Then,when the flow comes back to the initial state,the viscosity of system is restored,
which corresponds to the build-up of the microstructure of the
particles driven mainly by the Brownian motion. In addition,the
recovery rate was obtained by differentiating the viscosity values
with time,as depicted in Fig. 5(b). It can be seen that the recovery
rate is high at the initial moment of the recovery interval(within
3 s),then decreases to zero after about 15s. Notice that the recovery rate of bare iron based suspension is slightly higher than other two samples,which conforms the adsorbed surfactant layer
will slow down the movement of particles in the oil medium.
The structure decomposition under load and the following