Baljinder K. Kandola

This work has investigated epoxy composites reinforced with wool fabrics modified by an organosolv lignin coating deposited via a sustainable protocol. The lignin layer was introduced to tailor the fiber/matrix interphase, aiming to improve adhesion and reduce water-related degradation associated with the intrinsic hygroscopicity of wool. Laminates were manufactured by vacuum-assisted resin transfer molding (VARTM) and systematically characterized. Thermogravimetric analysis demonstrated improved thermal stability and higher char yield in lignin-coated composites. Mechanical tests revealed enhanced flexural strength (+21%) and modulus (+31%), together with a modest increase in interlaminar shear strength. SEM analysis of the fracture surfaces provided additional evidence of changes in fiber–matrix interfacial interactions. Low-velocity impact and DMA results further supported the role of the coating in improving load transfer and viscoelastic response. Water absorption tests indicated reduced equilibrium uptake and slower diffusion kinetics, highlighting the hydrophobic barrier function of the lignin layer. Collectively, these results show that the lignin coating acts primarily as an interphase modifier and water-barrier layer, enabling low-value wool fabrics to be upgraded into functional reinforcements for more durable epoxy biocomposites.

Sustainable precursor fibres for low-cost carbon fibre production are being extensively explored, particularly those based on lignin that are melt-blended with other thermoplastic polymers. Being prone to melting during melt processing is one of the main issues of using lignin to replace petroleum-based polyacrylonitrile (PAN) as precursor fibres. A time-consuming thermostabilisation process is normally needed to convert the thermoplastic blend’s polymer molecular chains to thermally stable structures prior to carbonisation. In order to accelerate the thermostabilisation process to facilitate industrial carbon fibre manufacturing, promising suitable surface treatments of lignin-based precursor fibres have emerged. In this work, sulphuric acid was used as a surface treatment agent to sensitise the crosslinking chemistry between interspersed components during the thermal stabilisation of lignin/polyamide blend precursor fibres. The impact of sulphuric acid concentration and the accelerated thermostabilisation conditions on the chemical structure and mechanical properties of precursor fibres were investigated. The surface-treated precursor fibres were directly stabilised at a high temperature, i.e., 200 °C, without a slow temperature elevation stage and the fusion of fibres using sulphuric acid with a concentration as low as 0.5 M. This was attributed to the improved condensation and crosslinking process via the sulphonation of lignin and to some extent PA1010. The isothermal time (<5 h) and final temperature (<240 °C) of the thermostabilisation process had significant effects on the final properties of surface-treated precursor fibres. The mechanical properties of thermostabilised precursor fibres were also investigated. The tensile modulus of the thermally stabilised fibres derived from surface-treated precursor fibres was increased by up to 50% using an optimised stabilisation process; however, tensile strength was decreased due to crosslinking.

Coupling graphene oxide (GO) with functionalized CdS quantum dots (QDs) can form a promising assembly for the photocatalytic reduction of CO ₂ .

Flexible and wearable pressure sensors are essential for monitoring of human motion and are distinguished by their increased sensitivity and outstanding mechanical robustness. In this study, we systematically engineered a flexible and wearable pressure sensor with a multilayer conductive architecture, arranging a sponge substrate coated in a consecutive manner with a barium zirconium titanate thin film, followed by polypyrrole, multiwalled carbon nanotubes, and eventually polydimethylsiloxane. The foundation of additional conductive pathways is enabled via the utilization of a porous framework and the hierarchical arrangement, causing the achievement of an excellent sensitivity of 9.71 kPa⁻¹ (0–9 kPa), a rapid 40 ms response time, and a fast 60 ms recovery period, combined with a particularly low detection limit (125 Pa) and an extended pressure range from 0 to 225 kPa. Furthermore, the integration of a rough and porous barium zirconium titanate/barium titanate thin film is expected to deliver a voltage output (1.25 V) through piezoelectric working mechanisms. This study possesses the potential to provide an innovative architecture design for advancing the development of future electronic devices for health and sports monitoring.

The integration of textile-based wearable electronic systems has garnered significant attention due to their potential to enhance the comfort and safety of electronic devices when incorporated into clothing. This study introduces a fabrication strategy for a versatile e-textile utilizing a sequential combination of polydimethylsiloxane, functionalized carbon nanotubes, and polypyrrole integrated onto a cotton towel fabric adorned with zinc oxide nanoplate structures. The growth of zinc oxide nanoplate structures on the towel fabric surface enhances the fabric’s roughness and pressure sensitivity. Additionally, the application of a polydimethylsiloxane coating onto the conductive towel fabric provides adhesion for the conductive layer, imparts superhydrophobicity to the sensors, and enhances the stability of the pressure-sensitive device. The resulting sensor demonstrates a broad sensing range (0–225 kPa) coupled with heightened sensitivity (122 kPa⁻¹ in low-pressure regions), achieving a harmonious balance between working range and sensitivity. Of particular significance, this sensor is capable of monitoring various human motions such as wrist, elbow, and knee bending, as well as activities like walking and jumping, in addition to capturing physiological signals like swallowing. Furthermore, the sensors exhibit self-powering capabilities, manifesting a noteable 1.47 V peak-to-peak voltage from renewable sources like human movement, eliminating the need for external power or frequent battery replacement and enabling flexible design. In conclusion, this multifunctional e-textile exhibits exceptional sensing and energy harvesting characteristics, while its straightforward manufacturing process underscores its potential for diverse applications within the domain of wearable technology.