Synthesis and influence of modified Nano-SiO2 Grafted poly (AM-AA-AMPS) onto Swelling behavior, Degradation and its Viscosity.

This study presents the synthesis and evaluation of a novel nanocomposite using dispersion polymerization of Acrylamide (AM), Acrylic Acid (AA), 2-acrylamido-2-methyl propane sulfonic acid (AMPS), and N, N’-methylenebisacrylamide (MBA) grafted onto the surface of modified nano-SiO 2 (M-NS). The modification, achieved using γ-Methacryloyloxypropyltrimethoxysilane (KH570), enhances hydrophobicity and stability. Comprehensive characterization techniques, including ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared (FTIR), laser particle size analysis, and zeta potential measurements were employed to confirm the structural integrity and functionalization of the nanocomposite. Emphasis was placed on examining swelling, viscosity, and dispersion stability under various temperature, salinity, and water conditions to determine its effectiveness under high-temperature and high salinity environments typical of oil reservoirs. The results revealed significant enhancements in swelling behavior and dispersion stability, with high resistance to thermal degradation and salinity-induced aggregation. The nanocomposite demonstrates superior swelling behavior, viscosity retention, and thermal stability under high-temperature (70°C) and high-salinity (up to 20g/L NaCl) conditions, outperforming traditional grafted polymers. Results demonstrated that swelling ratios improve by 45% with 2wt% M-NS, and viscosity degradation is significantly reduced over 20 days of aging. Ionic effects, analyzed show enhanced resistance to divalent ions (Mg 2+ and Ca 2+ ), critical for harsh reservoirs environments. These findings suggest superior conformance control, compliance, and thermal stability, which were further improved with the rise of modified nano-SiO 2 positioning this nanocomposite as a promising option for chemical-enhanced oil recovery applications, addressing in permeability heterogeneity and salinity-induced aggregation.