Past exam of the MPhil in micro- and nanotechnology enterprise course of the University of Cambridge / 2018 / Paper 1 / Section B / 9 / v / Solution

At the theta temperature, use the long-chain ideal-coil relationsThe two stated molar masses have ratio $M_2/M_1=5$. ThereforeThe input $11.2\mathrm{nm}$ is an end-to-end root-mean-square distance, not a radius of gyration: omitting $\sqrt{6}$ would give the wrong result. The apparent missing superscript in the printed masses does not affect the factor-five ratio used here. The estimate assumes the same chain architecture and unperturbed segment statistics, and uses the long-chain rather than finite-link correction.