We have performed an experimental investigation on the electrokinetic properties of charged rod-like fluorinated latex colloids. Systematic measurements of electrophoretic mobility, dielectric constant and electric birefringence have been performed as a function of the concentration of added nonionic surfactant and salt. In the investigated range of parameters, the zeta potential is a strongly decreasing function of the concentration of nonionic surfactant, while it is basically independent from ionic strength. We have obtained the frequency dependence of dielectric constant and Kerr constant as a function of zeta-potential and ionic strength. We observe the transition from a low frequency behavior, where both the dielectric constant and the Kerr constant are enhanced by the presence of the double layer, to a high frequency behavior, where both quantities take the value expected for unchanged particles in an insulating medium. The shape of the frequency dispersion of the Kerr constant coincides with that of the dielectric constant, but the cut-off frequencies are the same only when the zeta-potential of the particles is low.

Delgado, A., Carrique, F., Arroyo, F., Bellini, T., Mantegazza, F., Giardini, M., et al. (1998). Frequency dependence of the dielectric and electro-optic response in suspensions of charged rod-like colloidal particles. In Colloids and Surfaces A: Physicochemical and Engineering Aspects (pp.157-167). Elsevier Sci B.V. [10.1016/S0927-7757(97)00274-4].

Frequency dependence of the dielectric and electro-optic response in suspensions of charged rod-like colloidal particles

Mantegazza, F;
1998

Abstract

We have performed an experimental investigation on the electrokinetic properties of charged rod-like fluorinated latex colloids. Systematic measurements of electrophoretic mobility, dielectric constant and electric birefringence have been performed as a function of the concentration of added nonionic surfactant and salt. In the investigated range of parameters, the zeta potential is a strongly decreasing function of the concentration of nonionic surfactant, while it is basically independent from ionic strength. We have obtained the frequency dependence of dielectric constant and Kerr constant as a function of zeta-potential and ionic strength. We observe the transition from a low frequency behavior, where both the dielectric constant and the Kerr constant are enhanced by the presence of the double layer, to a high frequency behavior, where both quantities take the value expected for unchanged particles in an insulating medium. The shape of the frequency dispersion of the Kerr constant coincides with that of the dielectric constant, but the cut-off frequencies are the same only when the zeta-potential of the particles is low.
paper
Dielectric dispersion; Electric birefringence; Elongated teflon particles; Zeta potential;
English
1996 Electrokinetic Phenomena30 September 1996 through 4 October 1996
1996
Colloids and Surfaces A: Physicochemical and Engineering Aspects
1998
140
1-3
157
167
none
Delgado, A., Carrique, F., Arroyo, F., Bellini, T., Mantegazza, F., Giardini, M., et al. (1998). Frequency dependence of the dielectric and electro-optic response in suspensions of charged rod-like colloidal particles. In Colloids and Surfaces A: Physicochemical and Engineering Aspects (pp.157-167). Elsevier Sci B.V. [10.1016/S0927-7757(97)00274-4].
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/32258
Citazioni
  • Scopus 12
  • ???jsp.display-item.citation.isi??? 12
Social impact