A novel strategy to reinforce double network hydrogels with enhanced mechanical strength and swelling ratio by nano cement hydrates

• Published in: Polymer (Guilford) 2023-03, Vol.269, p.125725, Article 125725
• Main Authors: Wang, Han, Lu, Zeyu, Wang, Fengjuan, Li, Yali, Ou, Zhongwen, Jiang, Jinyang
• Format: Article
• Language: English
• Subjects: Hybrid; Nano-C-S-H gels; Smart materials
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2023.125725

Nano-reinforcement has become a promising strategy to enhance the crosslinking microstructure and mechanical properties of hydrogels. In this study, a new type of nanomaterials from cement hydration, nano-calcium-silicate-hydrate (nano-C-S-H) gels, was for the first time to be adopted to strengthen the double network hydrogels, consisting of N-isopropylacrylamide and sodium acrylate. The experimental results indicated that 10 wt% addition of nano-C-S-H gels contributed to 40% and 157% enhancement in swelling ratio and compressive strength of N-isopropylacrylamide-co-sodium acrylate (Poly(NIPAm-SA)) hydrogels, respectively, which was attributed to the stronger chemical interactions between the nano-C-S-H gels and polymer matrix. Furthermore, 10 wt% addition of nano-C-S-H gels also improved the thermal stability of Poly(NIPAm-SA) hydrogels by 3.7%. In conclusion, the developed nano-C-S-H gels reinforced Poly(NIPAm-SA) hydrogels have great potential to be used as an efficient internal curing agent to develop high-performance concrete. [Display omitted] •FT-IR and SEM results proved nano-C-S-H increased hydrogel's crosslinking degree.•The addition of nano-C-S-H can increase the swelling ratio of hydrogels 16%∼40%.•The compressive strength of hydrogels can be enhanced 142%∼233% by nano-C-S-H.