LASER-CONTROLLED ASSEMBLING OF REPULSIVE UNIMOLECULAR MICELLES IN AQUEOUS-SOLUTION

Laser manipulation techniques were applied to the control of molecular assembling in D2O. An amphiphilic random copolymer, which has hydroph ilic and hydrophobic segments in a single chain and forms a monopolyme r micelle through self-organization, is demonstrated to receive photon pressure of a focused near-infrared laser beam. Upon prolonged irradi ation with the beam, a single microparticle is formed at a focal point , and it dissolves very quickly after switching off the laser beam. Th e behavior indicates that electrostatic repulsion between micelles is overcome by photon pressure. The assembling processes were examined as a function of irradiation time and polymer concentration and are disc ussed.