Structure and potential applications of polyamide 6/protein electro - spun nanofibrous mats in sorption of metal ions and dyes from industrial effluents

The main objective of this work is the preparation of nanofibrous mats (NFM) from polyamide 6 (PA6) reinforced and functionalized by renewable proteinic waste and examining their potential use for the sorption of heavy metal ions and dyes from wastewater from textile plants. Two renewable waste biopolymers; namely keratin (from waste of wool combing) and sericin (from degumming of natural silk) were extracted and regenerated. NFMs were prepared by electrospinning of PA6/biopolymer composites in formic acid using nozzle-less electro-spinneret. The potential of the prepared mats for sorption of Cr+6, Cr+3, Cu+2, and Pb+2 cations as well as anionic and cationic dyes from wastewater were assessed. The prepared composites were characterized by measuring their viscosity, nanofiber diameter, porosity, thickness, and air permeability. The morphological structure of the electro-spun NFM was investigated by scanning electron microscopy (SEM). Chemical and physicalproperties of the obtained mat were studied using Fourier Transform Infrared Spectroscopy (FTIR), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), and X-ray diffraction pattern (XRD). In the NFMs from PA 6 only, PA 6/keratin, PA 6/sericin, and PA 6/keratin and sericin, the sorption capacity of the prepared NFMs towards the examined cations varies according to the NFM composition and the nature of the adsorbed cation. In all cases, the maximum dye sorption was attained after 96 hours for basic dye and 72 hours for acid dye.