We report the characterization and, modification of materials based on biodegradable polyesters and fluorocarbon chemistry. Ultrathin films with thickness less thaw, the maximum ESCA detecting depth. were prepared, by spin-coating method to ovoid any effects of preferential surface orientation. Quantitative angle-dependent, ESCA was used to investigate number-average molecular weight (Mn) of end-functionalized polymers, fluorocarbon end-capped poly(lactide)s (F-PLA). The exposure time of F-PLA ultrathin films to Methanol/H-2, plasma controlled densities of hydroxyl, groups on the surface, and then. these groups provide sites for the covalent attachment of a specific component such as proteins or peptides.