Zhao Lianjie, Wang Yingchao, Wang Qiang, Liu Shanshan, Ji Xingxiang
State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China.
Polymers (Basel). 2023 Dec 22;16(1):49. doi: 10.3390/polym16010049.
The valorization of the black liquor produced during the chemical pulping of wheat straw is the key to the sustainable use of this abundant agricultural waste. However, the silica problem has hampered the recovery process. Herein, nanoprecipitation technology was used to produce lignin nanoparticles (LNPs) from wheat straw black liquor using γ-valerolactone (GVL) as a solvent and water as an anti-solvent. The results showed that a uniform, well-dispersed, and stable LNP was produced. The particle size and Zeta potential of 161 nm and -24 mV of the LNP suspension were obtained at a GVL concentration of 87%. The chemical structure and bonding of the lignin were adequately preserved after nanoprecipitation based on two-dimensional heteronuclear single quantum coherence nuclear magnetic resonance (2D-HSQC NMR) spectroscopy, Fourier transform infrared (FTIR) analysis, and thermal stability was improved based on thermogravimetric analysis. In addition, the abundant phenolic hydroxyl groups of LNP quantified by P-NMR analysis are beneficial for chemical cross-linking and modification. This work not only achieved the valorization of wheat straw black liquor but also opened up a new avenue for advanced nanomaterials.
麦草化学制浆过程中产生的黑液的价值化是可持续利用这种丰富农业废弃物的关键。然而，硅问题阻碍了回收过程。在此，采用纳米沉淀技术，以γ-戊内酯（GVL）为溶剂、水为抗溶剂，从小麦秸秆黑液中制备木质素纳米颗粒（LNPs）。结果表明，制备出了均匀、分散良好且稳定的LNP。在GVL浓度为87%时，LNP悬浮液的粒径和Zeta电位分别为161 nm和 -24 mV。基于二维异核单量子相干核磁共振（2D-HSQC NMR）光谱、傅里叶变换红外（FTIR）分析，纳米沉淀后木质素的化学结构和键合得以充分保留，基于热重分析，热稳定性得到提高。此外，通过P-NMR分析定量的LNP丰富的酚羟基有利于化学交联和改性。这项工作不仅实现了小麦秸秆黑液的价值化，还为先进纳米材料开辟了一条新途径。
