Enhancing the Magnetoviscosity of Ferrofluids by the Addition of Biological Nanotubes

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• 作者：Zhenyu Wu ; Anna Mueller ; Sven Degenhard ; S. Emil Ruff ; Fania Geiger ; Alexander M. Bittner ; Christina Wege ; Carl E. Krill III
• 刊名：ACS Nano
• 出版年：2010
• 出版时间：August 24, 2010
• 年：2010
• 卷：4
• 期：8
• 页码：4531-4538
• 全文大小：377K
• 年卷期：0
• ISSN：1936-086X

文摘

Applying a magnetic field to many ferrofluids leads to a significant increase in viscosity, but the phenomenon has yet to find technological exploitation because of the thinning caused by even weak shear flows. We have discovered that the addition of plant-virus-derived nanotubes to a commercial ferrofluid can give rise to a dramatic enhancement in magnetoviscosity and a suppression of shear thinning. The dependence of this effect on nanotube aspect ratio and surface charge, both of which were varied biotechnologically, is consistent with a “scaffolding” of magnetic particles into quasi-linear arrays. Direct support for this explanation is derived from transmission electron micrographs, which reveal a marked tendency for the magnetic nanoparticles to decorate the outside surface of the virus nanotubes.