Compositional Depth Profiling of Block Copolymer Surfaces Using NEXAFS

摘要

Surfaces of block copolymers with amphiphilic side-chains have been recently found to exhibit interesting anti-biofouling properties Two different algal species, commonly found in marine biofilms, are known to show opposite adhesion strengths on hydrophobic fluorinated and hydrophilic poly(ethylene glycol) (PEG) containing surfaces. The green alga Ulva shows strong adhesion to the PEGylated surfaces and weaker adhesion to the fluorinated surfaces, while the diatom Navicula shows exactly the opposite behavior. However, when both the perfluoroalkyl and PEG segments were present in the same side-chain (cf. Figure 1), the resulting surfaces were resistant to adhesion by either of the two organisms. The molecular composition at the surface of a thin film of such a polymer was studied using near-edge X-ray absorption fine structure spectroscopy (NEXAFS).