The surface structure and surface molecular mobility of diblock copolymers were investigated based on X-ray photoelectron spectroscopy (XPS) and the dynamic Wilhelmy plate technique. The A-B diblock copolymers used in this study contain styrene as A-component, and hydroxy poly (ethylene glycol)methacry rate (HPEGM), methoxy poly-(ethylene glycol)methacryrate (MPEGM), hydroxy poly(propylene glycol)methacryrate (HPPGM), or ftuoroalkoxy-methylstyrene (FAMSt) as B component. The surface chemical composition of the air-solid interface depended very much on the difference in surface free energy between A and B components. The XPS measurement revealed that the air facing surface was enriched with the components of lower surface free energy. The end group of side chain of B components was also one of the important factors to decide the surface chemical composition. Dynamic contact angle measurements revealed that the advancing contact angle was dependent on the components of lower surface free energy, whereas the receding contact angle was influenced by the components of higher surface free energy. A large scale surface structural reorganization upon environmental change was observed for the block copolymer whose overlayer component had a low glass transition temperature.
All Science Journal Classification (ASJC) codes
- Chemical Engineering (miscellaneous)
- Materials Science (miscellaneous)
- Environmental Science(all)
- Polymers and Plastics