Dehydration and crystallization of amorphous calcium carbonate in solution and in air.
Dehydration and crystallization of amorphous calcium carbonate in solution and in air.
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DOI：
10.1038/ncomms4169
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发表时间：
2014
影响因子：
16.6
通讯作者：
Meldrum FC
中科院分区：
文献类型：
--
作者：
Ihli J;Wong WC;Noel EH;Kim YY;Kulak AN;Christenson HK;Duer MJ;Meldrum FC
无定形中间体转化为结晶材料的机制知之甚少。目前，吸引巨大兴趣的是无定形碳酸钙的结晶，无定形碳酸钙是合成、生物和环境系统中的关键中间体。在这里，我们试图通过详细调查这一过程来统一许多对比鲜明和明显矛盾的研究。我们表明，无定形碳酸钙可以结晶前，在溶液和空气中，而热分析和固态核磁共振测量显示，它的水是存在于不同的环境。最后的水部分的损失-包含少于15%的总量-然后触发结晶。这一步的高活化能表明，它发生的部分溶解/重结晶，介导的表面水，和大部分的颗粒，然后通过固态转变结晶。这种机制很可能在固态反应中广泛存在，它们的特性将有助于对这些过程进行更好的控制。 无定形碳酸钙的结晶是一个广泛研究的过程。在这里，作者探索的机制，并表明，转化为方解石之前的脱水，即使在溶液中，和最终的水部分的损失触发结晶。
The mechanisms by which amorphous intermediates transform into crystalline materials are poorly understood. Currently, attracting enormous interest is the crystallization of amorphous calcium carbonate, a key intermediary in synthetic, biological and environmental systems. Here we attempt to unify many contrasting and apparently contradictory studies by investigating this process in detail. We show that amorphous calcium carbonate can dehydrate before crystallizing, both in solution and in air, while thermal analyses and solid-state nuclear magnetic resonance measurements reveal that its water is present in distinct environments. Loss of the final water fraction—comprising less than 15% of the total—then triggers crystallization. The high activation energy of this step suggests that it occurs by partial dissolution/recrystallization, mediated by surface water, and the majority of the particle then crystallizes by a solid-state transformation. Such mechanisms are likely to be widespread in solid-state reactions and their characterization will facilitate greater control over these processes. The crystallization of amorphous calcium carbonate is a widely studied process. Here, the authors probe the mechanism and show that transformation to calcite is preceded by dehydration, even in solution, and that loss of the final water fraction triggers crystallization.
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影响因子：
2.1
作者：
Adnadevic, Borivoje;Mojovic, Zorica;Jovanovic, Jelena
通讯作者：
Jovanovic, Jelena
影响因子：
3
作者：
Bentov, Shmuel;Weil, Simy;Berman, Amir
通讯作者：
Berman, Amir
DOI：
10.1098/rspb.1997.0066
发表时间：
1997-03-22
影响因子：
4.7
作者：
Beniash, E;Aizenberg, J;Weiner, S
通讯作者：
Weiner, S
影响因子：
19
作者：
Cantaert, Bram;Kim, Yi-Yeoun;Meldrum, Fiona C.
通讯作者：
Meldrum, Fiona C.
影响因子：
1.4
作者：
Günther, C;Becker, A;Epple, M
通讯作者：
Epple, M