Table 1.

Comparison of the structural parameters of Porod approximation and the S_SAXS interfacial area as the porous features of the investigated systems, with the parameters obtained from low-temperature nitrogen sorption data. The surface properties, as pH_PZC, are summarized in the last column.

Sample	Porod Approximation				SSAXS e [m2/g]	Surface Area (SBET) [m2/g]		Pore Volume [cm3/g]		pHPZC
	KP a	Q b [Å−1]	C0 c	S/V d [Å−1]		SBET_Total f	SMIC g	VTotal h	VMIC i
ChNS_05	1.59	88	−28	0.072	277	244	3.6	0.93	0.001	-
ChNS_1	1.05	67	−23	0.062	219	209	26.0	0.84	0.013	5.2
ChNS_1_GA	1.35	69	−35	0.078	227	214	9.5	0.71	0.003	5.8
ChSG_05	1.59	81	−27	0.078	269	257	-	0.83	-	-
ChSG_1	1.40	77	−27	0.072	239	201	8.0	0.70	0.003	6.2
ChSG_1_GA	1.32	78	−23	0.067	190	188	27.7	0.65	0.01	6.5

^a Porod constant, ^b Scattering invariant Q is proportional to the mean-square density fluctuation of scattering volume. Q = 2π²·Δρ²·V where volume V and scattering contrast Δρ, ^c Bacground constant which illustrates asymptotic decay of the SAXS curve at the high q values, ^d The surface-to-volume ratio from the ratio of the Porod constant K_P to the Porod invariant Q, S/V = 4K_P/Q; ^e Surface area by SAXS calculated by $S_{SAXS}=\frac{10000·\frac{S}{V}\left[{\AA }^{-1}\right]}{d\left[\frac{\mathrm{g}}{{\mathrm{c}\mathrm{m}}^3}\right]},$ where d is the bulk density of the material; ^f The S_BET BET surface area was calculated using experimental points at a relative pressure of (P/P₀) 0.035–0.31, where P and P₀ are denoted as the equilibrium and saturation pressure of nitrogen; ^g S_MIC, the micropore surface area calculated using the t-plot method with fitted statistical thickness in the range of 3.56 to 4.86 Å, ^h Vt is the total pore volume calculated using 0.0015468 of the amount of nitrogen adsorbed at P/P₀ = 0.99, ⁱ V_MIC the micropore volume by t-plot.