基于碳酸钙标记的水泥基材料裂缝自修复表征  

Characterization of Self-healing Cracks in Cement-based Materials Based on Labled Calcium Carbonate

作　　者：陈沁文 苏依林 李敏[1,2,3] 钱春香[1,2,3] CHEN Qinwen;SU Yilin;LI Min;QIAN Chunxiang(College of Materials Science and Engineering,Southeast University,Nanjing 211189,China;Research Institute of Green Construction Materials,Southeast University,Nanjing 211189,China;Key Laboratory of Microbial Technology in Building Materials Industry,Southeast University,Nanjing 211189,China)

机构地区：[1]东南大学材料科学与工程学院,南京211189 [2]东南大学绿色建筑材料研究中心,南京211189 [3]东南大学中国建材行业微生物技术重点实验室,南京211189

出　　处：《材料导报》2021年第14期14045-14051,共7页Materials Reports

基　　金：国家自然科学基金重点项目(51738003)。

摘　　要：为表征微生物自修复水泥基材料裂缝修复深度,提出两种微生物矿化产物碳酸钙的标记方法。一是吸附Cu^(2+)法,通过生物碳酸钙吸附Cu^(2+)在其表面形成碱式碳酸铜进行标记;二是掺杂Eu^(3+)法,通过在生物碳酸钙中掺杂Eu^(3+)形成具有发光性能的CaCO_(3)∶Eu^(3+)进行标记。采用XRD对溶液和水泥基材料中标记前后的生物碳酸钙进行分析,再利用荧光激发和发射光谱对溶液和水泥基材料中掺杂Eu^(3+)的生物碳酸钙进行分析,采用X射线计算机断层成像技术(X-CT)对两种方法标记后的水泥基材料进行表征。结果表明:在Cu^(2+)浓度为12.5 mg/mL,温度为25℃,吸附3 h的条件下,吸附Cu^(2+)标记生物碳酸钙效果最好;在Eu^(3+)掺量为2%,温度为45℃,掺杂48 h的条件下,掺杂Eu^(3+)标记生物碳酸钙效果最好。两种方法对微生物自修复水泥基材料修复深度的评价结果均为3 mm,与热重分析检测结果趋于一致。吸附Cu^(2+)和掺杂Eu^(3+)的方式均能够标定修复产物,且能准确地表征水泥基材料的修复深度。In order to characterize the crack repair depth of mocrobial self-healing cement-based materials,two methods were proposed to characterize calcium carbonate,the mineralized product of microorganisms.One method was to adsorb Cu^(2+) by biological calcium carbonate and form basic copper carbonate mark on its surface.Another method was to label the mineralized products by doping Eu^(3+) to form CaCO_(3)∶Eu^(3+).XRD was used to analyze biocarbonate before and after labeling in solution and cement-based materials.Fluorescence excitation and emission spectroscopy were used to analyze the calcium carbonate doped with Eu^(3+).X-CT was used to characterize the cement-based materials labeled by two methods.The results showed that:under the condition of 12.5 mg/mL Cu^(2+),25℃,and 3 h,the adsorption effect of Cu^(2+) labeled biocarbonate was the best.Under the condition of 2% Eu^(3+),45℃and 48 h,the effect of labeling biocarbonate with Eu^(3+) was best.The evaluation results of the two methods on the repair depth were 3 mm,which were consistent with the results of thermogravimetric analysis.By adsorption of Cu^(2+) and doping of Eu^(3+),the products can be calibrated and the repair depth of cement-based materials can be characterized with good accuracy.

关 键 词：生物碳酸钙 修复产物标定 离子掺杂 水泥基材料裂缝表征 

分 类 号：TU526[建筑科学—建筑技术科学]