Carbon nanomaterials are an emerging class of nano-reinforcements to substitute for metal-based nanomaterials in polymer matrices. These metal-free nano-reinforcement materials exhibit a high surface area, thermal stability, and a sustainable nature. Compared to conventional reinforcements, nano-carbon-reinforced polymer composites provide enhanced mechanical and thermal properties. While previous reviews summarized the functionality of nanocomposites, here, we focus on the thermomechanical properties of nano-carbon-reinforced nanocomposites. The role of carbon nanomaterials, including graphene, MXenes, carbon nanotubes, carbon black, carbon quantum dots, fullerene, and metal–organic frameworks, in polymer matrices for the enhancement of thermal and mechanical properties are discussed. Different from metal-based nanomaterials, carbon nanomaterials offer high specific strength, abundance, and sustainability, which are of considerable importance for commercial-scale applications.

Nanoreinforcements increase the stiffness of composite, however, CQDs enhance the toughness, thereby increasing both elongation and strength.

Composites are a promising material for high-specific strength applications; specifically, fiber-reinforced polymer composites (FRPCs) are in the limelight for their extraordinary mechanical properties. Amongst all FRPCs, carbon fiber reinforcements are dominant in the aerospace and automotive industry; however, their high cost poses a great obstacle in commercial-scale manufacturing. To this end, we explored alternate low-cost inorganic fibers such as basalt and rockwool as potential replacements for carbon fiber composites. In addition to fibrous inclusions to polymers, composites were also fabricated with inclusions of their respective particulates formed using ball milling of fibers. Considering automotive applications, composites’ mechanical and thermo-mechanical properties were compared for all samples. Regarding mechanical properties, rockwool fiber and basalt fiber composites showed 30.95% and 20.77% higher impact strength than carbon fiber, respectively. In addition, rockwool and basalt fiber composites are less stiff than carbon and can be used in low-end applications in the automotive industry. Moreover, rockwool and basalt fiber composites are more thermally stable than carbon fiber. Thermogravimetric analysis of carbon fiber composites showed 10.10 % and 9.98 % higher weight loss than basalt and rockwool fiber composites, respectively. Apart from better impact and thermal properties, the low cost of rockwool and basalt fibers provides a key advantage to these alternate fibers at the commercial scale.

The efficient electron transport layer (ETL) plays a critical role in the performance of perovskites solar cells (PSCs). Ideally, an unobstructed network with smooth channels for electron flow is required, which is lacking in the pristine TiO₂-based ETL. As a potential solution, here we tuned the structure of TiO₂ via optimized heteroatom doping of Al. Different concentrations (1, 2, and 3 wt%) of Al were doped in TiO₂ and were successfully applied as an ETL in PSC using spin coating. A significant difference in the structural, opto-electronic, chemical, and electrical characteristics was observed in Al-doped TiO₂ structures. The opto-electronic properties revealed that Al doping shifted the absorption spectra toward the visible range. Pure titania possesses a bandgap of 3.38 eV; however, after 1, 2, and 3% Al doping, the bandgap was linearly reduced to 3.29, 3.25, and 3.18 eV, respectively. In addition, higher light transmission was observed for Al-doped TiO₂, which was due to the scattering effects of the interconnected porous morphology of doped-TiO₂. Al-doped titania shows higher thermal stability and a 28% lower weight loss and can be operated at higher temperatures compared to undoped titania (weight loss 30%) due to the formation of stable states after Al doping. In addition, Al-doped TiO₂ showed significantly high conductivity, which provides smooth paths for electron transport. Thanks to the effective tuning of band structure and morphology of Al-doped TiO₂, a significant improvement in current densities, fill factor, and efficiency was observed in PSCs. The combined effect of better Jsc and FF renders higher efficiencies in Al-doped TiO₂, as 1, 2, and 3% Al-doped TiO₂ showed 12.5, 14.1, and 13.6% efficiency, respectively. Compared to undoped TiO₂ with an efficiency of 10.3%, the optimized 2% Al doping increased the efficiency up to 14.1%. In addition, Al-doped TiO₂ also showed improvements in antibacterial effects, required for photoactive textiles.

The goal of this study was to elucidate the interaction of complex feed solutions under modified membrane fouling models for constant flux operation. The polyvinylidene fluoride membrane (PVDF) was tested for three types of solutions containing inorganic foulants (Al, Mn, and Fe), organic foulants, and suspended solids at 0.5 mM Ca²⁺ ionic strength. The membrane’s performance was evaluated by measuring the increase in transmembrane pressure (TMP) during two different filtration scenarios: continuous filtration lasting 1 h and cyclic filtration lasting 12 min, with 3 min backwashing cycles included. Statistical analysis (linear regression results (R²), p-value) was used to verify the fouling model propagation along with the determination of the contributing constant of each fouling model. An increasing TMP percentage of 164–302%, 155–300%, and 208–378% for S1 (HA + Ca²⁺), S2 (inorganics + kaolin + Ca²⁺), and S3 (HA + inorganics + kaolin + Ca²⁺) was recorded for 1 h filtration, respectively. Furthermore, a five percent increase in irreversible resistance was noted for the S3 solution due to the strong adsorption potential of foulants for the PVDF membrane caused by the electrostatic and hydration forces of foulants. In addition to that, the participation equation elucidated the contribution of the fouling model and confirmed that complete blocking and cake layer contribution were dominant for the S1 and S3 solutions, while standard blocking was dominant for the S2 solution with a high significance ratio. Moreover, R² and cyclic filtration analysis also confirmed the propagation of these fouling models. The statistical confirmation and regression results analysis of the modified model gave comparative results and satisfied the filtration mechanism and can be used for the constant flux dead filtration analysis of water treatment.