The smart releasing behavior of a microcapsule based on chemical self-healing system caused by chemical trigger activation

A novel chemical self-healing system based on microcapsule technology for cementitious composites is established in Guangdong Key Laboratory of Durability for Coastal Civil Engineering, Shenzhen University. The key issue of this system is how to release the healing material and how to activate the healing mechanism. In this paper, the study is focused on the releasing behavior. The smart releasing behavior of healing material in the microcapsule is characterized by EDTA (Ethylene Diamine Tetraacetic Acid) titration method. The experimental results show that releasing procedure of the corrosion inhibitor covered with PS is a function of the time, and is controlled by the wall thickness of the microcapsule. Moreover, the pH value affects the release rate of corrosion inhibitor. With the increasing of pH value, the releasing rate will increase greatly