Atomic surface composition data of GO-COOH, GO-COOH/TX-100 and all uncrosslinked samples obtained from XPS analysis.

Sample	C%	O%	N%	Na%
GS	63.82	18.71	17.46	—
HGS-0.1	64.75	19.30	15.34	—
HGS-0.2	66.13	19.87	14.57	—
AS	64.94	32.51	—	2.55
HAS-0.1	65.48	32.21	—	2.32
HAS-0.2	66.23	31.75	—	2.02
AGS	68.00	20.85	10.63	0.51
HAGS-0.1	68.70	21.27	9.41	0.63
HAGS-0.2	70.11	21.53	7.88	0.47
GO-COOH	73.91	26.09	—	—
GO-COOH/TX-100	77.42	22.57	—	—