Lignin nanoparticles (LNPs) are regarded as a sustainable and advanced way to use residual lignin for application in composites. However, some challenges remain to achieve the controllable preparation of LNPs or tuning the polymeric properties with LNPs. In this study, size-controlled LNPs were prepared with three narrow lignin fractions, then added into poly(vinyl alcohol) (PVA) matrix. LNPs and different LNPs-filled PVA, analyzed by GPC, ³¹P NMR, and 2D HSQC NMR, TEM, rheology and tensile tests, revealed substantial differences in terms of lignin structures-LNPs sizes-PVA mechanical properties. With the addition of fractionated LNPs (LNPs₇₀), the toughness and strength of PVA can be improved to 6.33 % and 289.9 %, respectively. This study will promote the development of not only advanced hydrogels but also lignin chemistry and biorefinery technologies.

木质素纳米颗粒 (LNP) 被认为是一种可持续且先进的方法，可将残留的木质素用于复合材料中。然而，在实现 LNP 的可控制备或利用 LNP 调整聚合物特性方面仍然存在一些挑战。在本研究中，使用三种窄木质素组分制备尺寸受控的 LNP，然后将其添加到聚乙烯醇 (PVA) 基质中。LNPs 和不同 LNPs 填充的 PVA，通过 GPC、³¹ P NMR 和 2D HSQC NMR、TEM、流变学和拉伸测试分析，揭示了木质素结构 - LNPs 尺寸 - PVA 机械性能方面的显着差异。添加分馏 LNP (LNP ₇₀)，PVA的韧性和强度可分别提高到6.33%和289.9%。这项研究不仅将促进先进水凝胶的发展，还将促进木质素化学和生物精炼技术的发展。