Nanocomposite Microdomain Inversion in Au Nanoparticle/ PS-b-PFOMA Block Copolymer Films

We report that Au nanocrystals sequestered within the microdomains of self-assembled aggregates of polystyrene-b- poly(1,1',2,2'-tetrahydroperflurooctyl methacrylate) (PS-b- PFOMA) thin films are capable of following the structure-guiding matrix in a morphological transition from spherical PFOMA aggregates in a PS matrix to the inverse morphology upon supercritical CO2 (scCO2) sorption. Furthermore, the domain size of the aggregates can be finely tuned by adjusting the scCO2 density. By pretreating the particle´s surface with a host of ligands with different chemical affinities for the constituent blocks, we observe that the Au/diblock co-assembly process is dependent not only on the ligand size and ligand- matrix compatibility, but also on the interaction of the ligands with the interfaces that confine the film.