Tunable Surface Plasmon Band of Position Selective Ag and Au Nanoparticles in Thin Block Copolymer Micelle Films

The manuscript describes a novel method to fabricate a thin composite film based on spin coating in which surface plasmon bands of Au and Ag nanoparticles are effectively coupled with each other because of position-selective deposition of both nanoparticles on a self-assembled block copolymer structure. Simple solution blending and subsequent spin coating of Au nanoparticles (NPs) and a block copolymer micelles containing Ag NPs in the core regions offers a facile route for controlling coupled surface plasmon band (SPB) of the two NPs over 100 nm in wavelength in thin solid films. Effective coupling of two individual SPBs relies upon the self-assembled composite structure where Ag and Au NPs are preferentially located in the core and corona regions of the micelles, respectively, allowing not only a controlled interparticle distance but also homogeneous dispersion of the NPs throughout film.