A study of nanochitosans and their applications

Abstract

This project provided a simple and fast method for the preparation of nanochitosan emulsions and studied the applications of nanochitosan emulsions. First, a novel ultrasound method was developed for the preparation of nanochitosan without any chemicals except water. The nanochitosan was characterized using laser scanning, FT-IR, ¹H NMR, X-ray, SEM, TEM, and AFM. The prepared nanochitosan emulsion was then used for dye sorption studies and dyeability enhancement of nylon. The capacities of the nanochitosan as an adsorbent for 5 anionic dyes including Acid Orange 7, Acid Red 1, Acid Red 18, Direct Red 84, and Direct Red 80, were studied. The sorption behaviors of microchitosan were also studied for comparison. It was found that the nanochitosan had higher sorption capacities than those of the microchitosan, especially for the dyes with large molecular sizes. The sorption mechanism, sorption kinetics and equilibrium isotherm were also investigated. The nanochitosan was also applied to nylon fabrics and the corresponding dyeing properties were studied. The nanochitosan-treated and control nylon were dyed with 8 anionic dyes. The results showed that the dyeing depths of the chitosan-treated fabrics were higher and the fastness was not affected.