Shu Benan, Wu Shaopeng, Dong Lijie, Wang Qing, Liu Quantao
State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China.
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China.
Materials (Basel). 2018 Apr 19;11(4):630. doi: 10.3390/ma11040630.
This work aims to develop an original alginate micro-emulsion combining with droplets microfluidic method to produce multinuclear Ca-alginate microcapsules containing rejuvenator for the self-healing of bituminous binder. The sizes of the Ca-alginate microcapsules could be easily controlled by tuning flow rates of the continuous and dispersed phases. The addition of a surfactant Tween80 not only improved the stability of the emulsion, but it also effectively reduced the size of the microcapsules. Size predictive mathematical model of the microcapsules was proposed through the analysis of fluid force. Optical microscope and remote Fourier infrared test confirmed the multinuclear structure of Ca-alginate microcapsules. Thermogravimetric analysis showed that the microcapsules coated with nearly 40% rejuvenator and they remained intact during the preparation of bitumen specimen at 135 °C. Micro self-healing process of bituminous binder with multinuclear Ca-alginate microcapsules containing rejuvenator was monitored and showed enhanced self-healing performance. Tensile stress-recovery test revealed that the recovery rate increased by 32.08% (in the case of 5% microcapsules), which meant that the Ca-alginate microcapsules containing rejuvenator could effectively enhance the self-healing property of bituminous binder.
本研究旨在开发一种原创的海藻酸钠微乳液，并结合液滴微流控方法来制备含有再生剂的多核海藻酸钙微胶囊，用于沥青结合料的自愈合。通过调节连续相和分散相的流速，可以轻松控制海藻酸钙微胶囊的尺寸。添加表面活性剂吐温80不仅提高了乳液的稳定性，还有效减小了微胶囊的尺寸。通过分析流体力，建立了微胶囊尺寸预测数学模型。光学显微镜和远红外傅里叶测试证实了海藻酸钙微胶囊的多核结构。热重分析表明，微胶囊包覆了近40%的再生剂，并且在135℃制备沥青试样的过程中保持完整。监测了含有再生剂的多核海藻酸钙微胶囊对沥青结合料的微自愈合过程，结果显示其自愈合性能得到增强。拉伸应力恢复试验表明，恢复率提高了32.08%（在微胶囊含量为5%的情况下），这意味着含有再生剂的海藻酸钙微胶囊能够有效提高沥青结合料的自愈合性能。
