Table 2.

Characteristic parameters of 11-2-11-2Y, 13-2-13-2Y, 15-2-15-2Y (Y = HCOO⁻, CH₃COO⁻ and CH₃CHOHCOO⁻) aqueous solution at 25°C. The method 1 stands for surface tension measurement. The method 2 stands for conductivity measurement. The standard error σ_μ are σ_μ(CMC) = 1 × 10⁻³ mmol l⁻¹, σ_μ(γ_CMC) = 0.01 mN m⁻¹, σ_μ(pC₂₀) = 0.01, σ_μ(Γ_max) = 0.01 × 10⁻¹⁰ mol cm⁻², σ_μ(A_min) = 0.01 nm², σ_μ(A_min) = 0.01 nm², σ_μ(A_min) = 0.01 nm², σ_μ(ΔG_ads) = −1 kJ mol⁻¹ and σ_μ(ΔG_ads) = −1 kJ mol⁻¹.

Gemini surfactant	CMC (mmol l−1)		γCMC (mN m−1)	pC20	Γmax (×10−10 mol cm−2)	Amin (nm2)	ΔGads (kJ mol−1)	$\mathrm{\Delta }{G}_m^{\theta }(\mathrm{kJ}\hspace{0.17em}\mathrm{mo}{\mathrm{l}}^{-1})$
	method 1a	method 2b						method 1a	method 2b	β
11-2-11-2HCOO−	5.72 × 10−2	5.73 × 10−2	26.51	5.42	2.09	0.79	−55.81	−34.17	−26.43	0.556
11-2-11-2CH3COO−	6.32 × 10−2	6.18 × 10−2	26.92	5.37	1.91	0.87	−57.54	−33.92	−26.06	0.549
11-2-11-2CH3CHOHCOO−	0.101	0.105	27.63	5.14	1.90	0.88	−56.28	−32.76	−23.84	0.512
13-2-13-2HCOO−	3.16 × 10−2	3.18 × 10−2	27.62	5.40	2.41	0.69	−54.08	−35.64	−26.76	0.509
13-2-13-2CH3COO−	4.09 × 10−2	4.10 × 10−2	27.99	5.20	2.69	0.62	−51.43	−35.00	−25.70	0.492
13-2-13-2CH3CHOHCOO−	8.92 × 10−2	6.78 × 10−2	28.49	4.87	2.54	0.65	−50.10	−33.07	−23.53	0.453
15-2-15-2HCOO−	1.05 × 10−2	1.41 × 10−2	28.32	5.61	3.35	0.50	−51.52	−38.37	−27.49	0.462
15-2-15-2CH3COO−	2.09 × 10−2	2.19 × 10−2	28.35	5.34	3.14	0.53	−50.60	−36.67	−25.86	0.440
15-2-15-2CH3CHOHCOO−	2.63 × 10−2	3.34 × 10−2	29.09	5.23	3.09	0.54	−50.06	−36.10	−24.93	0.442