达克罗涂层中六价铬在不同介质中的析出规律

摘要

采用可见分光光度法研究了含铬达克罗涂层分别在NaCl、蒸馏水、Na2 SO4、NH4 Cl溶液中析出六价铬的规律.结果表明:达克罗涂层在40℃的不同浓度NaCl和Na2 SO4溶液中浸泡13 d时,六价铬仅有微量析出,其最大析出量分别为2.25μg.cm-2和8.56μg.cm-2;在40℃的蒸馏水和不同浓度NH4Cl溶液中浸泡13 d时,六价铬析出量几乎为0,涂层显示出了良好的稳定性.%Precipitation law of hexavalent chromium from dacromet coating containing Cr in NaCl,distilled water,Na2 SO4 and NH4 Cl solutions,respectively,were studied by visible spectrophotometry.The results show that when the dacromet coating was immersed in the different-concentration NaCl or Na2 SO4 solutions at 40 ℃ for 13 d,the hexavalent chromium precipitated slightly,with the maximum precipitated mass of 2.25 μg.cm-2 and 8.56μg.cm-2 ,respectively.When immersed in distilled water and different-concentration NH4 Cl solution at 40 ℃for 13 d,the precipitated mass of the hexavalent chromium was nearly zero,indicating an excellent stability of the coating.