Preparation and interaction mechanism of Nano disperse dye using hydroxypropyl sulfonated lignin

Particles size of disperse dye in dye bath seriously affected its dyeing quality. Here, we prepared a nano disperse dye with average particles size of 94 nm by self-assembly using a hydroxypropyl sulfonated alkali lignin dispersant (HSAL) and azo disperse dye (C.I. disperse Blue 79). The nano disperse dye exhibited excellent dispersion and stability at high temperature (130 °C), the particle size of that was 1.97 μm. The reducing effect of nano dye (azo structure) was decreased to 5.39% and the dye uptake reached up to 94.27%. The interaction mechanism between lignin derivatives dispersant and dye particles was investigated through the adsorption behaviors by employing quartz crystal microbalance with dissipation monitoring and AFM. The higher adsorption amount of HSAL on the dye surface displayed the more viscoelastic adsorption layer than that of sodium lignosulfonate. High sulfonic group attached to the long alkyl chain in HSAL molecules can stretch out to the aqueous phase to provide a strong electrostatic repulsion to disperse dye particles and form the nano disperse dye self-assembly. The present study provided a novel preparation method of nano disperse dye, that would broaden the efficient and value-able utilization of biomass lignin in dyeing and printing field.