溶解
铝酸盐
解吸
吸附
离解(化学)
水泥
化学物理
协调球
硅酸盐水泥
离子
从头算
材料科学
离子交换
化学
化学工程
物理化学
有机化学
冶金
工程类
作者
Mingli Cao,Shuming Wen,Qingliang Yu,Zhaoyang Sun,Guotao Qiu,Mingli Cao,Yunjian Li,Zongjin Li
标识
DOI:10.1038/s41467-024-47164-0
摘要
Portland cement (PC) is ubiquitously used in construction for centuries, yet the elucidation of its early-age hydration remains a challenge. Understanding the initial hydration progress of tricalcium aluminate (C3A) at molecular scale is thus crucial for tackling this challenge as it exhibits a proclivity for early-stage hydration and plays a pivotal role in structural build-up of cement colloids. Herein, we implement a series of ab-initio calculations to probe the intricate molecular interactions of C3A during its initial hydration process. The C3A surface exhibits remarkable chemical activity in promoting water dissociation, which in turn facilitates the gradual desorption of Ca ions through a metal-proton exchange reaction. The dissolution pathways and free energies of these Ca ions follow the ligand-exchange mechanism with multiple sequential reactions to form the ultimate products where Ca ions adopt fivefold or sixfold coordination. Finally, these Ca complexes reprecipitate on the remaining Al-rich layer through the interface-coupled dissolution-reprecipitation mechanism, demonstrating dynamically stable inner-sphere adsorption states. The above results are helpful in unmasking the early-age hydration of PC and advancing the rational design of cement-based materials through the bottom-up approach.
科研通智能强力驱动
Strongly Powered by AbleSci AI