The size induced effect on rheological properties of Co-ferrite based ferrofluid

Finite size effect on structural, magnetic and rheological properties of Co-ferrite based ferrofluids has been investigated in detail. The shape and size distribution has been confirmed by transmission electron microscopy. The average particle size varies in the range 8 nm <= x <= 34 nm. The size induced rheological studies of ferrofluid with varying magnetic field and shear rate gives an insight to the work. The large size particles show less viscosity as compared to small size particles. Using H-B model, particle size dependent interaction with flow properties has been established. In addition, time dependent formation and destruction of magnetically induced structures has been described. The result of our investigations shows that the rheological measurements are in accordance with structural and magnetic properties of the ferrofluids. (C) 2012 Elsevier B.V. All rights reserved.