Ellipsometric characterization of ethylene oxide-butylene oxide diblock copolymer adsorption at the air-water interface
2005 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 21, no 11, p. 5061-5068Article in journal (Refereed) Published
Abstract [en]
Ellipsometry was used to determine the adsorbed layer thickness (d) and the surface excess (adsorbed amount, Γ) of a nonionic diblock copolymer, E106B16, of poly(ethylene oxide) (E) and poly(butylene oxide) (B) at the air−water interface. The results were obtained (i) by the conventional ellipsometric evaluation procedure using the change of both ellipsometric angles Ψ and Δ and (ii) by using the change of Δ only and assuming values of the layer thickness. It was demonstrated that the calculated surface excesses from the different methods were in close agreement, independent of the evaluation procedure, with a plateau adsorption of about 2.5 mg/m2 (400 Å2/molecule). Furthermore, the amount of E106B16 adsorbed at the air−water interface was found to be almost identical to that adsorbed from aqueous solution onto a hydrophobic solid surface. In addition, the possibility to use combined measurements with H2O or D2O as substrates to calculate values of d and Γ was investigated and discussed. We also briefly discuss within which limits the Gibbs equation can be used to determine the surface excess of polydisperse block copolymers.
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2005. Vol. 21, no 11, p. 5061-5068
Keywords [en]
Adsorption, Interfaces, Layers, Polymers, Thickness
National Category
Physical Chemistry
Identifiers
URN: urn:nbn:se:mau:diva-5353DOI: 10.1021/la0468040ISI: 000229243800046PubMedID: 15896051Scopus ID: 2-s2.0-20444372651Local ID: 2687OAI: oai:DiVA.org:mau-5353DiVA, id: diva2:1402208
2020-02-282020-02-282024-11-25Bibliographically approved