Nanoscale最新文献

Lanthanide-doped upconversion nanoparticles (UCNPs) have garnered extensive attention in fundamental research and cutting-edge applications due to their unique optical properties. Particularly in sensing, UCNP-based fluorescent probes provide a versatile platform for microfluidic flow velocity calibration. However, designing nanoprobes with efficient luminescence modulation for broad-range flow velocimetry remains challenging. Herein, we engineered a core-multishell UCNP probe: NaGdF₄:Tm³⁺/Yb³⁺@NaGdF₄@NaGdF₄:Eu³⁺@NaYF₄, in which spatially isolated Tm³⁺ (blue) and Eu³⁺ (red) activators enable dual emissions. The intensity ratio between these channels exhibits a laser pulse-width-dependent behavior, enabling real-time dynamic optical modulation. Leveraging this mechanism, we showed fluid velocity assessment by dispersing nanoprobes in a fluid stream under fixed laser excitation. The flowing medium underwent flow-velocity-dependent effective excitation pulse width variations, establishing a quantitative emission ratio-velocity mapping for precise calibration. This paradigm advances flow velocimetry technology while significantly broadening the measurable velocity range via energy migration-mediated kinetics. This sensing paradigm not only advances fluid velocimetry techniques but also expands the multifunctional utility of core-multishell UCNPs in emerging photonic technologies.

With the rapid advancement of electronic devices, the demand for high-performance thermal interface materials (TIMs) to ensure integrated circuit reliability is increasing. Carbon nanotubes (CNTs), known for their exceptional thermal properties, are commonly used as additives in polymer matrices for composite TIMs. However, due to their random dispersion and lack of structural control, thermal conductivity improvements are limited, even at high content levels. In this study, we report a method for aligning CNTs within a polymer matrix using a magnetic field (0.3 T), leveraging the intrinsic diamagnetic properties of carbon nanotubes. This approach enables the preparation of composite materials with significantly enhanced thermal conductivity. Specifically, a thermal conductivity of up to 1.1 W m⁻¹ K⁻¹ was achieved at a low content of 10 wt% CNTs, and the thermal conductivity of CNT/F2311 was improved by 647% compared to that of F2311. Furthermore, cooling performance tests on heat sink fins incorporating this CNT/F2311 composite demonstrate a temperature reduction of 10.6 K compared to fins without CNTs, highlighting the potential for advanced thermal management applications in materials.

Effective water management is essential for improving the performance of air-cooled proton exchange membrane fuel cells (PEMFCs). While extensive efforts have been made over the past decades to design advanced flow field architectures and external humidification systems to alleviate membrane electrode assembly (MEA) dehydration, these strategies often increase the structural and operational complexity of PEMFC systems. A promising alternative lies in engineering the intrinsic material properties of MEAs to enable self-humidification. In this review, we first elucidate the fundamental mechanisms governing water transport within the MEA and assess the detrimental effects of inadequate water regulation on fuel cell performance. We then provide a comprehensive overview of diagnostic techniques for water management, encompassing both physicochemical and electrochemical approaches. Emphasizing self-humidifying capabilities, we highlight a range of innovative strategies aimed at mitigating MEA dehydration. Furthermore, we conduct a comprehensive discussion on the synergistic modification of multiple components and the influence of improvement strategies on stability. Finally, we outline prospective research directions for the development of self-humidifying MEAs.

Chemical recycling of polyester through depolymerisation processes is a promising strategy to mitigate the environmental burden of polyester-containing textile waste. However, residual disperse dyes in depolymerised products often degrade the purity and whiteness of recovered monomers. Conventional dye removal methods, such as solvent extraction, frequently fail to achieve complete dye removal. Herein, we report the development of iron oxide magnetic nanoadsorbents capped with three hydrophobic ligands for the efficient removal of disperse dyes from monomer solutions. Strong hydrophobic interactions between the ligands and dye molecules significantly enhance adsorption efficiency. Systematic evaluation with different dyes reveals that molecular features such as contour length, polarisability, and flexibility strongly influence adsorption performance. The dye-adsorbed nanoadsorbents are readily recovered through magnetic separation and reused without structural degradation. By applying the nanoadsorbents to the decolourisation of depolymerised coloured textiles, we obtained highly pure white monomers suitable for repolymerisation into textile-grade materials. These findings highlight a sustainable and reusable nanomaterial platform for dye removal during the recycling of polyester textiles.