Influence of carbon black and carbon nanotube on mechanical and piezoelectric properties of γ–C2S–PZT composite

This paper investigated the influence of carbon black (CB) and carbon nanotube (CNT), used at 0-1%, by volume, on mechanical performance and piezoelectricity of 0-3 gamma-C2S-based piezoelectric composite. The gamma-C2S-based piezoelectric composite was prepared through carbonation of the proportioned mixture. Parameters d(33), g(33), and epsilon r were characterized with the CB and CNT additions. The influence of PZT size and volume on these parameters were also studied. Tested results showed that a greater PZT average size and volume significantly improved the d(33), g(33), and epsilon r values of gamma-C2S-based piezoelectric composite given the increased contact among PZT particles. The use of 1.0% CB can lead to 50% and 265% enhancements in d33 and epsilon r, respectively. Such improvements in d(33) and epsilon r values were 50% and 190%, respectively, with the addition of 0.3% CNT. This is attributed to the enhanced conductivity of gamma-C2S-based piezoelectric composite, which can promote the poling of PZT particles. Moreover, the compressive strength of gamma-C2S-based piezoelectric composite were improved by 12 and 3 MPa with the use of CB and CNT, respectively. In addition, the gamma-C2S-based piezoelectric composite had 2-6 folds greater d33 and epsilon r values given the similar CB and CNT contents relative to those of cementitious piezoelectric composite. Therefore, the use of CB and CNT can advance the development of gamma-C2S-based piezoelectric composite with enhanced mechanical performance and piezoelectricity.