Measurement of Thermal Transport Properties in Metal Doped Polypyrrole

Simultaneous measurement of effective thermal conductivity (λ e ) and effective thermal diffusivity (χ e ) of three samples of polypyrrole doped with metals Ni and Co in different percentage: polypyrrole doped with 100% Co (S1), polypyrrole doped with 50-50% Ni and Co (S2), and polypyrrole doped with 100% Ni (S3) have been made using transient plane source (TPS) technique. The amorphous nature of polypyrrole composites was confirmed by XRD studies. Characterization through SEM and EDX gives the information of surface morphology and elemental analysis of samples. From surface morphology it is found that surface is not smooth and contains macro-granular structure. EDX results confirm the presence of metal present in the samples. Thermal transport properties i.e., effective thermal conductivity (λ e ) and effective thermal diffusivity (χ e ) were measured at normal pressure from room temperature to 170oC. From these investigations, it has been found that both λ e and χ e increase to maximum up to 110o and then a constant value is attained with further increase of temperature i.e., 170oC. The values of λ e and χ e of sample S3 doped with 100% Ni is higher as compared to sample S1 (Co 100%) and sample S2 (Ni, Co 50-50%). This result has been explained on the basis of bonding of cobalt and nickel with polypyrrole matrix during the polymerization and higher values for S3 are attributed to the more metallic nature of Ni.