Structural changes of poly(butadiene)-poly(ethyleneoxide) diblock-copolymer micelles induced by a cationic surfactant: scattering and cryogenic transmission electron microscopy studies.
Micelles of the diblock copolymer poly(butadiene)-poly(ethyleneoxide) (B40-b-EO62) and mixed micelles of this polymer with the cationic surfactant dodecyltrimethylammonium bromide (C12TAB) were investigated using static and dynamic light scattering and small-angle neutron scattering. It is shown that the surfactant induces a major structural change from large mainly rodlike aggregates to smaller spherical mixed micelles. The rodlike assemblies found in the absence of surfactant have a contour length L of ca. 500 nm and a diameter d approximately 30 nm. The spherical mixed micelles obtained upon addition of C12TAB possess a hydrodynamic radius of 15 nm and still contain several polymer molecules. The results of the scattering experiments are consistent with observations of the aggregates by cryogenic transmission electron microscopy.
Nordskog
Anette
A
TU Berlin, Stranski-Laboratorium f. Physikalische und Theoretische Chemie, Strasse des 17.Juni 112, D-10623 Berlin, Germany.
Egger
Holger
H
Findenegg
Gerhard H
GH
Hellweg
Thomas
T
Schlaad
Helmut
H
Von Berlepsch
Hans
H
Böttcher
Christoph
C
D055592:Biophysical Phenomena; D001703:Biophysics; D002070:Butadienes / Q000737:chemistry*; D002412:Cations; D020724:Elastomers; D008027:Light; D008823:Micelles; D008854:Microscopy, Electron / Q000379:methods*; D009502:Neutrons; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012542:Scattering, Radiation
D002070:Butadienes; D002412:Cations; D020724:Elastomers; D008823:Micelles; D011108:Polymers; D000644:Quaternary Ammonium Compounds; D011092:Polyethylene Glycols; C028834:polybutadiene; C022806:dodecyltrimethylammonium