Lubricant-Interface Induced Mobile Crystallization for Hypersaline Wastewater Management

Hypersaline wastewater management is a crucial issue for water-energy nexus. Evaporation-based zero liquid discharge (ZLD) desalination shows great promise to detoxify the hypersaline wastewater. However, salt formed on the evaporation surface compromises the efficiency and continuity of desalination. Here, the study reports a photothermal lubricant-infused surface (PLIS), capable of inducing mobile salt crystallization and eliminating salt scaling during desalination. Few nuclei initiate away from the PLIS, followed by migration inward as salt growth, leading to compact crystal. The final dewetting process leaves only scattered protrusions from crystal bottom contacting with the PLIS. Such a converged small area plus pinpoint contacting mode produce an ultralow adhesion of salt to the substrate (approximate to 2 mN mg(-1)), approximate to 40 times lower than that on a regular-used hydrophobic surface. The salt crystal precipitated on the PLIS can be blown off easily by air flow, refreshing the evaporating surface for continuous desalination and realizing ZLD.