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The development of phase change materials (PCMs) composites with high light‐to‐thermal energy conversion efficiency is of great importance for solar energy storage. Herein, the preparation of novel PCMs composites by incorporation of fatty amines (FAs) into the carbon membranes (CMs) with aligned nanochannels network is first reported, which is obtained by employing an anodic alumina oxidation membrane as sacrificing template and using polypyrrole and asphalt as carbon precursor via a simple carbonization treatment. The carbonized membranes possess abundant porosity and aligned nanochannels, which is beneficial to harvest solar light combined with their carbon in nature. In addition, organic PCMs, i.e. 1‐Hexadecanamine (HDA, ΔH = 311.1 kJ/kg) and 1‐Aminoheptadecane (AHD, ΔH = 293.0 kJ/kg) can be spontaneously loaded into the nanochannels of CMs by the capillary action and surface tension. The fabricated FAs/CMs composites present an enhanced thermal conductivity ranging from 0.291 to 0.525 W m−1 K−1. Compared to pure FAs, the thermal conductivities of the PCMs composites are 144.8–357.1% higher than that of the control. Meanwhile, the as‐synthesized FAs/CMs composites also exhibit a remarkable high photothermal energy storage efficiency of up to 93.8%, which is one of the highest values reported to date, making them promising candidates for a broad range of applications in solar energy harvesting, conversion, and storage. [ABSTRACT FROM AUTHOR]

Spongy carbon soot (s‐CS) was prepared and used as novel host material of the form‐stable composite phase change materials (PCMs). The s‐CS was constructed by the interconnected and compact large agglomerates of the soot particles with an average size of 25–60 nm. The average pore diameter of the s‐CS was measured to be 15.3 nm. Owing to capillary forces of s‐CS, n‐carboxylic acids can be easily absorbed into the pores and stay stable without leakage. The PCMs/s‐CS composite present a high heat storage capacity between 83.42 J g−1 and 99.63 J g−1, corresponding to the mass fraction of n‐carboxylic acids between 50.10% and 53.20%. The effects of the supporting material on thermal stability and thermal conductivity of composites were investigated by means of thermogravimetry and flash thermal conductivity testing. The PCM/spongy CS composites exhibit excellent thermal stability and durability, and may have great potential for renewable energy saving applications. [ABSTRACT FROM AUTHOR]

In order to improve the energy storage and conversion efficiency of phase change materials, a mixed clay sponge (MCS) containing palygorskite (Pal) and Halloysite Nanotubes (HNTs) was successfully constructed by solution polymerization. Expanded graphite (EG) was used to enhance the overall thermal conductivity and carbonized MCS with EG (mark as EG-MCS, C-EG-MCS). A series of form stable phase change materials (FSPCMs) were prepared by using them as scaffolds and encapsulated organic phase-change material 1-Hexadecylamine (HDA) by direct impregnation. By means of SEM, TEM, FTIR, XRD, XPS, DSC, TG, etc., their microstructure, chemical compatibility and thermophysical properties were systematically studied. The DSC results demonstrate that PCM composites exhibit relatively high thermal energy storage density of 214.2 kJ kg−1, 237.5 kJ kg−1 and 239.2 kJ kg−1 respectively. The reliability test shows that the PCM composites retain shape stability and almost no leakage of HDA even after 200 thermal cycles. Compared with the pure component HDA, the thermal conductivity of the as-prepared C-EG-MCS-HDA was improved from 0.147 W m−1 K−1 to 0.667 W m−1 K−1 and EG-MCS-HDA was improved from 0.147 W m−1 K−1 to 0.454 W m−1 K−1 owing to the high thermal conductivity of EG (only 6 wt%). Besides, the light-thermal conversion efficiency of EG-MCS-HDA and C-EG-MCS-HDA is 74.6%, 80.8% respectively. Therefore, the fabricated FSPCMs with high latent heat, good melting/freezing cycles reliability and high thermal conductivity, remarkable light-thermal energy conversion ability which have a broad application prospect in energy conversion and storage devices. Unlabelled Image • 1-Hexadecanamine (HDA) was first exploited as a new class of organic PCMs. • Form-stable PCMs composites were fabricated based mixed clay sponge. • The as-prepared PCM composites exhibit high light-thermal conversion efficiency. [ABSTRACT FROM AUTHOR]

The fabrication of composite phase change material (CPCM) with splendid light-to-thermal conversion efficiency and enhanced thermal conductivity is of significance for solar energy storage and transition. Hence, we report the creation of a novel CPCM prepared by impregnating 1-hexadecanamine (HDA) into nickel foam (NF) bearing with carbon nanotubes (CNTs) nanoarray via simple vacuum impregnation for photothermal conversion. The NF bearing with CNTs nanoarray employed in this study show outstanding light absorption of higher than 97% originated from its vertical aligned CNTs nanoarray which makes it possible for trapping the light to the most extent. Moreover, the metal nature of NF coupled with the carbon nature of CNTs nanoarray endow it excellent thermal conductivity, e.g. the thermal conductivity of CPCM is improved by 46.3% compared to that of the pure HDA. Thanks to the high latent heat of HDA (240 J/g), the latent heat of the CPCM are measured to be 132.2 J/g. In addition, it shows excellent thermal stability, e.g. the latent heat of the CPCM remains nearly unchanged after 50 times of melting/freezing cycles. Beneficial from their outstanding light absorption, excellent thermal conductivity and high latent heat, the as-prepared CPCM is an ideal platform solar energy harvesting, storage and transition. Under 1sun irradiation, the light-to-thermal conversion efficiency of the CPCM was measured to be 80.10%. Moreover, we detected the temperature-time curve of the CPCM under 30 V voltage, the result show that the CPCM also has great potential in the electro-to-thermal conversion application. [Display omitted] [ABSTRACT FROM AUTHOR]

The construction of high-performance materials with superior light-to-thermal conversion efficiency is of great importance for harvesting and utilization of solar energy. Hence, we report the creation of novel composite phase change materials (CPCMs) CPCMs by incorporating three kinds of organic phase change materials (PCMs), i.e. 1-Tetradecylamine (TDA), 1-hexadecanamine (HDA) and Octadecylamine (ODA), into hollow carbon nanospheres (HCNS) via a simple impregnation treatment for efficient light-to-thermal transition. Owing to their carbon in nature, the HCNS show better light absorption of higher than 90%. After incorporation of organic PCMs, their light absorption could still attain 62–70%, which can compete with the existing CPCMs. Beneficial from their abundant porosity and high specific surface areas, organic PCMs can be spontaneously diffused and immersed into the porous architecture of HCNS. In this way, the as-resulted CPCMs containing with TDA, HDA and ODA show high phase change enthalpy of 61.23J/g, 119.5J/g and 101.8J/g, respectively. The CPCMs also exhibit better thermal conductivity and excellent thermal stability, e.g., the enthalpy of HAD based CPCMs remains nearly unchanged even after 100 times of melting/freezing cycles. Under 1 sun irradiation, the light-to-thermal conversion efficiency of CPCMs containing with TDA, HDA and ODA were measured to be 73.04%, 74.46% and 71.74%, respectively, Thus showing great potential as a kind of promising photothermal conversion devices for solar or thermal energy storage applications. • A novel CPCMs was fabricated to improve light-to-thermal conversion efficiency. • The CPCMs can harvest and transfer visible light efficiently. • The CPCMs own excellent thermal stability and enhanced thermal conductivity. [ABSTRACT FROM AUTHOR]