With the rapid development of 5G communication technology, the surge in the number of antenna modules for intelligent terminal equipment has led to the intensification of electromagnetic radiation and interference problems, posing a major threat to electronic equipment safety, information systems stability, and human health. Traditional electromagnetic shielding materials have made it difficult to meet the demand for intelligent, integrated electronics. In this study, we proposed an in-situ sedimentation strategy to fabricate flexible polyacrylonitrile/graphene@multi-walled carbon nanotubes (PAN/Gr@MWCNTs) composite film with hierarchical double-layered structures, thus realizing ultra-thin, highly conductive, and excellent electromagnetic shielding and Joule heating properties. Particularly, the as-formed hierarchical film possessed an ultra-thin thickness of 0.158 mm and a high conductivity of 1660.26 S/m, simultaneously accompanied by an electromagnetic interference shielding efficiency (EMI SE) of 42.82 dB and a specific shielding efficiency (SSE) of 271.01 dB/mm. In addition, the film exhibited excellent Joule heating capability in the voltage range of 1.50-2.25 V. This study provides innovative ideas for developing flexible electromagnetic shielding films, which are of great scientific significance and potential application in electromagnetic radiation protection.

A comprehensive learning of the mechanical behavior change mechanism of oxide/oxide composites is of great significance as a guide for their industrial applications. This study focused on examining how matrix microstructure impacted the micro- and macro- mechanical properties of the composites mainly by nanoindentation tests, macro-mechanical tests and x-ray computed tomography. The results showed that the sintering phenomenon of matrix sintered at 1200 ºC was more obvious, and there were visible transverse and longitudinal cracks. The in-situ modulus of matrix and interfacial shear modulus of the composite increased by 61.1% and 36.4%, respectively, with the increase of matrix sintering densification. Combined with these micro-mechanical parameters of the composites, the He-Hutchinson model predicted the same crack propagation modes as those obtained from fracture toughness tests. Moreover, more matrix cracks directly led to a 45.4% reduction in the flexural strength of the composites sintered at 1200 ºC compared to that sintered at 1100 ºC. In addition, a comparison analysis was conducted on the evolution of microstructure, micro- and macro- mechanical properties of 2.5D and 2D composites with the same preparation parameters.

To meet the continuously growing demands of sustainable engineering and environmental accountability, the fusion of biowaste-derived carbon particles with biodegradable polymers emerges as a beacon of innovation, presenting a persuasive approach to address environmental dilemmas while propelling the frontiers of material science, offering a compelling avenue for sustainable advancements. The present investigation delves into the development of novel betel nut shell-derived carbon (BNAC) infused PLA filament for Fused Deposition Modeling (FDM) applications. Detailed morphological and thermal analysis was conducted on the developed blends, including mechanical strength measurements. The microstructural analysis revealed a homogeneous diffusion of carbon particles within the PLA matrix. The results indicate a significant improvement in tensile strength, increasing by 51.1% at 0.1 wt% biocarbon doping. However, the flexural strength showed only a moderate enhancement, with a maximum increase of 24.5% at 0.025 wt% doping, indicating that adding BNAC does not simultaneously optimize both tensile and flexural properties. Beyond contributing to the progress of sustainable practices, the study illuminates the promising prospects of biodegradable PLA-BNAC composites as a compelling and eco-conscious alternative for 3D printing materials, particularly in packaging applications.

The paper aimed to investigate the performance of multi-walled carbon nanotube-coated GF (MWCNT@GF) sensors on interlayer shear damage monitoring and sensing capability of glass fiber-reinforced polymers (GFRPs) based on the resistance change under short beam shear (SBS) load. The MWCNT@GF sensor, manufactured by physical vapor deposition (PVD), was embedded into the neutral layer of laminates to form an in-situ sensing network in different directions and positions. “The MWCNT@GF sensor, manufactured by physical vapor deposition (PVD), was embedded into the neutral layer of laminates to form an in-situ sensing network.” “With the help of Keithley 2700 programmable electrometer and the 3D-digital image correlation(3D-DIC), monotonic and cyclic tests were carried out.” The monotonic test found that the off-axis sensor is more sensitive to shear failure than the on-axis sensor because of its lower shear strength. In addition, the qualitative relationship between shear damage and relative resistance was established by selecting crucial moments. In the cyclical test, the relative resistance of off-axis sensors presented a cyclic mode under cyclic load. Furthermore, the relative resistance under the first 20 cyclic loads was similar to that under monotonic loads. “Furthermore, the relative resistance under the first 20 cyclic loads was similar to that under monotonic loads, which shows that the sensor has superior sensing ability. Finally, the quantitative relation between shear damage and relative resistance was established.” “That means MWCNT@GF sensors can be used to reasonably evaluate the damage state and further evaluate the service performance, reliability and remaining life of the structure.”

As composites become increasingly prevalent in aerospace structures, their resistance to high temperatures in extreme environments has captured the attention of numerous scholars. This paper discussed the development of a new basalt fiber-reinforced phthalonitrile matrix (BFRPN) composite, examining its mechanical performance across a spectrum of temperatures, including -55 °C low-temperature dry state (CTD), 23 °C room-temperature dry state (RTD), 250 °C, 350 °C, and 450 °C. The reliability of the mechanical properties was assessed by calculating the B-basis value. Additionally, optical and scanning electron microscope (SEM) photos were employed to analyze the damage morphology and elucidate the failure mechanisms at both high and low temperatures. The study revealed that the BFRPN composites maintained functional integrity from -55 °C to 350 °C. For representative unnotched plate tensile (UPT) and unnotched plate compression (UPC) specimens, the retention of UPT strength and UPC strength stayed above 100% and 83% respectively. At 450 °C, the retention rate of UPT strength consistently exceeds 78%, while the matrix undergoes significant oxidative decomposition, with delamination being the main observed damage mode.

The influence of adding graphene oxide (GO) fillers into CNT nanocomposites on the formation of CNT agglomerates and on their synergistic effect to the mechanical properties are investigated in this paper. To this end, a two-scale homogenization scheme and a GO-dependent morphological model of CNT agglomeration is built to predict the effective elastic moduli and strain-hardening behaviors of the hybrid composite. We adopt the Mori-Tanaka method, self-consistent theory and field-fluctuation approach to derive the effective secant moduli and Mises stress of each phase in or outside CNT agglomerates. In addition, the interface effects including imperfect mechanical bonding and interfacial tangential sliding between fillers and matrix are also considered. The results show that addition of GO significantly reduces the size and volume fraction of CNT agglomerates, leading to an enhanced dispersion of CNTs within the PVA matrix. The effective mechanical properties of the hybrid nanocomposites, including tensile strength and Young’s modulus, are also improved. The combinatorial impact of GO and CNTs to the composites is found to be superior to one with either GO or CNTs alone.

Spray coating process stands out among film manufacturing techniques to fabricate nanocomposite films because of its high production efficiency, and broad material applicability. However, the issues such as blockages, overspray, and rebound in the spray coating process restrict the fabrication of high-quality nanocomposite films. The atomization pressure field describes the spraying characteristics, and measuring and analyzing this parameter is vital to ensure the spray coating process functions properly. In this paper, a scanning manometry method is proposed to measure the atomization pressure field. The method involves setting a tube array to scan the atomization field, and reconstructing the pressure distribution by applying an imaging algorithm. This paper elaborates on the technical principle, implementation steps, and calibration of the scanning manometry method. Besides, the proposed method was validated by designing an actual testing system, and the 2D and 3D distribution images of the atomization pressure field were successfully obtained. The scanning manometry method features great potential for applications in nanocomposite spraying systems, assisting in fine-tuning the systems and stabilizing the production of nanocomposite films.