LAUSR

Abstract Super-absorbent hydrogels (SAH) as an advanced material have drew great interest owing to their wide applications in various areas such as forestry, agriculture, sewage treatment and sanitary products. Swelling rate (SR) and water retention ratio (WRR) are usually the pivotal elements for its application. However, high SR of SAH with excellent WRR is rarely reported, which can be mainly due to unsuitable crosslinker. Here we show that a novel SAH with a dual stretchable single network was prepared through a free radical polymerization of AA and AM (acrylic acid-co-acrylic amide) monomer with self-made controllable vinyl hybrid silica nanoparticles (VSNPs) as crosslinker. Particularly, the dual stretchable single network was designed by the molecular chains grafting on the surface of VSNPs and hydrogen bonding on polymer chains, which can significantly improve the cross-linking density and enhance swelling performance. Therefore, SR of the SAH can reach up to 5066 g/g and remain over 70% moisture after exposed to the air for 3 days at 293k with humidity around 50%. This SAH also has an incomparable swelling property in other solution like urea, salt. The adsorption behavior of this SAH matches well with the Fickian diffusion model. Collectively, the design of this work opens a new way for the development of SAH with obviously enhanced swelling performance and water retention capacity in the biomaterial fields.