Self-Secreting Organohydrogels with Adaptive Lubrication for Extreme Environments

Abstract

Autonomous lubrication mechanisms in nature inspire the development of self-secreting materials to address tribological challenges in extreme environments. Traditional hydrogels rely heavily on hydration lubrication, which is ineffective in dry conditions and severely compromised in subzero environments due to water loss and freezing. In this study, we present a novel organohydrogel (OHG) system that integrates supramolecular organogels within a hydrogel matrix, enabling temperature-responsive and shear-responsive self-secretion for lubrication in dry, wet, and subzero conditions. Experimental results demonstrate that OHGs exhibit effective lubrication even in completely dry conditions, overcoming reliance on hydration lubrication seen in traditional hydrogels. In dry conditions, the friction coefficient (COF) of OHGs decreases from 0.4 to 0.1 due to thermally or shear induced self-secretion of the lubricating phase. Additionally, OHGs maintain low-temperature lubrication at -10 °C, retaining flexibility and achieving a stable COF of 0.1. In aqueous environments, OHGs not only exhibit hydration lubrication like traditional hydrogels but also benefit from oil-phase secretion, further reducing the COF to 0.07. Furthermore, self-secretion-controlled hydration swelling behavior was observed, resulting in a swelling equilibrium time eight times greater than that of conventional hydrogels. This controlled swelling behavior enables prolonged migration and enhanced sealing performance, making OHGs particularly suited for deep profile control in oilfield applications. These findings highlight the potential of OHGs as a next-generation self-lubricating material that overcomes the limitations of hydration-based hydrogels, offering enhanced lubrication functionality with promising applications in oilfield development, robotics, and biomedical engineering.