Prediction and phase segregation in thin‐film of conjugated polymer blends

Blending conjugated polymers is an efficient method to improve the properties of the films. The phase diagram of poly(9,9‐dihexylfluorene) (PF) and poly(2‐methoxy‐5‐(2′‐ethyl‐hexyloxyl)‐p‐phenylene vinylene) (MEHPPV) was predicted by a modified Flory–Huggins theory based on the topological method (graph theory) for the structure‐property correlations. It shows that the two polymers have a strong trend to separate. Atomic/friction force microscopy (AFM/FFM) measurements show there exist microphase separations in film prepared at room temperature. After annealing at 160 °C, serious phase segregations took place in both the lateral and vertical direction. The photoluminescence of the thin films was also measured by a fluorophotometer. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1382–1391, 2005     

SYNTHESIS OF PERFLUORO-1-OCTANESULFONATED FULLERENE AND THE FRICTION PROPERTIES OF ITS THIN FILM

A star-shaped compound of perfluoro-1-octanesulfonated fullerene was synthesized. The measurement of thefriction for its spin-coating film by friction force microscopy (FFM) reveals that the films possess lower friction forcecompared to that of the star-shaped C_(60)-polystyene films.     

FABRICATION AND AFM/FFM STUDIES OF C60-CONTAINING POLYELECTROLYTE SELF-ASSEMBLED FILMS*

An initial investigation on the roughness and frictional properties of the self-assembled thin films frompolyelectrolytes is presented. Star-shaped C_(60)-poly(styrene-maleic anhydride) was successful prepared. The multilayer thinfilms have been fabricated on mica with diazoresin as the cationic polyelectrolyte and hydrolyzed star-shaped C_(60)-poly(styrene-maleic anhydride) as the anionic polyelectrolyte via self-assembly technique. The crosslinking structure of thefilms is formed from the conversion of ionic bond to covalent bond after UV irradiation. AFM/FFM investigations provideinsights into the roughness and frictional properties on a microscale. The roughness depends strongly on the number of filmlayers in the case of C_(60)-containing films. The frictional forces of the films exhibited a well behaved non-linear relationshipin response to the change of applied load. It supports the prediction of enhanced load-bearing property of C_(60)-containing thinfilms.