基于正异丙基丙烯酰胺的杂化水凝胶,两性离子共聚单体,并合成了氧化石墨烯,研究了它们的物理力学性能。与机械性能相比,组成变化在很大程度上影响了混合水凝胶的溶胀特性,即,伸长和压缩。此外,对溶胀的水凝胶进行流变溶胀测量,直到它们达到平衡,显示非常低的相位角δ,表明强共价网络。随着两性离子和GO含量的增加,其含量增加。研究了肿胀动力学,发现遵循Fickian动力学,尽管含有两性离子的凝胶显示出独特的两步溶胀模式。有趣的是,对于具有来自其1D纳米填料CNT(碳纳米管)的2DGO(氧化石墨烯)纳米填料的水凝胶,溶胀机制的差异也是清楚的。.在伸长率方面,在Hencky应变εmax约为0.4-0.65时,样品以脆性方式断裂,对于具有高Zw含量和0.2%GO的样品,观察到最大应力,这可以用GO锋利边缘的应力上升特性来解释。相比之下,压缩中的数据受益于较高的GO含量,因为在这种变形模式下,裂纹扩展不太重要。这项工作将有助于未来的复合凝胶应用。
Hybrid hydrogels based on n-isopropylacrylamide, zwitterionic comonomer, and graphene oxide were synthesized to
study their physical and mechanical properties. The compositional variation largely influenced the swelling characteristics of the hybrid hydrogels compared to mechanical properties, i.e., elongation and compression. Additionally, Rheometric swelling measurements on the swollen hydrogels were performed until they reached equilibrium showed a very low phase angle δ indicating strong covalent network, which intrun increases with increasing content of zwitterions and GO. Swelling kinetics were studied and found to follow Fickian dynamics, albeit zwitterion-containing gels showed a peculiar 2-step swelling pattern. Interestingly, differences in the swelling mechanism are also clear for the hydrogels with 2D GO (Graphene oxide) nano-fillers from its 1D nano-filler CNTs (Carbon nanotubes). In elongation, the samples break in a brittle fashion at Hencky strains εmax around 0.4-0.65 with the maximum stress being observed for samples with high Zw-content and 0.2% GO, which can be explained by the stress-rising properties of sharp edges of GO. In contrast, the data in compression profits from higher GO-contents as crack growth is less important in this deformation mode. This work will contribute to future composite gel applications.