Transient Phase of Ice Observed by Sum Frequency Generation at the Water/Mineral Interface During Freezing

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• 作者：Kaitlin A. Lovering ; Allan K. Bertram ; Keng C. Chou
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2017
• 出版时间：February 16, 2017
• 年：2017
• 卷：8
• 期：4
• 页码：871-875
• 全文大小：336K
• ISSN：1948-7185

文摘

We observed a transient noncentrosymmetric phase of ice at water/mineral interfaces during freezing, which enhanced the intensity of the IR-visible sum frequency generation intensity by up to 20-fold. The lifetime of the transient phase was several minutes. Since the most stable form of ice, hexagonal and cubic ice, are centrosymmetric, our study suggests the transient existence of stacking-disordered ice during the freezing process at water/mineral interfaces. Stacking-disordered ice, which has only been observed in bulk ice at temperatures lower than −20 °C, is a random mixture of layers of hexagonal ice and cubic ice. However, the transient phase at the ice/mineral interface was observed at temperatures as high as −1 °C. It suggests that the mineral surface may play a role in promoting and stabilizing the formation of stacking-disordered ice at the interface.