S. Fraden et al., ANGULAR-CORRELATIONS AND THE ISOTROPIC-NEMATIC PHASE-TRANSITION IN SUSPENSIONS OF TOBACCO MOSAIC-VIRUS, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 48(4), 1993, pp. 2816-2837
The specific magnetic-field-induced birefringence is measured in aqueo
us suspensions composed of the charged rodlike particle tobacco mosaic
vims (TMV) as a function of temperature, TMV concentration, ionic str
ength, and TMV polydispersity over the entire isotropic range. This qu
antity is proportional to the magnitude of the interparticle angular c
orrelations at zero field. Theoretical expressions for the field-induc
ed birefringence for both the mono- and polydisperse samples are deriv
ed based on extensions of the Onsager model [L. Onsager, Ann. N.Y. Aca
d. Sci. 51, 627 (1949)] and compare well with experiment. In addition,
the isotropic-nematic phase coexistence concentrations are measured a
s a function of ionic strength and temperature. The agreement between
experiment and theory indicates that the TMV particles interact primar
ily through electrostatic repulsion and that attractive forces are neg
ligible.