First-principles study for the adsorption of segments of BPA-PC on alpha-Al2O3(0001)

We have studied the adsorption of bisphenol-A-polycarbonate (BPA-PC) on the alpha-Al2O3(0001) surface using density-functional theory (DFT) with van der Waals (vdW) corrections. The BPA-PC polymer can be divided into its chemical fragments which are phenylene, carbonate and isopropylidene groups. We have calculated the adsorption energy and geometry of the BPA-PC segments that consist of two to three adjacent groups of the polymer. Our DFT results show that the adsorption is dominated by the vdW interaction. It is also important to include the interaction of nearest-neighbor groups in order to provide a realistic environment for the adsorption of the polymer onto the surface. Our results also show that the BPA-PC molecule attaches to the alumina surface via the carbonate group located in the middle of the molecule chain.