title: Real-time monitoring the adsorption of sodium dodecyl sulfate on a hydrophobic surface using dual polarization interferometry.
abstract: The adsorption process of sodium dodecyl sulfate (SDS) at a hydrophobic layer was investigated by dual polarization interferometry (DPI), which provided the real-time information at solid/liquid interface. In dilute solution, the molecules adsorb at the surface as isotropic layer. With the increase in concentration, the molecules aggregate to form hemimicelles and the critical hemimicelles concentration (HMC) is 1 mM. The adsorption of SDS at C18 surface obeys two-step process. The competitive formations of micelles in solution and hemimicelles on C18 surface lead to particular adsorption behavior in higher concentration. We also proposed a four-stage adsorption model of SDS at C18 surface according to bulk concentration.
authors.affiliation: State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China; School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, China. Electronic address: swpua124@126.com.
authors.forename: Ming
authors.initials: M
authors.lastname: Duan
authors.affiliation: State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China; School of Materials Science and Engineering, Southwest Petroleum University, Chengdu 610500, China. Electronic address: huwang@swpu.edu.cn.
authors.forename: Hu
authors.initials: H
authors.lastname: Wang
authors.affiliation: School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, China.
authors.forename: Shenwen
authors.initials: S
authors.lastname: Fang
authors.affiliation: School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liang
keywords: Adsorption; Dual polarization interferometry; Hydrophobic surface; Micelles; Sodium dodecyl sulfate