Investigation on the adsorption behavior of polyacrylamide on resin by dual polarization interferometry

Abstract

Polyacrylamide (PAM) is widely used in the petroleum industry to enhance oil recovery all over the world. However, introducing PAM into the liquid changes the property of the oil–water interface and, finally, makes the wastewater treatment more difficult. It is ambiguous whether PAM adsorbs onto the oil–water interface and influences the stability of the interface. In this study, resin, one of the most important components in crude oil, was immobilized onto the silicon oxynitride chip surface. The behavior of PAM on resin was investigated by dual polarization interferometry (DPI). DPI is a novel instrument to real-time monitor the adsorption behavior and structure changes of a polymer on resin. Different concentrations of PAM solutions were respectively injected onto the immobilized chips. The real-time mass, thickness and density changes of PAM on resin were accordingly recorded and calculated by DPI. In conclusion, when a low-concentration polymer solution was injected, polymer molecules were adsorbed on the resin in disorder; when a high-concentration polymer solution was injected, pre-adsorbed polymer molecules were rearranged to take in more molecules and an isotropic adsorption layer will be formed.