吸水性微胶囊界面修饰提高水泥基材料抗渗性研究

在自修复水泥基材料中,微胶囊与水泥基体间的界面结合决定着微胶囊被裂缝触发的概率,从而影响自修复效果。本文针对吸水性微胶囊的界面结合问题,利用硅烷偶联剂KH550修饰环氧/海藻酸钙微胶囊表面,以改善其与水泥基体间的界面结合情况。采用X射线光电子能谱仪、电感耦合等离子体发射光谱仪等表征硅烷偶联剂在微胶囊表面的键合状况,利用压汞法分析水泥基材料的孔结构,并测试水泥基材料的抗渗性与自修复效果。结果表明,硅烷偶联剂能够与微胶囊外壁的海藻酸钙发生化学键合,微胶囊与水泥基体间的界面结合得到有效改善,水泥基体中有害孔数量减少,无害孔和少害孔数量增加,水泥基材料的抗渗性和自修复效果获得提升。

Interface Modification of Water Absorbent Microcapsules to Improve Impermeability of Cement-Based Materials

In self-healing cement-based materials, the interface between microcapsules and cement matrix determines the probability of microcapsules triggered by cracks, which affects the self-healing effect. Aiming at the interface bonding problem of water absorbent microcapsules, the surface of epoxy/calcium alginate microcapsules was modified with silane coupling agent KH550 to improve the interface bonding between calcium alginate microcapsules and cement matrix. The X-ray photoelectron spectrometer and inductively coupled plasma emission spectrometer were used to characterize the bonding condition of silane coupling agent on the surface of microcapsules. The pore structure of cement-based materials was analyzed by mercury injection method, and the impermeability and self-healing effect of cement-based materials were tested. The results show that the silane coupling agent forms the chemical bonding with the calcium alginate on the outer wall of the microcapsule. The interface between the microcapsules and the cement matrix is effectively improved. The number of harmful pores in the cement matrix is reduced, and the number of harmless and less harmful pores increases. The impermeability and self-healing effect of cement-based materials are improved.