Measuring Surface Relaxation of Vitrimers

We used atomic force microscopy (AFM) to investigate the change of the surface roughness of an artificially rough epoxy-based vitrimer surface as a function of annealing temperatures. The results show that the asperities of the rough vitrimer surface partially relax at temperatures well below the bulk topology freezing transition temperature, T-v, an important technological temperature for vitrimers, where the bond exchange reactions slow down markedly. The estimated surface activation energy for bond exchange reactions, E-a, is much lower than that of the bulk. The results suggest that a layer with enhanced bond exchange reactions or a decreased T-v may exist at the surface of vitrimers, which should have important implications for self-healing, welding, and other applications involving surface properties of the vitrimers.

Automated summary

This study used atomic force microscopy to investigate the change of surface roughness of an artificially rough epoxy-based vitrimer surface with annealing temperatures. The results showed that the rough surface partially relaxed at temperatures below the freezing transition temperature, indicating the existence of a layer with enhanced bond exchange reactions or a decreased freezing temperature on the surface of vitrimers.