the plasmon resonance band appeared after 6 h while for pH 8 and
pH 11 (Figs. 3 and 4), it appeared within 10 min although a broad
spectrum was obtained for pH 8 at the beginning of the reaction.
The smaller sized nanoparticles obtained in the basic medium as
confirmed by the TEM analysis have been attributed to the high
dissociation rate of the hemiacetal and hydroxyl groups present
in the cellulose which are responsible for the reduction of silver
ions to silver nanoparticles (Park, Hong, Weyers, Kim, & Linhardt,
2011). As the reaction time increased from 5 min to 50 h for pH
8 and 11, the peak intensity also increased indicating increase in
the concentration of C–Ag-NPs. This trend is also observed at pH 4
except that the peak intensity was broad at 50 h indicating broad
size distribution.