The mechanical and physicochemical properties of diesel engine exhaust particles before and after diesel oxidation catalyst (DOC) treatment are analyzed. It is considered important to explore the interrelationships between these attributes in order to understand their relevance. Understanding of these properties provides insights into the deposition characteristics of particles within the system and the evolution of the particles after the DOC treatment, which may help the selection of appropriate aftertreatment strategies. In this paper, particle samples were collected before and after the DOC to explore the variations in the mechanical and physicochemical properties of the particles under different operating conditions. Atomic force microscopy, thermogravimetric analysis, transmission electron microscopy, and Raman spectroscopy were employed to investigate the attraction force, adhesion force, adhesion energy, oxidative reactivity, primary particle size, nanostructure, and graphitization degree of the particles. The results indicated that under post-injection conditions, the attraction force, adhesion force, and adhesion energy of the particles increased significantly. However, when the particles passed through the DOC, these properties decreased to varying degrees. By analyzing the combination of physicochemical properties, it was determined that the attraction force of the particles was primarily influenced by the primary particle size and the particle's graphite structure. The adhesion force was found to be closely related to the content of soluble organic matter. Additionally, the soluble organic matter affected the degree of particle agglomeration by altering the adhesion energy of the particles.

中文翻译：

---

基于柴油氧化催化系统的颗粒机械和物理化学性质之间的相关性分析

分析了柴油氧化催化剂（DOC）处理前后柴油机排气颗粒的机械和物理化学特性。探索这些属性之间的相互关系以了解它们的相关性被认为很重要。了解这些特性可以深入了解系统内颗粒的沉积特性以及 DOC 处理后颗粒的演变，这可能有助于选择适当的后处理策略。本文在DOC之前和之后收集了颗粒样品，以探讨不同操作条件下颗粒的机械和物理化学性质的变化。采用原子力显微镜、热重分析、透射电子显微镜和拉曼光谱研究了颗粒的吸引力、粘附力、粘附能、氧化反应性、初级粒径、纳米结构和石墨化程度。结果表明，在注射后条件下，颗粒的吸引力、粘附力和粘附能显着增加。然而，当颗粒通过DOC时，这些性能都有不同程度的下降。通过分析物理化学性质的组合，确定颗粒的吸引力主要受初级颗粒尺寸和颗粒的石墨结构的影响。研究发现，附着力与可溶性有机物的含量密切相关。此外，可溶性有机物通过改变颗粒的粘附能来影响颗粒团聚的程度。