Abstract:

The filter paper was used as raw material to prepare cellulose nanocrystals(CNCs) and gold nanoparticles(GNPs) were prepared by sodium citrate reduction method. Subsequently, CNCs/GNPs composite iridescence was prepared by blending GNPs and CNCs at different mass ratios, following by adding fructose to the above system in order to study the influence of fructose on the plasmon absorption resonance effect. Then, the composite films were analyzed by transmission electron microscopy(TEM), reflection spectroscopy, scanning electron microscopy(SEM), polarized light microscopy, infrared spectroscopy, X-ray diffraction(XRD), ultraviolet-visible(UV) spectroscopy and circular dichroism(CD). The results showed that CNCs have self-assembled during the film formation process and formed a left-handed chiral layered liquid crystal structure; the composite film had obvious iridescent color, periodic layered structure and fingerprint texture. The addition of GNPs did not change the CNCs itself, but the composite membrane had obvious plasmon resonance absorption peak and blue-shifted. Moreover, the addition of fructose could make the color of the film red-shifted and promote the more uniform dispersion of GNPs, thereby enhancing the plasmon resonance absorption effect of GNPs. Particularly, the addition of GNPs and fructose did not change the crystal structure of CNCs, nor did it affect the crystallinity of cellulose.

Key words: cellulose nanocrystals, gold nanoparticles, fructose, iridescent film, plasmon resonance