Preparation and properties of graphene oxide/polyacrylic acid conductive and adhesive hydrogels
Current conductive hydrogel materials have many shortcomings in practical application,and thus it is of great significance to design and prepare a hydrogel with high strength,high adhesion and high conductivity.Graphene oxide(GO)was used as synergistic component and introduced into the hydrogel matrix fabricated by N-hydroxysuccinimide(NHS)grafted polyacrylic acid(PAA).Subsequently,PAA-NHS/GO composite hydrogels were prepared by a photoinitiated one-step polymerization method.The introduction of GO improved the crosslinking degree of the hydrogel system,increased the stability of the hydrogel and endowed it with high conductivity.The tensile strength,elongation at break and conductivity of PAA-NHS/GO could reach 0.336MPa,302.6%and 0.93S/m,respectively.The functional groups of the composite hydrogel could generate strong adhesion effect with the tissue surface,and the adhesion strength could reach to more than 40kPa.Additionally,PAA-NHS/GO possessed high biosafety and excellent biocompatibility.The composite hydrogel exhibited the ability of stable deformation sensing under external force.When used for electrocardiosignal(ECG)signal monitoring,the composite hydrogel showed high sensitivity and could achieve stable and clear signal transmission.As a novel conductive and adhesive hydrogel,PAA-NHS/GO was expected to be used in the fields of flexible wearable devices,biosensor and electronic skin.