Energy Transfer Study of Polymer Chain Morphology in a Two-Dimensional Monolayer

The energy transfer method was utilized for evaluation of the two-dimensional chain morphology of poly(isobutyl methacrylate) in a deposited monolayer. A polymer labeled with phenanthrene as an energy donor and anthracene as an acceptor was diluted with unlabeled chains so that energy transfer occurring only within a single chain could be observed. As a result, from the fluorescence spectrum of the monolayer, the efficiency of the intrachain energy transfer was evaluated to be 19.2 (± 1.7)%. A computer simulation based on the Monte Carlo method was employed for the analysis of chain morphology. Various conformations of the model chains were generated by self-avoiding walk in the two-dimensional plane, and the statistical average value of energy transfer efficiency was obtained as a function of chain expansion. According to this relationship, the experimental efficiency corresponded to a radius of gyration of 6.2±0.8 nm. The morphological characteristics of the simulated chains suggest that the polymer chains take rather contracted forms and are segregated in two dimensions.