Liquid Crystal Cellulose Nanocrystal/ Polyvinylpyrrolidone Pigments Engineered from Agro‐Waste Sugarcane Bagasse

Abstract

AbstractBio‐inspired iridescent materials can possibly replace organic dyes and pigments, however, fabricating materials that resemble the appearance of absorbing pigments is challenging. Extracting cellulose nanocrystals (CNCs) from waste biomass is a sustainable practice in light of socio‐economic and environmental concerns. In an attempt, CNCs from sugarcane bagasse are isolated through acid hyrdolysis. Stable anisotropic dispersions of CNCs are doped with polyvinylpyrrolidone (PVP). Iridescent composite films are cast from these suspensions through evaporation–induced self‐assembly approach (EISA). The physicochemical properties of the films are studied at different loadings of PVP. These iridescent CNC/PVP composite films are then ball‐milled to produce iridescent red and blue tone color pigments. The morphology and optical properties of pigments are studied through Field emission scanning electron microscopy (FE‐SEM) and Hot‐stage Polarized Optical Microscopy (POM). These pigments are then re‐dispersed in a transparent polar polymer matrix to visually observe the color induced by them using solvent casting approach.