Physically and Chemically Dual-crosslinked Hydrogels with Superior Mechanical Properties and Self-Healing Behavior
An ideal hydrogel for biomedical engineering or flexible devices should have excellent properties, especially high stretchability, strength, resilience and self-healing ability to withstand cyclic loading and damage. The formation of hydrogels by physically and chemically dual-crosslinked structures is a powerful method to improve the strength and resilience. Here, we designed a dual-crosslinked hydrogel (PCDC) with sodium dodecyl sulfate-stearyl methacrylate (SDS-C18) micelles as physical crosslinkers, amphiphilic polyether modified polysiloxane terminated by isocyanoethyl methacrylate (SiPU) nanoparticles as chemical crosslinkers, and acrylamide (AM) as monomer. The prepared PCDC hydrogels have a tensile strength of above 130 KPa and tensile elongation at break of over 710%, and can quickly recover its original state in cyclic tensile and cyclic compression tests, exhibiting excellent stretchability, strength and resilience. Based on the hydrophobic interactions mechanism, remarkable self-healing behaviors of the hydrogels were also achieved, allowing re-adhesion between cut surfaces without external stimulus.