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

Abstract

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.

Machine learning enabled quantification of the hydrogen bonds inside the polyelectrolyte brush layer probed using all-atom molecular dynamics simulations

“…Polyelectrolyte (PE) brushes, which refer to charged PE chains densely grafted to a surface, have received wide attention [1][2][3][4][5][6][7][8] owing to their extensive applications in a variety of disciplines including fabrication of ionic diodes, 9 ion and biosensors, 10,11 and current rectifiers, 12 energy conversion, [13][14][15] targeted drug delivery, 16 water harvesting, 17 oil treatment, 18 and many more. For all these applications, the responsiveness of the PE molecules to the environmental stimuli (e.g., pH and ion concentration of the aqueous medium) becomes critical.…”