Advanced Composites and Hybrid Materials最新文献

The increased human demand for an intelligent life puts forward a great requirement for lightweight, stretchable, and comfort sensing and energy harvesting devices. Stretchable thermoelectric fiber becomes very attractive due to it can directly convert human body waste heat into electricity and enables stress, strain, and temperature sensing by designing the structure of the materials. However, the preparation of stretchable poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) fibers with enhanced performances and continuous p-n alternating structure remains a challenge. In this study, the stretchable continuous p-n alternating thermoelectric fibers were prepared by a simple and controllable microfluidic wet-spinning process, in which the single-walled carbon nanotubes (SWCNT)/PEDOT:PSS/polyurethane (PU) and polyethyleneimine (PEI) doped SWCNT/PEDOT:PSS/PU were used as p- and n-type segments, respectively. To optimize the performances, the effect of SWCNT and PEI concentration on the morphology, thermoelectric, and mechanical properties of p- and n-type fibers were analyzed. The power factor of the p- and n-type fibers were 2.67 and 3.48 µW m⁻¹ K⁻²_, respectively, with a stress of 16 ~ 19 MPa and strain of 70%. Then, the strain and temperature sensors were constructed by the stretchable TE fibers and used for respiration and motion monitoring, showing excellent sensitivity and stability. All the results demonstrate the multifunctions of the stretchable TE fibers used as flexible wearable electronics.

Haze represents a significant environmental concern, arising from particulate matter accumulated in smoke, dust, and steam, and gaseous pollutants such as sulfur dioxide and nitrogen oxides. These substances, once released into the atmosphere, lead to environmental pollution, disrupt transportation, and adversely affect human health. Numerous factors contribute to haze formation, including garbage incineration, traffic pollution, natural geographical conditions, and the level of forest coverage and fossil fuel combustion. Composite materials, which integrate two or more substances, are utilized and beneficial in effectively addressing pollution issues caused by a wide array of pollutants and the complex formation processes of phenomena such as haze. Carbon nanotubes have emerged as a promising material in the development of composite materials, largely due to their simple synthesis process. However, a comprehensive review detailing their role in haze removal and air purification is limited. Distinct from previous reviews on such composites, this review focuses on the functionalities of carbon nanotube composites in the absorption and transformation of haze-related air pollution. It describes and examines their efficacy in reducing bioaerosols associated with air pollutants, emissions of air pollutants, and their influence on plant evapotranspiration. The conclusion drawn is that the unique pore structure, toxicity, catalytic properties, and the counteractive effects of carbon nanotubes on soil pollutants underscore their critical role in addressing haze issues. This paper highlights the significant potential carbon nanotubes hold for future development in this area.

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This research explores the effectiveness of carbon nanotubes in mitigating emissions by adsorbing and reducing particulate matter and gases, and enhancing the accumulation of particulate matter on plant surfaces.

Catalytic methane (CH₄) decomposition (CDM) offers a direct pathway for hydrogen (H₂) gas production and valuable carbon nanotube (CNT) synthesis. However, the stability of this gas-to-solid reaction is hindered by limitations in CNT growth and reactor volume constraints. Departing beyond conventional nanopowder catalysts, we introduce basalt fiber-supported Ni/LTA catalysts that feature CO_x-free H₂ generation and up to 3.7 times longer CDM reaction times, delivering an H₂ production rate of 3.1 mol g_Ni⁻¹ h⁻¹ over 22 h at 500 °C, surpassing Ni/LTA nanopowder counterparts. The basalt fiber catalysts exhibit uniform and robust CNT growth, along with sustained and stable H₂ generation lasting up to three times longer relative to traditional CDM catalysts that deactivate within 10 h as reported in the literature. Integration of the flexible basalt fiber catalysts into an H₂-permeable LTA-Pd membrane reactor further enhances the reaction time by 36% and CH₄ conversion by 40%, achieving up to 45% CH₄ conversion over 27 h, surpassing expected equilibrium conversion rates. The excellent catalytic stability of the 10 wt% Ni/LTA basalt fiber catalyst is additionally showcased through multiple reduction-800 °C CDM reaction-CO₂ regeneration cycles. This transformative study propels the development of functional catalyst materials, revolutionizing thermocatalytic processes.

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A basalt fiber-supported LTA zeolite-based nickel catalyst advances methane decomposition, yielding CO_x-free hydrogen, multi-wall carbon nanotubes, and extensive reaction time.

During offshore natural gas extraction, the formation of hydrates in the wellbore poses a crucial issue that affects flow safety. There is a need to find a reliable solution to establish a wellbore with excellent thermal insulation and stability to prevent wellbore blockage. In this study, lightweight and thermally insulated (LWTI) composites with the desired mechanical strength for deep-sea natural gas development were prepared using oil-well cement (OWC) as the matrix and hollow glass microspheres (HGM) as the filler. A two-dimensional (2D) transient heat transfer mathematical model of the HGM/OWC LWTI composites was developed using the COMSOL Multiphysics software and solved using the finite element method. A transient heat transfer analysis of the HGM/OWC LWTI composites was performed. The effective thermal conductivities (k_eff) of the HGM/OWC LWTI composites were measured, and the values agreed well with the simulation results. The k_eff of the composites was approximately 0.371 W/(m·K) when the HGM (D51.8) content was 40 vol%. Compared to the traditional OWC (thermal conductivity ~ 0.889 W/(m·K)), the thermal insulation performance of the HGM/OWC LWTI composites was significantly improved. In addition, the density, mechanical properties, and water absorption of the HGM/OWC LWTI composites were investigated. The density of HGM/OWC LWTI composite material has been effectively reduced to a minimum of 1.31 g/cm³, 37% lower than that of pure cementing cement (2.08 g/cm³). The HGM/OWC LWTI composites exhibited good mechanical properties and low water absorption. This research can provide technical support for the efficient development of offshore natural gas.

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The medical domain is currently experiencing a significant shift from centralized healthcare models to home-based and personalized monitoring paradigms, particularly in the realm of cardiovascular monitoring. This move towards wearable systems is aimed at serving a wider population, reducing hospital resources’ burden, and cutting healthcare costs. There is growing interest in leveraging advanced nanomaterials to develop cutting-edge wearable biosensors for cardiovascular applications. These devices offer precise, real-time, and continuous data collection, which is crucial for creating personalized therapeutic interventions. Central to this innovation is the integration of various nanostructures with advanced biosensing techniques and microelectronics. These nanostructures play a pivotal role in enhancing preventative medical care by facilitating early diagnosis and management of critical health conditions. This review explores the latest advancements in wearable biosensors and assesses their role in monitoring cardiac vitals. It provides a comprehensive analysis of the materials, design principles, functional mechanisms, and recent breakthroughs related to these sensors, focusing on their applications in monitoring cardiac activity, measuring blood pressure, assessing pulse wave velocity, and detecting biomarkers.

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This review focuses on wearable biosensors designed for cardiovascular monitoring, particularly emphasizing the integration of nanomaterials.