ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
For “monodisperse”, randomly coiled macromolecules, we find that the molecular weight, intrinsic viscosity, and diffusion coefficient are accurately related by \documentclass{article}\pagestyle{empty}\begin{document}$$ \left[ \eta \right]M_{D,\eta } = 3.0 \times 10^{ - 27} \left( {D_t^0 {{\eta _0 } \mathord{\left/ {\vphantom {{\eta _0 } T}} \right. \kern-\nulldelimiterspace} T}} \right)^{ - 3} {{\left( {{{{\rm erg}} \mathord{\left/ {\vphantom {{{\rm erg}} {^\circ {\rm K}}}} \right. \kern-\nulldelimiterspace} {^\circ {\rm K}}}} \right)^3 } \mathord{\left/ {\vphantom {{\left( {{{{\rm erg}} \mathord{\left/ {\vphantom {{{\rm erg}} {^\circ {\rm K}}}} \right. \kern-\nulldelimiterspace} {^\circ {\rm K}}}} \right)^3 } g}} \right. \kern-\nulldelimiterspace} g} $$\end{document} This equation holds for denatured proteins in 6M GuHCl(aq) as well as for narrow polystyrene fractions in tetrahydrofuran. For a Schulz distribution of molecular weights, the weight measured from combining diffusion and viscosity data is closely approximated by \documentclass{article}\pagestyle{empty}\begin{document}$$ M_{D,\eta } = M_w^{0.425} M_z^{0.575} $$\end{document} These equations are verified with measurements of wide molecular distributions of polystyrene in toluene and data from the literature. These relations provide a rapid, nondestructive method to determine a well-specified molecular weight average of small quantities of polymers in a wide diversity of solvents using quasielastic light scattering techniques to evaluate polymer diffusion coefficients.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1977.070211207
