Table 1. Physical characteristics of the prepared materials.

Sample	O/N (exp)*	O/N (theor)	Amines (%)†			SBET (m2 g−1)‡	Vtotal (cm3 g−1)§	N contents (mmolN g−1)
			1o	2o	3o
SiO2	—	—	—	—	—	299	1.7	—
PEI/SiO2	—	—	36	37	27	37	0.34	10.4
0.15EB-PEI/SiO2	0.15	0.14	23	44	33	40	0.37	8.9
0.37EB-PEI/SiO2	0.37	0.36	10	56	34	43	0.37	6.7
0.54EB-PEI/SiO2	0.54	0.57	2	61	37	45	0.38	5.9

^*O/N mole ratio was determined from elemental analysis.

^†Amine state distributions of PEI and functionalized PEIs were calculated from ¹³C NMR analysis.

^‡BET surface areas were determined in the P/P₀ range of 0.05–0.20.

^§Total pore volumes (V_total) were evaluated at P/P₀=0.99.