Generating long-range order in gyroid terpolymer films by controlled solvent annealing

Gyroid-structured triblock terpolymer films can be used as templates for the fabrication of optical metamaterials. For samples with large gyroid grains these plasmonic materials exhibit interesting optical properties, e.g. linear dichroism (1). However, generating templates with long-range order still remains a challenge as only little is known about the self-assembly of gyroid-structured polymer films. In this work, we show that gyroid films with long-range order can be prepared by controlled solvent vapor annealing of a PI-b-PS-b-PGMA (ISG) triblock terpolymer. Gyroid grains of about 5-15 µm in size were produced by slowly removing the solvent from swollen, ordered ISG terpolymer films. These films were shown to serve as templates for the fabrication of optical metamaterials as demonstrated by the replication of gyroid-structured polymer films into gold. Gyroid terpolymer templates and gold replica were characterized by a combination of scattering (GISAXS, SAXS) and microscopy techniques (AFM, SEM).

(1) Advanced Materials, 24(10):OP23–OP27, 2012.