Iron Oxide Nanoparticles Grafted with Sulfonated and Zwitterionic Polymers: High Stability and Low Adsorption in Extreme Aqueous Environments

Abstract

A facile “grafting through” approach was developed to tether tunable quantities of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) as well as zwitterionic poly([3-(methacryloylamino)propyl]dimethyl(3-sulfopropyl)ammonium hydroxide) (PMPDSA) homopolymer onto iron oxide (IO) nanoparticles (NPs). In this case, homopolymers may be grafted, unlike “grafting to” approaches that often require copolymers containing anchor groups. The polymer coating provided steric stabilization of the NP dispersions at high salinities and elevated temperature (90 °C) and almost completely prevented adsorption of the NPs on silica microparticles and crushed Berea sandstone. The adsorption of PAMPS IO NPs decreased with the polymer loading, whereby the magnitude of the particle-surface electrosteric repulsion increased. The zwitterionic PMPDSA IO NPs displayed 1 order of magnitude less adsorption onto crushed Berea sandstone relative to the anionic PAMPS IO NPs. The ability to design homopolymer coatings on nanoparticle surfaces by the “grafting through” technique is of broad interest for designing stable dispersions and modulating the interactions between nanoparticles and solid surfaces.

Control of magnetite primary particle size in aqueous dispersions of nanoclusters for high magnetic susceptibilities

“…The biggest challenges for using IO NPs for oil reservoir applications lie in (i) synthesizing a IO NP core with high initial magnetic susceptibility which make it possible to generate enough signal for mapping under even low external magnetic field, and (ii) developing a surface coating procedure which enable the IO NPs to be stable in the subsurface oil reservoir environment, namely high temperature, high salinity aqueous solutions. Recently, long term colloidal stability of IO and other NPs was reported even over a wide pH range in high salinity, high temperature brines typically encountered in oil reservoirs [10][11][12][13][14][15][16] . For example polymers containing 2-acrylamido-2-methylpropane sulfonic acid (AMPS), which bind weakly to Ca 2+ , remain extended after coated on ~100 nm IO nanoclusters in American Petroleum Institute brine (API brine, 8% w/w NaCl + 2% w/w CaCl 2 , anhydrous basis) and provide efficient steric and electrostatic stabilization [16][17][18][19][20] .…”

“…Recently, long term colloidal stability of IO and other NPs was reported even over a wide pH range in high salinity, high temperature brines typically encountered in oil reservoirs [10][11][12][13][14][15][16] . For example polymers containing 2-acrylamido-2-methylpropane sulfonic acid (AMPS), which bind weakly to Ca 2+ , remain extended after coated on ~100 nm IO nanoclusters in American Petroleum Institute brine (API brine, 8% w/w NaCl + 2% w/w CaCl 2 , anhydrous basis) and provide efficient steric and electrostatic stabilization [16][17][18][19][20] . A key step for the crosswell EM imaging technology is to enhance the magnetic susceptibility of the IO cores in the form of an aqueous colloidal dispersion.…”

Nanotechnology Application in Chemical Enhanced Oil Recovery: Current Opinion and Recent Advances

“…infinitesimal and almost negligible [96]. Cheraghian et al performed static adsorption experiments to investigate the impact of nano-SiO 2 and nanoclay on the adsorption inhibition of polyacrylamide onto sandstone rocks.…”

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“…Zwitterionic NPs (ZW-NPs) are also less prone to aggregation under high ionic strengthconditions. [1,17,21,[24][25][26][27][28][29][30][31][32] interactions represents an important first step in the development of new nanomaterials intended for in vivo use.…”