Sunlight-Induced Self-Healing of a Microcapsule-Type Protective Coating
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- 作者：Young-Kyu Song ; Ye-Hyun Jo ; Ye-Ji Lim ; Sung-Youl Cho ; Hwan-Chul Yu ; Byung-Cheol Ryu ; Sang-In Lee ; Chan-Moon Chung
- 刊名：ACS Applied Materials & Interfaces
- 出版年：2013
- 出版时间：February 27, 2013
- 年：2013
- 卷：5
- 期：4
- 页码：1378-1384
- 全文大小：326K
- 年卷期：v.5,no.4(February 27, 2013)
- ISSN：1944-8252
文摘
Photopolymerization behavior of a methacryloxypropyl-terminated polydimethylsiloxane (MAT-PDMS) healing agent was investigated in the presence of benzoin isobutyl ether (BIE) photoinitiator by Fourier transform infrared (FT-IR) spectroscopy. MAT-PDMS and BIE were microencapsulated with urea-formaldehyde polymer. The surface and shell morphology of the microcapsules was investigated by scanning electron microscopy (SEM). Mean diameter and size distribution of the microcapsules could be controlled by agitation rate. A coating matrix formulation was prepared by sol鈥揼el reaction of tetraethyl orthosilicate (TEOS) in the presence of a polysiloxane and by subsequent addition of an adhesion promoter. The formulation and microcapsules were mixed to give a self-healing coating formulation, which was then sprayed to surface of cellulose-fiber-reinforced-cement (CRC) board or mortar. Contact angle measurements showed that both the polymerized MAT-PDMS and the prepared coating matrix are hydrophobic, and the coating matrix has good wettability with MAT-PDMS. It was confirmed by optical microscopy and SEM that, when the self-healing coating is damaged, the healing agent is released from ruptured microcapsules and fills the damaged region. The self-healing coating was evaluated as protective coating for mortar, and it was demonstrated by water permeability and chloride ion penetration tests that our system has sunlight-induced self-healing capability. Our self-healing coating is the first example of capsule-type photoinduced self-healing system, and offers the advantages of catalyst-free, environmentally friendly, inexpensive, practical healing.