Light‐Responsive Metal–Organic Framework (MOF)‐Based Liquid‐Like Coating for Sustainable Scale Resistance

Abstract

AbstractScale accumulation is a serious problem in several industrial fields. Although a series of surface coatings are developed for anti‐scaling, they generally suffer from limited anti‐scaling capability and longevity. Herein, a light‐responsive liquid‐like coating is prepared by constructing a metal–organic framework (MOF) functionalized with poly‐spiropyran (PSP) and further grafting it with linear polydimethylsiloxane (LPDMS), which enables high‐performance anti‐scaling. The prepared MOF/PSP/LPDMS (MPL) coating integrates multiple strategies to synergistically suppress scale formation. It utilizes the PSP component to delay scaling by adsorbing salt ions and the liquid‐like LPDMS component to inhibit scale nucleation through reducing the scale‐substrate affinity interaction. The MOF skeleton isolates PSP components to prevent unfavorable aggregation, which helps to maintain high ion‐adsorption capacity upon exposure to ultraviolet or darkness. Additionally, the coating allows rapid release of adsorbed ions upon exposure to visible light, enabling the recovery of adsorption sites. Consequently, the MPL coating exhibits highly effective and sustainable anti‐scaling capability. Scale buildup of only 0.41 mg cm−2 for CaCO3 and 0.69 mg cm−2 for CaSO4 is achieved on the MPL coating after 14 days’ scaling test, which is far superior to previously‐reported anti‐scaling surfaces. This work paves the way for designing light‐responsive liquid‐like coatings for sustainable scale resistance.