Two critical ratios in polymer solutions

Abstract

The interpenetration function Psi of a dilute solution of long randomly coiling molecules may be calculated by renormalisation group methods. This quantity is of special interest since it is entirely due to excluded volume effects. Two renormalisation methods give values for the excluded volume limit of Psi which are consistent with current experimental values. This indicates that the limiting value of Psi is easier to measure than previously thought. The experimental deviations from this limit can be well represented by a simple standard corrections-to-scaling formula. The authors also calculate the limiting ratio of average end-to-end distance to radius of gyration of these molecules. There is a small difference from the random chain value.