Autonomously moving nanorods at a viscous interface
Autonomously moving nanorods at a viscous interface
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DOI：
10.1021/nl052027s
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发表时间：
2006-01-01
期刊：
影响因子：
10.8
通讯作者：
Sen, A
中科院分区：
文献类型：
--
作者：
Dhar, P;Fischer, TM;Sen, A
我们研究了催化纳米棒在吉布斯单分子膜中的自主运动。催化活性的杆上过氧化氢水亚相引起异常的平移和旋转扩散。杆执行Levy-walk超扩散运动，其可以分解成热取向波动和杆沿其长轴以恒定速度沿着的主动运动。由于界面耗散相对于体相耗散增加，当使在界面中移动的物体的尺寸变小时，自主纳米棒允许精确测量低至几nN s/m的表面剪切粘度。从主动运动到被动扩散的交叉时，增加表面活性剂的浓度是由杆的摩擦不对称性的损失来解释。
We study the autonomous motion of catalytic nanorods in Gibbs monolayers. The catalytic activity of the rods on a hydrogen peroxide aqueous subphase gives rise to anomalous translational and rotational diffusion. The rods perform a Levy-walk superdiffusive motion that can be decomposed into thermal orientation fluctuations and an active motion of the rods with a constant velocity along their long axis. Since interfacial dissipation increases relative to bulk phase dissipation when miniaturizing the size of objects moving in the interface, the autonomous nanorods allow for precise measurements of surface shear viscosities as low as a few nN s/m. The cross over from active motion toward passive diffusion when increasing the surfactant concentration is explained by a loss of friction asymmetry of the rods.