| Abstract
| - We study the surface behavior of the asymmetric amphiphilic heteroarm poly(ethylene oxide) (PEO)/polystyrene (PS) star polymer on solid substrate. These star polymers differ in both architecture (four-and three-arm molecules, PEO-b-PS3 and PEO-b-PS2) and in the length of PS chains (molecular weightfrom about 10 000 up to 24 000). We observed that, for a given chemical composition with a predominantcontent of hydrophobic blocks, the compression behavior of the PS domain structure controls the surfacebehavior and the final morphology of the monolayers. New features of the surface behavior of star-blockcopolymers are high stretching of the PS arms from the interface and enhanced stability of the circularPS domain structure, even at high compression. We suggest that for asymmetric star-block copolymersboth architecture and chemical composition heavily favor the formation of highly curved interfaces and,thus, more stable circular domain structure with stretched PS arms.
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