Encapsulation within resin films is a promising approach for isolating perovskite materials from water. To gain fundamental insight into these systems, we performed first-principles calculations of macromolecule (polymerized siloxane; epoxy cured by phthalic anhydride; graphene sheet) coatings for the waterproofing of methylammonium lead iodide perovskite (MAPbI(3)) surfaces. Our calculations reveal that alternating attractive/resistant functional groups on the siloxane-or epoxy-modified MAPbI(3) surfaces hinder the water diffusion process. Moreover, we examined a no-defect graphene sheet for its ability to isolate MAPbI(3) from water molecules. The hydrophobicity of the graphene resulted in water molecules forming clusters, rather than dispersing, upon the sheet. (C) 2017 Elsevier B.V. All rights reserved.