Photon pressure-induced association of nanometer-sized polymer chains in solution

The photon pressure effect induced by a focused infrared laser beam upon two kinds of water-soluble carbazolyl-containing copolymers in aqueous solution is shown to result in the formation of single microparticles. The minimum size of the polymer chains at which the photon pressure overcomes the Brownian motion and the electrostatic repulsion is determined to be 10-20 nm. The rate of particle formation and the final particle size are shorter and larger, respectively, as the carbazolyl content of the polymer is higher. This indicates that the polarizability plays an important role in the photon pressure-induced association process.