Shandong Provincial Key Laboratory of Fine Chemicals, Key Laboratory of Fine Chemicals in Universities of Shandong, Qilu University of Technology , Jinan 250353, China.
School of Material Science and Engineering, Henan Polytechnic University , Jiaozuo 454003, China.
ACS Appl Mater Interfaces. 2017 Nov 1;9(43):38052-38061. doi: 10.1021/acsami.7b12932. Epub 2017 Oct 23.
Designing hydrogels with high mechanical properties without sacrificing their self-healing efficiencies remains great challenges. We have fabricated cationic polyacrylamide/graphene oxide (GO) hydrogels by free-radical polymerization of acrylamide (AM) and 2-(dimethylamino)ethylacrylatemethochloride (DAC) in the presence of GO. The mechanical properties and self-healing ability can be tuned by the GO content and the mass ratio of AM and DAC. The ionic bonds between DAC and GO and the hydrogen bonds between AM and GO can efficiently dissipate energy and rebuild the networks. The resulting composite hydrogels possess high stiffness (Young's modulus: ∼1.1 MPa), high toughness (∼9.3 MJ m), and high fatigue resistance, as well as high self-healing efficiency (>92% of tensile strength, >99% of tensile strain and >93% of toughness). In addition, the completely dried hydrogels can recover their original mechanical values by spraying water and still possess outstanding self-healing efficiency. Our design can provide better fundamental understanding of physical properties of hydrogels and should enable the development of tough, self-healing hydrogels for practical applications.
设计具有高机械性能而不牺牲自修复效率的水凝胶仍然是巨大的挑战。我们通过丙烯酰胺 (AM) 和 2-(二甲氨基)乙基丙烯酰胺甲基氯 (DAC) 的自由基聚合，在 GO 的存在下制备了阳离子聚丙烯酰胺/氧化石墨烯 (GO) 水凝胶。GO 的含量和 AM 与 DAC 的质量比可以调节机械性能和自修复能力。DAC 与 GO 之间的离子键和 AM 与 GO 之间的氢键可以有效地耗散能量并重建网络。所得复合水凝胶具有高硬度 (杨氏模量：约 1.1 MPa)、高韧性 (约 9.3 MJ m)、高耐疲劳性以及高自修复效率 (>92%的拉伸强度、>99%的拉伸应变和>93%的韧性)。此外，完全干燥的水凝胶通过喷水可以恢复其原始机械性能，并且仍然具有出色的自修复效率。我们的设计可以为水凝胶的物理性能提供更好的基础理解，并应该能够为实际应用开发坚韧、自修复的水凝胶。
