Research Article

Influence of the Branched Structure of Polyoxyethylene Units in Nonionic Surfactants on the Wettability of Anthracite: A Combined Modeling and Experimental Study

Figure 6

XPS spectrum of O 1s of anthracite after adsorbing different surfactants. (a) Tween 20-anthracite and (b) C12(EO)20-anthracite.
(a)
(b)