Magnetic dendritic materials for highly efficient adsorption of dyes and drugs.
Magnetic dendritic materials for highly efficient adsorption of dyes and drugs.
复制标题
DOI：
10.1021/am100114f
复制
发表时间：
2010-05
影响因子：
9.5
通讯作者：
Li Zhou;Chao Gao;Weijian Xu
中科院分区：
文献类型：
--
作者：
Li Zhou;Chao Gao;Weijian Xu
以羧基超支化聚甘油（Fe（3）O（4）/SiO（2）/HPG-COOH）对氧化铁-二氧化硅磁性粒子进行功能化修饰，制备了一种兼具磁性和高吸附容量的多功能吸附剂。通过傅里叶变换红外光谱（FTIR）、热重分析（TGA）、zeta电位和透射电子显微镜（TEM）对产物的结构进行了表征。TGA结果表明，Fe_3O_4/SiO_2/HPG-COOH表面羧基密度高达3.0mmol/g，是吸附染料和药物的强有力的载体。以5种染料和1种代表性抗癌药物为吸附剂，考察了磁性吸附剂的吸附性能。该吸附剂对所有被吸附物均表现出高效的吸附性能，尤其是对阳离子染料和药物的吸附性能。例如，Fe（3）O（4）/SiO（2）/HPG-COOH对甲基紫（MV）的饱和吸附容量可达0.60 mmol/g，远高于以往的磁性吸附剂（通常低于0.30 mmol/g）。在5 min内，95%的MV和90%的R6 G可被吸附，15 min左右达到吸附平衡。研究了吸附剂的吸附动力学和吸附等温线，发现吸附动力学和吸附平衡分别符合准二级动力学和Langmuir吸附等温线模型。此外，还考察了pH值和离子强度对吸附量的影响，发现pH值对吸附量的影响比离子强度大得多。再生实验表明，Fe（3）O（4）/SiO（2）/HPG-COOH在乙醇中可以很好地再生，在1 M HCl水溶液中可以部分再生。再生后的磁性吸附剂在10次解吸吸附循环后仍能保持较高的吸附容量。吸附-脱附循环10次后，磁感应强度没有明显下降，吸附剂也没有明显聚集。
A versatile and robust adsorbent with both magnetic property and very high adsorption capacity is presented on the basis of functionalization of iron oxide-silica magnetic particles with carboxylic hyperbranched polyglycerol (Fe(3)O(4)/SiO(2)/HPG-COOH). The structure of the resulting product was confirmed by Fourier transform infrared (FTIR) spectra, thermo gravimetric analysis (TGA), zeta-potential, and transmission electron microscopy (TEM). According to the TGA results, the density of the carboxylic groups on the surface of Fe(3)O(4)/SiO(2)/HPG-COOH is calculated to be as high as 3.0 mmol/g, posing a powerful base for adsorbing dyes and drugs. Five kinds of dyes and one representative anticancer drug were chosen to investigate the adsorption capacity of the as-prepared magnetic adsorbent. The adsorbent shows highly efficient adsorption performance for all of the adsorbates especially for the cationic dyes and drug. For example, the saturated adsorption capacity of the Fe(3)O(4)/SiO(2)/HPG-COOH for methyl violet (MV) can reach 0.60 mmol/g, which is much higher than the previous magnetic adsorbents (usually lower than 0.30 mmol/g). 95% of MV and 90% of R6G could be adsorbed within 5 min, and both of the adsorptions reached equilibrium in about 15 min. The adsorption kinetics and isotherm of the adsorbents were investigated in detail and found that the kinetic and equilibrium adsorptions are well-modeled using pseudo-second-order kinetics and Langmuir isotherm model, respectively. In addition, the influences of pH and ionic strength on the adsorption capacity were also examined and found that pH has much greater effect on the adsorption capacity compared with the ionic strength. Regeneration experiments showed that the Fe(3)O(4)/SiO(2)/HPG-COOH can be well-regenerated in ethanol and partially regenerated in 1 M HCl aqueous solution. After regeneration, the magnetic adsorbents can still show high adsorption capacity even for 10 cycles of desorption-adsorption. No obvious decreases of magnetic intensity and aggregation of adsorbents can be observed even after 10 cycles of adsorption-desorption.