The synthesis of hexamethylene diisocyanate microcapsules and mechanisms of self-healing geopolymer through an isocyanate- hydroxy system
Geopolymer materials represent a promising green cementitious material; however, their relatively poor volume stability and higher risk of cracking limit their engineering applications. Therefore, it is necessary to develop geopolymer concrete with self-healing capabilities. This study uses hexameth...
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| Language: | English |
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Elsevier
2025-07-01
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| Series: | Case Studies in Construction Materials |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2214509525003791 |
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| author | Yongming Han Wenting Dai Yanzhong Ju Dehong Wang Mo Liu Lu Zhou Xiaolei Zhang Xue Yang |
| author_facet | Yongming Han Wenting Dai Yanzhong Ju Dehong Wang Mo Liu Lu Zhou Xiaolei Zhang Xue Yang |
| author_sort | Yongming Han |
| collection | DOAJ |
| description | Geopolymer materials represent a promising green cementitious material; however, their relatively poor volume stability and higher risk of cracking limit their engineering applications. Therefore, it is necessary to develop geopolymer concrete with self-healing capabilities. This study uses hexamethylene diisocyanate as the core material and polyethylene wax as the wall material to prepare single-component microcapsules suitable for the highly alkaline environment of self-healing geopolymer concrete through a melt dispersion condensation method. The results show that the microcapsules possess a rough-surfaced spherical core-shell structure and appropriate particle size, offering high mechanical properties and reliable thermal stability. The core content of microcapsules can reach 71.6 % with good sealing performance. The addition of a small amount of microcapsules will improve the mechanical properties of geopolymer and improve the pore size distribution, and the compressive strength reserved rate can be increased by 36.6 %, and the crack repair rate can reach 64.2 %. When isocyanate interacts with hydroxyl groups and water molecules on the matrix surface in the cracked area, variations in microcapsule dosages result in the formation of polyurethane-polyurea bonding materials with diverse structures and types, as well as transition layer bonding with the matrix. The reaction of an appropriate amount of isocyanate with water molecules is beneficial to improving the bonding strength, whereas an excessive reaction weakens it. |
| format | Article |
| id | doaj-art-8d9be4cf11864adebcfafc70f41f5d8a |
| institution | DOAJ |
| issn | 2214-5095 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Case Studies in Construction Materials |
| spelling | doaj-art-8d9be4cf11864adebcfafc70f41f5d8a2025-08-20T02:49:22ZengElsevierCase Studies in Construction Materials2214-50952025-07-0122e0458110.1016/j.cscm.2025.e04581The synthesis of hexamethylene diisocyanate microcapsules and mechanisms of self-healing geopolymer through an isocyanate- hydroxy systemYongming Han0Wenting Dai1Yanzhong Ju2Dehong Wang3Mo Liu4Lu Zhou5Xiaolei Zhang6Xue Yang7College of Construction Engineering, Jilin University, Changchun, China; School of Civil Engineering and Architecture, Northeast Electric Power University, Jilin, ChinaCollege of Construction Engineering, Jilin University, Changchun, China; Corresponding author.School of Civil Engineering and Architecture, Northeast Electric Power University, Jilin, ChinaSchool of Civil Engineering and Architecture, Northeast Electric Power University, Jilin, ChinaCollege of Construction Engineering, Jilin University, Changchun, ChinaCollege of Construction Engineering, Jilin University, Changchun, ChinaSchool of Civil Engineering and Architecture, Northeast Electric Power University, Jilin, ChinaCollege of Construction Engineering, Jilin University, Changchun, ChinaGeopolymer materials represent a promising green cementitious material; however, their relatively poor volume stability and higher risk of cracking limit their engineering applications. Therefore, it is necessary to develop geopolymer concrete with self-healing capabilities. This study uses hexamethylene diisocyanate as the core material and polyethylene wax as the wall material to prepare single-component microcapsules suitable for the highly alkaline environment of self-healing geopolymer concrete through a melt dispersion condensation method. The results show that the microcapsules possess a rough-surfaced spherical core-shell structure and appropriate particle size, offering high mechanical properties and reliable thermal stability. The core content of microcapsules can reach 71.6 % with good sealing performance. The addition of a small amount of microcapsules will improve the mechanical properties of geopolymer and improve the pore size distribution, and the compressive strength reserved rate can be increased by 36.6 %, and the crack repair rate can reach 64.2 %. When isocyanate interacts with hydroxyl groups and water molecules on the matrix surface in the cracked area, variations in microcapsule dosages result in the formation of polyurethane-polyurea bonding materials with diverse structures and types, as well as transition layer bonding with the matrix. The reaction of an appropriate amount of isocyanate with water molecules is beneficial to improving the bonding strength, whereas an excessive reaction weakens it.http://www.sciencedirect.com/science/article/pii/S2214509525003791MicrocapsuleGeopolymerSelf-healing |
| spellingShingle | Yongming Han Wenting Dai Yanzhong Ju Dehong Wang Mo Liu Lu Zhou Xiaolei Zhang Xue Yang The synthesis of hexamethylene diisocyanate microcapsules and mechanisms of self-healing geopolymer through an isocyanate- hydroxy system Case Studies in Construction Materials Microcapsule Geopolymer Self-healing |
| title | The synthesis of hexamethylene diisocyanate microcapsules and mechanisms of self-healing geopolymer through an isocyanate- hydroxy system |
| title_full | The synthesis of hexamethylene diisocyanate microcapsules and mechanisms of self-healing geopolymer through an isocyanate- hydroxy system |
| title_fullStr | The synthesis of hexamethylene diisocyanate microcapsules and mechanisms of self-healing geopolymer through an isocyanate- hydroxy system |
| title_full_unstemmed | The synthesis of hexamethylene diisocyanate microcapsules and mechanisms of self-healing geopolymer through an isocyanate- hydroxy system |
| title_short | The synthesis of hexamethylene diisocyanate microcapsules and mechanisms of self-healing geopolymer through an isocyanate- hydroxy system |
| title_sort | synthesis of hexamethylene diisocyanate microcapsules and mechanisms of self healing geopolymer through an isocyanate hydroxy system |
| topic | Microcapsule Geopolymer Self-healing |
| url | http://www.sciencedirect.com/science/article/pii/S2214509525003791 |
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