Block Copolymer Micelles with Near Infrared Metal Phthalocyanine Dyes for Laser Induced Writing

A route has been developed to disperse metal-containing phthalocyanine dyes in a non-polar medium based on amphiphilic block copolymer micelles of poly[styrene-block-(4-vinylpyridine)] (PS-b-P4VP) and poly[styrene-block-(acrylic acid)] (PS-b-PAA) copolymers. Polar P4VP and PAA efficiently encapsulate cobalt(II), manganese(II), and nickel(II) phthalocyanine dyes by axial coordination of nitrogen and mu-oxo bridged dimerization with the transition metals, respectively. Good dispersion of the dyes is confirmed by the linear enhancement of Q-bands in UV-vis absorption spectra with dye concentration. A thin monolayered PS-b-P4VP micelle film that contained a nickel(H) phthalocyanine dye which efficiently adsorbs a laser beam on a localized area to generate a local heat higher than the glass transition temperatures of both blocks. One-dimensional laser writing on the dye-containing film allows the fabrication of a few submicrometer wide line patterns in which the self-assembled nanostructure of the block copolymer is modified by the directional heat arising from laser scanning.