COMPOSITES PART B-ENGINEERING
·
2020
·
IF 7.635
Xingang Wang,Zhongfa Chen,Wei Xu,Xingjing Wang
Fluorescence labelling and self-healing microcapsules (FLSM) with fluorescein sodium labelled epoxy resin as core materials and urea-formaldehyde resin as shell materials were synthesized by in situ polymerization via ultrasonic dispersion. Micromorphology, chemical structure , thermal stability and reactivity of FLSM were studied by ESEM , FTIR, TGA and DSC . Laser scanning confocal microscopy (LSCM) was served to characterize the surface microcracks repair process of cement paste mixed FLSM. The results showed that FLSM with full spherical particles and a certain roughness on the surface were well dispersed in the range of 150–300 μm of particle size. The addition of fluorescein sodium has no significant effect on the micromorphology, chemical structure, thermal stability and reactivity of FLSM. After being cut by the blade, the fluorescence width of FLSM increased from 9 μm to 22 μm within 0–12 h. The core materials of FLSM was basically lost, which indicated that the core materials had good fluidity. When the microcracks occur on the surface of cement paste, FLSM can not only detect the specific location of the microcracks and repair them, but also infer the width of the microcracks. It provides a new method for detecting and repairing microcracks on the surface of cement matrix .
研究领域:
材料科学
·
建筑工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2025
·
IF 5.2
Dongzhi Wang,Yanji Zhu,Hongda Zhou,Xinyu Bu,Huaiyuan Wang
Reducing the microcracks in concrete materials is critical for extending service life and improving safety in civil engineering. Despite much progress in self-healing concrete materials, the meticulous research in healing mechanisms is still inadequate. In this paper, self-healing microcapsules are prepared by in-situ polymerization method and the interfacial enhancement healing mechanism of microcracks based on organic–inorganic interpenetrated network is proposed. The epoxy resin, as core material, was encapsulated by urea–formaldehyde resin to prepare self-healing microcapsules (PUF-E). The microcapsules were pre-embedded in concrete composites to achieve healing of microcracks. The concrete composites containing 5 wt% PUF-E microcapsules demonstrate significant self-healing efficiency, which can completely repair microcracks and improve mechanical strength. The compressive and flexural strengths of the healed concrete are 22.36 MPa and 3.73 MPa, with recovery rates of 98.90 % and 112.69 %, respectively. The self-healing mechanism with triple enhancement reactions is investigated. On the one hand, the rapidly releasing epoxy resin from PUF-E microcapsules fills microcracks and cures to form the first polymer network. Subsequently the second inorganic skeleton is introduced through the hydrogen bonding between epoxy and inherent hydration products (calcium silicate hydrate), building an interpenetrating structure with the polymer network. On the other hand, the coordination interaction between epoxy groups and Ca 2+ further improves the strength of the interpenetrating structure and enhances interfacial adhesion, achieving excellent self-healing performance of the concrete composites. The interface-enhanced healing mechanism of organic–inorganic interpenetrated networks provides new ideas for the design and development of high-performance self-healing concrete materials.
研究领域:
土木工程材料
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2023
·
IF 6.6
Wentao Wu,Liangyong Chu,Santiago J. Garcia,Sybrand van der Zwaag,Ming Li,Liming Shen,Ningzhong Bao
In this paper, graphene oxide (GO) modified microcapsules have been developed for use in self-healing Cardanol-based epoxy anti-corrosion coatings on steel substrates. The microcapsules had a polymethyl methacrylate (PMMA) shell, covered with aminated GO flakes and contained either of the two complementary healing agents mixed with nanosized GO flakes. One set of capsules contained epoxidized nanosized GO and Cardanol-based epoxy resin , while the other contained aminated nanosized GO and Cardanol-based amine curing agent. The microcapsules had a narrow size distribution with a peak value of 4 μm. The Cardanol-based coatings containing various fractions of up to 20 wt% microcapsules in their stoichiometric ratio showed excellent anti-corrosion and self-healing properties. FT-IR, XPS , AFM, and Raman spectroscopy were used to characterize the size and chemical composition of the GO. Optical microscopy and SEM were used for morphological characterization. Double cantilever test upon bulk samples showed an excellent load transfer across the fracture plane after only 1 day curing at room temperature. The anti-corrosion properties of the Cardanol-based coating containing the two-component microcapsules were tested using electrochemical impedance spectroscopy (EIS). It was found that, after 60-day immersion in 3.5 wt% NaCl solution, the low-frequency impedance modulus |Z| 0.01Hz of the Cardanol-based coating containing GO-modified microcapsules was three orders of magnitude higher than that of the systems with capsules without GO. After scratching the coating containing 20 wt% GO-modified microcapsules and exposing it to an aqueous 3.5 wt% NaCl solution, the |Z| 0.01Hz of the Cardanol-based coating returned over a period of 7 days to the original value.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2021
·Vol. 56
·期 31
·17527-17541
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IF 4.22
Xue Ying,Li Chunmei,Liu Jin,Tan Jiaojun,Yin Hangyu,Yao Laifeng,Zhang Qiuyu
Abstract Using microcapsules as the stabilizers of Pickering emulsion can endow the resulted composite capsules with more storage microcavities, producing new functional and structural materials, which have potential application in the preparation of self-healing microcapsules to achieve multiple healing. However, the preparation and wettability of microcapsule-type stabilizers (MTS) have not been systematically researched. Herein, a facile method to prepare MTS containing a liquid healing agent (dicyclopentadiene, DCPD) was proposed, which exhibited excellent emulsifying properties in Pickering emulsion. MTS with adjustable wettability were successfully prepared and used to fabricate Pickering emulsions with different oil phases. It was found that when the mass ratio of the hydrophobic shell monomer reached 100%, MTS possessed the best emulsifying property and the resulted Pickering emulsion could be stably stored for 30 days. Additionally, via solidifying the activity monomers of the oil droplets, composite capsules with multi-storage cells were successfully prepared which confirmed the strong stability of this emulsion and the appropriate wettability of MTS again, as well as pave a new path for the preparation of new architecture microcapsules. We expected that MTS will be found more useful in encapsulation fields, such as self-healing microcapsules, biological medicine, cosmetics, and textile. Graphical abstract
研究领域:
材料科学
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化学工程
·
功能材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2019
·Vol. 19
·期 1
·57-65
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IF 1.093
Liu Wolong,Zhang Jiupeng,Liu Qi,Pei Jianzhong,Zhu Cunzhen,Liu Peng
Micro-damages always occur and accumulate in asphalt pavement materials under the effects of temperature, vehicle loads and other factors during service. Accordingly, self-healing microcapsules could be added into asphalt binder and repair micro-damages to prevent damage extension in
time. In this study, the emulsified rejuvenator and melamine-urea-formaldehyde resin (MUF) were selected as the core and cyst wall materials, respectively, and in-situ polymerization method was applied to synthesize the novel microcapsules. The effects of emulsifier dosage and curing
time were revealed on the particle size, dispersion, surface morphology and coating properties, and the optimum process parameters were determined for microcapsules. Then, the micro morphology, molecular structure, and thermal stability were further investigated to determine the optimal preparation
of the microcapsules. Finally, the linear amplitude sweep (LAS) test was performed to evaluate the self-healing efficiency of the asphalt binder with different dosages of prepared microcapsule, and the optimal dosage of microcapsules was determined as 0.5%.
研究领域:
材料科学
·
土木工程
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）