新型磁性超分子基功能吸附材料的制备及性能研究

Preparation and properties of a magnetic supermolecular-formed adsorption material

在重金属复合污染治理中,为开发具备高性能的新型功能吸附剂,研究采用共沉淀法制备磁性载体粒子(MNP),硅烷化、Michael加成及酰胺化反应以"发散"形态于表面合成端氨基超支化分子(MD),交联活化改性壳聚糖(CMCS),制备出新型磁性功能吸附材料(CCMD)。利用傅立叶变换红外光谱(FT-IR)、比表面积分析仪、元素分析仪结构表征产物;X射线衍射仪(XRD)、扫描/透射电镜(SEM/TEM)分析产物晶型及表观形貌;热重分析仪(TG)测试产物的热敏感性能;振动样品磁强计(VSM)和Zeta电位分析仪测试样品光电磁性;并开展吸附性能研究。结果表明:成功制备出目标功能化合物(CCMD),CCMD粒径为13～19nm,呈顺磁性磁铁矿晶型,MNP、MD、CCMD磁化值分别为11.6,11.3和9.0 emu×g^(-1),Zeta电位测试显示MD和CCMD电位随pH升高而降低,且CCMD表面电位高于MD,以上测试结果同时也进一步证实产物的成功制备。吸附研究结果表明:当pH分别为11和5时,对重金属Cd(II)离子与F离子表现出高效吸附能力,具有pH智能响应特征,且最大吸附容量为79.12和65.05mg×g^(-1)。重复吸附-脱附实验表明CCMD对Cd(II)和F去除率均在75%以上,再生性能良好。

Magnetic carrier particles(MNP)were prepared by co-precipitation,which was treated by silanization,Michael addition and amidation reactions on surface to form amino hyperbranched molecule(MD).This intermediate was cross-linked with activated modified chitosan(CMCS)to prepare a new magnetic functional adsorption material(CCMD)for heavy metal adsorption.The product was characterized by Fourier transform infrared spectroscopy(FT-IR),specific surface area analyzer and elemental analysis.X-ray diffractometer(XRD)and scanning/transmission electron microscopy(SEM/TEM)were used to analyze the crystal form and morphology.Thermogravimetric analysis(TG),vibrating sample magnetometer(VSM)and Zeta potential analysis were performed for thermal and photomagnetism property measurements.The adsorption performance of the product was studied.The results show that the target functional compound(CCMD)is successfully prepared in paramagnetic magnetite crystal form with particle size of 13~19 nm.The magnetization values of MNP,MD and CCMD were 11.6,11.3 and 9.0 emu·g^-1,respectively.Zeta potential results show that the surface potential of MD and CCMD decrease with the increase of pH,and the CCMD surface potential is higher than that of MD.These results also confirm the successful preparation of the product.Adsorption results show that the material has high adsorption capacity for Cd(II)and F ions at pH 11 and pH 5 with pH intelligent response characteristics.The maximum adsorption capacities are 79.12 mg·g^-1 and 65.05 mg·g^-1,respectively.Repeated adsorption-desorption experiments show that CCMD has Cd(II)and F removal rates over 75% with good regeneration performance.