College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science & Technology, Xi'an, Shaanxi 710021, China.
Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan.
ACS Appl Mater Interfaces. 2020 Sep 2;12(35):39892-39901. doi: 10.1021/acsami.0c10657. Epub 2020 Aug 19.
Hydrogels derived from lignin are typically weak and contain only a small amount of lignin, which limits their broad application prospects. In the present work, a novel lignin/poly(-dimethylacrylamide) (PDMA) hydrogel with a high lignin content, superb toughness, and ultrahigh antioxidative performance is constructed by employing a facile dissolve-dry-swell solvent exchange method. Through this process, lignin and PDMA are self-assembled into a multienergy dissipative structure containing rigid lignin-rich domains. Precisely, the PDMA chains both interpenetrated inside and adhered on the surface of these domains through hydrophobic associations. This structure enables the lignin hydrogels to dissipate energy efficiently during the fracture process. At an optimized ultrahigh lignin content of 58% (dry weight basis), the prepared lignin hydrogel exhibited remarkable mechanical properties, such as a high elastic modulus (2.5 MPa), tensile strength (2.5 MPa), and super tensile strain (11.3), and an extremely high fracture energy above 16 000 J m. In addition, the tough lignin hydrogel exhibited a commendable antioxidant property and nontoxicity. All these advantageous properties provide the lignin/PDMA hydrogels with the potential for use in biomedical materials applications.
由木质素衍生而来的水凝胶通常强度较弱，且只含有少量木质素，这限制了其广泛的应用前景。在本工作中，通过采用简便的溶解-干燥-溶胀溶剂交换方法，构建了一种新型木质素/聚（二甲基丙烯酰胺）（PDMA）水凝胶，其具有高木质素含量、出色的韧性和超高的抗氧化性能。通过该过程，木质素和 PDMA 自组装成一种包含刚性木质素丰富区域的多能量耗散结构。具体而言，PDMA 链通过疏水相互作用同时贯穿这些区域的内部和表面。这种结构使木质素水凝胶在断裂过程中能够有效地耗散能量。在优化的超高木质素含量为 58%（干重基础）时，所制备的木质素水凝胶表现出显著的机械性能，如高弹性模量（2.5 MPa）、拉伸强度（2.5 MPa）和超拉伸应变（11.3），以及超过 16000 J m 的极高断裂能。此外，坚韧的木质素水凝胶表现出良好的抗氧化性能和无毒特性。所有这些有利的性质使木质素/PDMA 水凝胶有可能应用于生物医学材料领域。
