Predesigning matrix-directed super-hydrophobization and hierarchical strengthening of cement foam

TY - JOUR

T1 - Predesigning matrix-directed super-hydrophobization and hierarchical strengthening of cement foam

AU - She, Wei

AU - Zheng, Zhihao

AU - Zhang, Qunchao

AU - Zuo, Wenqiang

AU - Yang, Jingxian

AU - Zhang, Yunsheng

AU - Zheng, Li

AU - Hong, Jinxiang

AU - Miao, Changwen

N1 - Funding Information: Authors gratefully acknowledge the financial support from National Natural Science Foundation of China ( 51890904 ) and National Key Research and Development Program of China ( 2017YFB0309904 ). Publisher Copyright: © 2020 Elsevier Ltd

PY - 2020/5

Y1 - 2020/5

N2 - The thermodynamically unstable nature of aqueous foam is a challenging problem for fabrication of ultra-lightweight foamed cement-based materials. Such materials are also facing many durability problems due to their hydrophilic property and porous microstructure. In this study, a matrix superhydrophobic cement foam with high specific strength was developed by a one-step process. The rational tomographic and chemical properties of the border-air interfaces of cement foam were simultaneously modified by a nanohybrid method, in which the nano silica was grafted with water repellent functional group, promoting the adsorption of nano silica onto the air-liquid interfaces. The joint effect of increased multi-scale roughness and hydrophilization of the interfaces produced bulk superhydrophobic cement foam, which revealed excellent mechanical robustness even upon major surface damage. Such foamed cement is of great importance for industrial thermal insulation applications, and potentially provide a solution to the long-standing durability problems of cement based porous materials.

AB - The thermodynamically unstable nature of aqueous foam is a challenging problem for fabrication of ultra-lightweight foamed cement-based materials. Such materials are also facing many durability problems due to their hydrophilic property and porous microstructure. In this study, a matrix superhydrophobic cement foam with high specific strength was developed by a one-step process. The rational tomographic and chemical properties of the border-air interfaces of cement foam were simultaneously modified by a nanohybrid method, in which the nano silica was grafted with water repellent functional group, promoting the adsorption of nano silica onto the air-liquid interfaces. The joint effect of increased multi-scale roughness and hydrophilization of the interfaces produced bulk superhydrophobic cement foam, which revealed excellent mechanical robustness even upon major surface damage. Such foamed cement is of great importance for industrial thermal insulation applications, and potentially provide a solution to the long-standing durability problems of cement based porous materials.

KW - Foamed cement

KW - Hierarchical structure

KW - Interfacial modification

KW - Nanohybrid

KW - Robust superhydrophobic

UR - https://www.scopus.com/pages/publications/85080982803

U2 - 10.1016/j.cemconres.2020.106029

DO - 10.1016/j.cemconres.2020.106029

M3 - Article

AN - SCOPUS:85080982803

SN - 0008-8846

VL - 131

JO - Cement and Concrete Research

JF - Cement and Concrete Research

M1 - 106029

ER -