Mechanism of the self-division. In previous work, when homopolymeric poly-U was used as a polyanion, we found droplet selfdivision towards the end of their lifetime. In the last minutes of their lifetime, a large droplet would fragment into tens of smaller droplet fragments. We hypothesize that the division results from the polydispersity of the polyanion. Specifically, we suspect that during the lifetime of the droplet, the long polyanion separates from the shorter polyanion and forms solid domains, a process referred to as maturation (Fig. ). As the droplet dissolves, the solid domains are expelled and survive longer than the main droplet.