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Towards enhanced oil recovery: Effects of ionic valency and pH on the adsorption of hydrolyzed polyacrylamide at model surfaces using QCM-D
- Source :
- Applied surface science, 560:149995. Elsevier
- Publication Year :
- 2021
-
Abstract
- Adding polymers to the injection water in water-flooding oil recovery increases the viscosity and thereby enhances recovery factor. However, the beneficial effects are often counteracted by adsorption of polymer to the ambient mineral surface. In here, we used Quartz Crystal Microbalance with Dissipation (QCM-D) measurements to study the adsorption of the frequently used hydrolyzed polyacrylamide (HPAM), a weak polyelectrolyte, to silica and alumina model surfaces representing sandstone reservoirs. At pH 6 and 8 and concentrations from 1 mM to 100 mM of NaCl and CaCl2, we find that negatively charged HPAM molecules generally adsorb more strongly to positively charged alumina surfaces. For silica surfaces, the presence of Ca2+ ions, which form strong complexes with the carboxyl groups on the polymer, as evidenced by titration measurements, strongly enhances HPAM adsorption. This effect is attributed to the formation of Ca2+-mediated ion bridges with the substrate. Kinetic measurements suggest a two-step adsorption process consisting of a primary polymer adsorption onto the surface followed – in most cases – by a slower secondary process, which involves rearrangements of previously adsorbed polymer molecules, including polymer-on-polymer adsorption.
- Subjects :
- Polyacrylamide
UT-Hybrid-D
General Physics and Astronomy
Ionic bonding
02 engineering and technology
QCM-D
010402 general chemistry
01 natural sciences
Hydrolyzed polyacrylamide
chemistry.chemical_compound
Adsorption
Enhanced oil recovery
chemistry.chemical_classification
Surfaces and Interfaces
General Chemistry
Polymer
Quartz crystal microbalance
Polymer adsorption
Polyelectrolyte
021001 nanoscience & nanotechnology
Condensed Matter Physics
0104 chemical sciences
Surfaces, Coatings and Films
chemistry
Chemical engineering
Calcium bridging
Titration
0210 nano-technology
Subjects
Details
- Language :
- English
- ISSN :
- 01694332
- Database :
- OpenAIRE
- Journal :
- Applied surface science, 560:149995. Elsevier
- Accession number :
- edsair.doi.dedup.....b2fe88bd43c1daafb12a3e15c77b9dcb