Chemical Response of Nanocomposite Membranes of Electroactive Polydiaminonaphthalene Nanoparticles to Heavy Metal Ions

Abstract

Poly(1,5-diaminonaphthalene) (P15DAN) is a novel multifunctional but intractable polymer, from which it is difficult to preparing a large uniform membrane directly. A unique electroactive composite membrane was facilely prepared by drop-casting the dispersion of the P15DAN nanoparticles in 0.1% poly(vinyl alcohol) aqueous solution. The cyclic voltammogram of an electrode modified by the nanocomposite membrane strongly depends on the potential sweeping rate and pH value of the electrolyte solution. The anodic/cathodic peak currents rise linearly with increasing the sweeping rate, but decline with increasing the pH value. The redox and coordination sensitivity of the nanocomposite membrane to heavy metal ions including silver, mercury, and copper ions was explored by open-circuit potential and cyclic voltammetry techniques. The results indicate that the three ions are all spontaneously and non-electrochemically reduced by the P15DAN and then adsorbed on the membrane surface upon contacting each other, but t...