Synergistic effect of the mesoporosity-turbostratic carbon on the six-fold piezoresistivity improvement of pristine polymer derived SiC pyrolyzed at high temperature

Abstract

This study reports the effect of the pyrolysis temperature on improving the piezoresistive property of pristine polymer derived SiC ceramics. Pyrolyzing the PDC SiC at 1600 ​°C improved the gauge factor by a factor of 6. Microstructural investigations demonstrated the formation of a network of turbostratic carbons above 1500 ​°C. The nitrogen (N2) adsorption isotherm demonstrates the presence of a mesoporous structure for 1600 ​°C, whereas lower temperature SiC showed microporosity. The improved piezoresistivity can be attributed to the tubostratic network, mesoporosity and tortuosity generated due to high pyrolysis temperature enabling tunneling-percolation mechanism with the incremental loading. The results provide new insights in designing PDC materials with improved piezoresistive performance.