A Hydroxy-Palmitic Acid-Functionalized Mechanoresponsive Hydrogel Offers a Sustainable Solution for the Selective Capture of Hydrogen Halides and Toxic Heavy Metals through Stimuli-Responsive Syneresis

In an effort to discover a dual-functional and eco-friendly platform to address the challenges of halide entrapment and removal of toxic metal ions from wastewater concurrently, this work delineates a novel approach of fishing out a potential weapon compound I, from a pool of three constructs, harnessing the concept of hydrophobic orchestration. We propose that the chloride-palmitic acid derivative, formed through nucleophilic substitution of the palmitic acid's alcoholic hydroxy group, plays a crucial role in driving self-assembly, which ultimately leads to hydrogel formation and halide entrapment. Furthermore, the resulting chloride-palmitic acid derivative undergoes heavy metal ion (Pb²⁺/Cd²⁺)-induced syneresis, likely due to the formation of metal-ligand complexes under the given experimental conditions, as supported by extensive experimental evidence. This dual-responsive behavior of compound I, along with its reusability for up to three cycles, represents a promising and effective strategy for environment management.