Preparation and characterization of a novel magnetic nano-adsorbent
Preparation and characterization of a novel magnetic nano-adsorbent
复制标题
DOI：
10.1039/b207158d
复制
发表时间：
2002-01-01
影响因子：
--
通讯作者：
Chen, DH
中科院分区：
文献类型：
--
作者：
Liao, MH;Chen, DH
以纳米Fe3O4(13.2 nm)为核，聚丙烯酸(PAA)为离子交换基团，制备了一种新型磁性纳米吸附剂。在氨水溶液中共沉淀Fe2+和Fe3+离子，在水热条件下处理，制备了Fe3O4磁性纳米粒子。通过碳二亚胺活化，将PAA共价键合到磁性纳米粒子上。透射电子显微镜显示，磁性纳米粒子与PAA结合后仍然是分散的，尺寸没有明显变化。X-射线衍射图表明磁性纳米粒子为纯净的尖晶石结构的Fe3O4，PAA的结合没有引起相变。磁性测量表明磁性纳米粒子是超顺磁性的，PAA结合后其饱和磁化强度仅略有降低。傅立叶变换红外光谱、热重-差热分析和X射线光电子能谱分析证实了PAA与磁性纳米粒子的结合，提出了PAA与磁性纳米粒子的结合机理，并揭示了PAA与磁性纳米粒子结合的最大重量比为0.12。此外，磁性纳米吸附剂的离子交换容量估计为1.64mequiv g(-1)，远高于商业离子交换树脂的离子交换容量。用磁性纳米吸附剂回收溶菌酶时，由于没有孔扩散阻力，1min内即可完成对溶菌酶的吸附/解吸。在适宜的条件下，吸附/解吸效率接近100%，回收的溶菌酶活性保持在95%以上。
A novel magnetic nano-adsorbent has been developed using Fe3O4 nanoparticles (13.2 nm) as cores and polyacrylic acid (PAA) as ionic exchange groups. The Fe3O4 magnetic nanoparticles were prepared by co-precipitating Fe2+ and Fe3+ ions in an ammonia solution and treating under hydrothermal conditions. PAA was covalently bound onto the magnetic nanoparticles via carbodiimide activation. Transmission electron micrographs showed that the magnetic nanoparticles remained discrete and had no significant change in size after binding the PAA. The X-ray diffraction patterns indicated the magnetic nanoparticles were pure Fe3O4 with a spinel structure, and the binding of PAA did not result in a phase change. Magnetic measurement revealed the magnetic nanoparticles were superparamagnetic, and their saturation magnetization was reduced only slightly after PAA binding. Fourier transform infrared spectroscopy, thermogravimetric and differential thermal analyses, and X-ray photoelectron spectroscopy confirmed the binding of PAA to the magnetic nanoparticles, suggested a binding mechanism for the PAA, and revealed the maximum weight ratio of PAA bound to the magnetic nanoparticles was 0.12. In addition, the ionic exchange capacity of the resultant magnetic nano-adsorbents was estimated to be 1.64 mequiv g(-1), much higher than those of commercial ionic exchange resins. When the magnetic nano-adsorbents were used for the recovery of lysozyme, the adsorption/desorption of lysozyme was completed within 1 min due to the absence of pore-diffusion resistance. Also, the adsorption/desorption efficiency could reach almost 100% under appropriate conditions, and the recovered lysozyme retained 95% activity.