Table 1. Theoretical and Experimental XPS Average Atomic Composition (%) and Carbon Contents of Different Types of Carbon Chemical Groups (%) from High-Resolution C 1s Peaks^a.

	C	N	O	N–C=O	O–C–O	C–O	C–N	C–C/C–H
chitosan (calculated)	55.0	8.7	36.2
chitosan	47.6	6.2	39.9	2.0	15.2	60.9	15.2	6.6
chitosan-g-EPEG	48.3	5.3	39.9	2.0	14.7	66.5	14.7	2.2

^aThe theoretical elemental composition of chitosan was calculated by the polymer chemical structure.