Abstract
We report the development of an extrinsic, self-healing coating system that shows no fluorescence from intact coating, yellowish fluorescence in cracked regions, and greenish fluorescence in healed regions, thus allowing separate monitoring of cracking and healing of coatings. This fluorescence-monitoring self-healing system consisted of a top coating and an epoxy matrix resin containing mixed dye loaded in a single microcapsule. The dye-loaded microcapsules consisted of a poly(urea-formaldehyde) shell encapsulating a healing agent containing methacryloxypropyl-terminated polydimethylsiloxane (MAT-PDMS), styrene, a photo-initiator, and a mixture of two dyes: one that fluoresced only in the solid state (DCM) and a second that fluoresced dramatically in the solid than in the solution state (4-TPAE). A mixture of the healing agent, photo-initiator, and the two dyes was yellow due to fluorescence from DCM. On UV curing of this mixture, however, the color changed from yellow to green, and the fluorescence intensity increased due to fluorescence from 4-TPAE in the solid state. When a self-healing coating embedded with microcapsules containing the DCM/4-TPAE dye mixture was scratched, the damaged region exhibited a yellowish color that changed to green after healing. Thus, the self-healing system reported here allows separate monitoring of cracking and healing based on changes in fluorescence color.
Highlights
One of the roles of a coating is to protect the underlying substrate from external impacts, thereby protecting it from corrosion and other processes that may compromise its mechanical properties.coatings can extend the lifetimes of materials and, in various contexts, enhance public safety.The development of self-healing coatings, and techniques for monitoring such coatings in real time, has proved to be an effective means of extending the lifetime of materials
We studied self-healing coatings containing fluorescence dye-loaded microcapsules, in which self-healing gave rise to aggregation-induced emission (AIE) that could be used to detect the healing process (See Figure 1) [1,11]
To examine the change in fluorescence color of the dyes during self-healing, a sample comprised of a liquid photo-curable healing agent containing the normal dye, AIE dye, or both dyes was subjected to photo-curing under UV irradiation, and the photo-polymerization
Summary
One of the roles of a coating is to protect the underlying substrate from external impacts, thereby protecting it from corrosion and other processes that may compromise its mechanical properties. We studied self-healing coatings containing fluorescence dye-loaded microcapsules, in which self-healing gave rise to aggregation-induced emission (AIE) that could be used to detect the healing process (See Figure 1) [1,11]. To capability is achieved by loading each microcapsule with two types of fluorescent dye: a normal properly monitor a self-healing system, cracking and healing should be detected separately, because. Thisfluorescent dual monitoring dye maintains its capability is achieved by loading each microcapsule with two types of fluorescent dye: a normal ACQ fluorescence intensity on going from the liquid to the solid phase [12,13], whereas the AIE dye exhibits (aggregation-caused quenching) dye with yellowish fluorescence and an AIE dye with a highly dramatically increased fluorescence in theThese solid torespond the liquid phase (see Figure 2a). The color to change from an orange to a greenish fluorescence (see Figure 2b)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
