Oxidation State of a Polyurethane Membrane after Plasma Etching

Table 4

Surface composition of PU membrane incubated with culture medium. Data shows mean with SD (𝑛=3). Cl 2s and Na 2s were excluded from the calculation of elemental proportions.

Incubation period (days) and substrate	Composition (at.%)
	C 1s		N 1s		O 1s		S 2p		Si 2p
	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD
5 d, etched	63.9	1.4	11.9	0.5	22.1	0.3	2.0	0.6	0.1	0.2
5 d, unetched	70.8	4.9	9.6	1.6	17.4	3.4	1.3	0.4	0.9	0.6
2 d, etched	65.5	2.8	11.5	0.2	21.4	2.0	1.5	0.9	0.1	0.1
2 d, unetched	71.1	4.0	7.0	1.9	17.5	2.3	0.5	0.4	3.9	0.5
1 d, etched	63.4	0.5	12.1	0.2	22.7	0.3	1.6	0.3	0.2	0.1
1 d, unetched	65.4	4.2	11.0	1.0	21.7	2.4	1.8	1.0	0.2	0.3
Control	76.9	2.8	3.1	0.3	15.8	1.9	Nil	—	4.3	0.64