A Switching-Type Positive Temperature Coefficient Behavior Exhibited by PPy/(PhSe)₂ Nanocomposite Prepared by Chemical Oxidative Polymerization

Abstract

In this study, we prepared a polypyrrole-diphenyl diselenide [PPy/(PhSe)2] nanocomposite by oxidative chemical polymerization for the purpose of temperature sensing applications. Fourier transform infrared spectroscopy, X-ray diffraction and scanning transmission electron microscopy confirmed the synthesis of the above material. Thermogravimetry (TG) revealed enhanced thermal stability as compared to pristine polypyrrole (PPy). Dielectric study showed the material to have a dielectric constant of colossal value. The material has been found to exhibit correlated barrier hopping conduction (CBH) wherein hopping of charge carriers takes place over the insulating (PhSe)2 barrier. The maximum barrier height was found to be 0.224 eV. The nanocomposite material was found to exhibit a switching-type positive temperature coefficient (PTC) behavior with a Curie temperature of 400 K. This has been explained by a CBH model wherein PPy chains expand upon heating, thereby reducing the barrier height to facilitate current flow. However, above 400 K, disruption of PPy chains allows to reflect a PTC behavior. This has been in agreement with TG data.

Multifunctional Textile Electronic with Sensing, Energy Storing, and Electrothermal Heating Capabilities

“…The resistance of PFCNS (5 cm), in fact, decreases first as temperature rises (Figure 10c), which is probably ascribed to more electron transportation inspired by high temperature. However, con- tinuous high temperature may cause degradation of PPy, 69 leading to a resistance increase, which in turn lowers the electrothermal temperatures. PFCNS presents a stable cycling process at 4 and 8 V, only a slight decrease at 12 V (Figure 10d).…”

Synthesis Cobalt Complexed Single Chain Polymer and its Nanographene-based Composites, Electrical, Optical, and Thermal properties

“…The Arrhenius equation (Eq. 7) demonstrates the relationship between the direct current electrical conductivity (σ dc ) and temperature, as seen in [41]:…”

One‐Step Cooperative Growth of High Reaction Kinetics Composite Homogeneous Core–Shell Heterostructure

“…[44] The peak at 1191cm −1 is indicative of C─N stretching of PPy and 1023 cm −1 attributed to aromatic C−H stretching in-plane vibration. [45,46] The electronic structures of composite electrode materials were particularly susceptible to change as a result of interactions between the compounds. X-ray photoelectron spectroscopy (XPS) was used to thoroughly examine the electronic structures of compounds in order to gain a better understanding of the interactions between the symbiotically developing composites.…”