Morphological Control and Orientation of Nanostructures in SIS and Partially Epoxidized SIS Block Copolymer Films Upon Solvent Evaproation

HERNÁN GARATE; NORMA B. D'ACCORSO; SILVIA GOYANES

Porto Galinhas

Simposio; Latin American Symposium on Polymers and Ibero American Congress on Polymers; 2014

   Controlling the nanostructure of self-assembled block copolymer films is critical for applications in nanotemplate design, nanoporous membranes, and organic optoelectronics. In this study, we employed partial epoxidation of poly(styrene-bisoprene-b-styrene) (SIS) block copolymer to examine the effects of the block interaction parameter (x) and the use of selective and non-selective solvents on the morphology and spatial orientation of block copolymer nanostructures. An epoxidation degree of 85 % led to an increased block interaction parameter which resulted in a nanostructure shift from parallel to the substrate cylinders to worm-like domains when toluene (non-selective solvent) was used. When THF was employed (poly(styrene) selective) SIS block copolymer developed cylindrical nanodomains oriented parallel and perpendicular to the substrate, while partially epoxidized SIS (SIS85) self-assembled in parallel cylinders with some degree of interconnection. Finally it was observed that the grain size of the nanodomain morphologies of SIS and SIS85 increased as the solvent evaporation rate was reduced.