Durhuus Frederik Laust, Wandall Lau Halkier, Boisen Mathias Hoeg, Kure Mathias, Beleggia Marco, Frandsen Cathrine
DTU Physics, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
Nanoscale. 2021 Jan 28;13(3):1970-1981. doi: 10.1039/d0nr08561h.
Magnetically guided self-assembly of nanoparticles is a promising bottom-up method to fabricate novel materials and superstructures, such as, for example, magnetic nanoparticle clusters for biomedical applications. The existence of assembled structures has been verified by numerous experiments, yet a comprehensive theoretical framework to explore design possibilities and predict emerging properties is missing. Here we present a model of magnetic nanoparticle interactions built upon a Langevin dynamics algorithm to simulate the time evolution and aggregation of colloidal suspensions. We recognise three main aggregation regimes: non-aggregated, linear and clustered. Through systematic simulations we have revealed the link between single particle parameters and which aggregates are formed, both in terms of the three regimes and the chance of finding specific aggregates, which we characterise by nanoparticle arrangement and net magnetic moment. Our findings are shown to agree with past experiments and may serve as a stepping stone to guide the design and interpretation of future studies.
纳米粒子的磁导向自组装是一种很有前景的自下而上的方法，可用于制造新型材料和超结构，例如用于生物医学应用的磁性纳米粒子簇。大量实验已证实了组装结构的存在，但缺少一个全面的理论框架来探索设计可能性并预测新出现的特性。在此，我们提出了一个基于朗之万动力学算法的磁性纳米粒子相互作用模型，以模拟胶体悬浮液的时间演化和聚集过程。我们识别出三种主要的聚集状态：非聚集、线性和簇状。通过系统模拟，我们揭示了单粒子参数与形成何种聚集体之间的联系，这既涉及三种状态，也涉及找到特定聚集体的概率，我们通过纳米粒子排列和净磁矩来表征这些聚集体。我们的研究结果与过去的实验结果一致，可作为指导未来研究设计和解释的垫脚石。
