Publications


Title : Neutron Spin-Echo Study of the Dynamic Behavior of Amphiphilic Diblock Copolymer Micelles in Aqueous Solution

Language: English
Type: Article
Authors: Hideki Matsuoka, Yusuke Yamamoto, Hitoshi Endo, Hitoshi Yamaoka, , Michael Monkenbusch, Dieter Richter, Hideki Seto, Youhei Kawabata and Michihiro Nagao
Journal: Langmuir
ISSN: 0743-7463
Volume: 16
Number: 24
Month: 11
Year: 2000
Actual year: 2000
Pages: 9177-9185
doi:   10.1021/la9915421
Abstract: We examined the dynamics of amphiphilic polymer micelles of the diblock copolymer HOVE-NBVE (hydroxyethylvinyl ether as a hydrophilic segment and n-butylvinyl ether as a hydrophobic segment) in aqueous solution using the neutron spin-echo (NSE) technique. The time-correlation function obtained for the polymer micelles was well fitted by double exponential function, and the fast and slow modes could be estimated separately. The slow mode was dominant at smaller scattering angles, and showed an excellent linearity in Gamma (decay rate) vs q(2) (scattering vector) plot. The diffusion coefficient evaluated from its slope and the hydrodynamic radius, R-h, by the Einstein-Stoke equation were consistent with the size of the polymer micelle that was estimated by small-angle neutron scattering (SANS), small-angle X-ray scattering (SAXS), and dynamic light scattering (DLS). Hence, this slow mode reflects the translational diffusion of the polymer micelle in aqueous solution. The fast mode, which was 1 order of magnitude faster than the slow mode, was a major factor for larger scattering angle regions in which the SANS curve showed blob scattering Thus, the fast mode appears to be an internal motion of the polymer micelle, like the breathing mode of the hydrophilic shell (corona) around the polymer micelle.

"Neutron Spin-Echo Study of the Dynamic Behavior of Amphiphilic Diblock Copolymer Micelles in Aqueous Solution"

Hideki Matsuoka, Yusuke Yamamoto, Hitoshi Endo, Hitoshi Yamaoka, , Michael Monkenbusch, Dieter Richter, Hideki Seto, Youhei Kawabata and Michihiro Nagao, Langmuir, 16, 9177-9185 (2000)