Cellulose Nanocrystals (CNCs) Derived from Dyed and Bleached Textile Waste

Abstract

Background: Bio-based nanomaterials such as cellulose nanocrystals (CNCs) have been increasingly explored in nanotechnology owing to their chemophysical properties, self-assembly, and low toxicity. Introduction: CNCs can be isolated from various cellulosic biomass sources. Textiles which are mostly made of cotton, are under-utilized biomass that after their lifetime is either burned or dumped into landfills. Method: In this study, cotton-based textiles are studied as a source of CNCs. CNCs were extracted from textiles with and without bleaching before the acid hydrolysis step, and further comparing them with the properties of industrial microcrystalline cellulose-derived CNCs. Nanocrystals were synthesized from the three different sources and their morphology, thermal properties, and colloidal stability were compared. Results: The result show similar thermal properties and morphological characteristics for the three synthesized CNCs, and similar colloidal stability between the two textile-based CNC dispersions, suggesting that the dyes on CNCs do not impact the quality of the product. Removing the bleaching pre-treatment -a water-demanding and toxically harmful step- before CNC extraction provides cost and environmental benefits without compromising on the CNC quality. Conclusion: This project seeks to streamline the CNC synthesis process with the long-term goal of eventually facilitating the textile recycling industry.