Dielectric, Conductance and Pyroelectric Characterization of MWCNT:PVDF Nanocomposite Thin Films for Multiple Device Applications

摘要

Through this communication dielectric, pyroelectric, and conductance properties of polyvinylidene fluoride (PVDF) nanocomposite thin films with multi-wall carbon nanotubes (MWCNT) embedded in it, as a function of temperature and frequency are reported. Samples, ranging from 15 - 280 microns in thickness, were measured in the temperature range of 20 to 90℃ and in frequencies range of 50Hz to 110MHz. The samples were prepared by the cost effective and yet simple, solution casting technique. Measurements indicate that at constant temperatures, the real dielectric constant decreases at lower frequencies, stays steady at low frequencies but rises at higher frequencies towards the strong resonance. The dielectric loss, a particular concern as it is inversely related to the conductance, decreases also at lower frequencies but rise at higher frequencies with a steeper slope in each case. Additionally, pyroelectric coefficient is measured in the same temperature range and results show higher values compared to addition of silver nano particles in PVDF thin films and provided preliminary evidence of the causative microscopic response mechanism. Our MWCNT:PVDF thin films yield higher figures of merit than that indicated by pure PVDF thin films and results indicate a usage of MWCNT:PVDF thin films in infrared uncooled sensors and vidicon technology.