Particle Shape
Nanoparticle shape impacts the melting point of a nanoparticle. Facets, edges and deviations from a perfect sphere all change the magnitude of melting point depression. These shape changes affect the surface to volume ratio, which affects the cohesive energy and thermal properties of a nanostructure. Equation 7 gives a general shape corrected formula for the theoretical melting point of a nanoparticle based on its size and shape.
Where: c=materials constant
-
- z=shape parameter of particle
The shape parameter is 1 for sphere and 3/2 for a very long wire, indicating that melting-point depression is suppressed in nanowires compared to nanoparticles. Past experimental data show that nanoscale tin platelets melt within a narrow range of 10 oC of the bulk melting temperature. The melting point depression of these platelets was suppressed compared to spherical tin nanoparticles.
Read more about this topic: Melting-point Depression
Famous quotes containing the words particle and/or shape:
“You don’t hold any mystery for me, darling, do you mind? There isn’t a particle of you that I don’t know, remember, and want.”
—Noël Coward (1899–1973)
“We cannot and must not get rid of nor deny our characteristics. But we can give them shape and direction.”
—Johann Wolfgang Von Goethe (1749–1832)