Abstract

Conductive hydrogels with excellent electronic and mechanical properties are promising materials for flexible sensors. Herein we present a facile method to prepare reduced graphene oxide (rGO)-containing composite hydrogels with suitable electronic and mechanical properties. Poly(acrylic acid) grafted reduced graphene oxide (rGO-g-PAA) was synthesized from GO via a two-step process and then incorporated into chemically crosslinked polyacrylamide (PAM) networks by in-situ polymerization to give rGO-g-PAA/PAM composite hydrogels. The grafted PAA chains on rGO helped produce a stable and homogeneous dispersion of rGO-g-PAA in the PAM in the polymerization process. Hydrogen bonds existed between the grafted PAA chains and the PAM matrix, which not only improved the interfacial interaction between rGO and PAM matrix but also served as sacrificial bonds to dissipate energy. The rGO-g-PAA/PAM composite hydrogels exhibited enhanced tensile properties, rapid self-recovery, satisfactory electrical conductivity and remarkable resistance change upon stretching, all of which means it has the potential to be used as flexible strain sensors.

摘要

具有优异电子和机械性能的导电水凝胶是柔性传感器的有前途的材料。在此，我们提出了一种简便的方法来制备具有合适的电子和机械性能的含还原氧化石墨烯 (rGO) 的复合水凝胶。聚（丙烯酸）接枝的还原氧化石墨烯（rGO-g-PAA）通过两步法由GO合成，然后通过原位聚合结合到化学交联的聚丙烯酰胺（PAM）网络中，得到rGO-g-PAA/ PAM 复合水凝胶。在聚合过程中，rGO 上接枝的 PAA 链有助于在 PAM 中产生稳定且均匀的 rGO-g-PAA 分散体。接枝的 PAA 链和 PAM 基体之间存在氢键，这不仅改善了 rGO 和 PAM 基质之间的界面相互作用，而且还充当了耗散能量的牺牲键。rGO-g-PAA/PAM 复合水凝胶表现出增强的拉伸性能、快速的自我恢复、令人满意的导电性和显着的拉伸电阻变化，所有这些都意味着它具有用作柔性应变传感器的潜力。