Dependence of nucleation on shear-induced initial conditions

Light scattering and photon correlation spectroscopy were used to study nucleation in a fluid that is initially exposed to uniform and time-independent shear, S. The shear is abruptly turned off, and subsequently we measure the time dependence of the mean droplet size R(t) and the droplet number density N(t). It is found that N(t) depends critically on the value of S that was present prior to its being switched off. Existing theories of nucleation, lacking a control parameter such as S, cannot be utilized to explain these observations, except when the shear is relatively weak.