In contrast, PET residues at the slab interfaces have a positive induced polarization response when exposed to water; that is, their dipole moments increase rather than decrease as in the case of the vacuum systems (Figure ). As shown in the broad induced dipole distributions at the interfaces (|Z| > 25 Å), PET residues sampled induced dipole values up to 3 D, with an average close to 1 D per residue. The cumulative effect of this polarization response among all residues at the slab-water interface is likely to be relevant when modeling solvent interactions or protein-PET binding interactions. Based on these findings, we set out to further characterize the electrostatic potential surface of the amorphous slab. As shown in Figure , the hydration of the slab surface increases the electrostatic potential