High strength zwitterionic nano-micelle hydrogels with superior self-healing, adhesive and ion conductive properties

Abstract

Zwitterionic nano-micelle hydrogels were prepared by in situ co-polymerization of zwitterionic monomer- [2-(methacryloyloxy) ethyl] dimethyl-(3-sulfopropyl) ammonium hydroxide (SBMA) and nonionic monomer-hydroxyethyl methacrylate (HEMA) for the first time using Pluronic F127 di-acrylate (F127DA) as macro-crosslinkers. This novel hydrogel featured tough mechanical properties (sustained a strain at 98% without fracture, and a tensile fracture strain at about 1000%), adhesiveness, as well as good conductive properties (two times than the traditional chemical cross-linked zwitterionic hydrogels). Due to strong electrostatic attraction constructed by the positively and negatively charged groups in the zwitterionic hydrogels, and the reversible dissociation-association of the micelle cross-linked zones via hydrophobic associations in the gel network, the prepared micelle-based hydrogels also exhibited excellent self-healable properties, the self-healed hydrogels exhibited almost the same stretching behavior compared with the original hydrogels. This superior zwitterionic nano-micelle hydrogel could therefore have great potential in applications like wearable sensors, human-health monitors, artificial skin and axon.