The melting points of the phase change materials (PCMs) incorporated into the walls of buildings should be within the human thermal comfort temperature range. In this paper, 15 wt.% of MgCl₂·6H₂O was mixed with CaCl₂·6H₂O to obtain the eutectic with a melting point of 23.9 °C. SrCl₂·6H₂O suppresses the supecooling of the eutectic. The combination with expanded perlite (EP) via the impregnation method overcomes the phase separation and liquid leakage of the CaCl₂∙6H₂O-MgCl₂∙6H₂O mixture. The composite PCM is form-stable with the maximum loading mass fraction up to 50 wt.% and latent heat of 73.55 J/g. EP also significantly reduces the thermal conductivity of the CaCl₂∙6H₂O-MgCl₂∙6H₂O from 0.732 to 0.144 W/(m·K). The heating-cooling cycling test reveals that the composite PCM is thermally stable. The cheap eutectic salt hydrate, with little supercooling, no phase separation and liquid leakage, low thermal conductivity and good thermal reliability, show great potential as envelope materials to save energy consumption in buildings.
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http://dx.doi.org/10.3390/ma11122369 | DOI Listing |
Chem Asian J
January 2025
Kanagawa University, Department of Chemistry, JAPAN.
Thermoelectric properties of undoped crystals of dibenzo[g,p]chrysene (DBC), deuterated DBC (DBC-d16), and 2,10-dimethyl-DBC (DBC-Me2) have been studied to obtain some insights into the relationship between the structural parameters of materials and the giant Seebeck effect. X-ray crystallography showed one-dimensional columnar packing with the interlayer distances (d) for DBC-d16, DBC, and DBC-Me2 were 3.78 Å, 3.
View Article and Find Full Text PDFACS Nano
January 2025
State Key Laboratory of Materials Processing and Die & Mould Technology, and School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei, P. R. China.
Intensifying the severity of electromagnetic (EM) pollution in the environment represents a significant threat to human health and results in considerable energy wastage. Here, we provide a strategy for electricity generation from heat generated by electromagnetic wave radiation captured from the surrounding environment that can reduce the level of electromagnetic pollution while alleviating the energy crisis. We prepared a porous, elastomeric, and lightweight BiTe/carbon aerogel (CN@BiTe) by a simple strategy of induced in situ growth of BiTe nanosheets with three-dimensional (3D) carbon structure, realizing the coupling of electromagnetic wave absorption (EMA) and thermoelectric (TE) properties.
View Article and Find Full Text PDFNat Mater
January 2025
Max Planck Institute for Chemical Physics of Solids, Dresden, Germany.
High thermoelectric performance is generally achieved by synergistically optimizing two or even three of the contradictorily coupled thermoelectric parameters. Here we demonstrate magneto-thermoelectric correlation as a strategy to achieve simultaneous gain in an enhanced Seebeck coefficient and reduced thermal conductivity in topological materials. We report a large magneto-Seebeck effect and high magneto-thermoelectric figure of merit of 1.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
College of Material, Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 311121, P. R. China.
Thermoelectric technology enables the direct and reversible conversion of heat into electrical energy without air pollution. Herein, the stability, electronic structure, and thermoelectric properties of methoxy-functionalized MC(OMe) (M = Sc, Ti, V, Cr, Y, Zr, Nb, Mo, Hf, Ta, and W) were systematically investigated using first-principles calculations and semiclassical Boltzmann transport theory. All MXenes, except those with M = Cr, Mo, and W, can be synthesized by substituting Cl- and Br-functionalized MXenes with deprotonated methanol, with stability governed by the M-O bond strength.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Center for Phononics and Thermal Energy Science, School of Physics Science and Engineering, Tongji University, Shanghai 20092, China.
In contrast to normal diffusion processes, thermal conduction in one-dimensional systems is anomalous. The thermal conductivity is found to vary with the length as κ∼L^{α}(α>0), but there is a long-standing debate on the value α. Here, we present a canonical example of this behavior in polymer-grafted spherical nanoparticle (GNP) melts at fixed grafting density and nanoparticle radius.
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