A magneto-responsive deformable coating with lubricant self-replenishment towards on-demand scale repellence

Scale formation poses a considerable threat to various industries, such as heat exchange, water treatment, and the medical sector. Significantly, lubricant-infused surfaces (LISs) have emerged as a promising strategy to address this issue. However, most conventional LISs suffer from irreversible lubricant depletion in complex fluid environments, which severely compromises their long-term anti-scaling efficacy. In this study, we present a triple-layer magneto-responsive deformable coating (MRDC) with lubricant self-replenishment capability, which exhibits exceptional scale repellency capacity even under complex fluid conditions. The MRDC is composed of three functional layers, including a lubricant spreading layer (LSL), a magneto-responsive layer (MRL), and a lubricant reservoir layer (LRL). The sustainable anti-scaling comes from the stability of the lubricant on the LSL, which not only prevents scale nucleation but also reduces the scale adhesion. Upon the application of an external magnetic field, the MRL undergoes controllable deformation, prompting the LRL to release the internally stored lubricant and thereby replenishing the lubricant loss on the LSL caused by harsh environments. Notably, after lubricant replenishment, the deposited scale on the MRDC can be easily removed with a removal efficiency of approximately 96.8%. Thus, this work provides a versatile solution to challenges associated with scale deposition, offering new insights and a universal paradigm for designing durable stimuli-responsive anti-scaling coatings and extending the service life of liquid-infused materials in complex aqueous environments.