB with the water layer. In both cases the distribution of R 1 values indicates that a H 2 O molecule is trapped, either in a HB bridge or at a single GO layer (see also the movies in the Supporting Information).