摘要
以有机羧酸为添加剂,研究了聚丙烯酸(PAA)、柠檬酸(CA)在半水硫酸钙(HCS)表面的吸附作用和吸附机理。采用总有机碳分析仪(TOC)分析添加剂在HCS表面的吸附特征,用透射电镜-能量损失谱(TEM-EELS)、X射线电子能谱(XPS)、激光显微拉曼光谱、傅里叶红外光谱(FTIR)等微观表征方法对吸附层结构进行分析,最后结合HCS晶体结构探讨添加剂的吸附机理。结果表明有机羧酸在HCS表面的吸附符合Langmuir等温吸附理论,吸附动力学更符合二级反应。
In this paper,the adsorption and adsorption mechanism of poly(acrylic acid)(PAA) and citric acid (CA) on the surface of calcium sulfate hemihydrate (HCS) were studied using organic carboxylic acids as additives.The adsorption characteristics of additives on HCS surface were analyzed by using total organic carbon analyser (TOC).TEM-EELS,X-ray electron spectroscopy (XPS),laser Raman spectroscopy,FTIR and other characterization methods were used to analyze the adsorption layer structure.Finally,the adsorption mechanism of additives was explored in combination with the crystal structure of HCS.The results show that the adsorption of organic carboxylic acid on the surface of HCS can be fitted by the Langmuir isotherm adsorption theory,and the adsorption kinetics was found to follow the second-order rate equation.Organic carboxylic acid was absorbed on the surface of gypsum through the interaction between carboxyl group and Ca^2+.The carboxyl group of CA was preferentially adsorbed in the C-axis direction of the HCS crystal compared to crystal planes in other directions.PAA was adsorbed on each crystal surface of HCS,and it exerts a dispersion effect through electrostatic repulsion and steric hindrance,which in turn affects the crystal morphology.At the same time,taking CA as an example,the stability constants of the complexes adsorbed on the surface of HCS were studied.
作者
付文健
林美庆
何慧艳
陈杰
程雲
赵敏
FU Wenjian;LIN Meiqing;HE Huiyan;CHEN JIE;CHENG Yun;ZHAO Min(School of Chemistry and Molecular Engineering,East China University of Science and Technology,Shanghai 200237,China)
出处
《华东理工大学学报(自然科学版)》
CAS
CSCD
北大核心
2019年第2期266-274,共9页
Journal of East China University of Science and Technology
关键词
柠檬酸
聚丙烯酸
吸附
络合
citric acid
poly acrylic acid
adsorption
chelation