What are the properties of nanoparticles?
Posted October 21, 2019
Answer
At nanoscale, material properties can be altered in multiple ways, primarily due to the higher percentage of atoms at the surface. This high surface area to volume ratio has several immediate, general affects.
- Nanoparticles can be sintered more easily, quickly, and at lower temperatures. Melting points are lower, sometimes dramatically so. (For example, bulk gold melts at 1064°C, but nanoparticulate gold melts at 300°C)
- Nanoparticles are far more susceptible to diffusion forces as well, since their surface interactions with the solvent are strong enough to overcome variations in density that typically would have the material falling out suspension.
Other properties of nanoscale materials vary by what the base material is. See Table 1 below.
Table 1. Nanoparticle base material and associated properties.
Nanoparticle Type | Properties |
Carbon-based | Extremely high strength, electrical conductivity |
Ceramic | Heat resistance, chemical inertness |
Metal | High surface energy, small molecule adsorption |
Semiconductor | Wide bandgaps, quantization of energy levels |
Polymeric | Encapsulated morphology, biodegradable/biocompatible |
Lipid-based | Self-assembly, biocompatible |
For more details, see review 'Nanoparticles: Properties, applications, and toxicities' available here: https://www.sciencedirect.com/science/article/pii/S1878535217300990
Additional resources
Dr. Richard Feynman's Original 'There's Plenty of Room at the Bottom' Nanotechnology Speech