Homogenization of a phase-separated droplet in a polymer mixture caused by the dielectric effect of a laser.

It is found that a micrometer-sized droplet in an aqueous solution of binary polymers [water/polyethylene-glycol (PEG)/dextran] disappears upon irradiation with a focused yttrium-aluminum-garnet laser. The interface of the dextran-rich droplet broadens and disappears, and it reappears upon turning the laser off, whereas the PEG-rich droplet shrinks and disappears. These phenomena are discussed in terms of the free energy by considering the laser-induced dielectric potential.