Carbon black and graphite filled conducting nanocomposite films for temperature sensor applications

Conductive polymer composites have attracted remarked interest over the last decades and employed as functional materials in many important applications due to their ease in production, chemical durability and low weights. Regarding to this motivation, conductive polymer nanocomposite films were produced to be utilized as temperature sensors. Relatively low cost conductive fillers such as graphite and carbon black were employed to produce the films. The fillers with various concentrations were added in to styrene acrylic copolymer emulsion and subsequently deposited on glass substrates. The films were dried at 80 °C for 1 h in air. The individual effects of graphite and carbon black fillers on the percolation behavior were investigated. The percolation thresholds were recorded as 17 and 20 wt% for carbon black and graphite, respectively. As a second step, which is defined as co-percolation, composite films including both graphite and carbon black fillers with various amounts were also produced to scrutinize the synergetic effects of the fillers. Structural, electrical and thermo-resistive properties of the films were evaluated in details. Thanks to the synergetic effect of the fillers, lower percolation thresholds and enhanced thermo-resistive properties were obtained and consequently the composites developed in this study are good candidates for temperature sensors.