title: Influence of demulsifiers of different structures on interfacial dilational properties of an oil-water interface containing surface-active fractions from crude oil.
abstract: The influences of two commercial demulsifiers that have a straight chain and branch chain, respectively, on the dilational viscoelasticity of an oil-water interfacial film containing surface-active fractions from crude oil were investigated. The branch-chain demulsifier AE-121 could efficiently substitute surface-active fractions of different average molecular weights from the oil-water interface, while straight-chain SP-169 could only efficiently substitute those of large average molecular weight. It was apt to form a mix-adsorption layer with surface-active fractions of small average molecular weight. The results showed that the molecular size (or represented by average molecular weights) of the surface-active fractions was an important factor influencing the reciprocity of demulsifiers and surface-active fractions at the oil-water interface. This effect could be well explained by the difference between sizes of surface-active fraction molecules and vacancies between demulsifier molecules at the interface. The results of SDBS also proved this explanation.
authors.affiliation: Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, No. 3 Datun Road, Beijing 100101, P. R. China. suntl@sina.com.cn
authors.forename: Taolei
authors.initials: T
authors.lastname: Sun
authors.forename: Lu
authors.initials: L
authors.lastname: Zhang
authors.forename: Yiyang
authors.initials: Y
authors.lastname: Wang
authors.forename: Sui
authors.initials: S
authors.lastname: Zhao
authors.forename: Bo
authors.initials: B
authors.lastname: Peng
authors.forename: Mingyuan
authors.initials: M
authors.lastname: Li
authors.forename: Jiayong
authors.initials: J
authors.lastname: Yu