D. Sohn et al., POLARIZED AND DEPOLARIZED DYNAMIC LIGHT-SCATTERING OF A RODLIKE POLYELECTROLYTE IN A STRONG ACID, Berichte der Bunsengesellschaft fur Physikalische Chemie, 100(6), 1996, pp. 821-828
Citations number
30
Categorie Soggetti
Chemistry Physical
Journal title
Berichte der Bunsengesellschaft fur Physikalische Chemie
Unusual dynamic light scattering behavior of poly(benzoxazole), a stif
f backbone rodlike polymer, has been found in methane sulfonic acid/me
thane sulfonic acid anhydride. A very rapid, angle-independent decay m
ode characterized the short-time autocorrelation functions al various
levels of added salt, sodium methane sulfonate, in both polarized and
depolarized dynamic light scattering experiments. In some ways, the be
havior qualitatively resembles the long-predicted ''plasmon'' mode, wh
ich has never been seen in more conventional polyelectrolyte systems.
However, calculations based on a point charge model are inconsistent w
ith the plasmon mode, even allowing for the high viscosity of the meth
ane sulfonic acid solvent. The absence of angle dependence means that
the rapid decay mode cannot be explained by the diffusion of oligomers
. The meaning of the rapid, angle-independent decay mode remains uncle
ar.