Several factors influence the stability of nanoparticle dispersions, including:
1. Particle Size and Shape: Smaller nanoparticles have a higher surface area-to-volume ratio, which can enhance their interaction with the medium and other particles. However, this also increases the likelihood of agglomeration. 2. Surface Charge: The zeta potential of nanoparticles affects their electrostatic repulsion. A higher zeta potential typically indicates better stability due to increased repulsive forces between particles. 3. Medium Properties: The viscosity, pH, and ionic strength of the dispersion medium can significantly impact stability. For example, high ionic strength can screen electrostatic repulsive forces, leading to agglomeration. 4. Surface Modification: Functionalizing the surface of nanoparticles with specific ligands or polymers can enhance stability by providing steric hindrance or additional electrostatic repulsion.
