Table 6. Surface Tensions σ of Aqueous Solutions Containing MEA (2), HEIA (3), and CO₂ (4)^a.

						σ (mN/m)
x2	x3	x4	α0	α1	α2	298.15 K	303.15 K	308.15 K	313.15 K	318.15 K	323.15 K	328.15 K	333.15 K
0.1128	0	0	0	0	0	63.570	62.440	61.460	60.570	59.530	59.150	58.180	–
0.1091	0	0.0271	0.248	0	0	67.710	66.645	65.970	65.800	–		–
0.1062	0	0.0527	0.496	0	0	72.333	71.620	71.720	71.150	–	69.890	68.935	–
0.1111	0.0130	0	0	0	0	63.913	63.165	–	61.223	–	59.180	–	59.454
0.1078	0.0127	0.0297	0.275	0.1078	0.0127	65.960	65.140	64.340	63.846	63.203	62.540	–	–
0.1047	0.0123	0.0576	0.55	0.1047	0.0123	70.813	70.260	69.508	69.153	68.733	68.085	–	–
0.1091	0.0273	0	0	0	0	64.900	64.340	63.773	63.338	62.458	61.705	61.183	60.440
0.1067	0.0270	0.0304	0.285	0.228	0.19	–	67.485	–	66.540	–	64.860	–	–
0.1029	0.0257	0.0586	0.57	0.456	0.380	70.333	70.190	69.542	69.036	–	67.565	–	65.785

^ax_i is the mole fraction of component i in aqueous solution, T is temperature and α_i (i = 0, 1, 2) are measures of the CO₂ loading as determined from the definitions in Table 3. Expanded uncertainties at 95% confidence are U(T) = 0.02 K, U(α₀) = 0.03, U(x₂) = 0.0002, and U(σ) = 1.2 mN/m. Expanded uncertainties at 95% confidence are U(T) = 0.02 K, U(α₀) = U(α₁) = 0.01, U(α₂) = 0.0098, U(x₂) = U(x₃) = 0.0002, and U(σ) = 1.2 mN/m.