A fast and low energy-consumption method for the conversion of lignocellulosic biomass to sustainable structural color materials†

Abstract

Structural color materials are widely applied in advanced optical, biomedical, and energy fields. As the demand for sustainable development and green manufacturing continues to grow in the functional materials sector, the next-generation structural color materials are expected to be prepared with renewable, biocompatible, and biodegradable resources such as lignocellulosic biomass. In this work, we present a fast and low energy-consumption method for converting lignocellulosic biomass to sustainable structural color materials. The lignocellulosic biomass is first treated with an organic–water cosolvent to obtain the extracted solution. Then, the lignin component in the extracted solution, without any purification and fractionation treatment, is assembled into uniform clusters by increasing the water content in the cosolvent to 80 vol%. Finally, the structural color materials are prepared by constructing a periodically ordered array of lignin clusters after centrifugation. The acetone–water cosolvent (6 : 4, v/v) was found to exhibit the best performance for the preparation of structural color materials among 12 different cosolvents, as the extracted lignin in this cosolvent system shows good uniformity and appropriate surface charge. Moreover, the structural color materials obtained from lignocellulosic biomass exhibit tunable colors and good water-responsive properties, and show promising potential as green paints and cosmetics. This strategy greatly simplifies the production process of structural color materials from lignocellulosic biomass, and thus significantly reduces the consumption of energy, time, and solvent compared with the existing methods.