Block copolymer based strategies for controlling the arrangement of open and closed nanoreactors on planar substrates

POLY 213

Robert E. Cohen, Department of Chemical Engineering, Massachusetts Institute of Technology, MA
We have developed several successful strategies for varying the diameter, the center-to-center spacing, and the areal density of block copolymer micelles, and the inorganic nanoclusters that can be synthesized in the cores of these micelles, on planar substrates. The amphiphilic block copolymer poly(styrene-b-acrylic acid) (PS/PAA) forms micelles in toluene solution that can be spin-coated onto a substrate to create quasi-hexagonal arrays of spherical PAA domains within a PS matrix. The carboxylic acid groups within the PAA domains can be utilized in a nanoreactor synthesis scheme to create inorganic nanocluster arrays, or the PAA domains can be cavitated to expose the carboxylic acid groups directly to the surroundings. The strategies we use to vary the planar arrangements include variation of the molecular weight of PS/PAA, variation of the amount of metal loaded into the micellar solution, addition of PS and PAA homopolymers into the micellar solution, and mixing of different micellar solutions.