کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1384674 | 982413 | 2009 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Macromolecular conformation of chitosan in dilute solution: A new global hydrodynamic approach Macromolecular conformation of chitosan in dilute solution: A new global hydrodynamic approach](/preview/png/1384674.png)
Chitosans of different molar masses were prepared by storing freshly prepared samples for up to 6 months at either 4, 25 or 40 °C. The weight-average molar masses, Mw and intrinsic viscosities, [η] were then measured using size exclusion chromatography coupled to multi-angle laser light scattering (SEC-MALLS) and a “rolling ball” viscometer, respectively.The solution conformation of chitosan was then estimated from:(a)the Mark–Houwink–Kuhn–Sakurada (MHKS) power law relationship [η] = kMwa and(b)the persistence length, Lp calculated from a new approach based on equivalent radii [Ortega, A., & Garcia de la Torre, J. (2007). Equivalent radii and ratios of radii from solution properties as indicators of macromolecular conformation, shape, and flexibility. Biomacromolecules,8, 2464–2475].Both the MHKS power law exponent (a = 0.95 ± 0.01) and the persistence length (Lp = 16 ± 2 nm) are consistent with a semi-flexible rod type (or stiff coil) conformation for all 33 chitosans studied. A semi-flexible rod conformation was further supported by the Wales–van Holde ratio, the translational frictional ratio and sedimentation conformation zoning.
Journal: Carbohydrate Polymers - Volume 76, Issue 4, 16 May 2009, Pages 616–621