where U tot is the sum of host-guest and guest-guest interactions. In Figures S2 to S4, we report the evolution of the heat of intrusion and extrusion in each zeosil. The hydrophobic nature of the zeosils is clearly visible from the heat of adsorption at very low loading, which is dominated by interaction of water with the zeosil structure. In each case, the heat of adsorption is comprised between 20 and 30 kJ/mol, which is much lower that the bulk vaporization enthalpy of water (44 kJ/mol for TIP4P water at 300 K). After water intrusion, the heat of adsorption becomes higher than the bulk vaporization enthalpy of water, due to the formation of a dense liquid-like water phase in the pores of the zeosils. In this case, the heat of adsorption is dominated by interaction between water molecules.