Send to

Choose Destination
See comment in PubMed Commons below
ACS Appl Mater Interfaces. 2013 Apr 24;5(8):3329-39. doi: 10.1021/am4003974. Epub 2013 Apr 12.

Iron oxide nanoparticles grafted with sulfonated copolymers are stable in concentrated brine at elevated temperatures and weakly adsorb on silica.

Author information

Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, USA.


Magnetic nanoparticles that can be transported in subsurface reservoirs at high salinities and temperatures are expected to have a major impact on enhanced oil recovery, carbon dioxide sequestration, and electromagnetic imaging. Herein we report a rare example of steric stabilization of iron oxide (IO) nanoparticles (NPs) grafted with poly(2-acrylamido-2-methylpropanesulfonate-co-acrylic acid) (poly(AMPS-co-AA)) that not only display colloidal stability in standard American Petroleum Institute (API) brine (8% NaCl + 2% CaCl2 by weight) at 90 °C for 1 month but also resist undesirable adsorption on silica surfaces (0.4% monolayer NPs). Because the AMPS groups interacted weakly with Ca(2+), they were sufficiently well solvated to provide steric stabilization. The PAA groups, in contrast, enabled covalent grafting of the poly(AMPS-co-AA) chains to amine-functionalized IO NPs via formation of amide bonds and prevented polymer desorption even after a 40,000-fold dilution. The aforementioned methodology may be readily adapted to stabilize a variety of other functional inorganic and organic NPs at high salinities and temperatures.

PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for American Chemical Society
    Loading ...
    Support Center