pH Controlled Reversible Interaction of Remazol Orange with Chitin

Abstract

Biomaterials offer alternative opportunities to build sustainable environment compared to synthetic polymeric materials. Here, we utilized a naturally occurring and plentiful biopolymer, chitin, for the studies on interactive phenomena of a reactive textile dye, Remazol Orange (RO), from aqueous solution. The functional groups and crystallinity of chitin were examined by Fourier transform infrared spectroscopy (FT-IR) and x-ray diffraction (XRD) study. Scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) were employed for the exploration of morphology and thermal stability of chitin. In order to investigate the effects of pH, contact time and initial RO concentration, batch studies were performed at room temperature of 25°C. Chitin exhibited a highly pH controlled reversible interaction with RO. RO was bounded 116.3 milligram per gram of chitin at pH 2.0 within 90 minutes of continuous shaking whereas 98.45% (w/w) RO were immediately unbounded from the chitin surface when the in-situ environment was changed at pH 10. Langmuir adsorption isotherm and pseudo-second order kinetic plot indicate homogeneous chemisorption and uniform monolayer of dye molecules on chitin surface. The findings from this study will certainly add value to analytical research leading to advanced applications in separation science and technology.