Collective Interactions of Molecules with an Interfacial Solid

Abstract

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, H 2 O, CCl 4 , 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 Cubased porous coordination polymer crystals can detect the surrounding stimuli such as CO 2 pressure change to vary the crystal lattice, accompanying gate adsorption.

Methane hydrate formation in confined nanospace can surpass nature

“…Condensation takes place at high relative pressures (p/p 0 40.8) with a saturation capacity of 1.8 g g À 1 of dry carbon, corresponding to a 93% filling of the total pore volume (under the assumption that density of the adsorbed water is 1.0 g cm À 3 ). The water adsorption isotherm has a remarkable hysteresis loop that comes from a metastable assembly structure of water in the adsorption branch 14,15 . Our initial hypothesis would be that the small thickness of the metastable water layer (that provides a very high-interfacial liquid water-methane contact area), together with the low interaction of water molecules with the hydrophobic carbon surface could speed up the methane hydrate formation process 16,17 .…”

Physisorption of gases, with special reference to the evaluation of surface area and pore size distribution (IUPAC Technical Report)

“…Well known are structural transformations in zeolites, like MFI ZSM-5, which are reflected in the appearance of low-pressure hysteresis loops below the range of pressures associated with capillary condensation. Structural transformations are observed in some metal-organic frameworks (MOFs) and their sorption behaviour is not easy to interpret [11,12]. Application of standard methods for the assessment of surface area and pore size analysis may lead to meaningless BET surface areas and pore size distributions.…”

Activation routes for high surface area graphene monoliths from graphene oxide colloids

“…The high electrical and thermal conductivities are superior to other nanoporous materials such as zeolites and metal organic frameworks (MOFs). Also nanoporous carbon has the strongest interaction potential for molecules per unit weight [9]. Furthermore, it has another merit of slit-shaped pores which enable to guarantee excellent accessibility for molecules and ions, being indispensable to industrial applications [10].…”