硝酸银显色法变色边界处氯离子浓度的影响因素  

FACTORS INFLUENCING CHLORIDE CONCENTRATION AT THE COLOR CHANGE BOUNDARY USING AgNO_3 COLORIMETRIC METHOD

作　　者：何富强[1] 史才军[1] 元强[1] 郑克仁[1] 邹庆焱[1] 

机构地区：[1]中南大学土木建筑学院,长沙410075

出　　处：《硅酸盐学报》2008年第7期890-895,共6页Journal of The Chinese Ceramic Society

摘　　要：研究了砂浆的碱度和AgNO3溶液指示剂的浓度对测量砂浆变色边界Cl-浓度的影响。将AgNO3,NaOH及NaCl 3种物质混合,发现溶液中生成的沉淀反应产物中的AgCl的质量分数随溶液中OH-浓度的增加而减少、沉淀反应产物的颜色随AgCl的含量而变化。用0.100mol/L和0.035mol/L的AgNO3指示剂喷洒到按北欧标准NTBuild492进行电迁移试验之后的砂浆试件上,并测试试件变色边界Cl-浓度,结果表明:0.035mol/L的AgNO3指示剂比用0.100mol/L的AgNO3指示剂测试试件变色边界的Cl-浓度小,因此,0.035mol/L的AgNO3指示剂检测到的变色深度大些;变色边界处的Cl-浓度随砂浆的pH值升高而增大。The effects of alkali of the mortar specimens and the concentrations of AgNO3 solution indicator on the CI- concentration at the color change boundary of the specimens were investigated. When AgNO3, NaOH and NaCI solutions were mixed, the mass fraction of AgCI in the precipitated products decreased as the OIT concentration increased and the color of the precipitated products changed with the mass fraction of AgCI. Different mortar specimens after the NT Build492 testing were sprayed with 0.100 mol/L and 0.035 mol/L AgNO3 solutions respectively. The color depth change and the CI^- concentrations at the color change boundary were also measured. Compared with the use of 0.100 mol/L AgNO3 solution, the CI^- concentration at the boundary was lower and thus the color depth change was greater when 0.035 mol/L AgNO3 was used. The CF concentration at the color change boundary increased as the pH value of the mortar specimens was increased.

关 键 词：氯离子 硝酸银显色法 变色边界 PH值 硝酸银浓度 

分 类 号：TU528[建筑科学—建筑技术科学]