DFT and Cluster Model Investigation on the Adhesion of Polyethylene Terephthalate on Metals

We investigate the adhesion mechanism of metal atoms (Al, Cu Ag, Au and Pt) on polyethylene terephthalate (PET) using Density Functional Theory (DFT) and cluster models. The structural geometry of the basic unit of PET is optimized then a metal atom is made to approach this structure at different orientations while calculating the total energy of the system under B3LYP functional. Results show that Al atom binds strongly when oriented linear to C=O at a distance of 1.80 Å. Orbital population analysis indicates that the good adhesion of Al at this orientation is due to the interaction of pz orbital of free oxygen in the carbonyl group and py orbital of Al atom. Binding is strongest for Al atom, followed by Pt, Cu, Ag, and Au, in decreasing order of adhesive strength. [DOI: 10.1380/ejssnt.2011.251]