Nanoscience & Nanotechnology-Asia - Volume 15, Issue 5, 2025

MXenes, 2D transition metal carbides, nitrides, or carbonitrides, have garnered significant research attention due to their exceptional properties. Delaminated MXenes (d-MXenes) have further expanded interest due to their enhanced functionalities. However, their instability in aqueous solutions and oxygen-rich environments at room temperature, leading to surface oxidation, remains a critical challenge.

In this study, Ti3C2Tx and Mo2CTx multilayer MXenes were synthesized from their respective MAX phases (Ti3AlC2 and Mo2Ga2C) using a mixed etching solution of 12 M HCl, DI water, and 48% HF with ratios of 6:3:1 (for Ti3AlC2) and 6:1:3 (for Mo2Ga2C). The etched MXenes were further treated with 0.5 M LiCl to obtain delaminated MXene (d-MXene) sheets, dispersed in nitrogen-degassed DI water.

The d-MXenes were characterized using UV-visible spectroscopy, HRSEM, and EDS. Samples were aged at room temperature for 20 days, after which fresh samples were also prepared from the same MXene solutions for comparison.

HRSEM and EDS analyses revealed that 20-day-old d-MXene samples exhibited surface oxide formation, with Ti3C2Tx forming pinecone-like structures (TiO2) and Mo2CTx showing spherical oxide particles (MoO3). In contrast, freshly prepared d-MXene samples exhibited unoxidized smooth surfaces and sharp edges for Ti3C2Tx and uneven surfaces with bent edges for Mo2CTx.

After 45 days in aqueous solutions at room temperature, the Ti3C2Tx solution color changed from transparent green to whitish, and the Mo2CTx from transparent brown to blue, confirming significant oxidation. These findings emphasize the need for deoxygenated storage conditions to enhance the stability and lifespan of Ti3C2Tx and Mo2CTx d-MXenes in both liquid and solid forms.

Polymeric nanocomposites have gained significant attention due to their potential for enhanced properties and applications across diverse industries, including automotive, aerospace, electronics, biomedical, and environmental sectors.

This review examines the advancements in polymeric nanocomposites made possible by nanofillers and highlights the transformative role of Artificial Intelligence (AI) in materials science.

Using a detailed description of the methodology to select studies for inclusion and exclusion, key nanofillers such as carbon nanotubes, graphene, and metal-organic frameworks were examined for their ability to enhance the mechanical, thermal, electrical, and barrier properties of polymer matrices. Additionally, AI-based optimization approaches for synthesis and property prediction are discussed, along with a focus on green synthesis methods to align with sustainability goals.

Nanofillers significantly improve polymer properties, enabling their use in various industries. AI has revolutionized nanocomposite synthesis, facilitating optimized processes and reliable property predictions. Green synthesis methods offer sustainable alternatives; however, challenges persist, including achieving uniform filler dispersion, ensuring biocompatibility for biomedical applications, and reducing the costs associated with large-scale synthesis.

This review highlights the potential of polymeric nanocomposites, emphasizing the importance of establishing standard synthesis and characterization procedures to enhance reliability and promote sustainable development in materials science. Further research is essential to address current limitations and fully realize the potential of nanocomposites in advancing industrial applications.

Graphene Nano-Ribbon Tunnel Field-Effect Transistors (GNR TFETs) have emerged as a promising device structure for low-power and high-frequency applications due to their superior electrical properties. Gate engineering in GNR TFETs offers enhanced performance compared to conventional TFETs by optimizing carrier transport characteristics.

The proposed model is formulated using Poisson’s Equation in a two-dimensional framework, solved analytically using the Parabolic Approximation method. The device structure incorporates two distinct gate metals (M1 and M2) and a high-k dielectric, Hafnium Di-Oxide (HfO2), to optimize bandgap narrowing. The analytical results are validated through simulations performed using the Technology Computer-Aided Design (TCAD) Silvaco tool, comparing Surface Potential, Electric Field, and Drain characteristics.

The Double Material Double Gate (DM DG) GNR TFET optimizes the device performance with the help of material and gate engineering and increases surface potential, electric field, and drain current. Due to the higher ION/IOFF ratio and decreased subthreshold swing, the proposed device is suitable for high-frequency applications and improves the switching performance.

The developed model demonstrates a sub-threshold swing of 24.49 mV/dec, an ION/IOFF ratio of 10⁸, and a cut-off frequency of 28 GHz. These results align closely with TCAD simulations, confirming the model’s accuracy. The introduction of double-gate and double-material engineering significantly enhances device performance.

The proposed DM DG GNR TFET exhibits superior electrical properties, making it a strong contender for low-power and high-frequency applications. Its improved ION/IOFF ratio and sub-threshold swing highlight its potential in next-generation electronic devices.

Polymer composites are used extensively in the automotive, aviation, and sports sectors. Recently, researchers have replaced glass fiber with recyclable natural fibers. The present investigation examined the sliding wear performance of glass/sisal fibre (GF/SF)-reinforced hybrid polymer nanocomposite under various axial loads (AL) and sliding velocity (SV), with and without nSiC fillers.

A novel GF/SF fiber-reinforced hybrid nanocomposite with and without nano-SiC that complied with ASTM specifications was developed using a vacuum infusion technique. The percentage of nSiC fillers varied among 1 wt.%, 2 wt.%, and 3 wt.%. The pin-on-disc tribometer was employed to assess the tribological performance, viz., coefficient of friction (CoF) and wear rate (WR), of the composites at various process conditions.

The hybrid nanocomposite with 2 wt. % nSiC had the lowest CoF and WR of all the constructed composites. At 30N AL and an SV of 0.419 m/s, the GF/SF/2% nano-SiC composite exhibited wear resistance approximately 2.3 times more than that of the GF/SF composite without nanofibers, 1.5 times higher than that of the GF/SF/1% nSiC composite, and 1.46 times higher than that of the GF/SF/3%nSiC composite. The CoF for unreinforced and 2 wt.% nSiC reinforced composites under an AL of 30 N was 0.481 and 0.394, respectively.

The better wear properties of the GF/SF/2%nSiC composite were found to be due to uniform dispersion of nanofillers and stronger bonding between the fibres and the matrix.

The findings indicated the nSiC filler loadings to significantly improve the GF/SF fibre composite's wear properties.