ABSTRACT
We employed agarose gel preparative electrophoresis to separate gold nanoparticles based on size, shape, and charge. The separating technique was first demonstrated by size separation of 5 nm, 15 nm, and 20 nm spherical gold nanoclusters; and further evidenced through the purification of crude 15 +/- 2.7 nm nanoclusters to nanoclusters that were 15 +/- 0.4 nm. The ability to separate gold nanoparticles by shape was also shown by the purification of a mixture of gold spheres, plates, and long rods.
Subject(s)
Electrophoresis, Agar Gel/methods , Gold Colloid/analysis , Gold/analysis , Metal Nanoparticles/analysis , Metal Nanoparticles/ultrastructure , Indicators and Reagents , Microscopy, Electron, Transmission/methods , Staining and LabelingABSTRACT
The reinforcing mechanisms of single-walled carbon nanotube-reinforced epoxy composites were studied by micromechanics models. The modeling results obtained from both Halpin-Tsai and Mori-Tanaka models are in good agreement with the experimental results. It has been found that these two models are also applicable to other single-walled carbon nanotube-reinforced, amorphous-polymer composites, given the existence of efficient load transfer. The reinforcing mechanisms that work in polymer-carbon nanotube composites were studied. The reasons responsible for the low mechanical property enhancement of single-walled carbon nanotube in polymer composites were discussed in conjunction with the effective fiber length concept, interface between nanotube bundles and the matrix, properties of the reinforcements and matrix, bundle effects, bundle curvature, and alignment.
Subject(s)
Crystallization/methods , Models, Chemical , Models, Molecular , Nanotechnology/methods , Nanotubes, Carbon/chemistry , Nanotubes, Carbon/ultrastructure , Polymers/chemistry , Computer Simulation , Elasticity , Macromolecular Substances/chemistry , Materials Testing , Molecular Conformation , Particle Size , Stress, Mechanical , Surface PropertiesABSTRACT
Arc-synthesized single-walled carbon nanotubes have been purified through preparative electrophoresis in agarose gel and glass bead matrixes. Two major impurities were isolated: fluorescent carbon and short tubular carbon. Analysis of these two classes of impurities was done. The methods described may be readily extended to the separation of other water-soluble nanoparticles. The separated fluorescent carbon and short tubule carbon species promise to be interesting nanomaterials in their own right.
