The role of Al in C-S-H: NMR, XRD, and compositional results for precipitated samples
The role of Al in C-S-H: NMR, XRD, and compositional results for precipitated samples
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DOI：
10.1016/j.cemconres.2005.03.002
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发表时间：
2006-01-01
影响因子：
11.4
通讯作者：
Kirkpatrick, RJ
中科院分区：
文献类型：
--
作者：
Sun, GK;Young, JF;Kirkpatrick, RJ
通过X射线衍射、成分分析以及Si-29和Al-27 MAS NMR谱研究了由溶液沉淀法制备的Al取代的雪硅钙石型C-S-H，为了解Al取代在这一重要而复杂的相中的结构机制提供了新的见解。Al以4-、5-和6-配位（Al[4]、Al[5]和Al[6]）存在，并发挥多种结构作用。Al[4]存在于干燥的硅酸铝链的桥连四面体上，Al[5]和Al[6]存在于中间层和颗粒表面。铝既不进入中央的钙-氧片，也不进入雪硅钙石型层的配对四面体。Al[4]存在于三种类型的桥接位点上，Q（3）位点跨层桥接; Q（2）位点通过层间Ca+2、Na+或H+进行电荷平衡;以及Q（2）位点最可能通过Al[4]-O-Al[5，6]键通过层间或表面Al[5]和Al[6]进行电荷平衡。虽然这里提供的数据是相对结晶良好的雪硅钙石型C-S-H与C/S比
X-ray diffraction, compositional analysis, and Si-29 and Al-27 MAS NMR spectroscopy of Al-substituted tobermorite-type C-S-H made by precipitation from solution provide significant new insight into the structural mechanisms of Al-substitution in this important and complicated phase. Al occurs in 4-, 5-, and 6-coordination (Al[4], Al[5], and Al[6]) and plays multiple structural roles. Al[4] occurs on the bridging tetrahedra of the drierkette Al-silicate chains, and Al[5] and Al[6] occur in the interlayer and perhaps on particle surfaces. Al does not enter either the central Ca-O sheet or the pairing tetrahedra of the tobermorite-type layers. Al[4] occurs on three types of bridging sites, Q(3) sites that bridge across the interlayer; Q(2) sites that are charge balanced by interlayer Ca+2, Na+, or H+; and Q(2) sites that are most likely charge balanced by interlayer or surface Al[5] and Al[6] through Al[4]-O-Al[5,6] linkages. Although the data presented here are for relatively well-crystallized tobermorite-type C-S-H with C/S ratios