Online Determination of Structural Properties and Observation of Deviations from Power Law Behavior

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• 作者：Agn&#xe8 ; s Rolland-Sabat&#xe9 ; Maria Guadalupe Mendez-Montealvo ; Paul Colonna ; V&#xe9 ; ronique Planchot
• 刊名：Biomacromolecules
• 出版年：2008
• 出版时间：July 2008
• 年：2008
• 卷：9
• 期：7
• 页码：1719 - 1730
• 全文大小：1064K
• 年卷期：v.9,no.7(July 2008)
• ISSN：1526-4602

文摘

Synthetic amyloses, pullulans, phytoglycogen, rabbit liver glycogen, oyster glycogen, and dextrans were studied using high-performance size-exclusion chromatography combined with multiangle laser light scattering (MALLS) and online quasi-elastic light scattering (QELS), which provided the R_H distributions up to 65 nm. Different structural parameters were extracted from entire molar mass distributions, including the slope of the log–log plot of R_Hi versus M_i and the ρ_i = R_Gi/R_Hi ratio. This approach enabled to observe deviations from the De Gennes scaling law concept. Evidences that the power laws do not obey the general universality were furnished by the observation of strong deviations in the relation between radii and molar masses for the branched polysaccharides, a decrease of ρ-parameter with molar mass toward values much lower than theoretically expected, and the fact that relation between ρ-parameter and apparent segment density did not show the expected power law decrease with an exponent of ¹/₃. The universality of scaling behavior seems no longer to be realized if structural heterogeneity governs the system.