Control of the interparticle spacing in superparamagnetic iron oxide nanoparticle clusters by surface ligand engineering

• 作者: 吴君 唐惠儒 夏春潮 宋彬 林兵兵 王丹 申太鹏 艾华 豪富华 龚启勇
• 来源期刊: 中国物理B（英文版）
• 关键词: nanoparticle clusters interparticle spacing ligand exchange magnetization
• 年，卷（期）: 2016,（7）
• 页码范围: 077504-1-077504-8
• 页数: 1页
• 语种: 英文
• DOI: 10.1088/1674-1056/25/7/077504

摘要

Polymer-mediated self-assembly of superparamagnetic iron oxide (SPIO) nanoparticles allows modulation of the structure of SPIO nanocrystal cluster and their magnetic properties. In this study, dopamine-functionalized polyesters (DA-polyester) were used to directly control the magnetic nanoparticle spacing and its effect on magnetic resonance relaxation properties of these clusters was investigated. Monodisperse SPIO nanocrystals with different surface coating materials (poly(ε-caprolactone), poly(lactic acid)) of different molecular weights containing dopamine (DA) structure (DA-PCL2k, DA-PCL1k, DA-PLA1k)) were prepared via ligand exchange reaction, and these nanocrystals were encapsulated inside am-phiphilic polymer micelles to modulate the SPIO nanocrystal interparticle spacing. Small-angle x-ray scattering (SAXS) was applied to quantify the interparticle spacing of SPIO clusters. The results demonstrated that the tailored magnetic nanoparticle clusters featured controllable interparticle spacing providing directly by the different surface coating of SPIO nanocrystals. Systematic modulation of SPIO nanocrystal interparticle spacing can regulate the saturation magnetization (Ms) and T2 relaxation of the aggregation, and lead to increased magnetic resonance (MR) relaxation properties with de-creased interparticle spacing.