Self‐healing Polyol/Borax Hydrogels: Fabrications, Properties and Applications

Self‐healing polyol/borax hydrogels have found great applications in various areas; especially in sensors, flexible electronics and biomedical fields. In this review, fabrication and characteristics of various types of borax‐based hydrogels are discussed. Mechanical properties and self‐healing behaviors of these hydrogels are strongly affected by the types of polyol, ratio of polyol:borax, and concentration of each component. Incorporation of highly polar nanofillers (such as cellulose nanofibers) into hydrogels and fabrication of double‐network structures have been employed as the promising strategies for improving the mechanical properties. Other additives have also been examined to generate nanocomposite hydrogels for a wide variety of uses; e. g. polyphenols for developing adhesives, conducting polymers, and hybrid structures based on carbon nanotubes and graphenes for electroconductivity, Ag and ZnO nanoparticles for antibacterial property, and quantum dots for fluorescence. Self‐healing polyol/borax hydrogels are great candidates for sensors, flexible electronics and biomedical devices. In this review, fabrication and characteristics of borax‐based hydrogels are discussed. Mechanical, electrical, antibacterial, and self‐healing properties are controlled by the types of polyol, ratio of polyol:borax, addition of various additives (cellulose nanofibers, polyphenols, conducting polymers, graphenes, carbon nanotubes Ag and ZnO nanoparticles) and concentration of each component. Representative examples in each case are discussed and the potential applications in specific cases have been addressed.