Characterization of Self-Contamination from PVA Roll Brush with Atomic Force Microscopy and Fluorescent Microscopy

We have found three suspected self-contamination sources from PVA brushes using high resolution AFM imaging and fluorescence microscopy. The first source is thin layers on the surface of the fresh (not used) PVA brushes. The second source is a weariness of the brush surface during the cleaning process. The third source is the particles embedded in the bulk region (inside) of the brushes. We have not yet identified the right source of contamination. In addition, the stripe like nano-structure is firstly observed in the bulk region of PVA brush both with AFM lateral force and viscoelastic measuring mode. We need to perform further precise studies to comprehend contamination phenomena during cleaning.