聚丙烯酰胺/凹凸棒粘土复合吸附材料的研究

采用溶液聚合法在硅烷化凹凸棒粘土(OATP)表面接枝丙烯酰胺(AM),制备聚丙烯酰胺/凹凸棒粘土(PAM/ATP)复合吸附材料。通过考察PAM/ATP复合吸附材料对汞离子吸附性能的影响,对其制备条件进行了优化。采用热重/差示扫描量热(TG/DSC)和傅里叶变换红外光谱(FT-IR)对PAM/ATP进行了表征。结果表明,当AM质量分数(相对OATP质量,下同)为30%,聚合反应时间为6h,引发剂质量分数为3.0%,反应温度为80℃时,制备的PMA/ATP对汞离子的最大吸附容量可达到135.5mg·g-1。TG/DSC分析表明,PAM/ATP的DSC曲线在345℃出现一有机物分解吸热峰,且PAM/ATP的热失重率(18.0%)明显高于ATP(5.0%)和OATP(7.0%);FT-IR分析表明,PAM/ATP在1604cm-1(-NH2或-NH的弯曲振动)和3190cm-1(-NH2或-NH伸缩振动)及1671cm-1(-C=O伸缩振动)有新的吸收峰出现,表明PAM成功接枝于OATP表面。与ATP、OATP相比,PAM/ATP对Hg2+离子的吸附容量增大了6倍以上。

Study on Polyacrylamide/Attapulgite Adsorbent Composite

Using solution polymerization, polyacrylamide/attapulgite (PAM/ATP) adsorbent was synthesized by grafting acrylamide (AM) onto the silane coupling reagent modified ATP (OATP). The preparing conditions of the PAM/ATP were investigated, and the analyses by TG/DSC and FT-IR were conducted to characterize the synthesized PAM/ATP. The results show that the prepared PAM/ATP gives a maximum Hg~(2+) adsorption capacity of 135.5 mg·g~(-1) under following conditions: AM mass concentration of 30.0% (relative to OATP mass, the same hereinafter), reaction time of 6 h, initiator dosage of 3.0% (weight) and reaction temperature of 80℃. TG/DSC analyses reveal that the DSC curve of the PAM/ATP exhibits an endothermic peak of organic decomposition at 345℃, and in the temperature range of 280℃ to 600℃, the weight loss of the PAM/ATP (18.0%) is much more than those of the ATP (5.0%) and the OATP (7.0%). The FT-IR spectra show that the new absorption bands at 1604 cm~(-1) (-NH_2 or -NH bending vibration), 3190 cm~(-1) (-NH_2 or -NH stretching vibration) and 1671 cm~(-1) (-C=O stretching vibration) appear on the spectrum of PAM/ATP; It indicates that the PAM is successfully grafted onto the surface of OATP. It was found that the Hg~(2+) adsorption capacity of the PAM/ATP prepared under the above conditions is more than 6 folds compared with those of the ATP and OATP.