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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 6: Thin Films

CPP 6.5: Talk

Monday, March 23, 2009, 15:00–15:15, ZEU 160

”Micro-structure - Macro-response” Relationship in Swollen Block Copolymer Films — Julia Gensel and •Larisa Tsarkova — Physikalische Chemiee II, Universität Bayreuth, Bayreuth 95440, Deutschland

We present experimental evidence on the correlation between micro-structure and macro-response of diblock copolymer films towards swelling in a selective solvent. The starting morphology of poly(styrene)-b-poly(2-vinylpyridin) (SV) films has been adjusted by the fast quench from selective or non selective solvents. The structure at films surface was characterized by scanning force microscopy (SFM), while grazing-incidence small-angle X-ray scattering (GISAXS) measurements have been used to access the microstructure in the interior of the films. The swelling under controlled atmosphere of selective solvent was monitored by in-situ spectroscopic ellipsometry. The long-term annealing under atmosphere of a selective solvent (toluene) revealed up to 10% stronger swelling of the films with the initial bulk lamella morphology as compared to the films with the non-bulk micellar phase. Moreover, we observed clear dependence of the degree of swelling on the film thickness in a thickness range of 0.5-10 layers irrespective to the initial microstructure. These findings bring novel insights into the solvent processing of block copolymer films and indicate roots for designing nano-structured responsive materials.