Formation Mechanism of Combined Crystals and Applications to Development of New Functional Materials

在以前的研究中，我们观察到氯化钾晶体在氯化钠表面与过饱和NaCl-KCl-H_2水溶液接触时自发成核，形成复合晶体。本研究的目的是阐明形成的机制，并探讨其应用于新的功能材料的可能性。对于NaCl-KCl-H_2O三元体系，在NaCl基质稳定生长过程中，氯化钾自发成核被诱导。清楚地观察到氯化钾晶体在氯化钠基质晶体上的沉积，并且发现沉积的晶体处于相同的取向。通过观察放置在含有氯化钾并且相对于氯化钠不饱和的水溶液中的氯化钠底物晶体的溶解表面，观察到氯化钾的成核。成核作用是由 ...更多信息 由于氯化钠溶解到母液中而产生的局部高过饱和度。用分子动力学模拟方法研究了氯化钠晶体与NaCl-KQ-H_2O三元溶液固液界面附近的溶液结构，以阐明复合晶体的形成机理。固液界面附近的溶液结构和局部组成与母液完全不同。在氯化钠基体与氯化钾存款界面处观察到浅槽的形成，且槽的宽度和深度较大，形状随时间变化。这可能是因为凹槽的结构不稳定，因此受到水分的影响。在NaNO_ 3-KNO_3-H_2O和NaCl-KNO_3- H_2O三元体系中也观察到了复晶的形成，这一结果将有助于复晶在新型功能材料中的应用。少

We, in the previous studies, observed the formation of combined crystals by the spontaneous nucleation of potassium chloride crystals on the surfaces of sodium chloride contacted with supersaturated NaCl - KC1 - H_2Oernary solutions. The present study aims to elucidate the mechanism of formation of the combined crystals and to investigate their possibilities of applications to new functional materials. For the NaCl - KC1 -H_2Oternary system, spontaneous nucleation of potassium chloride was induced during the steady growth of NaCl substrate. Deposition of potassium chloride crystals on the sodium chloride substrate crystals was clearly observed and the crystals deposited were found to be in the same orientation. From the observation of dissolving surfaces of sodium chloride substrate crystals placed in aqueous solutions that contained potassium chloride and were undersaturated with respect to sodium chloride, nucleation of potassium chloride was observed. The nucleation was caused by th … More e local high supersaturation created by the dissolution of sodium chloride into the mother liquor. The solution structures near the solid-liquid interface between sodium chloride crystals and NaCl - KQ - H_2Oternary solutions were studied by molecular dynamics simulations to elucidate the mechanism of formation of the combined crystals. The solution structures and the local compositions near the solid-liquid interfaces were completely different from those of the mother liquors. The formation of shallow grooves at the interface between sodium chloride substrate and potassium chloride deposit was observed, and the width and depth of the grooves were larger and the shape changed with time. This would be because the structure of the grooves was unstable and was therefore affected by moisture. The formation of combined crystals were also observed for the NaNO_ 3-KNO_3 -H_2O and NaCl - KNO_3 - H_2O ternary systems, and this result will be useful for the applications of the combined crystals to the new functional materials. Less