Sharma Vivek, Park Kyoungweon, Srinivasarao Mohan
School of Polymer Textile and Fiber Engineering, Center for Advanced Research on Optical Microscopy, and School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Proc Natl Acad Sci U S A. 2009 Mar 31;106(13):4981-5. doi: 10.1073/pnas.0800599106. Epub 2009 Mar 2.
We demonstrate the use of centrifugation for efficient separation of colloidal gold nanorods from a mixture of nanorods and nanospheres. We elucidate the hydrodynamic behavior of nanoparticles of various shapes and illustrate that the shape-dependent drag causes particles to have shape-dependent sedimentation behavior. During centrifugation, nanoparticles undergo Brownian motion under an external field and move with different sedimentation velocities dictated by their Svedberg coefficients. This effects a separation of particles of different shape and size. Our theoretical analysis and experiments demonstrate the viability of using centrifugation to shape-separate a mixture of colloidal particles.
我们展示了利用离心法从纳米棒和纳米球的混合物中高效分离胶体金纳米棒的方法。我们阐明了各种形状纳米颗粒的流体动力学行为，并表明形状依赖性阻力导致颗粒具有形状依赖性沉降行为。在离心过程中，纳米颗粒在外场作用下进行布朗运动，并以由其斯维德伯格系数决定的不同沉降速度移动。这实现了不同形状和尺寸颗粒的分离。我们的理论分析和实验证明了使用离心法对胶体颗粒混合物进行形状分离的可行性。
