Reclined trend of alkyl chain of sodium dodecylbenzenesulfonate molecules induced by friction

Abstract Surfactants tend to adsorb on the surface/interface mostly in a directional manner. The alkyl chain orientation and conformation order for molecular monolayers of sodium dodecylbenzenesulfonate (SDBS) at low concentrations are studied by using sum frequency generation vibrational spectroscopy (SFG-VS). arrangement surfactants adsorbed solid/liquid interface is further investigated. It found that SDBS becomes relatively ordered with increasing bulk concentration. Meanwhile, angle reduces gradually, molecules be upright state. In addition, effect friction also analyzed. intensity contraction peak lower after friction, which indicates anion has reorientation process interface. more disordered due friction. increases slightly, monolayer an inclined trend relative lateral direction A modified adsorption model considering proposed. This work may provide reference study mechanism application surfactants.