Tuning Graphene Oxide Oxidation Degree for Enhanced Strain Sensing andMechanical Properties in PVA/GO Composite Hydrogels

Controlling the concentration of oxygen-functional groups on graphene oxide (GO) nanosheets is acrucial approach to tune the related electrical and mechanical properties. Increasing the oxidationdegree of graphene sheets can lead to a significant reduction in electrical conductivity, whileenhancing the mechanical properties. In this study, the concentration of oxygen-functional groups onGO nanosheets was manipulated by modifying the Hummer's synthesis process. To investigate thestrain sensor behavior and mechanical properties, polyvinyl alcohol/graphene oxide (PVA/GO)composite hydrogels were prepared.The electrical and mechanical test results indicate that hydrogelscontaining graphene oxide with the lowest degree of oxidation exhibit excellent strain sensitivity(gauge factor, GF = ۲.۳۱) and good mechanical performance (tensile stress = ۴۳.۸ kPa, elongation atbreak = ۱۵۵%). In contrast, the hydrogels reinforced with highly oxidized GOs showed a hinderingeffect on electron transport efficiency. These findings can be widely utilized in the development ofhigh-performance wearable sensors and soft robotics applications

کلیدواژه ها:

Smart and functional polymers ، Graphene oxide ، Composite hydrogel ، Strain sensor.