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, 5061-5068 p.Article in journal (Refereed) Published
Ellipsometry was used to determine the adsorbed layer thickness (d) and the surface excess (adsorbed amount, Gamma) of a nonionic diblock copolymer, E106B16, of poly(ethylene oxide) (E) and poly(butylene oxide) (13) at the air-water interface. The results were obtained (i) by the conventional ellipsometric evaluation procedure using the change of both ellipsometric angles, T and A and (ii) by using the change of A 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/m(2) (400 A(2)/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 F 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
2005. Vol. 21, no 11, 5061-5068 p.
reflection-absorption spectroscopy, dynamic surface excess, triblock copolymers, aqueous-solution, air/water interface, block-copolymers, liquid interfaces, overflowing cylinder, cationic surfactants, polymer monolayers
IdentifiersURN: urn:nbn:se:kth:diva-25136DOI: 10.1021/la0468040ISI: 000229243800046ScopusID: 2-s2.0-20444372651OAI: oai:DiVA.org:kth-25136DiVA: diva2:356086
QC 201010112010-10-112010-10-112012-09-27Bibliographically approved