Thin water films and magnesium hydroxide fiber growth
Thin water films and magnesium hydroxide fiber growth
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DOI：
10.1039/c5ra18202f
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发表时间：
2015-01-01
期刊：
影响因子：
3.9
通讯作者：
Diwald, Oliver
中科院分区：
文献类型：
--
作者：
Gheisi, Amir;Sternig, Andreas;Diwald, Oliver
水薄膜覆盖高度分散的金属氧化物可以引起氢氧化物纤维在环境空气中的自发和空间可控的生长。有关基本形成机制的知识是合理开发金属氧化物纳米材料和相关微观结构的关键。我们使用SiCl 4作为无水氯离子源用于MgO纳米立方体的表面功能化，并探索它们在与水蒸气接触时随后转化为氯氧镁Mg-3（OH）（5）Cl中心点4 H（2）O纤维。具体来说，我们展示了官能化过程和材料分散的温度如何控制反应途径，从而产生非常不同的产物，如Mg（OH）（2）、MgCl 2中心点6 H（2）O或Mg-3（OH）（5）Cl中心点4 H（2）O，并描绘了反应机理。从这种在环境条件下形成氢氧化物纤维的独特途径中吸取的教训可以应用于各种微观结构演变过程，这些过程涉及亚稳固体和表面水作为反应物和金属氧化物颗粒水合的反应介质。
Thin films of water covering highly dispersed metal oxides can give rise to the spontaneous and spatially controllable growth of hydroxide fibers in ambient air. Knowledge about the underlying formation mechanisms is key to the rational development of metal oxide nanomaterials and associated microstructures. We used SiCl4 as a water free chlorine ion source for the surface functionalization of MgO nanocubes and explored their subsequent transformation into magnesium oxychloride Mg-3(OH)(5)Cl center dot 4H(2)O fibers upon contact with water vapor. Specifically we show how the temperature of the functionalization process and material dispersion control the reaction pathway that can lead to very different products like Mg(OH)(2), MgCl2 center dot 6H(2)O, or Mg-3(OH)(5)Cl center dot 4H(2)O and delineate a reaction mechanism. Lessons to be learned from this unique route to form hydroxide fibers under ambient conditions can be applied to a variety of microstructural evolution processes that involve metastable solids and superficial water acting both as a reactant and as a reaction medium for the hydration of metal oxide particles.