Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China; Institute of Chemical Industry of Forestry Products, Chinese Academy of Forestry (CAF), Jiangsu Province, No 16, Suojin Wucun, Nanjing 210042, China.
Institute of Chemical Industry of Forestry Products, Chinese Academy of Forestry (CAF), Jiangsu Province, No 16, Suojin Wucun, Nanjing 210042, China.
Int J Biol Macromol. 2021 Aug 1;184:200-208. doi: 10.1016/j.ijbiomac.2021.06.054. Epub 2021 Jun 11.
To develop the hydrogels with high mechanical strength and excellent conductivity is always a challenging topic. In this study, the ultra-strong hydroxypropyl cellulose (HPC)/polyvinyl alcohol (PVA) composite hydrogels were prepared by combination of the triple-network and mechanical training. The proposed composite hydrogels were achieved by physically crosslinking HPC with PVA to form the first crosslinking network, in which the HPC fibers could decrease the crosslinking density of PVA matrix and generate a lot of water-rich porous area. Then, 2-hydroxyethyl acrylate (HEA), acrylamide (AM) and aluminium chloride diffused into the first network to fabricate the chemical crosslinking network and ionically cross-linked domains. The formation of triple-network enhanced the mechanical strength and toughness to 1.87 MPa and 339.09 kJ/m, respectively. Especially, the crystalline domains of PVA chains could improve the hydrogel's fatigue resistance, and the orderly arrangement of the crystalline domains achieved through mechanical training process could further enhance the mechanical strength. The mechanical strength of pre-stretched composite hydrogel was increased up to 2.8 MPa. The composite hydrogels exhibit great applications in sensors, human-machine interactions, and wearable devices.
开发具有高机械强度和优异导电性的水凝胶一直是一个具有挑战性的课题。在这项研究中，通过三重网络和力学训练的结合，制备了具有超高强度的羟丙基纤维素（HPC）/聚乙烯醇（PVA）复合水凝胶。所提出的复合水凝胶是通过 HPC 与 PVA 物理交联形成第一交联网络来实现的，其中 HPC 纤维可以降低 PVA 基体的交联密度并产生大量富含水的多孔区域。然后，2-羟乙基丙烯酸酯（HEA）、丙烯酰胺（AM）和氯化铝扩散到第一网络中，形成化学交联网络和离子交联区域。三重网络的形成分别将机械强度和韧性提高到 1.87 MPa 和 339.09 kJ/m。特别是，PVA 链的结晶域可以提高水凝胶的耐疲劳性，并且通过力学训练过程实现的结晶域的有序排列可以进一步提高机械强度。预拉伸复合水凝胶的机械强度增加到 2.8 MPa。复合水凝胶在传感器、人机交互和可穿戴设备方面具有很大的应用前景。
