Low Adsorption of Magnetite Nanoparticles with Uniform Polyelectrolyte Coatings in Concentrated Brine on Model Silica and Sandstone

详细信息    查看全文

• 作者：Esteban E. Ureña-Benavides ; Edward L. Lin ; Edward L. Foster ; Zheng Xue ; Michael R. Ortiz ; Yunping Fei ; Eric S. Larsen ; Anthony A. Kmetz II ; Bonnie A. Lyon ; Ehsan Moaseri ; Christopher W. Bielawski ; Kurt D. Pennell ; Christopher J. Ellison ; Keith P. Johnston
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2016
• 出版时间：February 17, 2016
• 年：2016
• 卷：55
• 期：6
• 页码：1522-1532
• 全文大小：458K
• ISSN：1520-5045

文摘

In subsurface imaging and oil recovery where temperatures and salinities are high, it is challenging to design polymer-coated nanoparticles with low retention (high mobility) in porous rock. Herein, the grafting of poly(2-acrylamido-2-methyl-1-propanesulfonic acid-co-acrylic acid) (poly(AMPS-co-AA)) on magnetic iron oxide nanoparticles was sufficiently uniform to achieve low adsorption on model colloidal silica and crushed Berea sandstone in highly concentrated API brine (8% NaCl and 2% CaCl₂ by weight). The polymer shell was grafted via amide bonds to an aminosilica layer, which was grown on silica-coated magnetite nanoparticles. The particles were found to be stable against aggregation in American Petroleum Institute (API) brine at 90 °C for 24 h. For IO nanoparticles with ∼23% polymer content, Langmuir adsorption capacities on colloidal silica and crushed Berea Sandstone in batch experiments were extremely low at only 0.07 and 0.09 mg of IO/m², respectively. Furthermore, upon injection of a 2.5 mg/mL IO suspension in API brine in a column packed with crushed Berea sandstone, the dynamic adsorption of IO nanoparticles was only 0.05 ± 0.01 mg/m², which is consistent with the batch experiment results. The uniformity and high concentration of solvated poly(AMPS-co-AA) chains on the IO surfaces provided electrosteric stabilization of the nanoparticle dispersions and also weakened the interactions of the nanoparticles with negatively charged silica and sandstone surfaces despite the very large salinities.