Collective Interactions of Molecules with an Interfacial Solid

Confinement of molecules in nanoscale pores of an interfacial solid such as single wall carbon nanotubes of which all component carbon atoms are exposed to the interface with gas phase induces collective phenomena; the confinement effect is interpreted by the interaction potential theory. The nanoconfinement effect gives rise to in-pore phase anomalies for NO, H2O, CCl4, superhigh-pressure effect, hydrophobic to hydrophilic transformation for carbon, and a marked quantum molecular sieving. The confinement of KI in the nanotube space below 0.1 MPa produces high-pressure-phase KI above 1.9 GPa. Water molecules gain hydrophilicity with cluster formation in order to accommodate in the hydrophobic carbon spaces. The subnanometer quantum fluctuation for H-2 and D-2 gives rise to a marked quantum molecular sieving effect in nanoscale pores. The Cu-based porous coordination polymer crystals can detect the surrounding stimuli such as CO2 pressure change to vary the crystal lattice, accompanying gate adsorption.