Effect of Ionic Liquid Surfactants on Coal Oxidation and Structure

Table 2

Surface tension of the ILs solutions.

Solutions	Distilled water	[HOEtMIm][NTf2]	[HOEtMIm][BF4]	[N8,8,8,1]Cl	[N2,2,2,2]Cl	[C12MIm]Br	[C14MIm]Br
Surface tension (mN/m)	72.55	36.29	42.71	28.53	50.96	35.80	34.21
Standard deviation	0.10	0.07	0.15	0.11	0.14	0.11	0.10