Polarization Mediated Chemistry on Ferroelectric Polymer Surfaces

We have investigated the chemisorption of two isomers of diiodobenzene on the molecular ferroelectric copolymer poly(vinylidene fluoride) with trifluoroethylene (70:30) as a function of the polymeric ferroelectric domain orientation. We find that the 1,4-p-diiodobenzene adsorption at 150 K strongly favors a positive ferroelectric domain orientation while the 1,2-o-diiodobenzene adsorption at 150 K strongly favors a negative ferroelectric domain orientation. Both polar and nonpolar adsorbates are influenced by the substrate dipole direction. Because a nonpolar isomer is also affected by the surface dipole direction, and hence the surface chemical termination, it is clear that surface chemistry and not simply surface dipoles matter in the chemisorption process.