Effect of Amine-Functionalized Nanoparticles (SiO2/Amine) on HPAM Stability under Chemical Degradation Environments: An Experimental and Molecular Simulation Study

This work aimed to develop SiO2 nanoparticles functionalized with amine (SiO2/amine) to inhibit the chemical degradation of partially hydrolyzed polyacrylamide (HPAM) in the presence of different ionic species through static experiments and molecular simulations. The effect of the SiO2/amine on the rheological behavior of HPAM solution was evaluated in the presence of monovalent, divalent, and trivalent cations. To understand the relationships between polymers, ions, and nanostructures, interaction energies and the radii of gyration under all saline scenarios were calculated by molecular dynamics (MD). The SiO2/amine was spherical with a size <100 nm. There is a correlation between the ion's valence and the chemical degradation of HPAM: in the presence of polyvalent cations, the viscosity losses of the HPAM solutions reached up to 94%, incorporating SiO2/amine at 100 mg L–1 mitigated the viscosity losses by up to 16%. The molecular simulations showed that the self-folding of the HPAM chains increased in brine containing trivalent cations leading to the viscosity loss of the solutions. The presence of SiO2/amine increased the radius of gyration of the polymer up to 17%, improving the viscosity of the HPAM solutions. This study opens a broader landscape regarding nanotechnology to improve polymer flooding applied to the oil industry.