Distribution of Conjugation Lengths in an Ensemble of Lattice Polymers

The distribution of segment sizes, that is, the average and dispersion of the number of segments of a given size per chain, is investigated in an ensemble of lattice polymers. This distribution is the lattice version of the conjugation length distribution of conjugated polymers, which is central for both electronic and photophysical properties of conjugated polymer materials. Clear evidence is found that, when the chains interact only via excluded volume, both the average and the dispersion depend exponentially on the segment size and, at least for the more prevalent segment sizes, are identical to what is found in an isolated self‐avoiding chain. Whereas the polymer concentration has a clear effect on the end‐to‐end distances of the chains, it does not affect significantly the segment size distribution of the chains. It is argued that this happens whenever there is no distance or orientation correlation in the polymer distribution, that is, in a truly amorphous system, but not in the presence of aggregates or nematic order.