Physicochemical study of extractants for extraction of rare earth element

Journal of Analytical Science and Technology

Table 4 Excess intermolecular free length (L_f ^E), excess surface tension (σ^E), excess molar volume (V^E _m) and excess of pure tributyl phosphate (TBP), toluene, and binary mixture of TBP and toluene at different mole fractions with different frequencies (1–4 MHz) for temperature 303.15 K

Mole fraction of TBP	L_f ^E (m) × 10⁻⁷				σ^E (Nm⁻¹)				V^E _m (m³mol⁻¹) × 10⁻⁷	η^E (Nsm⁻²) × 10⁻³
X1	1 MHz	2 MHz	3 MHz	4 MHz	1MHZ	2 MHz	3 MHz	4 MHz
0.0000	0	0	0	0	0	0	0	0	0	0
0.0712	−5.5956	−5.4484	−6.8047	−8.1131	1917.2819	1914.73468	1317.45752	721.1185634	1.71085	−0.19532
0.1692	−9.3571	−0.1040	−0.1167	−0.1144	4205.7083	3594.97437	2985.18984	2980.563116	2.92216	−1.01283
0.2570	−0.1207	−0.1293	−0.1275	−0.1309	5041.4163	4422.12243	4416.07006	4103.943175	3.26293	−1.40152
0.4356	−0.1047	−0.1095	−0.1202	−0.1280	6332.9984	5701.36007	5070.70978	4441.054575	4.91720	−1.56675
0.5052	−0.1047	−0.1081	−0.1182	−0.1182	5918.0402	5283.47561	4649.90730	4330.474264	4.73284	−1.40087
0.5820	−9.9252	−0.1010	−0.1106	−0.1164	5365.6501	4728.40132	4092.15698	3456.922601	4.18167	−1.29212
0.7059	−7.0718	−7.6757	−8.5515	−8.9522	4634.7341	3676.19462	3036.78807	2398.401336	3.28712	−1.13512
0.7781	−5.2872	−5.7421	−6.5675	−6.8693	3956.2692	2995.21656	2354.44540	1714.698945	2.58474	−1.01863
0.8712	−4.4291	−4.0174	−4.7783	−4.9529	2193.7445	1551.11883	909.521706	268.9558308	1.09628	−0.28534
1.0000	0	0	0	0	0	0	0	0	0	0