| We studied chemical species formed on copper foil surface immersed in solutions containing various organic molecules such as formamide, ammonia, and N-isopropylacrylamide (NIPAM). Copper foils were kept in a glass vial containing aqueous solution over a week at room temperature. The copper foil immersed in an aqueous solution of formamide showed flower-like structures with the diameter of ca. 80μm. The flower-like crystals consisted of Cu(OH)<sub>2</sub>・H<sub>2</sub>O. When immersed in ammonia water, bundles of a few dozen of microplatelets formed. The microplatelets consisted of Cu(OH) <sub>2</sub>. Interestingly, Cu<sub>2</sub>O microcrystals formed in a NIPAM solution. The microcrystals showed systematic shape evolution from cubic to octahedron with increased immersed time. |