Dresden 2011 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 47: Heterogeneous Nucleation and Microstructure Formation (related to SYMF, jointly with MM)

CPP 47.3: Vortrag

Freitag, 18. März 2011, 11:00–11:15, ZEU 160

Influence of Pattern Height on the Dewetting of Polymer Thin Films on Topographically Patterned Substrates — •Rabibrata Mukherjee — Departmnet of Chemical Engineering, IIT Kharagpur, Pin 721302, India

Controlled dewetting of thin polymer films on physically patterned complex surfaces produces variety of ordered meso-scale structures like arrays of ordered droplets, membranes etc. In contrast to dewetting of a thin polymer film on a defect free surface, which occurs spontaneous amplification of capillary surface waves, on a topographically patterned substrate dewetting is engendered by a rapid rupture of the film along the contours of the substrate pattern. The subsequent morphological evolution is therefore strongly influenced by the geometry of the substrate pattern. We show that the final structure depends not only on a commensuration between the initial film thickness and substrate pattern geometry, but is also influenced significantly by the film preparation condition. For example, when the film is directly spin coated on to the topographically patterned substrate, the resulting morphology is strongly influenced by the height of the features, in addition to their periodicity. In contrast, when a film of uniform thickness is transferred and then dewetted on the patterned substrate, the influence of height variation of the substrate features is rather limited. In the latter case, the initial conformation of the film with respect to the underlying substrate dominates the positioning of the dewetted droplets.