Acrylic copolymers with pendant 1,2,4‐triazole moieties as colorimetric sensory materials and solid phases for the removal and sensing of cations from aqueous media

Linear water‐soluble polymers and nets with gel‐like behavior were prepared for use as colorimetric sensors and selective extracting agents for naked eye detection and solid–liquid removal of heavy‐metal cations from aqueous environments. Triazole is a well‐known, heavy‐metal cation host. A water‐insoluble methacrylamide containing a 1,2,4‐triazole receptor derivative was copolymerized with highly hydrophilic and water‐soluble methacrylamides to yield a water‐soluble polymer or a cross‐linked network as a powder or a dense membrane. In powder form, the material selectively removed Hg²⁺, Pb²⁺, and Ag⁺ from aqueous media. In the form of swelled dense membranes or films, the material acted as colorimetric sensor for Fe³⁺. When the membrane was soaked in a yellow aqueous solution of Fe³⁺, the former colorless, transparent membrane became reddish (but retained its transparency), and the solution became colorless. Aqueous conductivity studies confirmed that both the extraction and the sensing phenomena arose from the interaction of the cations with the triazole moieties. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011