Application of Calixarenes as Macrocyclic Ligands for Uranium(VI): A Review

Table 8

The synergistic coefficients of UO₂^2+a.

Entry	System (pH)	𝐷^b	SF^c	Reference
1	5 × 10^−3 M 15 (pH 6.5)	3.380	—	[64]
2	5 × 10^−3 M 23 (pH 5.0)	0.035	—	[64]
3	5 × 10^−3 M 15 + 5 × 10^−3 M HTTA (pH 6.5)	8.931	1.343	[64]
4	5 × 10^−3 M 23 + 5 × 10^−3 M HTTA (pH 5.0)	10.240	2.905	[64]

^a[Na⁺] = 0.04 M.
^bD: distribution coefficient, D = [UO₂²⁺]_org/[UO₂²⁺]_aq.
^cSF: synergistic factor, SF = 𝐷_syn/(𝐷_HTTA + 𝐷_CALIX), where 𝐷_syn is the distribution coefficient of the synergistic mixture.