The 3rd International Symposium on Nanocellulosic Materials (3rd ISNCM)

Efficient and sustainable functionalization is one of the key issues toward realizing high-value and scale-up application of lignocellulose nanopaper (LNP) that a renewable nanomaterial possesses unique technological appeal. Similar to its role in plant cell walls, lignin serves as a vital functional component in LNP matrices. However, its intrinsic light absorption property renders LNP undesirable for optical engineering applications. Here, a highly efficient, controllable and ecofriendly lignin modification strategy is developed for modulating the optical performance of LNPs by taking advantage of the beneficial synergistic effect of H2O2 and UV light in selectively eliminating lignin chromophores. The obtained lignin-modified LNP features not only a high visible light transmittance (89%) but also a high haze (90%) and excellent UV-shielding capacity, owing to the well-preserved lignin aromatic skeleton structures after lignin modification. Furthermore, patterning is easily achieved on hot-pressing-induced densified LNPs through a selective lignin modification approach, which endows LNPs with intriguing optical designability. Benefitting from the multifunctionality of lignin components for nanopaper matrices, patterned LNPs demonstrate outstanding water and thermal stability, barrier properties, durability and biodegradability, which are of great significance for practical applications. This optically designable LNP with admirable multifunctionality is a promising candidate material for next-generation optical management, sensing and conversion systems.