A novel assessment method for the catalytic activity of ionic liquid degradation of PET.

• The interaction between IL and PET plays a decisive role in the glycolysis of PET. • The relative interface adhesion between IL and PET was measured by AFM and LFM. • A novel method for screening efficient IL catalysts is proposed. Ionic liquids (ILs) have been recognized as environmentally friendly and effective catalysts for poly (ethylene terephthalate) (PET) glycolysis. However, further investigation is required to gain a deeper understanding of the depolymerization mechanism. In this study, a series of experiments are conducted to investigate the impact of metallic and non-metallic ILs, containing diverse anions, on the interaction with PET surfaces. The findings indicate that the catalytic efficiency of IL is strongly correlated to the intensity of the interaction with PET. When the interface adhesion strength is more than twice that of PET/PET, the IL exhibits efficient catalytic properties in PET glycolysis. Therefore, an innovative approach involving the use of AFM for efficiently assessing highly effective IL catalysts is proposed. In addition, attenuated total reflectance Fourier transform-infrared (ATR-FTIR) spectroscopy and density functional theory (DFT) calculations further demonstrate the predominant interaction mechanism between ILs and PET. This research provides guiding significance for understanding the mechanism of PET glycolysis. [ABSTRACT FROM AUTHOR]