Synthesis of carboxymethyl starch-g-polyvinylpyrolidones and their properties for the adsorption of Rhodamine 6G and ammonia

Carboxymethyl starch-g-polyvinylpyrolidones (CMS-g-PVPs) were prepared by grafting of carboxymethyl starch (CMS) with N-vinylpyrolidone (NVP) using different initiators. The grafting percentage of all the modified starches was determined and the modified starch (CMS-g-PVP-5) with maximum grafting percentage was characterized by elemental analysis, 1H NMR and FT-IR spectroscopy. Crystallinity and thermal properties of CMS-g-PVP-5 were analysed by XRD and TGA, respectively. CMS-g-PVP-5 was then utilized for the adsorption of Rhodamine 6G (dye) from water under different pH, temperature, adsorbate doze and adsorbent concentration. This modified starch showed good adsorption ability towards Rhodamine 6G. CMS-g-PVP-5 was also applied for the adsorption of ammonia gas and proved an exciting adsorbent for ammonia.