A novel class of carbon nanotube (CNT)-based nanomaterials has been surging since 1991 due to their noticeable mechanical and electrical properties, as well as their good electron transport properties. This is evidence that the development of CNT-reinforced polymer composites could contribute in expanding many areas of use, from energy-related devices to structural components. As a promising material with a wide range of applications, their poor solubility in aqueous and organic solvents has hindered the utilizations of CNTs. The current state of research in CNTs—both single-wall carbon nanotubes (SWCNT) and multiwalled carbon nanotube (MWCNT)-reinforced polymer composites—was reviewed in the context of the presently employed covalent and non-covalent functionalization. As such, this overview intends to provide a critical assessment of a surging class of composite materials and unveil the successful development associated with CNT-incorporated polymer composites. The mechanisms related to the mechanical, thermal, and electrical performance of CNT-reinforced polymer composites is also discussed. It is vital to understand how the addition of CNTs in a polymer composite alters the microstructure at the micro- and nano-scale, as well as how these modifications influence overall structural behavior, not only in its as fabricated form but also its functionalization techniques. The technological superiority gained with CNT addition to polymer composites may be advantageous, but scientific values are here to be critically explored for reliable, sustainable, and structural reliability in different industrial needs.

The electrochemical stability and charge-transport properties of biopolymer blend films are significantly affected by blend composition, as each polymer component contributes uniquely to segmental mobility, bulk resistance, amorphous structure, and interfacial stability. In this study, salt-free agarose:phytagel (AG:PY) biopolymer blend films were fabricated at various weight ratios using the solution-casting method to identify an optimal host matrix for the development of salt-doped electrolytes. Linear voltammetry measurements showed that the 50:50 mass ratio AG:PY mixture has an electrochemical stability window of 3.25 V, indicating substantial resistance to electrochemical decomposition within the tested potential range. Electrochemical impedance spectro­scopy analysis showed that the 50:50 blend achieved the highest room-temperature conductivity of 1.56 mS cm⁻¹, attributed to reduced bulk resistance and indicating more favourable charge-transport characteristics within the polymer host. X-ray diffraction analysis verified this finding, revealing the lowest crystallinity in the 50:50 mass ratio, suggesting increased amorphous content and greater polymer chain flexibility. Fourier-transform infrared spectroscopy spectral shifts confirmed interactions between the functional groups of agarose and phytagel, indicating improved blend compatibility. Collectively, the 50:50 mass ratio AG:PY blend exhibited the most advantageous combination of electrochemical stability, ionic conductivity, amorphous structure, and polymer interaction, establishing it as a promising sustainable host matrix for future salt-doped biopolymer electrolyte applications.