Role of the interface on electron transport in electro‐conductive polymer‐matrix composite: A review

Abstract

Conductive polymer nanocomposites (CPC) are considered to be one of the best materials for the various applications like sensors, electrolyte membrane, photovoltaic cell, electromagnetic interference shielding materials, overcurrent protection devices, and many more due to the balance between electrical and mechanical properties, low cost, and ease of manufacturing. The most important aspect of an electro‐CPC is the interface between the polymer and conductive filler. In order to be electro‐conductive the fillers need not be in physical contact between them rather a few nanometer (typically ~10 nm) gap exist between two neighboring filler. Electrical conductivity of the composites arises from electron tunneling and hopping between conducting network. A typical way of preparing polymeric nanocomposites is the direct incorporation of inorganic nanoparticulate filler into polymers. Primarily focus has been given to carbonaceous nanoparticles in this article. Nanoparticles are an automatic choice for preparing the nanocomposites owing to their high‐interfacial interaction. However, it is often very difficult to well disperse nanoparticles in polymers because the nano particles with high‐surface energy are easy to agglomerate, which in turn adversely affects electron conduction in nanocomposites. One of the most used techniques to overcome this difficulty is to modify the interface of the polymer and filler as often the interface between polymer and filler played a crucial role in electron conduction. The aim of this review article is to report the most recent developments in improving the interface of filler and polymers in CPC. The discussions are primarily focused on different methodologies for the preparation of CPC characterization of the interface and finally interface modification techniques.

Conducting Polymers for the Design of Tactile Sensors

“…The transition of electron flow properties occurs by forming interconnected filler networks at a certain threshold filler concentration. The interface between the polymer and conductive filler [ 106 ] also plays an important role.…”

Enhanced thermal conductivity of polycarbonate‐based composites by constructing a dense filler packing structure consisting of hybrid boron nitride and flake graphite

“…Under such circumstances, it was conjectured that the presence of 10 wt% BN improved the distribution of Gt within PC. As a result, the distance between adjacent Gt decreased which was beneficial to the transport of electrons via variable range hopping or fluctuation induced tunneling mechanism, 79,80 thereby leading to a reduction of electrical resistivity. However, the electrical resistivity of PC/BN20/Gt composites increased when compared with their PC/BN10/Gt counterparts.…”

A review concerning the main factors that interfere in the electrical percolation threshold content of polymeric antistatic packaging with carbon fillers as antistatic agent

“…The resultant partial destruction of the conjugated chemical structure of graphitic structures may also impair the mechanism of electron transport, decreasing the electrical conductivity and disturbing the formation of a continuous conductive-electron network inside the nanocomposite, which may increase the electrical percolation threshold. [50,51] Braga et al [52] developed PTT/CNT nanocomposites for antistatic packaging and evaluated the influence of the CNT functionalization (with nitric acid) on the electrical properties of the materials. The authors verified that the nanocomposites with 0.5 or 1 wt% of functionalized-CNT presented higher values of electrical resistivity when compared with the values presented by the nanocomposites with the same content of pristine CNT.…”