Integration of Functional Nanomaterials in Biopolymer Composites using Ionic Liquid Based Methods

摘要

In this work, metallic silver nanoparticles were synthesized in linen powders by the process of incipient wetness impregnation. Linen powders with varying concentrations of silver particles were prepared by control of the amount of silver nitrate added during the synthesis. These composite materials were characterized by XPS, SEM, EDS, ATR-IR, and Raman. XPS showed that the silver was predominately zero valent. SEM did not show any distinct silver particles at the limit of the instrument resolution. However, EDX indicated a uniform distribution of silver in all linen powders. The ATR-IR exhibited no significant change in the linen substrate after silver nanoparticle synthesis. Raman spectroscopy of the linen powders displayed significant variability depending upon the amount of silver present. At low silver concentrations, the auto fluorescence of the lignin in the Linen powders dominated the Raman spectrum. At higher silver concentrations, the auto fluorescence declined dramatically and the Raman spectra of the cellulose emerged. At 10 wt % silver, the fluorescence was completely quenched and the cellulose spectrum was significantly enhanced. These results are consistent with the presence of nanoparticles that quench underlying linen fluorescence and give a surface enhanced Raman spectrum of the linen. The linen containing silver nanoparticles were then added to an IL to make an "ink" that was used to print patterns on a cellulose substrate.