The Link Between Self-Assembly and Molecular Conformation of Amphiphilic Block Copolymers Monolayers at the Air/Water Interface: The Spreading Parameter

Autor(es)

Li Destri, Giovanni ^[1] ; Malfatti Gasperini, Antonio A. ^[2] ; Konovalov, Oleg ^[1]

Afiliação do(s) autor(es)

^[1] ESRF European Synchrotron, F-38000 Grenoble - France

^[2] CNPEM, Brazilian Synchrotron Light Lab, BR-13083970 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Langmuir; v. 31, n. 32, p. 8856-8864, AUG 18 2015.
• Citações Web of Science: 15

Resumo

Two amphiphilic block copolymers, namely polystyrene-b-poly(methyl-methacrylate) (PS-b-PMMA), at the air/water interface were studied combining the in situ structural characterization, by means of X-ray reflectivity (XRR) and grazing incidence small-angle X-ray scattering (GISAXS), and the ex situ morphological one, by atomic force microscopy (AFM). We observed that the conformation of the hydrophilic block spread on the water surface is dramatically influenced by the morphology of the monolayer. Our results showed that the hydrophilic PMMA block adopts an expanded conformation when thermodynamically stable nanodots are formed, whereas a coiled conformation is observed when the block copolymer formed kinetically frozen nanostrands. This effect is interpreted in terms of the spreading parameter, which changes with the relative length ratio between the two blocks. Finally, we proved that, even for block copolymer monolayer with fixed block length ratio, it is possible to change the morphology, and in turn the conformation of the hydrophilic block, by changing the spreading parameter value. (AU)

• Processo FAPESP: 11/19952-6 - Caracterização estrutural de sistemas anfifílicos com aplicação industrial utilizando espalhamento de raios x a baixos ângulos e técnicas complementares
• Beneficiário: Antonio Augusto Malfatti Gasperini
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/13149-2 - Técnicas de caracterização de monocamadas de Langmuir utilizando radiação síncrotron
• Beneficiário: Antonio Augusto Malfatti Gasperini
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado