Lignin nanoparticles with improved dispersive stability as multifunctional sun-blocker for human wearable protection products

Advances in the processing of lignin based materials have brought to a new approach for the development of human- and eco- friendly wearable ultra violet (UV)shielding products. However, it is still a challenge to achieve the trade-off between UV shielding property and biocompatibility. Herein, dispersion stable lignin nanospheres (LNPs) with biocompatible property were designed via a simple and inexpensive method in a water/tetrahydrofuran (THF) system, and its chemical characteristics were hardly changed. Subsequently, an optics protective film with multifunction and safety was prepared without any chemical modifiers by adulterating LNPs into Polyvinyl alcohol (PVA). The LNPs/PVA film exhibited advanced characteristics, including UV shielding property (≥99.9 % at wavelength range of UVB), optical transparency (84.85 % at 550 nm) and mechanical performances (strength to 18.25 MPa and strain to 316.12 %). Meanwhile, a scalable strategy was proposed that LNPs was used to the surface functional coating of cotton fabric (CF) to fabricate human wearable UV shielding products. The prepared LNPs/CF exhibited superior UV shielding property with UV protection factor (UPF) of ＞900 and air permeability of 372.25 cm 3 /m 2 . d . Pa. Significantly, the LNPs/CF showcased superior comprehensive properties, including washing resistance, sewaging resistance and abrasing resistant, which maintained its original properties at extreme environment ( e.g. high and low temperature). This work paves a feasible avenue to develop multifunctional bio-based materials supported on future wearable UV protection products.