论文标题
对温度诱导的非磁性纳米颗粒分散体中温度诱导的聚集的原位研究，小角度X射线散射
In-situ investigation of temperature induced agglomeration in non-polar magnetic nanoparticle dispersions by small angle X-ray scattering
论文作者
论文摘要
冷却后，非极性磁性纳米颗粒团聚。此过程之后是原位的小角度X射线散射，以评估新出现的聚集物的结构特性。在几个颗粒直径的长度尺度上，在小（d = 12nm）和大（d = 22nm）纳米颗粒之间没有发现差异。像随机包装一样的硬球，可以看到$η$ = 0.4的本地包装分数。在较大的长度尺度上，小粒子形成紧凑的上层建筑，而大颗粒则排列成类似于萨克斯中链状结构的团聚。这可以通过主导较大颗粒的定向磁偶极相互作用来解释，而各向同性范德华的相互作用控制较小颗粒的聚集。
Non-polar magnetic nanoparticles agglomerate upon cooling. This process is followed by in-situ small angle X-ray scattering to assess structural properties of the emerging agglomerates. On the length scale of a few particle diameters, no differences are found between the agglomerates of small (d = 12nm) and large (d = 22nm) nanoparticles. Hard-sphere like random packing with a local packing fraction of $η$ = 0.4 is seen. On larger length scales, small particle form compact superstructures, while large particles arrange into agglomerates that resemble chain-like structure in SAXS. This can be explained by directed magnetic dipole interactions that dominate larger particles, while isotropic van der Waals interaction governs the agglomeration of smaller particles.
