Electrokinetic properties of colloids of variable charge. III. Observationof a Maxwell-Wagner relaxation mechanism by high-frequency electric-birefringence spectroscopy

Frequency resolved electric birefringence measurements were made on dilute aqueous suspensions of charged, rodlike latex particles. Ionic amphiphile a dsorption was used to vary the particle charge as described in the first pa per of this series [J. Chem. Phys. 103, 8228 (1995)]. Using the high freque ncy part of the birefringence spectra, the electric polarizability is compu ted from the Kerr constant following the approach set out in the second pap er of the series [J. Chem. Phys. 109, 6905 (1998)]. Then, the polarizabilit y spectra were interpreted with our extended Maxwell-Wagner model [J. Chem. Phys. 113, 6974 (2000), preceding paper]. Theory and experiment are in goo d agreement. The procedure provides a new and simple way to extract the par ticle charge from birefringence data. (C) 2000 American Institute of Physic s. [S0021-9606(00)51140-4].