Dual Monitoring of Cracking and Healing in Self-healing Coatings Using Microcapsules Loaded with Two Fluorescent Dyes
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-moni...
Main Authors: | , , , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
MDPI AG
2019-04-01
|
Series: | Molecules |
Subjects: | |
Online Access: | https://www.mdpi.com/1420-3049/24/9/1679 |
id |
doaj-6acf04ea2efe4dd38ff90bf91bcef9c8 |
---|---|
record_format |
Article |
spelling |
doaj-6acf04ea2efe4dd38ff90bf91bcef9c82020-11-25T02:11:58ZengMDPI AGMolecules1420-30492019-04-01249167910.3390/molecules24091679molecules24091679Dual Monitoring of Cracking and Healing in Self-healing Coatings Using Microcapsules Loaded with Two Fluorescent DyesYoung Kyu Song0Tae Hee Lee1Jin Chul Kim2Kyu Cheol Lee3Sang-Ho Lee4Seung Man Noh5Young Il Park6Research Center for Green Fine Chemicals, Korea Research Institute of Chemical Technology, Ulsan 44412, KoreaResearch Center for Green Fine Chemicals, Korea Research Institute of Chemical Technology, Ulsan 44412, KoreaResearch Center for Green Fine Chemicals, Korea Research Institute of Chemical Technology, Ulsan 44412, KoreaResearch Center for Green Fine Chemicals, Korea Research Institute of Chemical Technology, Ulsan 44412, KoreaResearch Center for Green Fine Chemicals, Korea Research Institute of Chemical Technology, Ulsan 44412, KoreaResearch Center for Green Fine Chemicals, Korea Research Institute of Chemical Technology, Ulsan 44412, KoreaResearch Center for Green Fine Chemicals, Korea Research Institute of Chemical Technology, Ulsan 44412, KoreaWe 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.https://www.mdpi.com/1420-3049/24/9/1679extrinsic self-healingself-healing detectionaggregation-induced emissiondye-loaded microcapsuleself-healing monitoring |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Young Kyu Song Tae Hee Lee Jin Chul Kim Kyu Cheol Lee Sang-Ho Lee Seung Man Noh Young Il Park |
spellingShingle |
Young Kyu Song Tae Hee Lee Jin Chul Kim Kyu Cheol Lee Sang-Ho Lee Seung Man Noh Young Il Park Dual Monitoring of Cracking and Healing in Self-healing Coatings Using Microcapsules Loaded with Two Fluorescent Dyes Molecules extrinsic self-healing self-healing detection aggregation-induced emission dye-loaded microcapsule self-healing monitoring |
author_facet |
Young Kyu Song Tae Hee Lee Jin Chul Kim Kyu Cheol Lee Sang-Ho Lee Seung Man Noh Young Il Park |
author_sort |
Young Kyu Song |
title |
Dual Monitoring of Cracking and Healing in Self-healing Coatings Using Microcapsules Loaded with Two Fluorescent Dyes |
title_short |
Dual Monitoring of Cracking and Healing in Self-healing Coatings Using Microcapsules Loaded with Two Fluorescent Dyes |
title_full |
Dual Monitoring of Cracking and Healing in Self-healing Coatings Using Microcapsules Loaded with Two Fluorescent Dyes |
title_fullStr |
Dual Monitoring of Cracking and Healing in Self-healing Coatings Using Microcapsules Loaded with Two Fluorescent Dyes |
title_full_unstemmed |
Dual Monitoring of Cracking and Healing in Self-healing Coatings Using Microcapsules Loaded with Two Fluorescent Dyes |
title_sort |
dual monitoring of cracking and healing in self-healing coatings using microcapsules loaded with two fluorescent dyes |
publisher |
MDPI AG |
series |
Molecules |
issn |
1420-3049 |
publishDate |
2019-04-01 |
description |
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. |
topic |
extrinsic self-healing self-healing detection aggregation-induced emission dye-loaded microcapsule self-healing monitoring |
url |
https://www.mdpi.com/1420-3049/24/9/1679 |
work_keys_str_mv |
AT youngkyusong dualmonitoringofcrackingandhealinginselfhealingcoatingsusingmicrocapsulesloadedwithtwofluorescentdyes AT taeheelee dualmonitoringofcrackingandhealinginselfhealingcoatingsusingmicrocapsulesloadedwithtwofluorescentdyes AT jinchulkim dualmonitoringofcrackingandhealinginselfhealingcoatingsusingmicrocapsulesloadedwithtwofluorescentdyes AT kyucheollee dualmonitoringofcrackingandhealinginselfhealingcoatingsusingmicrocapsulesloadedwithtwofluorescentdyes AT sangholee dualmonitoringofcrackingandhealinginselfhealingcoatingsusingmicrocapsulesloadedwithtwofluorescentdyes AT seungmannoh dualmonitoringofcrackingandhealinginselfhealingcoatingsusingmicrocapsulesloadedwithtwofluorescentdyes AT youngilpark dualmonitoringofcrackingandhealinginselfhealingcoatingsusingmicrocapsulesloadedwithtwofluorescentdyes |
_version_ |
1724911563858509824 |