Polystyrene-block-Poly(ethylene oxide) Stars as Surface Films at the Air/Water Interface

Star diblock copolymers containing polystyrene (PS) and poly(ethylene oxide) (PEO) were investigated as surface films at the air/water interface. Both classic and dendritic-like stars were prepared containing either a PS core and PEO corona or the reverse. The investigated polymers, consisting of sy...

Full description

Saved in:
Bibliographic Details
Published in:Langmuir 2005-08, Vol.21 (16), p.7380-7389
Main Authors: LOGAN, Jennifer L., MASSE, Pascal, GNANOU, Yves, TATON, Daniel, DURAN, Randolph S.
Format: Article
Language:English
Subjects:
Chemical Sciences
Chemistry
Exact sciences and technology
Gas-liquid interface and liquid-liquid interface
General and physical chemistry
Polymers
Surface physical chemistry
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Star diblock copolymers containing polystyrene (PS) and poly(ethylene oxide) (PEO) were investigated as surface films at the air/water interface. Both classic and dendritic-like stars were prepared containing either a PS core and PEO corona or the reverse. The investigated polymers, consisting of systematic variations in architectures and compositions, were spread at the air/water interface, generating reproducible surface pressure-area isotherms. All of the films could be compressed to higher pressures than would be possible for pure PEO. For stars containing 20% or more PEO, three distinct regions appeared. At higher areas, the PEO absorbs in pancakelike structures at the interface with PS globules sitting atop. Upon compression, a pseudoplateau transition region appeared. Both regions strongly depended on PEO composition. The pancake area and the pseudoplateau width and pressure increased in a linear fashion with an increasing amount of PEO. In addition, minimum limits of PEO chain length and mass percentage were determined for observing a pseudoplateau. At small areas, the film proved less compressible, producing a rigid film in which PS dominated. Here, the film area increased with both molecular weight and the amount of PS. Comparison with pure linear PS showed the stars spread more, occupying greater areas. Among the stars, the PEO-core stars were more compact while the PS-core stars spread more. The influence of architecture in terms of the core/corona polymers and branching were also examined. The effects of architecture were subtle, proving less important than PEO chain length or mass percentage.
ISSN:0743-7463
1520-5827
DOI:10.1021/la050787c