An investigation on piezoresistive behavior of carbon nanotube/polymer composites: II. Positive piezoresistive effect

Due to the diversity of carbon nanotubes (CNTs), polymers, and the preparation processes of the composites, CNT-filled polymeric composites present various piezoresistive properties. One puzzling issue is the concurrence of a negative piezoresistive effect and a positive piezoresistive effect in composites with different polymer matrixes. In this paper, we present a microscopic view of the nature of the positive piezoresistive effect and its dependence on the polymer matrix types based on the model in our previous study, in which the piezoresistive behavior was tailored by a parameter—the average junction gap variation ( AJGV )—describing the statistical property of the CNT conductive network. The microscopic movement process of CNTs embedded in a polymer matrix was analyzed and then the Poisson’s ratio of the polymer matrix was determined as a key factor that is in charge of negative or positive piezoresistive properties. The obstacle effect of polymer chains on the movemen...

Zhifeng Wang and Xiongying Ye

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