A coarse-grained molecular dynamics method is used to investigate a. microferrogel (MFG); a. small polymer object containing nanoparticles of magnetoactive filler. Despite the fact that an applied magnetic field acts directly on only the nanoparticles, structural and mechanical changes occur throughout the entire composite system due to the coupling between these particles and the polymer. The study of these changes is important in view of widely discussed prospects of using MFGs as field-controlled microcontainers for delivering bioactive substances or drugs. In this work, a. numerical model is proposed and realized, which enables one to perform a. detailed analysis of stationary states of an MFG suspended in a. neutral solvent. The effect of concentration of particles and their magnetic characteristics (magnetic moment magnitude, degree of uniaxial magnetic anisotropy, and interparticle dipolar coupling parameter) on the structure formation in the absence of an external magnetic field and under its influence is investigated. It is shown that the chain-like clusters are in fact the only type of aggregates arising in MFG. However, their effect on the polymer subsystem depends strongly on the type of magnetic anisotropy and on the magnetic phase concentration. This, in turn, entails different scenarios of the mechanical response of MFG and, in particular, differently affects the change in the amount of solvent present in the sample.

中文翻译：

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微铁凝胶对外部磁场响应的模拟

粗粒度分子动力学方法用于研究。微铁凝胶（MFG）; 一种。包含磁活性填料纳米粒子的小聚合物物体。尽管事实上施加的磁场仅直接作用于纳米粒子，但由于这些粒子与聚合物之间的耦合，结构和机械变化会在整个复合系统中发生。鉴于广泛讨论了将MFG用作现场控制的微容器来递送生物活性物质或药物的前景，对这些变化的研究非常重要。在这项工作中 提出并实现了一个数值模型，使人们能够执行 详细分析了悬浮在其中的MFG的稳态。中性溶剂。粒子浓度及其磁特性（磁矩大小，研究了在没有外部磁场的情况下以及在其影响下单轴磁各向异性的程度（以及单粒子间偶极耦合参数）对结构形成的影响。结果表明，链状簇实际上是MFG中出现的唯一聚集体类型。但是，它们对聚合物子系统的影响在很大程度上取决于磁各向异性的类型和磁相浓度。反过来，这会导致MFG的机械响应发生不同的情况，尤其是会影响样品中存在的溶剂量的变化。结果表明，链状簇实际上是MFG中出现的唯一聚集体类型。但是，它们对聚合物子系统的影响在很大程度上取决于磁各向异性的类型和磁相浓度。反过来，这会导致MFG的机械响应发生不同的情况，尤其是会影响样品中存在的溶剂量的变化。结果表明，链状簇实际上是MFG中出现的唯一聚集体类型。但是，它们对聚合物子系统的影响在很大程度上取决于磁各向异性的类型和磁相浓度。反过来，这会导致MFG的机械响应发生不同的情况，尤其是会影响样品中存在的溶剂量的变化。