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.

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Chemical stress-induced alterations in the number-density and the architecture of conducting interjunctions impart chemiresistivity in conducting polymer composites (CPCs). Herein, marked enhancement in the chemiresistive response of CPCs is reported by maneuvering interfacial and percolation characteristics of carbon nanotube (CNT) based chemiresistors, through CNT functional group variation and high energy radiation exposure. Unfunctionalized (CNT-UF), hydroxyl functionalized (CNT-OH), amine functionalized (CNT-NH2), and carboxyl functionalized (CNT-COOH) carbon nanotubes, polydimethylsiloxane (PDMS), and γ radiation were used in different combinations to prepare PDMS/CNT chemiresistors. Even at the same ϕCNT, PDMS/CNT-NH2 chemiresistors exhibited significantly milder response against toluene vapors than PDMS/CNT-COOH chemiresistors, whereas PDMS/CNT-OH chemiresistors were unresponsive due to poor nanotube dispersion and low electrical conductivity. PDMS/CNT-COOH chemiresistors had the lowest surface energy, highest entanglement density, and highest critical strain for CNT–CNT structure breakdown under shear, suggesting superior interfacial interactions. Dielectric, CNT percolation, and XPS analysis also revealed marked variations in CPC properties with change in functional groups on CNT. The gel content of all irradiated chemiresistors increased with radiation dose; however, amine-functionalized CNT was found to inhibit interfacial radical combinations. With the increase in radiation dose, the chemiresistivity increased in a dose-dependent fashion, suggesting the possibility of interfacial grafts and immobilization of PDMS segments onto the CNT-COOH surface. The chemiresistivity of the PDMS/CNT-COOH chemiresistor was highly dependent on polymer–solvent interaction parameters. The chemiresistor displayed excellent sensitivity, reversibility, and reproducibility, underscoring its potential in monitoring hazardous volatile organic compounds.