CHINESE JOURNAL OF POLYMER SCIENCE
·
2019
·Vol. 38
·期 1
·45-52
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IF 2.804
Song Yan,Chen Kai-Feng,Wang Jing-Jing,Liu Yuan,Qi Tao,Li Guo Liang
One-component, catalyst-free self-healing coatings with double-shelled polymer microcapsules have drawn considerable attention due to wide applications. In this work, the synthesis parameters of double-shelled polymer microcapsules and the mechanism of the self-healing process were systematically investigated. Apart from the chemical structure of the microcapsule shell, the shell thickness, the microcapsule size, and the core fraction could affect the self-healing anticorrosion properties. The synthesis parameters were further optimized in terms of the agitation rate, pH, weight ratio of core to shell, and temperature. Under these conditions, the microcapsule shell consisting of a rough surface formed by poly(urea-formaldehyde) and a smooth inner wall by polyurethane was prepared. The size of the microcapsules and core fraction were calculated to be approximately 30 μm and 75%, respectively. The self-healing anticorrosion coating incorporating as-synthesized microcapsules exhibited corrosion resistance in artificially scratched areas, which was further characterized by electrochemical impedance spectroscopy.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2023
·Vol. 13
·期 11
·7385-7391
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IF 3.9
Wenyan Chen,Shuen Liang,Yan Peng,Yixia Wang,Tao Liu
In this study, we report on a novel and effective approach for the encapsulation of the shear thickening fluid in polyurethane polyurea double layer microcapsules. Under the action of dibutyltin disilicate as a catalyst, CD-MDI reacted with polyethylene glycol to form polyurethane inner shell and reacted with diethylenetriamine to form a polyurea outer shell. The results show that the shear thickening liquid was emulsified using liquid paraffin as a solvent and Span80 as a surfactant to form a lotion similar to water-in-oil. The shear thickened droplets can be stably and uniformly dispersed to a diameter of 100 μm at a rotation speed of 800 rpm min−1. The bilayer shell material achieves a good coating effect on STF, which provides support for strength and stress conduction and improves the compatibility between STF and polyurea matrix. The toughness and impact resistance of the composites were analyzed by a universal testing machine and drop hammer impact tester. Finally, compared with the pure polyurea material, the elongation at break of 2% added amount is increased by 22.70%, and the impact resistance of 1% added amount is the best, which is 76.81 N more than that of the pure specimen.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
KEY ENGINEERING MATERIALS
·
2019
·
IF 0
Yan Xuan Ma,Yingrui Zhang,Jia Tong Liu,Meng Yao Li,Ya Qian Xu
The effectiveness of preploymer and 1,6-Hexamethylene diamine encapsulated by double-walled microcapsules based polyurea (PUA) was explored for healing the cracks generated in epoxy coatings. Double-walled microcapsules were systhesized by interfacial polymerization at the interface between the prepolymer droplets and the 1,6-Hexamethylene diamine droplets to form the polyurea shell. The effect of synthetic stirring speed on the morphology of the microcapsules was observed by scanning electronmicroscopy (SEM) and optical microscopy (OM). The chemical structure as well as the thermal properties and the core content were characterized by Fourier transform infrared spectroscopy (FTIR) and Thermogravimetric analyzer (TGA) respectively. Electrochemical impedance spectroscopy (EIS) studies of the artificial scratched area showed that the coating containing 2wt% and 5wt% microcapsules could effectively prevent further corrosion of the coating with high corrosion resistance efficiencies of 61.61% and 45.99% after immersing for 144h in seawater.
研究领域:
材料科学
·
腐蚀与防护
·
表面工程
✓ 已验证
产品关联
DOI
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Zhihui Zhu,Xuanzhe Zhang,Kaijin Guo,Mengfei Wang,Xianfeng Wang,Guangming Zhu
Microcapsules have been widely used in the field of self-healing anticorrosion. By adding self-healing microcapsules, the coating's anticorrosion performance can be enhanced, and its service life can be extended. This study suggests a novel method for creating biomimetic mineralized microcapsules. Organic-inorganic double-walled microcapsules using benzotriazole and flaxseed oil as core ingredients were effectively made by combining the biomimetic mineralization method and photopolymerization technology. The outside layer was a titanium dioxide inorganic shell while the inner layer was a polyepoxy acrylate shell. Our approach uses photopolymerization technology to finish the inner organic wall, which changes the organic wall and effectively encapsulates the core material. A biomimetic mineralization technique was then used to create a second layer of inorganic wall on the microcapsules' surface. Following biomimetic mineralization, biomimetic mineralized double-walled microcapsules exhibit exceptional mechanical, solvent, and thermal durability when compared to single-layer organic microcapsules. The biomimetic mineralization microcapsules had exceptional solvent barrier performance in the solvent resistance test, and the solvent release rate was three times lower than that of the single-layer organic microcapsules. After applying the biomimetic mineralized microcapsules to the epoxy resin coating, scratch and corrosion resistance tests were performed. The coating's outstanding corrosion resistance and self-healing capabilities indicated its potential for use in self-healing anticorrosive coatings.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2024
·
IF 8.1
Quanqing Cui,Na Sun,Hongliang Ding,Xiaowei Mu,Wei Wang,Yan Zhang,Keqing Zhou,Liancong Wang,Bin Yu
The flammable nature of thermoplastic elastomer (TPE) leads to poor fire safety performance. It is difficult to be flame-retardant. A large amount of flame retardant (30–46 wt%) is usually added, weakening their mechanical properties heavily. To address these issues, this study prepared a novel core–shell flame retardant, PAPP@MF@TA, by encapsulating melamine formaldehyde resin (MF) and tannic acid (TA) on the surface of piperazine pyrophosphate (PAPP). Benefiting by the bridging effect of the core–shell structure, the compatibility between TPE and PAPP@MF@TA was improved, and the tensile strength of TPE/PAPP@MF@TA increased by 25.6% compared to TPE/PAPP. The flame-retardant performance was also enhanced. Compared to pure TPE, the peak heat release rate, total heat release and total smoke production of TPE/PAPP@MF@TA decreased by 73.7%, 37.9% and 35.5%, respectively. Besides, the flame-retardant mechanism was studied. This study provides a new approach for designing of TPE composites with comprehensively enhanced flame retardancy and mechanical properties.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Nano
·
2024
·
IF 15.8
Wen Li,Yichen Liu,Xiaoming Zheng,Jing Han,Anchen Shi,Chi Chun Wong,Ruochen Wang,Xunan Jing,Yan Li,Shu Fan,Cuiyu Zhang,Yinnan Chen,Gang Guo,Jun Yu,Junjun She
Intestinal dysbiosis and the associated l-tryptophan metabolic disorder are pivotal in inflammatory bowel disease progression, leading to a compromised intestinal barrier integrity. Remedying the dysfunction in tryptophan metabolism has emerged as a promising therapeutic strategy. Herein, we reprogram the tryptophan metabolism in situ by EcN-TRP@A/G, encapsulating the engineered probiotic, EcN-TRP, with enhanced tryptophan synthesis capacity, for sustained modulation, thereby restoring intestinal barrier function and microbial homeostasis. The pH-responsive dual-layered EcN-TRP@A/G microcapsule developed via high-voltage electrospraying and liquid interface self-assembly, preserved probiotic viability in the harsh gastrointestinal milieu, and facilitated targeted colon release. Bioluminescent tracking in mice reveals a 22.84-fold increase in EcN-TRP@A/G viability and distribution compared to naked EcN-TRP. Targeted metabolomics highlights EcN-TRP@A/G’s modulation of the tryptophan–indole pathway. Oral administration of EcN-TRP@A/G sustained elevates indole metabolites, particularly indole-3-acetic acid and indole-3-propionic acid, in colon tissue for up to 7 days. In IBD mice, EcN-TRP@A/G improves intestinal permeability, reduces inflammation, and recovers the gut microbiome by enhancing beneficial bacteria abundance like Prevotellaceae_UCG-001 and Anaerostipes while suppressing pathogenic strains like Escherichia–Shigella. Our findings offer a cost-effective approach, harnessing the probiotic metabolic potential in situ through engineered modifications for effective IBD treatment.
研究领域:
胃肠病学
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微生物学
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药学
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生物技术
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）