Table 1. XPS analysis of the O/C ratio on the surface of UVO-treated and untreated plastics immediately following UVO exposure.

		PMMA	COC	PC
Untreated		0.34 ± 0.05	0.12 ± 0.02	0.19 ± 0.02
UVO-treated	20 min	0.48 ± 0.07	0.42 ± 0.10	0.47 ± 0.12
	40 min	0.54 ± 0.09	0.56 ± 0.06	0.59 ± 0.04
	60 min	0.53 ± 0.02	0.54 ± 0.07	0.55 ± 0.04
	80 min	0.56 ± 0.08	0.55 ± 0.05	0.56 ± 0.04