Höfgen Egon Götz, Bandyopadhyay Sulalit
Particle Engineering Centre, Department of Chemical Engineering, Norwegian University of Science and Technology, Trondheim, 7491, Norway.
Discov Nano. 2025 Jan 7;20(1):5. doi: 10.1186/s11671-024-04167-6.
The increasing demand for magnetic iron oxide nanoparticles (IONPs) in biomedicine necessitates efficient and scalable production methods. Thermal decomposition offers excellent tailoring of the particle properties but its discontinuous batch-operation is restricting scale-up and industrial application. To overcome these challenges, several studies have demonstrated semi-continuous thermal decomposition by slowly injecting the precursor, though only half of them produce magnetite IONPs and even fewer use iron oleate precursors. The available studies are limited, often focusing on single synthesis variables and a comprehensive mapping of the physicochemical properties to reaction conditions is missing. Here we present our investigation of semi-continuous thermal decomposition of iron oleate as a route for the synthesis of magnetic IONPs. We achieved the semi-continuous synthesis of spherical IONPs with properties matching those obtained via the conventional heat-up method. We explored the the effect of multiple synthesis variables, namely addition rate, dwell time, iron oleate amount, oleic acid amount, temperature and consistently report magnetic saturation of our samples. We found that the dwell time seemingly has a stronger effect on particle sizes and magnetic saturation than the addition speed, within moderate addition rates, and further are we the first to report the effect of reaction temperature on semi-continuous synthesis. The iron oleate precursor obtained from salt exchange was employed without pretreatment or dilution thereby facilitating a streamlined synthesis process. An oxidative phase transfer was used to mitigate the key challenge of hydrophobicity of oleate-capped IONPs, enabling their potential use in biomedical applications. Our work advances the understanding of of synthesis-property relationships of IONPs by demonstrating the translation of established synthesis protocols into more efficient and scalable processes through which it provides insights for developing and optimizing future production protocols for various applications.
生物医学领域对磁性氧化铁纳米颗粒（IONPs）的需求不断增加，这就需要高效且可扩展的生产方法。热分解法能出色地调控颗粒性质，但其间歇式批量操作限制了放大生产和工业应用。为克服这些挑战，多项研究展示了通过缓慢注入前驱体实现半连续热分解的方法，不过其中只有一半能制备出磁铁矿IONPs，使用油酸铁前驱体的更少。现有研究有限，往往只关注单一合成变量，缺乏对物理化学性质与反应条件的全面映射。在此，我们展示了对油酸铁半连续热分解作为合成磁性IONPs途径的研究。我们实现了球形IONPs的半连续合成，其性质与通过传统加热法获得的颗粒性质相当。我们探究了多个合成变量的影响，即添加速率、停留时间、油酸铁用量、油酸用量、温度，并持续报告了我们样品的磁饱和度。我们发现，在适中的添加速率范围内，停留时间对颗粒尺寸和磁饱和度的影响似乎比添加速度更强，而且我们首次报告了反应温度对半连续合成的影响。从盐交换获得的油酸铁前驱体未经预处理或稀释就被使用，从而简化了合成过程。采用氧化相转移来缓解油酸包覆的IONPs疏水性这一关键挑战，使其有可能用于生物医学应用。我们的工作通过展示将既定合成方案转化为更高效、可扩展的过程，推进了对IONPs合成 - 性质关系的理解，为开发和优化未来各种应用的生产方案提供了见解。
