Nuclear dipolar ordering state in two-dimensional liquid

Averaged intramolecular dipole–dipole interactions of nuclear spins are negligible due to the random motion of molecules in bulk liquid and three-dimensional liquid-filled nanopores. Our theoretical findings reveal for the first time that a dipolar ordering state is created in a two-dimensional liquid confined in nanopores. This arises from nonzero averaged values of both the intramolecular and the intermolecular nuclear dipolar interactions. Our theoretical analysis of the molecular motion of water in a two-dimensional nanopore shows that the residual intramolecular dipole–dipole interactions are on the same order as the intermolecular ones. This contrasts with the behavior of liquid contained in the previously discussed three-dimensional nanopores, where averaged intermolecular interactions dominate. Using the obtained expressions and experimental T₂ data for a vermiculite single crystal, we estimated the nanopore radius and predicted the relaxation time T_1D, which is in good agreement with the experimental value.