= Good-solvent size calibration for polystyrene
{title2=$R_g/\mathrm{nm}\simeq0.0123[M/(\mathrm{g\,mol^{-1}})]^{0.593}$}
The <radius of gyration> of a dilute linear <polystyrene> coil in a <good solvent> depends on its <molar mass> as $R_g=KM^\nu$, with a material- and solvent-dependent amplitude. A manufacturer-supplied light-scattering calibration for <polystyrene> in <benzene> or toluene near room temperature is the displayed relation, quoted over $M\simeq2\times10^5$ to $5\times10^7\,\mathrm{g\,mol^{-1}}$. The exponent is close to the <Flory approximation> $3/5$. Values outside the quoted mass range are extrapolations, not extra measured data. Using $c^*=M/[N_A(4\pi/3)R_g^3]$ then gives the <polymer overlap concentration> scaling $c^*\propto M^{1-3\nu}$. https://www.brookhaveninstruments.com/wp-content/uploads/2023/08/ParSEC-Manual.pdf[Brookhaven Instruments, How to Use ParSEC, Appendix C, PDF page 47: polystyrene good-solvent radius-of-gyration calibration and its stated molar-mass range]{ref}
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