摘要
制备了新型聚多巴胺/甲酸钙复合速凝剂来实现喷射混凝土的快速凝结。红外结果表明,在水泥浆搅拌过程中,多巴胺与氧气发生氧化自聚合反应生成聚多巴胺。扫描电镜结果显示水化10分钟,含有速凝剂的水泥浆体中的氢氧化钙和钙钒石晶体表面生长出柱状钙钒石枝晶。当速凝剂掺量为0.075%时,水泥浆体初凝时间由118 min 45 s缩短至3 min 51 s,终凝时间由212 min 45 s缩短至10 min 7 s。水泥砂浆1天和28天抗压强度分别达到7.36 MPa和31.31 MPa,可以满足建筑工程的要求。机理分析,甲酸钙电离产生甲酸根离子吸附在氢氧化钙和钙钒石晶体上并引导聚多巴胺沉积在其表面。
This study prepared a novel polydopamine/calcium formate accelerator to achieve rapid setting of shotcrete.The infrared spectrum results show that the dopamine reacts with O2 to produce polydopamine via the oxidative self-polymerization.The results of scanning electron microscope shows that cylindrical ettringite dendrites grows on the surface of calcium hydroxide and ettringite at the 10 min of hydration.When the dosage is 0.075%,the initial setting time of cement paste is shortened from 118 min 45 s to 3 min 51 s.The final setting time is shortened from 212 min 45 s to 10 min 7 s.The 1 day and 28 days compressive strength of cement mortar can reach 7 MPa and 33.6 MPa respectively,which can meet the requirements of construction engineering.The mechanism analysis suggests that the ionization of calcium formate produces formate ions.These ions are adsorbed to the surface of crystals of calcium hydroxide and ettringite.This directs the deposition of polydopamine on these surfaces.
作者
李佳霖
周珊珊
黄月文
王斌
LI Jialin;ZHOU Shanshan;HUANG Yuewen;WANG Bin(Guangzhou Institute of Chemistry,Chinese Academy of Sciences,Guangzhou 510650,China;University of Chinese Academy of Sciences,Beijing 100049,China;CAS Engineering Laboratory for Special Fine Chemicals,Chinese Academy of Sciences,Guangzhou 510650,China;CASH GCC Shaoguan Research Institute of Advanced Materials,Shaoguan 512400,China;CASH GCC(Nanxiong)Research Institute of Advanced Materials Co.,Ltd.,Nanxiong 512400,China)
出处
《广州化学》
2025年第4期33-39,共7页
Guangzhou Chemistry
关键词
速凝剂
聚多巴胺
甲酸钙
水泥
吸附
accelerator
polydopamine
calcium formate
cement
adsorption
