Preparation of cotton fabric containing amidoxime functional group by graft polymerization

In this thesis, amidoxime group containing nonwoven cotton fabrics were prepared by grafting with acrylonitrile (AN) using plasma-induced graft polymerization method for the recovery of uranium ions in trace amounts from seawater. Different parameters such as power applied and plasma treatment time were studied to determine optimum plasma treatment conditions in order to perform graft polymerization. The experiments were carried out by applying three different plasma powers (60, 80 and 100 watts) and three different treatment periods (3, 5 and 10 min) in the plasma process. Grafting of AN onto nonwoven cotton fabrics by using plasma-induced graft polymerization were carried out in emulsion solutions at different reaction temperatures (40, 60 and 70°C) and different concentrations (10% (w/w), 30% (w/w), 50% (w/w) and 70% (w/w)) for 24 h to increase the degree of grafting of AN. For the preparation of uranyl ion selective adsorbent, the nitrile groups in the AN grafted nonwoven cotton fabric was converted to amidoxime groups by using hydroxylamine. Desorption of uranyl ions from nonwoven cotton fabrics was performed by using %3 HNO3 and nearly 100% of U (VI) ions were desorbed. Five adsorption desorption cycles were obtained as a result of reusability studies. The adsorption amount was determined as 0,17 mg (VI)/g adsorbent from 10 mL of seawater for 24 hours. The chemical structures, surface morphology and thermal properties of nonwoven cotton fabric, AN grafted, AO group modified and U (VI) adsorbed nonwoven cotton fabrics were characterized by using FTIR, XPS, SEM, EDX and TGA techniques.