Use of hybrid polyacrylonitrile/polypyrrole/polyaniline nonwoven mats for removal of the Remazol Black B dye

Abstract

We report the preparation of polyacrylonitrile/polypyrrole/polyaniline (PAN/PPy/PANI) mats, a new type of composite membrane obtained through an in situ chemical polymerization of pyrrole and aniline on an electrospun polymeric matrix of polyacrylonitrile, and their use for the capture and removal of Remazol Black B (RBB) dye molecules dissolved in an aqueous media. We characterized these membranes through scanning electron microscopy (SEM), Fourier Transform Infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–vis), thermogravimetric analysis (TGA), and contact angle measurements. We observed that the coating of electrospun PAN fibers was uniform, with the resulting membrane exhibiting a hydrophilic character. When exposed to RBB aqueous solutions at room temperature, the PAN/PPy/PANI mats presented the highest adsorption capacity (247.7 mg g−1) at pH 2. While the kinetics and adsorption isotherm data were best described by pseudo-second-order (PSO) and Langmuir models, respectively, the RBB adsorption was favored by an increase in the temperature. After subjecting the RBB-loaded membrane to different elution procedures, we were able to achieve full desorption in just 10 min. The thermal and environmental stability of the composite membranes allowed us to use them in at least 6 consecutive adsorption/desorption cycles without noticeable loss of their properties. These results suggest that PAN/PPy/PANI membranes are promising adsorbent materials for use in water remediation protocols.