Diffusion and Viscosity in a Crowded Environment: from Nano- to Macroscale

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• 作者：Jedrzej Szyma//pubs.acs.org/images/entities/nacute.gif" border="0">ski ; Adam Patkowski ; Agnieszka Wilk ; Piotr Garstecki ; Robert Holyst
• 刊名：Journal of Physical Chemistry B
• 出版年：2006
• 出版时间：December 28, 2006
• 年：2006
• 卷：110
• 期：51
• 页码：25593 - 25597
• 全文大小：308K
• 年卷期：v.110,no.51(December 28, 2006)
• ISSN：1520-5207

文摘

Although water is the chief component of living cells, food, and personal care products, the supramolecularcomponents make their viscosity larger than that of water by several orders of magnitude. Using fluorescencecorrelation spectroscopy (FCS), photon correlation spectroscopy (PCS), NMR, and rheology data, we showhow the viscosity changes from the value for water at the molecular scale to the large macroviscosity. Wedetermined the viscosity experienced by nanoprobes (of sizes from 0.28 to 190 nm) in aqueous micellarsolution of hexaethylene-glycol-monododecyl-ether (in a range of concentration from 0.1% w/w to 35% w/w)and identified a clear crossover at the length scale of 17 ± 2 nm (slightly larger than persistence length ofmicelles) at which viscosity acquires its macroscopic value. The sharp dependence of the viscosity coefficientson the size of the probe in the nanoregime has important consequences for diffusion-limited reactions incrowded environments (e.g., living cells).