Preparation and performance regulation of advanced temporary plugging gels using dual-ion crosslinked strategy and surface coating technology

Abstract The development of temporary plugging gels is consistently challenged by the intrinsic trade-off between high swelling capacity and mechanical robustness. Moving beyond conventional trial-and-error optimization, this work introduces a rational design strategy that transitions from performance tuning to fundamentally overcoming this trade-off. Specifically, a dual-ion coordination system composed of rigid Ni ²⁺ and dynamic Zn ²⁺ is employed to precisely tailor the network architecture of poly (acrylic acid-co-acrylamide) gels. Systematic regulation of the Ni ²⁺ /Zn ²⁺ molar ratio serves as a powerful control parameter, enabling predictive access to a wide spectrum of property combinations. The optimized formulation (Ni ²⁺ /Zn ²⁺ = 5:3) successfully breaks the conventional trade-off, achieving a synergistic integration of a high swelling capacity of 480 g·g ⁻¹ and a relatively stable compressive strength of 32 kPa at 40 °C. Furthermore, the well-defined network is integrated with a temperature-responsive coating, yielding an intelligent plugging agent capable of sequentially achieving deep placement, effective sealing, and clean removal. This work provides a promising strategy by integrating dual-ion (Ni ²⁺ /Zn ²⁺ ) coordination regulation with a temperature-responsive surface coating, which may offer new insights for tuning the strength–swelling balance and achieving spatiotemporally controlled plugging performance in related systems.