Electrooptical properties of aqueous suspensions of nickel hydrosilicate nanotubes

Abstract

We present the results of our investigations of electrooptical effects that occur as a result of light scattering by an aqueous polydisperse system the disperse phase of which consists of nickel hydrosilicate nan otubes with a chrysotile structure. Multilayer nanotubes were synthesized by the hydrothermal method and had the composition . The dimensions of nanotubes were as follows: the length was 0.1-1 µm or more, the outer diameter was 10-15 nm, and the inner diameter was 3 nm. We have studied relative changes in the intensities of light transmitted and scattered by the suspension that were caused by the orien tation of nanotubes in an external electric field. Experiments have been performed at different directions of the linear polarization of the incident and scattered light, different scattering angles, and different degrees of orientation of nanotubes along the field. These measurements allowed us to determine the magnitude of elec trooptical effects, such as the conservative dichroism, the light scattering, and the influence of the orientation of nanotubes in the field on the intensity and degree of depolarization of light scattered by them. Curves of free relaxation of electrooptical effects and their field dependences allowed us to determine the distributions of nanotubes and their aggregates in the colloid over lengths and polarizability anisotropy values. The depen dences of the degree of depolarization of the scattered radiation on the scattering angle and the relaxation dependences of electrooptical effects allowed us to characterize the aggregation stability of nanotubes in water.