二乙烯三胺改性聚多巴胺包覆硅胶吸附日落黄

采用二乙烯三胺(DETA)改性聚多巴胺(PDA)包覆硅胶(SG)得到吸附剂SG@DETA/PDA。通过FTIR、SEM和氮气吸附-脱附等技术对SG@DETA/PDA进行了形貌和结构表征,并考察了其对阴离子染料日落黄的吸附性能。表征结果显示,SG@DETA/PDA表面有PDA微球团聚形成的较为致密的包覆层,其比表面积和孔体积均比吸附剂SG@PDA有小幅提高。实验结果表明:SG@DETA/PDA吸附日落黄的最佳工艺条件为溶液p H 2.0、吸附时间2.0 h、初始染料质量浓度150 mg/L,在上述最佳工艺条件及298 K温度条件下SG@DETA/PDA对日落黄的吸附容量为175.56 mg/g。SG@DETA/PDA吸附日落黄的过程可以分别用准二级动力学方程和Langmuir等温吸附方程很好地拟合,该吸附过程主要是通过静电作用的单分子层吸附,是一个吸热自发的熵增过程。

Adsorption of sunset yellow by diethylenetriamine modified polydopamine-coated silica gel

SG@DETA/PDA was prepared by modifying polydopamine（PDA）coated silica gel（SG）with diethylenetriamine（DETA）. The morphology and structure of SG@DETA/PDA were characterized by FTIR,SEM and N₂ adsorption-desorption isotherms measurement.The adsorption effects of sunset yellow（SY）on SG@DETA/PDA were investigated. The characteristic results showed that a relatively dense coating layer consisting of agglomerate PDA microspheres were formed on the surface of SG@DETA/PDA,whose specific surface area and pore volume were a little higher than those of SG@PDA. The experimental results indicated that under the optimum conditions for SY adsorption on SG@DETA/PDA of solution pH 2.0,adsorption time 2.0 h,initial dye mass concentration 150 mg/L,adsorption temperature 298 K,the adsorption capacity of SG@DETA/PDA to SY was 175.56 mg/g. The adsorption process fitted the pseudo-second-order kinetics equation and Langmuir adsorption isotherm equation well. This adsorption process was a monolayer adsorption by means of electrostatic interaction,and was also an endothermic,spontaneous and entropy increment process.