Fig. 2: Nanoconfined three-layer water organization is governed by interfacial effects.
From: Interfaces govern the structure of angstrom-scale confined water solutions
a Experimental \({{\rm{Im}}}{\chi }_{{yyz}}^{(2)}\) spectra of nanoconfined three-layer (3 L) water (red solid line). The sum of the water/graphene and CaF2/water signals obtained from HD-SFG experiments is also shown for comparison (grey dashed line). b, c Experimental \({{\rm{Im}}}{\chi }_{{yyz}}^{(2)}\) spectra at the (b) bulk water/graphene interface and (c) CaF2/bulk water interface. We used a 2 M LiCl aqueous solution for the HD-SFG experiments shown in (b) and (c). d–f Theoretical \({{\rm{Im}}}{\chi }_{{yyz}}^{(2)}\) spectra of (d) the nanoconfined three-layer water (red solid line); (e) the water/graphene interface; and (f) the CaF2/water interface. The sum of the water/graphene (e) and CaF2/water (f) signals is shown in (d) for comparison (grey dashed line). g Snapshots of the nanoconfined three-layer water (MLFF-MD), water/graphene interface (AIMD), and CaF2/water interface (MLFF-MD) obtained from the MD simulations. The yellow, light yellow, red, light pink, green, grey, and cyan spheres indicate the Ca, F, O, H, Cl, Li, and C atoms, respectively. The inset in the bottom-left corner illustrates the molecular orientation of a water molecule. The z-direction is taken as the surface normal across the interfaces. Dashed lines in (a–f) serve as zero lines. Source data are provided as a Source Data file.
