Figure 3.

Statistical results of ESR spectra of hydroxyl and DPPH free radicals based on as-prepared PAW (red), various 30 day aged PAW and DI water (black) for reference. (A) Hydroxyl free radicals. (B) DPPH free radicals. Green: slowly frozen/slowly melted PAW-1-30; blue: slowly frozen/quickly melted PAW-2-30; pink: quickly frozen/slowly melted PAW-3-30; orange: quickly frozen/quickly melted PAW-4-30; yellow: super-quickly frozen/slowly melted PAW-5-30; purple: super-quickly frozen/quickly melted PAW-6-30. *, p < 0.05; **, p < 0.01; ***, p < 0.001.