Department of Chemistry, University of Bayreuth, Universitätsstr.30, 95440, Bayreuth, Germany.
JCNS-1/IBI-8: Neutron Scattering and Biological Matter, Forschungszentrum Jülich Gmbh, Wilhelm-Johnen-Straße, 52428, Jülich, Germany.
ChemistryOpen. 2020 Nov 27;9(11):1214-1220. doi: 10.1002/open.202000313. eCollection 2020 Nov.
Applications in biomedicine and ferrofluids, for instance, require long-term colloidally stable, concentrated aqueous dispersions of magnetic, biocompatible nanoparticles. Iron oxide and related spinel ferrite nanoparticles stabilized with organic molecules allow fine-tuning of magnetic properties via cation substitution and water-dispersibility. Here, we synthesize≤5 nm iron oxide and spinel ferrite nanoparticles, capped with citrate, betaine and phosphocholine, in a one-pot strategy. We present a robust approach combining elemental (CHN) and thermal gravimetric analysis (TGA) to quantify the ratio of residual solvent molecules and organic stabilizers on the particle surface, being of particular accuracy for ligands with heteroatoms compared to the solvent. SAXS experiments demonstrate the long-term colloidal stability of our aqueous iron oxide and spinel ferrite nanoparticle dispersions for at least 3 months. By the use of SAXS we approved directly the colloidal stability of the nanoparticle dispersions for high concentrations up to 100 g L.
例如，在生物医学和铁磁流体应用中，需要长期胶体稳定、浓缩的水基分散的磁性、生物相容的纳米颗粒。用有机分子稳定的氧化铁和相关尖晶石铁氧体纳米颗粒允许通过阳离子取代和水分散性来精细调整磁性。在这里，我们使用一锅法合成了≤5nm 的氧化铁和尖晶石铁氧体纳米颗粒，其表面用柠檬酸盐、甜菜碱和磷胆碱封端。我们提出了一种稳健的方法，将元素（CHN）和热重分析（TGA）结合起来，定量计算颗粒表面上残留溶剂分子和有机稳定剂的比例，与溶剂相比，对于含有杂原子的配体具有特别高的准确性。小角 X 射线散射（SAXS）实验证明了我们的水基氧化铁和尖晶石铁氧体纳米颗粒分散体至少在 3 个月内的长期胶体稳定性。通过使用 SAXS，我们直接证明了纳米颗粒分散体在高达 100g/L 的高浓度下的胶体稳定性。
