Carboxymethyl cellulose for green synthesis and stabilization of silver nanoparticles

Cotton samples having different degrees of polymerization (DPs) were prepared and used for synthesis of carboxymethyl cellulose (CMC) derivatives with different degrees of substitution (DSs). Thus obtained CMC products were, in turn, used for preparation of silver nanoparticles using silver nitrate under different conditions. UV-vis spectra of the silver colloidal solution reveal that increasing the pH of the latter causes appreciable changes in the absorption spectra and reaches its maximum at pH 12.5 indicating full reduction of silver ions. Prolonging the reaction time from 30 to 60 min brings about outstanding enhancement in the plasmon intensity indicating reduction of larger amounts of silver ions. Complete transformation of silver ions into silver nanoparticles occurs at 70 °C. Dispersion of silver nanoparticles improved upon increasing the DS of CMC from 1.22 to 2.2. The DP of CMC has significant effect on reduction efficiency, particle size and stabilization by CMC macromolecules. Silver nanoparticles colloidal solutions with concentrations higher than 100 ppm could be prepared by using AgNO3:CMC ratio 0.017 g:0.3 g per 100 ml solution. © 2010 Elsevier Ltd. All rights reserved.