Table 3.

Thermodynamic parameters for the adsorption of Pb²⁺ ions onto the pristine and functionalized ECNFs.

T (K)	van’t Hoff equation	Kc	ΔG° (kJ/mol)	ΔH° (kJ/mol)	ΔS° (J/mol)
ECNFs
298	y = −1870.93x + 5.15 R2 = 0.8656	0.3149	2.86	15.55	42.84
308		0.4229	2.20
318		0.4665	2.01
o-ECNFs
298	y = −3626.66x + 14.1 R2 = 0.9463	6.6500	−4.69	30.15	117.23
308		11.0000	−6.14
318		14.2600	−7.03
melam-ECNFs
298	y = 11118.11x − 32.17 R2 = 0.8814	201.4300	−13.14	−92.43	−267.44
308		36.2200	−9.19
318		19.4900	−7.85
PmPDA-ECNFs
298	y = −8146.18x + 28.35 R2 = 0.9969	2.8100	−2.56	67.73	235.72
308		6.4500	−4.77
318		15.7200	−7.28