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In this work, Ti 3 C 2 MXene, a novel two-dimensional nanosheet, was introduced to waterborne polyurethane (WPU) coatings to prepare a composite coating. First, MAX phase materials were in situ etched by HF acid and further intercalated by water molecules to obtain exfoliated single-layer MXene nanosheet. And then, composite coatings were prepared via solution-blending low addition (0–0.4 wt%) of MXene, self-prepared waterborne polyacrylate emulsion (PAE) and isocyanate hardener, applying on Q235 mild steel. Results of AFM, XRD SEM and SEM–EDS confirm that single-layer MXene nanosheets with large lateral-to-thickness ratio are successfully prepared and achieved homogenous distribution within WPU matrix. With 0.4 wt% MXene incorporated, the WPU/Ti 3 C 2 MXene composite coatings reach a lowest corrosion current of 2.143 × 10 –6  A/cm 2 , a decrease of one order of magnitude compared with blank WPU (1.599 × 10 –5  A/cm 2 ) and own an excellent UV-blocking property (almost block the whole UV light). Graphical abstract

HighlightsAn innovative class of versatile form-stable composite phase change materials (CPCMs) was fruitfully exploited, featuring MXene/phytic acid hybrid depositing on non-carbonized wood as a robust support.The wood-based CPCMs showcase enhanced thermal conductivity of 0.82 W m−1 K−1 (4.6 times than polyethylene glycol) as well as high latent heat of 135.5 kJ kg−1 (91.5% encapsulation) with thermal durability and stability throughout at least 200 heating and cooling cycles.The wood-based CPCMs have good solar-thermal-electricity conversion, flame-retardant, and electromagnetic shielding properties.Phase change materials (PCMs) offer a promising solution to address the challenges posed by intermittency and fluctuations in solar thermal utilization. However, for organic solid–liquid PCMs, issues such as leakage, low thermal conductivity, lack of efficient solar-thermal media, and flammability have constrained their broad applications. Herein, we present an innovative class of versatile composite phase change materials (CPCMs) developed through a facile and environmentally friendly synthesis approach, leveraging the inherent anisotropy and unidirectional porosity of wood aerogel (nanowood) to support polyethylene glycol (PEG). The wood modification process involves the incorporation of phytic acid (PA) and MXene hybrid structure through an evaporation-induced assembly method, which could impart non-leaking PEG filling while concurrently facilitating thermal conduction, light absorption, and flame-retardant. Consequently, the as-prepared wood-based CPCMs showcase enhanced thermal conductivity (0.82 W m−1 K−1, about 4.6 times than PEG) as well as high latent heat of 135.5 kJ kg−1 (91.5% encapsulation) with thermal durability and stability throughout at least 200 heating and cooling cycles, featuring dramatic solar-thermal conversion efficiency up to 98.58%. In addition, with the synergistic effect of phytic acid and MXene, the flame-retardant performance of the CPCMs has been significantly enhanced, showing a self-extinguishing behavior. Moreover, the excellent electromagnetic shielding of 44.45 dB was endowed to the CPCMs, relieving contemporary health hazards associated with electromagnetic waves. Overall, we capitalize on the exquisite wood cell structure with unidirectional transport inherent in the development of multifunctional CPCMs, showcasing the operational principle through a proof-of-concept prototype system.

Two-dimensional (2D) materials have a comprehensive application in anti-corrosion coatings as nano-packing due to their large diameter/thickness ratio and wonderful barrier performance for water and oxygen. However, some disadvantages restrict the introduction of 2D materials into polymer matrix, including complicated preparation and modification processes, high costs, etc. In this study, an environment-friendly melamine phytate (PM) nanosheets were prepared and then introduced into the polymer matrix without any modification for fabricating water-borne epoxy (WEP) composite coatings. Long-term electrochemical test shows that 1.0 wt% PM/WEP exhibits the best anti-corrosion performance: highest log |Z| at 0.01 Hz value (7.8 Ω cm2) and lowest Icorr (2.83 × 10–9 A cm−2), and the minimum corrosive iron content in corrosion products after film remove (the oxygen and chlorine contents are 4.66% and 0.05%, respectively). These results reveal that proper addition of PM nanosheets could extremely improve the anti-corrosion performance in composite coatings. This research provides a mentality for the large-scale application of 2D materials into polymer coatings.PM nanosheets were prepared by hydrothermal process which using melamine (MA) and phytic acid (PA), two green and eco-friendly raw materials. And then the nanosheets were firstly introduced into water-borne epoxy resin (WEP). On the lower right, it is a scanning electronic image (SEM) of PM nanosheets. To the lower left, it is the corrosion protection between blank WEP, 0.5 wt% PM/WEP, 1.0 wt% PM/WEP and 1.5 wt% PM/WEP coatings.

In this study, ZnAl-layered double hydroxide (ZnAl-LDH) was functionalized with 2-Phenylbenzimidazole-5-sulfonic acid (PBSA) to prepare ZnAl-PBSA-LDH using a simple one-step method. The electrochemical impedance spectroscopy (EIS) result of the solution phase demonstrated excellent corrosion inhibition performance of ZnAl-PBSA-LDH. Subsequently, 0.6 wt.% ZnAl-PBSA-LDH with shielding effects and active inhibition was incorporated into the water-based epoxy (WEP) for preparing the high-performance anti-corrosion coating (6-ZPL/WEP). The EIS test illustrated that the 6-ZPL/WEP coating maintained a high low-frequency impedance modulus (|Z0.01 Hz|) after 30 days of immersion, which is nearly two orders of magnitude higher compared to that of the blank coating. These results demonstrated that ZnAl-PBSA-LDH could efficiently improve the corrosion resistance of the WEP coating. Therefore, this study introduces new insights into the use of layered double hydroxides (LDHs) in the domain of anti-corrosion.

To explore the effects of physical activity on anxiety levels in college students, as well as to examine the mediating role of emotion regulation. A convenience sample of 1,721 college students from Shanghai, Jiangsu, Shandong, Guangxi, and Hunan was used to conduct an evaluation and a survey through the Physical Activity Rating Scale (PARS-3), the Anxiety Self-Rating Scale (SAS), and the Emotion Regulation Scale (ERQ). College students' anxiety level, cognitive reappraisal, and expression inhibition scores were (44.72 ± 10.37), (30.16 ± 6.51), and (16.96 ± 4.99), respectively. There were significant grade and physical activity level differences in anxiety levels and cognitive reappraisal, and significant gender and physical activity level differences in expression inhibition among college students. Process model 4 mediated effect regression analysis showed that physical activity had a significant positive effect on cognitive reappraisal ( = 0.14, = 0.04,  < 0.001), and physical activity did not have a significant expression inhibition effect ( = 0.17, = 0.01, 0.27). Physical activity ( = -0.03, 0.012), cognitive reappraisal ( = -0.59,  < 0.001), and expression inhibition had a significant effect on ( = 0.57,  < 0.001) anxiety levels ( = 0.37). In the model effect relationship, the direct and indirect effects of physical activity on anxiety levels were -0.028 and -0.019, respectively. Physical activity has a significant negative effect on college students' anxiety levels. Cognitive reappraisal is a mediating variable for the effect of physical activity on anxiety levels. The higher the level of physical activity and the higher the intensity of the activity, the lower the level of anxiety.

Background The cut-off date in the education system causes a relative age difference, with developmental advantages for children who are born on the “early side” of the cut-off date and disadvantages for those born later, which is known as the relative age effect (RAE). Very few studies have examined whether there is a RAE on the development of fundamental movement skills (FMSs) in preschool children, and no studies have been conducted in China. The purpose of this study is to identify whether a RAE exists on FMS in Chinese preschool children, comparing RAEs according to gender and age. Methods From a total of 378 invited preschool children regularly registered at one Chinese kindergarten, a total of 288 healthy and typically developing preschoolers (4.33 ± 0.84 years-old; 56.6% boys) were included in this study. All children were required to take part in anthropometry and FMS assessments. Analysis of covariance (ANCOVA) was applied to examine the difference in each of the FMS items across quarter categories, year and gender groups, controlling for body mass index (BMI). Results For the overall sample, the data show the significant main effects on the quarter of birth factor in locomotor skills (LC; F (3, 265) = 2.811, p  = 0.04, η p 2  = 0.031), object control skills (OB; F (3, 265) = 6.319, p  = 0.04, η p 2  = 0.031), and total test score (TTS; F (3, 265) = 5.988, p  = 0.001, η p 2  = 0.063). There were also significant differences in the age effect on all the domains of FMS ( F LC (2, 265) = 100.654, p  < 0.001, η p 2  = 0.432; F OB (2, 265) = 108.430, p  < 0.001, η p 2  = 0.450; F TTS (2, 265) = 147.234, p  < 0.001, η p 2  = 0.526) but a gender effect only in LC ( F (1, 265) = 20.858; p  < 0.001; η p 2  = 0.073). For gender and quarter of birth groups, RAEs in LC only exists in girls. Moreover, regarding age and quarter of birth factors, RAEs are only found at younger ages. Conclusions This study suggests the existence of RAEs in the FMS of Chinese preschool children. Teachers need to be aware of the effect of RAEs on the FMS when approaching development, evaluation, and teaching approaches in preschools.

Core/shell titanium dioxide (TiO 2 ) nanoparticle/poly(methyl methacrylate-butyl acrylate-methacrylic acid) [P(MMA-BA-MAA)] nanocomposite colloidal microspheres have been successfully synthesized via in situ emulsion polymerization. TiO 2 nanoparticles were firstly modified by silane coupling agent, vinyl triethoxysilane (A-151), to increase the dispersibility of TiO 2 nanoparticles into the polyacrylate matrix. The A-151-modified TiO 2 nanoparticles were characterized by Fourier transform infrared spectra (FTIR), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and transmission electron microscopy (TEM) techniques. The synthesized nanocomposite colloidal microspheres were characterized by TEM, scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), and differential scanning calorimetry analysis (DSC). The results showed that A-151 coupling molecules was chemically bonded on the TiO 2 nanoparticles surface, and the amount of coated A-151 was 3.0 wt%. According to TEM micrographs and DLS results, the dispersibility of modified TiO 2 nanoparticles was obviously improved. TEM analysis revealed that an obvious core/shell structure morphology was observed with the core TiO 2 particles surrounded by a uniform 10∼15-nm thick polymer shell. SEM–EDS result showed that TiO 2 nanoparticles were homogenously monodispersed in the polymer matrix. DSC measurements indicated a glass transition temperature ( T g ) enhancement of P(MMA-BA-MAA).

With the rapid development of new generations of miniaturized, integrated, and high-power electronic devices, it is particularly important to develop advanced composite materials with efficient thermal management capability and excellent electromagnetic interference (EMI) shielding performance. Herein, an innovative biomass/MXene-derived conductive hybrid scaffold, cellulose nanocrystal (CNC)-konjac glucomannan (KGM)/MXene (CKM), was prepared by freeze-drying and thermal annealing, and then paraffin wax (PW) was encapsulated in CKM using vacuum impregnation method to obtain CNC-KGM/MXene@PW phase change composites (CKMPCCs). The results show that the obtained CKMPCCs possess considerable reusable stabilities, excellent EMI shielding properties, and thermal energy management capacities. Among them, the CKMPCC-6 with 2.3 wt.% MXene exhibits excellent solar-thermal and electro-thermal conversion capabilities. In addition, the EMI shielding effectiveness value is as high as 45.0 dB at 8.2–12.4 GHz and the corresponding melting enthalpy value is 215.7 J/g (relative enthalpy efficiency of 99.9%). In conclusion, the synthesized multifunctional phase change composites provide great potential for integrating outstanding EMI shielding and advanced thermal energy management applications.

Fire and smoke suppressions of polyvinyl alcohol (PVA) aerogels are urgently required due to the serious fire hazard they present. MXene, a 2D transition-metal carbide with many excellent properties, is considered a promising synergist for providing excellent flame retardant performance. PVA/ammonium polyphosphate (APP)/transition metal carbide (MXene) composite aerogels were prepared via the freeze-drying method to enhance the flame retardancy. Thermogravimetric analysis, limiting oxygen index, vertical burning, and cone calorimeter tests were executed to investigate the thermal stability and flame retardancy of PVA/APP/MXene (PAM) composite aerogels. The results demonstrated that MXene boosted the flame retardancy of PVA-APP, and that PAM-2 (with 2.0 wt% MXene loading) passed the V-0 rating, and reached a maximum LOI value of 42%; Moreover, MXene endowed the PVA-APP system with excellent fire and smoke suppression performance, as the the peak heat release rate and peak smoke production rate were significantly reduced by 55% and 74% at 1.0 wt% MXene loading. The flame retardant mechanism was systematically studied, MXene facilitated the generation of compact intumescent residues via ita catalyst effects, thus further restraining the release of heat and smoke. This work provides a simple route to improve the flame retardancy of PVA aerogels via the synergistic effect of MXene and APP.