CONTROL OF NANOPARTICLES DISPERSION STABILITY THROUGH DIELECTRIC CONSTANT TUNING, AND DETERMINATION OF INTRINSIC DIELECTRIC CONSTANT OF SURFACTANT-FREE NANOPARTICLES

摘要

A composition including a medium and surfactant-free nanoparticles (SFNPs) at different dispersion state or aggregation form. The composition includes: (a) a primary form, wherein the dielectric constant value (DE value) of the medium is equal to or larger than the intrinsic dielectric constant value (IDE) of the SFNPs and smaller than about 1.5 times of the IDE of the SFNPs; (b) a reaction-limited aggregation form of SFNPs, wherein the DE value of the medium is much larger than the IDE of the surfactant-free nanoparticles; (c) a diffusion-limited aggregation form of SFNPs, wherein the DE value of the medium is smaller than the IDE of the surfactant-free nanoparticles; and (d) a redispersible aggregation form of surfactant-free nanoparticles, wherein the surfactant-free nanoparticles are induced to aggregate in the diffusion-limited fashion in a medium with a DE value that is smaller than the IDE of the surfactant-free nanoparticles.