The structure of PEO–PPO–PEO triblock copolymers at the water/air interface

• Published in: Physica. B, Condensed matter Vol. 315; no. 4; pp. 267 - 272
• Main Authors: Sedev, R., Steitz, R., Findenegg, G.H.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-04-2002; Elsevier
• Subjects: Block copolymers; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fluid surfaces and fluid-fluid interfaces; Material types; Neutron diffraction and scattering; Neutron reflectivity; Neutron reflectometry; Physics; Polymer brush; Rheology; Structure of solids and liquids; crystallography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Water/air interface; Neutron reflectivity; 68.03.Hj; Water/air interface; Polymer brush; 61.12.Ha; 83.80Qr; Block copolymers; Chain length; Thick films; Solubility; Parabolic approximation; Air water interface; Neutron reflection; Density; Layer thickness; Ellipsometry; Copolymers; Formates; Block copolymer; Reflectance
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/S0921-4526(02)00513-6

Neutron reflectivity was employed to detect a layer of water-soluble PEO–PPO–PEO triblock copolymers adsorbed from D
2O. The thickness of the layer (estimated from single-layer fits) grows linearly with the chain length in agreement with the theory of the “simple brush”. The results are consistent with previous ellipsometric findings indicating the formation of a PEO brush at the water/air interface. The segment density profile is more diffuse than predicted by the simple brush model but the higher approximation (known as “parabolic brush”) does not describe our results adequately.