水合物
硅酸盐
雪硅钙石
材料科学
化学工程
水溶液
离子交换
作者
Ellina Bernard,Yiru Yan,Barbara Lothenbach
标识
DOI:10.1016/j.cemconres.2021.106393
摘要
Abstract The binding of alkalis and calcium to calcium silicate hydrate (C-S-H) can be measured by cation exchange using cobalt hexamine solution with adapted pH. The effective cation exchange capacity (CEC) decreased at higher Ca/Si in C-S-H. A maximum of chargeexch/Si of 0.08–0.10 was measured at Ca/Si = 0.8 decreasing to 0.01–0.02 at Ca/Si = 1.6. At high Ca/Si, only a minor fraction of Ca was present at exchangeable sites, while most of the Ca2+ present in interlayer or surface was specifically bound and thus not exchangeable. In contrast, sodium was present only at exchangeable sites in the C-S-H, more at low than at high Ca/Si. An increase of pH in the presence of 100 mmol/L NaOH increased the effective CEC of C-S-H by 5–10% indicating a limited influence of pH on the deprotonation of the silanol groups.
科研通智能强力驱动
Strongly Powered by AbleSci AI