Table 4.

Surface chemical composition of the active layers in different TFC membranes by XPS O 1 s spectral analysis.

Membranes	OI	OII	OI/OII
TFC0	53,204.92	20,627.32	2.58
TFC0.5	54,435.55	21,724.29	2.51
TFC1	55,050.29	22,332.47	2.47
TFC2.5	57,721.78	24,354.10	2.37
TFC5	57,969.02	30,565.92	1.90
TFC10	53,865.64	34,567.34	1.56