Surface Morphologies of Langmuir−Blodgett Monolayers of PEOnPSn Multiarm Star Copolymers

• Published in: Langmuir 2006-07, Vol.22 (14), p.6168-6176
• Main Authors: GUNAWIDJAJA, Ray, PELESHANKO, Sergiy, GENSON, Kirsten L., TSITSILIANIS, Constantinos, TSUKRUK, Vladimir V.
• Format: Article
• Language: English
• Subjects: Chemistry; Exact sciences and technology; General and physical chemistry; Langmuir blodgett films; Surface physical chemistry
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la060299k

Star polymers composed of equal numbers of poly(ethylene oxide) (PEO) and polystyrene (PS) arms with variable lengths and a large (up to 38 total) number of arms, PEO(n)PS(n), have been examined for their ability to form domain nanostructures at the air-water and air-solid interfaces. All PEO(n)PS(n) star polymers formed stable Langmuir-Blodgett (LB) monolayers transferable to a solid substrate. A range of nanoscale surface morphologies have been observed, ranging from cylindrical to circular domains to bicontinuous structures as the weight fraction of the PEO block varied from 19% to 88% and n from 8 to 19. For the PS-rich stars and at elevated surface pressure, a two-dimensional supramolecular netlike nanostructure was formed. In contrast, in the PEO-rich star polymer with the highest PEO content, we observed peculiar dendritic superstructures caused by intramolecular segregation of nonspherical core-shell micellar structures. On the basis of Langmuir isotherms and observed monolayer morphologies, three different models of possible surface behavior of the star polymers at the interfaces were proposed.