シュウ酸カルシウムの過飽和溶液から CaC₂O₄・3H₂O 被膜の生成機構

抄録

The formation of calcium oxalate films on stainless steel from dilute aqueous solutions containing Ca²⁺ ions and dimethyl oxalate has been studied by measuring the precipitate rate of calcium oxalate in the solutions, and by the thermal analysis and the X-ray analysis of calcium oxalate in the films and of the precipitates in the solutions. It was found that the supersaturation of solutions was maintained during the film formation and the initiation of the film formation was not consistent with that of the precipitation of calcium oxalate. The solubility of calcium oxalate and the rate of the hydrolysis of dimethyl oxalate affected the degree of the supersaturation of calcium oxalate. The water content of crystallized calcium oxalate in the films was different from that of the precipitates in the solutions.