Self-healing microcapsules for polymer coatings on spacecraft
Researchers have introduced UV-triggered self-healing SiO2/PDA hybrid microcapsules with both enhanced UV-shielding ability and improved compatibility for epoxy resin coatings.
UV-triggered single-microcapsule self-healing materials have significant potential in effectively repairing microcracks and improving the reliability of polymer coatings on spacecraft as of the abundant UV radiation in space. Unfortunately, UV light can also cause undesirable curing of the repair agent within the microcapsules before self-repairing and make the latent UV-cured healing agent fail.
Great self-repairing ability
Scientists have terefore developed UV-triggered self-healing SiO2/polydopamine (PDA) hybrid microcapsules with enhanced UV-shielding ability and compatibility for epoxy resin coating. The microcapsules contain a liquid core of mixed epoxy resin (E-51 and A1815) and UV initiator (PI6992) and a novel UV-shielding SiO2/PDA hybrid shell with uniform embedment of an ultrathin PDA layer into the SiO2 mesoporous structure of the shell. As a UV absorber, PDA endows SiO2/PDA hybrid microcapsules with a UV-shielding hybrid shell and protects the core material from undesirable UV-cured behavior before self-repairing in space with abundant UV radiation.
The epoxy coatings containing SiO2/PDA microcapsules aged for 192 h under UV irradiation maintained great self-repairing ability, which was attributed to the enhanced UV-shielding ability and compatibility.
The study has been published in Progress in Organic Coatings, Volume 163, February 2022.
