Etched glass bubbles as robust micro-containers for self-healing materials

Abstract

Etched glass bubbles (GBs) with through-holes at the micron level were fabricated by etching them using dilute hydrofluoric acid (HF) in a specially designed mixer. The semi-segmented mixer under mechanical agitation produces circulation of the GBs in solution, purposely completing the processes of the etching reaction on the GBs, filling the etched GBs with solution, and depositing the well etched GBs in the mixer bottom for collection. Highly reactive primary amine and diisocyanate monomer were separately infiltrated into the etched GBs and formulated as self-healing materials with satisfactory healing performance, indicating the robustness and versatility of the etched GBs.