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Published on: December 20, 2016
Separation of nanorods by density gradient centrifugation
Bin Xiong1, Jing Cheng, Yanxia Qiao
1College of Chemistry and Chemical Engineering, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, China.
Journal of Chromatography. A
|May 17, 2011
Summary
Separating gold nanorods by size and shape is challenging. Density gradient centrifugation effectively separates gold nanorods by exploiting their mass and shape, yielding distinct size-sorted layers.
Area of Science:
- Nanotechnology
- Materials Science
- Physical Chemistry
Background:
- Synthesizing well-defined nanoparticles with controlled size and shape is experimentally challenging.
- Polydispersity in nanoparticle size and shape necessitates post-synthesis separation techniques.
- Gold nanorods are versatile nanomaterials with applications in optics and medicine.
Purpose of the Study:
- To investigate the theoretical and experimental feasibility of separating gold nanorods by aspect ratio using density gradient centrifugation.
- To develop a predictive model for nanorod sedimentation based on mass and shape.
- To demonstrate the practical application of this method for purifying gold nanorod colloids.
Main Methods:
- Theoretical modeling of Brownian rod sedimentation in Stokes flow, considering mass and shape factors.
- Experimental implementation of sucrose density gradient centrifugation for gold nanorod separation.
- Characterization of separated nanorod fractions to determine aspect ratio distributions.
Main Results:
- A rigorous model was derived, quantitatively linking nanorod sedimentation rates to their mass and shape.
- Sedimentation is primarily mass-dependent, but shape significantly influences separation outcomes.
- Density gradient centrifugation successfully separated gold nanorod colloids into two distinct layers with narrow aspect-ratio distributions.
Conclusions:
- Density gradient centrifugation is a viable method for separating gold nanorods based on their aspect ratios.
- The developed theoretical model accurately predicts separation behavior, aiding in method optimization.
- This technique offers a pathway to obtain size- and shape-controlled gold nanorods for advanced applications.
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