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Shell materials play significant impact on corrosion resistance and mechanical properties on self-healing coating of composite with core-shell nanofiber. In this paper, three promising shell materials were investigated to optimize the performance of self-healing coating. Self-healing core-shell nanofibers with different shell materials were prepared with coaxial electrospinning. The resulting nanofibers were used to prepare self-healing corrosion resistance coating. The tensile test revealed a notable enhancement in the tensile strength of PA6 core-shell nanofiber epoxy composite coatings compared with the epoxy coating, demonstrating increase of 26.92%. Friction and wear test indicated reductions in the friction coefficients of PAN, PVDF, and PA6 core-shell nanofibers by 13.82%, 12.44%, and 26.27%, respectively. The self-healing and anti-corrosion abilities were evaluated through electrochemical impedance spectroscopy (EIS) test. All three coatings exhibited exceptional self-healing efficiencies exceeding 90%, highlighting the substantial potential of the chosen shell materials as nanocontainers for self-healing agent. Results indicate that the nanofibers with PA6 as shell material can achieve the best enhancement performance, which has a greater potential for the corrosion protection and long-lasting use of offshore wind turbine tower coatings. Highlights * Optimizing coating performance by screening coaxial nanofibers for shell materials * Shell material can improve the tensile strength of coating up to 26.92% * Friction coefficient of PA6 nanofiber coating was about 15% lower than PAN and PVDF * All three coatings exhibited exceptional self-healing efficiencies exceeding 90% KEYWORDS coating, core-shell nanofibers, mechanical properties, self-healing, shell material, 1 | INTRODUCTION Offshore wind turbine towers are easy to be corrosive under high humidity and high salt spray marine environments. (1) Application of anti-corrosion coating with self-healing ability is [...]

Onion-like fullerenes (OLFs) have spherical and tunable shell structures that make them perfect solid lubricants, but their molecular mechanical properties are largely unknown as they are extremely difficult to measure. In this computational study, double-shelled OLFs C60@C180, C80@C180, C60@C240 and C80@C240 are subject to uniaxial elastic strains to obtain their mechanical response. Compressive and tensile elastic moduli are calculated using density functional theory with van der Waals correction. We found that the tensile elastic moduli of the single- and double-shelled fullerenes are always larger than the compressive ones by about 50% to 100%. Inserting C80 into C180 causes an increase in compressive elastic modulus from 96.8 GPa to 178.6 GPa, while inserting C60 into C240 cause much smaller increases. The key factor that determines the stiffening effects is the relative sizes of the inner and outer shells. [ABSTRACT FROM AUTHOR]

C21H25ClO, orthorhombic, Pna21 (no. 33), a = 14.152(2) Å, b = 22.112(3) Å, c = 6.0109(7) Å, V = 1880.9(4) Å3, Z = 4, Rgt(F) = 0.0586, wRref(F2) = 0.1227, T = 150 K.

Carbon fiber reinforced polymer (CFRP) composites with self‐sensing and self‐healing capabilities was developed in this work. Uniform dispersion of CNTs within a core‐shell nanofiber structure was achieved through a combination of electrospinning and subsequent surface spraying of CNTs. The resulting core‐shell nanofibers were incorporated into CFRP composites using a vacuum‐assisted resin transfer molding process. Mechanical testing demonstrated improved mechanical properties in the composites treated with CNT spraying. Real‐time, precise monitoring of structural damage was enabled through the measurement of electrical signal changes caused by composite deformation in static loading experiments. Furthermore, self‐healing experiments demonstrated that the thermally conductive network formed by CNTs facilitated more uniform heat transfer within the composites. During the healing process, resistive heating of damaged specimens was applied, resulting in a remarkable healing efficiency of 95.2%. The experiments indicate that the composite developed in this paper possess excellent self‐sensing and self‐healing capabilities. Highlights: Damage self‐sensing and self‐healing CFRP composites were developed.CNTs‐modified nanofibers were applied to endow the composite specific abilities.Resistivity signals were collected for real‐time damage monitoring.The self‐healing efficiency of the designed composite reached up to 95.2%.Self‐sensing and self‐healing occurred autonomously within closed‐loop structure. [ABSTRACT FROM AUTHOR]

Carbon emissions and land use intensity serve as crucial indicators of land management. This paper proposes a methodological framework to elucidate the sustainability of carbon emissions in rural areas via a coordination model, scrutinizes the correlation with land use intensity, and investigates the significance of influential factors. The study focuses on village-level units within Ningde City, and finds the pronounced spatial heterogeneity characterizing the distribution of carbon emissions across different villages: (1) Villages exhibiting high levels of carbon emissions are predominantly concentrated in the southeast region, whereas those with low carbon emission levels are primarily clustered in the northwest region. The majority of the villages serve as net carbon emission sources. (2) Spatial disparities exist in the impact of land use intensity on economic benefits from carbon sources, ecological benefits from carbon sinks, and carbon emission sustainability. (3) Significant variations exist in the influence of factors affecting land use intensity, economic benefits of carbon sources, ecological benefits of carbon sinks, and the sustainability of carbon emissions in rural areas. These findings could guide governments in implementing distinct land use control policies and provide a framework for assessing carbon emission sustainability within land management strategies. [ABSTRACT FROM AUTHOR]

As the impact of climate change intensifies, meeting the energy demand of buildings in China's cold regions is becoming increasingly challenging, particularly in terms of cooling energy consumption. The effectiveness of integrating phase change material (PCM) into building envelopes for energy saving in China's cold regions is unclear. The aim of this study is to assess the effectiveness of PCM integration in building enclosures for energy efficiency in these regions. The research monitored and recorded indoor temperature data from typical residential cases from May to September. This measured data was then used to validate the accuracy of EnergyPlus22-1 software simulation models. Subsequently, the calibrated model was utilized to conduct a comparative analysis on the effects of PCM on indoor temperatures and cooling energy consumption across these regions. The results of these comparative analyses indicated that PCM can alleviate indoor overheating to varying degrees in severe cold regions of China. Focusing on north-facing bedrooms, applying PCMs reduced the duration of overheating in non-air-conditioned buildings in severe cold regions of China by 136 h (Yichun), 340 h (Harbin), 356 h (Shenyang), and 153 h (Dalian). In terms of cooling energy consumption, the energy saved by applying PCMs ranged from 1.48 to 13.83 kWh/m2. These results emphasize that the performance of PCM varies with climate change, with the most significant energy-saving effects observed in severe cold regions. In north-facing bedrooms in Harbin, the energy-saving rate was as high as 60.30%. Based on these results, the study offers guidance and recommendations for feasible passive energy-saving strategies for buildings in severe cold and cold regions of China in the face of climate change. Additionally, it provides practical guidance for applying PCMs in different climatic zones in China. [ABSTRACT FROM AUTHOR]

Self‐healing composites are promising for engineering, but self‐healing structures or components usually induce reduction in the composite's mechanical properties. In this paper, core‐shell nanofibers which accommodating healing agent in the core and incorporating carbon nanotubes (CNTs) in the shell were produced to develop non‐destructive self‐healing carbon fiber/epoxy (CF/EP) composites. The epoxy resin and curing agent were encapsulated in CNTs‐reinforced polyacrylonitrile (PAN) core‐shell electrospinning nanofiber mats and the mats were placed on carbon fibers to fabricate CF/EP composite laminates by the vacuum‐assisted resin transfer molding (VARTM) process. The results indicated that the flexural strength, flexural modulus, tensile strength, tensile modulus, and Mode II interlaminar fracture toughness of composites with suitable self‐healing components increased by 49%, 44%, 8%, 13%, and 43%, respectively, compared to the pristine CF/EP. The healing flexural strength of the composite with 1 wt% CNTs recovered up to 93.57%, observed 24 h after the bending fracture, which is higher than the initial strength of CF/EP composites without self‐healing components. The research indicates that self‐healing composites can be developed without mechanical properties degrade and even achieve stronger mechanical properties. [ABSTRACT FROM AUTHOR]