The chemical components and adhesion performance of the oil fume fouling sourced from cooking: Experimental investigation and molecular simulation

To effectively remove cooking-generated oil fume fouling, it is necessary to understand the chemical compositions of fouling, its evolution in the aging process, and its effects on adhesion performance. In this study, the fouling was simulated using soybean oil. The chemical compositions after undergoing different aging time were analyzed by GC–MS, ¹H NMR, and so on. The interaction energies were investigated by the molecular dynamic simulation. The analysis results showed that fouling composition gradually evolved from linoleic-linoleic-linoleic triglyceride (LLL), palmitic-linoleic-linolenic triglyceride (PLLn), and linoleic-linoleic-oleic triglyceride (LLO) to primary oxidation products (hydroperoxides) and secondary oxidation products (such as epoxides, alcohols, and aldehydes). The simulation found that the interaction energies between molecules in fouling, between fouling layers, and between fouling and substrate increased continuously during aging. The former two were attributed to the increases in van der Waals interactions, while the latter was attributed to the rise in electrostatic interactions caused by oxidation products. Meanwhile, the weakest interaction energy between two fouling layers was a vulnerability of the fouling adhesion process. The experimental measurement of peeling force of fouling layers and fouling-substrate verified the simulation results. These findings can guide the design and development of the cleaning agents for fouling.