Breakup of an elongated droplet in a centrifugal field

The breakup of an elongated drop in the presence of a centrifugal field was studied. The system used was a phase-separated colloid-polymer suspension; the elongated drop consisted of the lighter polymer-rich fluid phase and t he surrounding fluid was its coexisting colloid-rich fluid phase. We found that the growth rate of the fastest growing disturbance of the drop, which eventually leads to its break-up, is decreasing upon an increase of the rot ational speed, whereas the wavelength of the disturbance is increasing upon an increase of the rotational speed. We present a simple analysis of the e ffect of the centrifugal field which accounts quantitatively for these feat ures. Furthermore, this analysis allows for the determination of the interf acial tension from the measured growth rates.