This title appears in the Scientific Report :
2005
Please use the identifier:
http://dx.doi.org/10.1063/1.1879892 in citations.
Please use the identifier: http://hdl.handle.net/2128/19096 in citations.
Dynamics of deuterated polystyrene-protonated butadiene diblock copolymer micelles by neutron spin echo
Dynamics of deuterated polystyrene-protonated butadiene diblock copolymer micelles by neutron spin echo
We report on neutron spin-echo (NSE) measurements on deuterated styrene-protonated butadiene diblock copolymer micelles in deuterated n-decane to investigate the dynamics of butadiene blocks in the corona. Before the NSE measurements, we performed small-angle neutron-scattering (SANS) measurements o...
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Personal Name(s): | Kanaya, T. |
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Monkenbusch, M. / Watanabe, H. / Nagao, M. / Richter, D. | |
Contributing Institute: |
Neutronenstreuung; IFF-INS |
Published in: | The @journal of chemical physics, 122 (2005) S. 144905 |
Imprint: |
Melville, NY
American Institute of Physics
2005
|
Physical Description: |
144905 |
DOI: |
10.1063/1.1879892 |
PubMed ID: |
15847563 |
Document Type: |
Journal Article |
Research Program: |
Kondensierte Materie |
Series Title: |
Journal of Chemical Physics
122 |
Subject (ZB): | |
Link: |
Get full text OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/19096 in citations.
We report on neutron spin-echo (NSE) measurements on deuterated styrene-protonated butadiene diblock copolymer micelles in deuterated n-decane to investigate the dynamics of butadiene blocks in the corona. Before the NSE measurements, we performed small-angle neutron-scattering (SANS) measurements on the micelles to evaluate the structure to give a basis for the discussion of the dynamics. In the SANS study, we have estimated the form factor P(Q) in terms of a hard-core-shell model from the direct evaluation without curve-fitting procedure while a more flexible core-shell model with the structure factor S(Q) gives a better fit to the observed data. The observed normalized intermediate scattering function I(Q,t)/I(Q,0) by NSE does not show the collective motions corresponding to the so-called breathing mode but rather single chain motion (Zimm modes) for both the 2 and 20 wt % micelle solutions. The Zimm decay rate Gamma(z) in the micelle solution is slow compared with that in the homopolymer solution. This slowing down is assigned to the effective high concentration in the corona. The differences in Gamma(z) between concentrated solutions and the 20% micellar solution are attributed to end-tethering effect of the corona chains on the core surface. The possible reasons why the breathing mode was not observed in the present micelle system are discussed on the basis of chain density in the corona. |