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 nanoparticlesfunctionalizedwith amine (SiO2/amine) to inhibit the chemical degradationof partially hydrolyzed polyacrylamide (HPAM) in the presence of differentionic species through static experiments and molecular simulations.The effect of the SiO2/amine on the rheological behaviorof 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 gyrationunder all saline scenarios were calculated by molecular dynamics (MD).The SiO2/amine was spherical with a size <100 nm. Thereis a correlation between the ion's valence and the chemicaldegradation of HPAM: in the presence of polyvalent cations, the viscositylosses of the HPAM solutions reached up to 94%, incorporating SiO2/amine at 100 mg L-1 mitigated the viscositylosses by up to 16%. The molecular simulations showed that the self-foldingof the HPAM chains increased in brine containing trivalent cationsleading to the viscosity loss of the solutions. The presence of SiO2/amine increased the radius of gyration of the polymer upto 17%, improving the viscosity of the HPAM solutions. This studyopens a broader landscape regarding nanotechnology to improve polymerflooding applied to the oil industry.