School of Engineering, Deakin University, Geelong, Victoria 3216, Australia.
Laboratory of Sustainable Nanomaterials, Department of Wood Engineering and Technology, Gorgan University of Agricultural Sciences and Natural Resources, 4913815739 Gorgan, Iran.
Carbohydr Polym. 2022 Sep 1;291:119545. doi: 10.1016/j.carbpol.2022.119545. Epub 2022 Apr 30.
Presented here is the synthesis of a 3D printable nano-polysaccharide self-healing hydrogel for flexible strain sensors. Consisting of three distinct yet complementary dynamic bonds, the crosslinked network comprises imine, hydrogen, and catecholato-metal coordination bonds. Self-healing of the hydrogel is demonstrated by macroscopic observation, rheological recovery, and compression measurements. The hydrogel was produced via imine formation of carboxyl methyl chitosan, oxidized cellulose nanofibers, and chitin nanofibers followed by two subsequent crosslinking stages: immersion in tannic acid (TA) solution to create hydrogen bonds, followed by soaking in Fe solution to form catecholato-metal coordination bonds between TA and Fe. The metal coordination bonds were critical to imparting conductivity to the hydrogel, a requirement for flexible strain sensors. The hydrogel exhibits excellent shear-thinning and dynamic properties with high autonomous self-healing (up to 89%) and self-recovery (up to 100%) at room temperature without external stimuli. Furthermore, it shows good printability, biocompatibility, and strain sensing ability.
这里介绍了一种可 3D 打印的纳米多糖自修复水凝胶，可用于柔性应变传感器。该交联网络由三种不同但互补的动态键组成，包括亚胺键、氢键和邻苯二酚金属配位键。通过宏观观察、流变恢复和压缩测量证明了水凝胶的自修复能力。水凝胶通过羧甲基壳聚糖、氧化纤维素纳米纤维和甲壳素纳米纤维的亚胺形成制备，随后进行两次交联阶段：浸入单宁酸（TA）溶液中形成氢键，然后浸泡在 Fe 溶液中形成 TA 和 Fe 之间的邻苯二酚金属配位键。金属配位键对于赋予水凝胶导电性至关重要，这是柔性应变传感器的要求。水凝胶具有出色的剪切稀化和动态特性，在室温下无需外部刺激即可实现高达 89%的自主自修复和 100%的自恢复。此外，它还具有良好的可打印性、生物相容性和应变传感能力。
