Preparation and properties of novel pH‐sensitive core−shell microspheres for enhanced oil recovery

A novel pH-sensitive core−shell microsphere was synthesized by growing sodium acrylate as a shell on crosslinked polyacrylamide particles as the core by surface-initiated atom transfer radical polymerization. The structures and characteristics of the microspheres were confirmed by Fourier transform infrared spectroscopy, 1H NMR spectroscopy, SEM, transmission electron microscopy and AFM. The viscosity and size of the microspheres in response to changes in pH value were also investigated. As a kind of potential profile control and flooding agent, the performances of permeability reduction and enhanced oil recovery were studied in designed experiments. © 2017 Society of Chemical Industry