相转移方法制备水溶性Fe_3O_4纳米晶

Synthesis of Water-soluble Fe_3O_4 Nanocrystals with a Phase-transfer Method

在有机溶剂中合成了超顺磁性的油溶性Fe3O4纳米晶.利用相转移的方法成功地将油溶性Fe3O4纳米晶完全转移至水相中,其中两性齐聚物——聚马来酸脂肪胺酯作为修饰剂包裹在Fe3O4纳米晶的表面.利用透射电子显微镜(TEM)、红外光谱仪、热失重分析和动态光散射仪对水溶性纳米晶的形貌和结构进行了表征.所制备的水溶性磁流体在外加磁场的环境中表现出所预期的超顺磁性行为.两性齐聚物中疏水链的长度能够显著地影响相转移效果,研究发现利用含有十六个碳链的聚马来酸十六胺酯来转移纳米晶时效果最好.生物相容性测试实验表明两性齐聚物修饰的Fe3O4纳米晶在各种生理环境中都能够稳定地存在,并没有发生团聚现象.

Hydrophobic Fe3O4 nanocrystals with superparamagnetic behavior were synthesized in an or-ganic solvent.High quality water-soluble Fe3O4 nanocrystals were then prepared by a phase transfer method,in which amphiphilic oligomers（polymaleic acid aliphatic amine ester） was used as surface coating agents.The obtained aqueous Fe3O4 nanocrystals were characterized with transmission electron microscopy,Fourier transform infrared spectroscopy,thermal gravimetric analysis,and dynamic light scattering.A solution of Fe3O4 nanocrystals in water showed expected superparamagnetic behavior when subjected to an external magnetic field.We found that hydrophobic ester chain length of the amphiphilic oligomer can dramatically affect the phase transfer efficiency,which was explained by the impact of local hydrophobic environment on the stability of nanocrystals in water.A biocompatible test showed that the water-soluble Fe3O4 were very stable in various physiological conditions without particle aggregation.