Patterning of triblock copolymer film and its application for surface-enhanced Raman scattering

In this paper, microphase behavior of an ABC triblock copolymer, polystyrene-block-poly(2-vinylpyridine)-block-poly( ethylene oxide), namely PS-b-P2VP-b-PEO, was systematically studied during spin-coating and solvent vapor annealing based on various parameters, including the types of the solvent, spin speed and thickness. The morphological features and the microdomain location of the different blocks were characterized by atomic force microscope (AFM) and high resolution transmission electron microscopy (HRTEM). With increasing thickness, the order-order transition from nanopores array to the pattern of nanostripes was observed due to microdomain coarsening. These processes of pattern transformation were based on the selectivity of toluene for different blocks and on the contact time between solvent molecules and the three blocks. This work provides different templates for preparation of gold nanoparticle array on silicon wafer, which can be adopted as an active surface-enhanced Raman scattering (SERS) substrate for poly(3-hexylthiophene) (P3HT).