[M-IS11] [EJ] 結晶成長、溶解における界面・ナノ現象

[MIS11-04] 溶解する炭酸カルシウム近傍におけるpH変化の２次元イメージング

*川野 潤¹、西村 楓¹、豊福 高志²、長井 裕季子²、河田 佐知子²、Teng Henry³、永井 隆哉¹ (1.北海道大学、2.海洋研究開発機構、3.ジョージワシントン大学)

キーワード：pH、炭酸カルシウム、溶解

To understand the growth and dissolution mechanism of minerals, the pH monitoring of a solution is a useful technique. Actually a number of the previous studies has performed the pH measurements of bulk solution during the growth. However, to clarify the detail process on the surface, regional change of pH just above the crystal surface should be monitored. In the present study, we have tried to obtain two dimensional images of pH change around CaCO₃ crystals which inorganically grows or dissolves, by using the fluorescent probe 8-hydroxypyrene-1,3,6-trisul-fonic acid (HPTS) which has been applied for the research on the biogenic calcification of foraminifers. As a result, we succeeded to visualize the two dimensional distribution of pH around dissolved CaCO₃ crystal and its change with time, where pH increases above its surface. The results obtained by this technique may provide new insights into not only inorganic growth/dissolution mechanism of CaCO₃, but also the vital effect on the biomineralization by comparing with the results for bio-related process.