Microrheology of a Swollen Lyotropic Lamellar Phase

Abstract

Dynamics of nano-sized colloidal particles in a swollen lyotropic lamellar phase of a nonionic surfactant has been studied by three methods of microrheology. By electrophoretic microrheology (EPM), we find two relaxation processes respectively relating to the fluctuation of membranes and topological defects in lamellar structure. By direct tracking of particles under a microscope and manipulating them with an optical tweezers, we obtained detailed information on diffusion of a particle at low frequencies. We observed the jump-trap motion of a particle and the non-Newtonian rheological behavior at low frequencies.

Keywords:

• colloidal particles
• electrophoretic mobility
• microrheology
• optical tweezers
• particle-tracking microrheology
• swollen lamellar phase

Acknowledgments

The authors also thank Mr. T. Nishino, T. Mori and A. Yamamoto at the University of Tokyo for their experimental supports.

Additional information

Notes on contributors

Yasuyuki Kimura

Y. Kimura thanks to the full financial support by Grant-in-Aid for scientific research from Japan Society for the Promotion of Science and from Ministry of Education, Culture, Sports, Science and Technology of Japan.