Nanomaterials in hydraulic fracturing fluids: Enhancement mechanisms and rock–fluid interface engineering for surface modification

Hydraulic fracturing fluids increasingly incorporate nanomaterials to address the coupled challenges of viscosity loss, fluid leak-off, adverse wettability, and inadequate microfracture support. This review re-examines the field with emphasis on experimentally traceable evidence rather than secondary citation chains. Across reported systems, nano-Fe 2 O 3 improved foam thermal stability by about 52% at 80 °C, while ZrO 2 nanofluids shifted fractured limestone from oil-wet (152°) to strongly water-wet states (44° at 0.05 wt% and 19° in 20 wt% NaCl). CNT/rGO-reinforced urethane coatings increased glass-bead compressive strength by 83.68% and 41.10%, respectively, illustrating the potential of nanostructured coatings to improve proppant integrity. The review further discusses nano-crosslinker chemistry, interfacial disjoining-pressure mechanisms, nanoparticle preparation and surface functionalization, coating durability, and the evidence gap between laboratory optimization and field deployment. A comparative assessment against prior reviews highlights the need for better source traceability, standardized durability metrics, and clearer integration of rock-fluid interface engineering with proppant technology. Future progress depends on coupling mechanistic experiments with model-assisted formulation design, environmentally defensible nanoparticle selection, and field-scale validation under high-temperature/high-salinity conditions.