This study focuses on the synthesis, characterization, and performance evaluation of polyacrylamide (PAM)/polyethyleneimine (PEI) hydrogels enhanced with nanomaterials for potential application in conformance control in oil wells. The materials used include PAM with a molar mass of 25,000 Kg mol(-1), PEI with an average weight molar mass of 25 Kg mol(-1), and synthetic brine (ionic strength 0.6). Nanomaterials such as titanium dioxide (TiO2) nanoparticles, oxidized carbon nanotubes (CNT-ox), and graphene oxide (GO) were incorporated into the hydrogel matrix. A simple method was used for the incorporation of nanomaterials into the polymeric matrix, ensuring their good dispersion in the hydrogels formed. Characterization techniques including thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were employed to analyze the structure, morphology, and thermal stability of the hydrogels. Rheological measurements and gel strength evaluations were conducted to assess the performance of the hydrogels. Results indicate that the incorporation of nanomaterials enhanced the thermal stability, gel strength (Sydansk code), and resistance to syneresis of the hydrogels. Specifically, the addition of TiO2 nanoparticles exhibited the highest improvement in viscosity and thermal stability, attributed to strong interactions between TiO2 and PAM molecules. A notable decrease in syneresis percentages was observed with the inclusion of nanomaterials compared to the PAM reference sample, reaching 70.1 % for the hydrogel modified with GO. These findings suggest that nanomaterial-enhanced hydrogels hold promise for applications in conformance control in oil wells, offering improved stability and performance over extended periods of use.
