Comprehensive demetallization of crude oil using spherical polyelectrolyte brushes with submicron polybutadiene latex as a core

Stable oil-soluble metals complexes in crude oil bring various problems to the oil processing. In the previous work, four spherical polymer brushes with SiO 2 as a core showed high nickel and calcium removal efficiency, but SiO 2 has high density and smaller specific surface area, greatly limiting the demetallization efficiency. In the present work, spherical polyelectrolyte brushes (PAA@PB) were synthesized by emulsion grafting polymerization. DLS and TEM show that PAA@PB exhibits a uniform spherical core-shell structure with a diameter of 526.3 nm, and TGA exhibits that the grafting rate is 20.6%. The demetallization rate and selectivity of PAA@PB were investigated with varying concentration, electrical desalination conditions, pH value, and NaCl concentration. In contrast, the demetallization efficiency of PAA@PB is much greater than that of PAA@SiO 2 -G. Notably, PAA@PB exhibits excellent nickel removal efficiency, but a little more selective for iron. The optimal removal rate for calcium, nickel, and iron are 55.3%, 52.6%, and 46.1%, respectively. Compared with P4VP@SiO 2 -G, which possesses the highest demetallization efficiency among four polymer brushes with SiO 2 , to achieve the same nickel removal rate, the concentration of PAA@PB is almost eight times less than that of P4VP@SiO 2 -G. Consequently, PAA@PB has great potential as an excellent comprehensive demetallization agent.