The effect of size distribution on viscoelastic properties of ferrofluid

M. Chand - S. Kumar - A. Shankar - Sonia and Komal Jain - S. Singh - R. P. Pant

CSIR-National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi-110012, India

Abstract
The present article reports the preparation and optimization of controlled growth of \CoFe ₂O ₄ nanoparticles for ferrofluid preparation and its effect on structural and rheological properties. The average particle size varies in the range 8 nm   ≤ x ≤   34 nm. The effect of induced size on rheological measurements with the varying shear rate and magnetic field gives an insight into the work. The size variation of particles shows a change in viscoelastic properties. An H-B model was found to fit well the flow behavior of magnetic fluids. Time dependent viscosity measurement has been made to study the relaxation behavior of the particles. Tables 1, Figs 5, Refs 16.