Herein, a physicochemical pretreatment method, namely, a combination of recyclable acid hydrotrope (p-toluenesulfonic acid, p-TsOH) treatment and ultrasonic treatment (10 s), was employed to extract lignin-containing fibers (LFs) from wood material (poplar). The LFs were used to produce reinforced polyvinyl alcohol (PVA) hydrogels via a dissolution-regeneration process in LiBr⋅3H₂O solution. After coating the produced hydrogel on the end face of a single-mode fiber (SMF), a fiber-optic relative humidity sensor (FORHS) was fabricated to monitor environmental humidity. A high sensitivity (4.7 dB) and good repeatability (R ² = 0.98, the confidence factor) were found within a humidity range from 45 % to 80 %. Therefore, this study provides a sustainable approach for valorization of lignocellulosic biomass.

在此，采用物理化学预处理方法，即可回收酸性水溶助长剂（对甲苯磺酸，p- TsOH）处理和超声处理（10 s）相结合，从木材（杨树）中提取含木质素纤维（LFs）。）。LFs 用于通过在 LiBr·3H ₂ O 溶液中的溶解-再生过程生产增强型聚乙烯醇 (PVA) 水凝胶。在单模光纤 (SMF) 的端面上涂覆产生的水凝胶后，制造了光纤相对湿度传感器 (FORHS) 以监测环境湿度。高灵敏度 (4.7 dB) 和良好的可重复性 ( R ²= 0.98，置信因子）是在 45 % 到 80 % 的湿度范围内发现的。因此，本研究为木质纤维素生物质的增值提供了一种可持续的方法。