Direct observation of blocked nanoscale surface evaporation on SiO2 nanodroplets

摘要

Nano-scale surface evaporation of SiO2 nanodroplets from a volcano-shaped tip (tip diameter d ∼ 20 nm to 70 nm) was observed directly using an in situ transmission electron microscopy method. Au nanoparticles, those precipitated in the SiO2 matrix after an Au catalyzed growth, diffused and pinned onto the evaporation surface, which induced blocked evaporation dynamics. Our observations provide direct evidences of blocked evaporation dynamics caused by small-sized nanoparticles at the nanometer scale.