Condensed Exponential Correlation Functions in Multicomponent Polymer Blends Measured by X-ray Photon Correlation Spectroscopy
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- 作者：Megan L. Ruegg ; Amish J. Patel ; Suresh Narayanan ; Alec R. Sandy ; Simon G. J. Mochrie ; Hiroshi Watanabe ; Nitash P. Balsara
- 刊名：Macromolecules
- 出版年：2006
- 出版时间：December 12, 2006
- 年：2006
- 卷：39
- 期：25
- 页码：8822 - 8831
- 全文大小：212K
- 年卷期：v.39,no.25(December 12, 2006)
- ISSN：1520-5835
文摘
X-ray photon correlation spectroscopy experiments were conducted on bicontinuous microemulsionand lamellar phases in polystyrene/polyisoprene/poly(styrene-b-isoprene) blends. Regardless of the microstructure,the scattering intensity autocorrelation function at low temperatures in the vicinity of the primary X-rayscattering peak, g2(q,t) (q is the scattering vector), was found to be a condensed exponential, i.e.,g2(q,t) ~ exp{-[t/
(q)]
}with > 1. This is in direct contrast to previous observations of exponential and stretchedexponential correlation functions ( 
1) in microstructured materials comprising polymers as well as smallmolecules. At higher temperatures, more conventional stretched exponential correlation functions are recovered.We suggest that condensed exponential relaxation functions may be related to the spontaneous breakup ofmicrosctructure.
(q)]}with > 1. This is in direct contrast to previous observations of exponential and stretchedexponential correlation functions ( 1) in microstructured materials comprising polymers as well as smallmolecules. At higher temperatures, more conventional stretched exponential correlation functions are recovered.We suggest that condensed exponential relaxation functions may be related to the spontaneous breakup ofmicrosctructure.