Micellar Spheres in a High Frequency Oscillatory Field
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- 作者：Antonis Kelarakis ; Jé ; rô ; me J. Crassous ; Matthias Ballauff ; Zhuo Yang ; Colin Booth
- 刊名：Langmuir
- 出版年：2006
- 出版时间：August 1, 2006
- 年：2006
- 卷：22
- 期：16
- 页码：6814 - 6817
- 全文大小：55K
- 年卷期：v.22,no.16(August 1, 2006)
- ISSN：1520-5827
文摘
The viscoelasticity of aqueous micellar solutions of two oxyethylene/oxybutylene block copolymers (E92B18 andB20E510) has been investigated using a torsional resonator operated at 26 kHz. For both systems considered, valuesof the dynamic viscosity (
) point to partial draining of the micellar corona induced by the high-frequency oscillatoryfield. At low effective volume fractions, values of the elastic modulus (
) indicate that the repulsive interactionsbetween micelles can be modeled by a power law function u(r) 
1/r
with exponents close to 13 and 6 for copolymersE92B18 and B20E510 respectively. At a critical copolymer concentration (c*) plots of log(
) against log(c) deviate fromthe straight lines established at low concentrations, implying that the systems undergo ergodic/nonergodic transitions.
) point to partial draining of the micellar corona induced by the high-frequency oscillatoryfield. At low effective volume fractions, values of the elastic modulus () indicate that the repulsive interactionsbetween micelles can be modeled by a power law function u(r) 1/r with exponents close to 13 and 6 for copolymersE92B18 and B20E510 respectively. At a critical copolymer concentration (c*) plots of log() against log(c) deviate fromthe straight lines established at low concentrations, implying that the systems undergo ergodic/nonergodic transitions.