Enhanced Self-Organized Dewetting of Ultrathin Polymer Blend Film for Large-Area Fabrication of SERS Substrate.

ABSTRACT: We study the enhanced dewetting of ultrathin Polystyrene (PS)/Poly (methyl methacrylate) (PMMA) blend films in a mixed solution, and reveal the dewetting can act as a simple and effective method to fabricate large-area surface-enhanced Raman scattering (SERS) substrate. A bilayer structure consisting of under PMMA layer and upper PS layer forms due to vertical phase separation of immiscible PS/PMMA during the spin-coating process. The thicker layer of the bilayer structure dominates the dewetting structures of PS/PMMA blend films. The diameter and diameter distribution of droplets, and the average separation spacing between the droplets can be precisely controlled via the change of blend ratio and film thickness. The dewetting structure of 8?nm PS/PMMA (1:1?wt%) blend film is proved to successfully fabricate large-area (3.5?cm?×?3.5?cm) universal SERS substrate via deposited a silver layer on the dewetting structure. The SERS substrate shows good SERS-signal reproducibility (RSD?

SUBMITTER: Zhang H 

PROVIDER: S-EPMC5138605 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature