Most real core-shell nanoparticle (CSNP) samples deviate from an ideal core-shell structure potentially having significant impact on the particle properties. An ideal structure displays a spherical core fully encapsulated by a shell of homogeneous thickness, and all particles in the sample exhibit the same shell thickness. Therefore, analytical techniques are required that can identify and characterize such deviations. This study demonstrates that by analysis of the inelastic background in X-ray photoelectron spectroscopy (XPS) survey spectra, the following types of deviations can be identified and quantified: the nonuniformity of the shell thickness within a nanoparticle sample and the incomplete encapsulation of the cores by the shell material. Furthermore, CSNP shell thicknesses and relative coverages can be obtained. These results allow for a quick and straightforward comparison between several batches of a specific CSNP, different coating approaches, and so forth. The presented XPS methodology requires a submonolayer distribution of CSNPs on a substrate. Poly(tetrafluoroethylene)-poly(methyl methacrylate) and poly(tetrafluoroethylene)-polystyrene polymer CSNPs serve as model systems to demonstrate the applicability of the approach.

中文翻译：

---

通过分析 X 射线光电子能谱调查光谱的非弹性背景来确定核壳纳米粒子涂层的不均匀性

大多数真正的核壳纳米颗粒 (CSNP) 样品都偏离了理想的核壳结构，可能会对颗粒特性产生重大影响。理想的结构是球形核完全被均匀厚度的壳包裹，样品中的所有颗粒都表现出相同的壳厚度。因此，需要能够识别和表征此类偏差的分析技术。本研究表明，通过分析 X 射线光电子能谱 (XPS) 调查光谱中的非弹性背景，可以识别和量化以下类型的偏差：纳米颗粒样品内壳厚度的不均匀性和核的不完全封装由外壳材料。此外，可以获得 CSNP 壳厚度和相对覆盖率。这些结果允许在几个批次的特定 CSNP、不同的涂层方法等之间进行快速和直接的比较。所提出的 XPS 方法需要 CSNP 在基板上的亚单层分布。聚（四氟乙烯）-聚（甲基丙烯酸甲酯）和聚（四氟乙烯）-聚苯乙烯聚合物 CSNP 作为模型系统来证明该方法的适用性。