Adsorption Characteristics of WFD Heavy Metal Ions on New Biosourced Polyimide Films Determined by Electrochemical Impedance Spectroscopy

In this work, innovative biosourced polyimide polymers were derived from novel combinations of monomers (Isosorbide, 6-FDA and amine cardo). These obtained with satisfactory yields by polycondensation different percentages isosorbide (from 100% to 0%). The synthesized polyimides had number average molecular weight in the 17,600–22,000 g/mol range, they stable well above 451 °C (5% loss N2). glass transition temperature (Tg) found be range 318–414 °C, depending on composition copolymers. adsorption Water Framework Directive (WFD) heavy metals (Pb2+, Ni2+, Cd2+, Hg2+) films deposited a gold electrode was monitored measurements impedance electrolyte/polyimide polymer/electrode interface. isotherm Pb2+on modeled according Langmuir best fitting. relative capacities higher when content higher. Comparing WFD based polyimide, sequence is following one: Pb2+ ? Ni2+ > Cd2+ Hg2+. results are within paradigm Pearson’s HSAB principle about metal-oxygen interaction. When sensitive part an impedimetric sensor, detection limit for all 50 pM, very lower than environmental quality standards these priority hazardous substances.