Influence of Carbon Black on Properties of PZT-Cement Piezoelectric Composites

A novel piezoelectric composite has been developed using white cement as matrix, lead zirconate titanate as the piezoelectrically active phase, and carbon black (CB) as the conducting additive. By increasing the overall conductivity of the composites, CB facilitates the poling process of the composites so that it can be carried out at room temperature. The influences of CB on the piezoelectric and dielectric properties of the composites are investigated. A percolation threshold is observed with the threshold value for CB in the composites at about 1.4 vol.%. Before the threshold point, piezoelectric activity of the composites increases with increasing CB content. The highest piezoelectric strain factor (d(33)) is measured to be 28.5 pC/N, obtained by adding 1.0 vol.% CB. This is 148% higher than that of the composite without CB. This enhanced performance makes the composite particularly attractive for practical applications in the field of civil engineering.