iodine and nickel ions adsorption by conjugated copolymers bearing repeating units of dicyclopentapyrenyl and various thiophene derivatives

The synthesis of three conjugated copolymers TPP1–3 was carried out using a palladium-catalyzed [3+2] cycloaddition polymerization of 1,6-dibromopyrene with various dialkynyl thiophene derivatives 3a–c. The target copolymers were obtained in excellent yields and high purity, as confirmed by instrumental analyses. TPP1–3 were found to divulge a conspicuous iodine adsorption capacity up to 3900 mg g−1, whereas the adsorption mechanism studies revealed a pseudo-second-order kinetic model. Furthermore, recyclability tests of TPP3, the copolymer which revealed the maximum iodine uptake, disclosed its efficient regeneration even after numerous adsorption-desorption cycles. Interestingly, the target copolymers proved promising nickel ions capture efficiencies from water with a maximum equilibrium adsorption capacity (qe) of 48.5 mg g−1.