Phase Transition Enthalpy Research Articles

Effects of heat treatment at different moisture of mung bean flour on the structural, gelation and in vitro digestive properties of starch

Effects of heat treatment (100 °C) at different moisture content (13–70 %) on the structural, gelation and digestive properties of starch in real mung bean flour (MBF) systems are investigated. The results showed that the structural destruction of the starch, the starch-lipid complexion and starch-protein interaction were promoted with increasing moisture content. The starch-protein interaction was mainly driven by hydrophobic interaction forces, leading the increase of total phase transition enthalpy. Even though starch retained ordered structure after heating at 50 %–70 % moisture, the typical pasting curve almost disappeared. The less leached amylose to construct the continuous phase, and more flexible amylopectin swollen granules dispersed in the matrix may weakened the viscoelasticity of the gels. As a result, two distinct gel textures were presented: soft solids with good water-binding capacity (below 30 %) and pasty fluids (above 40 %). Starch-lipid/protein interactions were demonstrated to retard the digestion rate of starch during MBS gelatinization according to the two-stage first-order kinetic and LOS (logarithm of the slope) models.

Controlling the wax crystallization behaviors via the ratio of phenyl to aliphatic branches in block copolymer synthesized by RAFT copolymerization

AbstractThe precipitation and deposition of waxes in high waxy crude oil often result in the low throughput and clogging of pipeline. Adding polymers is a practical approach to solve these problems. In this study, poly(styrene‐co‐docosyl maleate)s (PSDMs) were synthesized by reversible addition‐fragmentation chain transfer polymerization. The chemical structure and molecular weight of copolymers were characterized using Fourier infrared spectroscopy, 1H nuclear magnetic resonance spectroscopy, and gel permeation chromatography. The ratio of phenyl to aliphatic branches varies from 10:8 to 25:8. The crystallization and morphology of waxes in model oil were investigated by x‐ray diffraction, differential scanning calorimetry, and polarized light microscopy. The cold flow behaviors of crude oil were evaluated by rheological methods. With the increase of the ratio of phenyl to aliphatic branches, the crystallinity, viscosity, and yield stress of crude oil first increase and then decrease. In the presence of PSDM‐2, the crystallinity and enthalpy of phase transition (ΔH) are reduced by 44.2% and 48.9%. Thus, the pour point, viscosity, and yield stress of crude oil are reduced by 6.0°C, 76.8% and 77.4%, respectively. Therefore, well‐defined PSDMs are promising to be remarkable flow improvers for waxy crude oils.

Lattice energy and specific impulse to hydrazoic acid, Pb, Ag and Cu azides

In this work, the gas phase formation enthalpies (kJmol−1) to hydrazoic acid, Pb, Ag and Cu azides were calculated as: HN3 = 310.00; AgN3 = 509.70, Pb(N3)2 = 768.37 and Cu(N3)2 = 855.45. The respective phase transition enthalpies (kJmol−1) are: HN3(l) → HN3(g) = 9.70; AgN3 (s) → AgN3 (g) = 198.70; Pb(N3)2(s) → Pb(N3)2(g) = 284.37 and Cu(N3)2(s) → Cu(N3)2(g) = 268.45. By using and empirical equation, the detonation velocity to cupric azide, Cu(N3)2 (s), was estimated as 7340 ms−1.

Rational design of electrochemical energy storage and thermal energy storage double network aerogel for in-situ temperature regulation of supercapacitors

During the charging/discharging process, a large amount of heat is constantly generated inside the supercapacitor. Therefore, thermal management of supercapacitors is crucial. In this work, a calcium alginate/polyaniline/polyethylene glycol (CA/PANI/PEG) double network multifunctional aerogels were prepared for thermal energy storage and electrochemical energy storage Due to the strong hydrogen bonding between PANI and CA and ionic cross-linking between CA molecular chains, the CA/PANI double network structure can be used to solidify PEG. CA/PANI/PEG aerogels can form stable porous network structures with excellent properties. For example, due to the in-situ thermal management of CA/PANI/PEG, CA/PANI/PEG exhibits a higher specific capacitance than the traditional PANI-based electrode at 55 °C. More importantly, the CA/PANI/PEG aerogel not only possessed a high enthalpy of phase transition (162.1 J/g) but also showed superior capacitive performance (175 mF/cm2 at 0.1 mA/cm2 at 55 °C). After 10,000 charge/discharge cycle tests, it can maintain 84.5 % of the initial capacitance. This study opens up a new way for the development and application of PCMs in the thermal management of supercapacitors.

Performance improvement of phase change materials encapsulated with graphene oxide for thermal storage

The thermal enhanced phase change microcapsules were prepared by paraffin as core material and the modified graphene as wall material. X-ray diffraction (XRD) and Fourier transform infrared spectroscope (FTIR) were applied to determine the microstructure and chemical structure of the microcapsules. A differential scanning calorimeter (DSC) test was done to investigate the thermal properties and thermal stability of the microcapsules. The results showed that the modified graphene/paraffin microcapsules have a regular spherical shape. The thermal conductivity of the microcapsules increases gradually with the increase of the content of the modified graphene. When the content of graphene content is 10 %, the thermal conductivity of the microcapsules is 4.01 times that of paraffin. The enthalpy of phase transition of the microcapsules is 100.3 J/g. Considering the suitable thermal properties, good thermal reliability, chemical stability and great thermal conductivity of the prepared microcapsules, it shows good application prospects in thermal or solar energy storage applications.

Investigation of Raman spectra and ionic conductivity of composites based on NaClO4 and KClO4 salts obtained by mechanoactivation

The work is aimed at studying the effect of mechanical activation on the structure and electrical conductivity of the NaClO4 – and KClO4 – basedcomposites. Based on the result of the analysis of the DSC curves of the (1–x) NaClO4 – x Al2O3 and (1–x) KClO4 – x Al2O3 composites measured while heating and cooling the samples, it was established that the enthalpy of phase transitions in them decreased with an increase in the concentration of the nanosized dopant. A complication of all active vibrational contours corresponding to internal vibrations of the molecular anion in the composites with increasing Al2O3 concentration and a shift of the band of the fully symmetric stretching vibration v1 (A) to a low-frequency region was revealed by Raman spectroscopy. Based on electrochemical impedance spectroscopy data, it was determined that for the 0.4NaClO4 – 0.6Al2O3 system subjected to mechanoactivation, the values of specific ionic conductivity increased by two orders of magnitude as compared to that of pure NaClO4, while for the 0.4KClO4 – 0.6Al2O3 system, the values of specific ionic conductivity increased by three orders of magnitude as compared to the initial salt at T = 320 °C.

A stable and visualized fatty acid-based phase transition material constructed by solid-phase molecular self-assembly for thermal management.

Fatty acids are excellent thermal management materials for thermal storage, release and preventing thermal runaway. However, the leakage of fatty acids leads to instability and prevents their application in thermal management. Herein, a stable and visualized fatty acid-based phase transition material P-S/PA was constructed through solid-state molecular self-assembly strategy from polydiallyldimethylammonium chloride (PDDA), sodium dodecyl benzene sulfonate (SDBS) and palmitic acid (PA). The electrostatic interaction between PDDA and SDBS and hydrophobic interaction between PA and SDBS can prevent PA leakage during phase transition, achieving stability. After 1000 cycles, the changes in the phase transition enthalpy (ΔH M, ΔH C) were less than 1%. The structural similarity also made P-S/PA phase transition visible, and the transmittance changed significantly from 0% to 68% during phase transition. In addition, P-S/PA can be remolded by hot-pressing without performance changes, showing temperature adjustability on varying the fatty acid carbon chain length. Thus, the stable and visualized P-S/PA fatty acid-based phase transition material constructed by solid-phase molecular self-assembly has promising application in thermal management.

Complex phase behavior of dihydroxyl-functionalized ionic liquids at low temperature.

Here, we have synthesized six dihydroxyl-functionalized ionic liquids for phase behavior studies at low temperature via crystallographic methods, Raman spectroscopy, differential scanning calorimetry (DSC), and density functional theory (DFT) calculations. Phase varieties are observed depending on the direction and strength of hydrogen bonding. Our studies also show that the ILs could be potentially excellent phase-change thermal storage materials with nearly no change of the phase transition enthalpy.

Preparation and application of high thermal conductivity phase change microcapsules with fluorescence characteristics based on a ZnWO4 shell.

Phase change microcapsules (NePCMs) with high latent heat values, thermal conductivity and stability were synthesized by coating stearic acid (SA) phase change materials (PCMs) with zinc tungstate (ZnWO4) as the shell material. The prepared ZnWO4 and microcapsule samples are characterized through various techniques, and their thermophysical properties under different core-shell ratios and emulsifiers are compared. The highest value that the phase transition enthalpy reaches is 83.63 J g-1 when the core-shell ratio is 1 : 1 and sodium dodecylbenzenesulfonate (SDBS) is adopted as the emulsifier. Based on SEM and TEM results, the regular spherical shape and the complete core-shell structure of the microcapsule can be found, and the particle size ranges between 100 and 300 nm. The thermal conductivity of SA increased by 141.18%-238.43% after using ZnWO4 as the shell material. Moreover, thermogravimetric and leak-proof performance tests demonstrated that microcapsule samples possess high thermal stability. There was no leakage from the six microcapsule samples after heating, proving their potential application in thermal energy storage (TES) under long-term high-temperature conditions. In addition, the cost of ZnWO4 prepared by this method can be reduced by about 40%. According to UV absorption and fluorescence spectrum evaluation, ZnWO4 and microcapsule samples exhibit good photoluminescence and UV absorption properties, indicating that the sample can be widely employed in fluorescent construction, coatings and textile industries at a lower cost.

Multiple H-Bonding Cross-Linked Supramolecular Solid-Solid Phase Change Materials for Thermal Energy Storage and Management.

Solid-solid phase change materials (SSPCMs) are considered among the most promising candidates for thermal energy storage and management. However, the application of SSPCMs is consistently hindered by the canonical trade-off between high TES capacity and mechanical robustness. In addition, they suffer from poor recyclability due to chemical cross-linking. Herein, a straightforward but effective strategy for fabricating supramolecular SSPCMs with high latent heat and mechanical strength is proposed. The supramolecular polymer employs multiple H-bonding interactions as robust physical cross-links. This enables SSPCM with a high enthalpy of phase transition (142.5 J g-1 ), strong mechanical strength (36.9MPa), and sound shape stability (maintaining shape integrity at 120 °C) even with a high content of phase change component (97 wt%). When SSPCM is utilized to regulate the operating temperature of lithium-ion batteries, it significantly diminishes the battery working temperature by 23 °C at a discharge rate of 3 C. The robust thermal management capability enabled through solid-solid phase change provides practical opportunities for applications in fast discharging and high-power batteries. Overall, this study presents a feasible strategy for designing linear SSPCMs with high latent heat and exceptional mechanical strength for thermal management.

Evaluation of phase change material-graphene nanocomposite for thermal regulation enhancement in buildings

The growth of high-efficiency phase change material (PCM) nanocomposites with good heat conduction and substantial thermal capacity was of vital significance for practical matters in the sustainable utilization of energy. A novel leakage-proof n-heptadecane-graphene nanocomposite was prepared by a direct impregnation procedure from n-heptadacne as a PCM and nanographene as a skeleton. The creation of shape-stabilized nanocomposite was checked with X-ray diffraction (XRD), Raman, and Fourier transform infrared (FTIR) spectroscopy. The scanning electron microscopy (SEM) analysis illustrated that the n-heptadecane and graphene had favourable compatibility and there was no phase separation and graphene accumulation. Thermal analysis showed that the shape-stabilized nanocomposite not only had a good phase transition enthalpy (101.7 J/g) and n-heptadecane content (45.6 %) but also possessed appropriate thermal stability. The heat conduction of the obtained mesoporous nanocomposite was up to 1.527 W/mK, with a growth of 808 % compared to pure n-heptadecane. Furthermore, the optimized nanocomposite held auspicious thermal reliability, being exposed to 400 thermal cycles. Moreover, the thermoregulation tests demonstrated that the gypsum boards containing optimized nanocomposite showed a slow heat release rate and improved the building temperature profile over only the gypsum board. By virtue of the combination of n-heptadecane and thermal conductive nanographene, the obtained engineered nanocomposite might be regarded as a smart material for energy-conserving and temperature regulation in buildings.

Thermodynamics of Reversible Hydrogen Storage: Are Methoxy-Substituted Biphenyls Better through Oxygen Functionality?

The reversible hydrogenation/dehydrogenation of aromatic molecules, known as liquid organic hydrogen carriers, is considered as an attractive option for the safe storage and release of elemental hydrogen. The recently reported efficient synthetic routes to obtain methoxy-biphenyls in high yield make them promising candidates for hydrogen storage. In this work, a series of methoxy-substituted biphenyls and their structural parent compounds were studied. The absolute vapour pressures were measured using the transpiration method and the enthalpies of vaporisation/sublimation were determined. We applied a step-by-step procedure including structure–property correlations and quantum chemical calculations to evaluate the quality of thermochemical data on the enthalpies of phase transitions and enthalpies of formation of the studied methoxy compounds. The data sets on thermodynamic properties were evaluated and recommended for calculations in chemical engineering. A thermodynamic analysis of chemical reactions based on methoxy-biphenyls in the context of hydrogen storage was carried out and the energetics of these reactions were compared with the energetics of reactions of common LOHCs. The influence of the position of the methoxy groups in the rings on the enthalpies of the reactions relevant for hydrogen storage was discussed.

Experimental investigation of nanoparticle enhanced polyol solid–solid phase change material aided heat sink with integrated heat pipe for electronic cooling application

Solid Solid phase change materials (SS_PCM) based thermal management systems (TMS) integrated with heat pipe are considered as excellent passive thermal management solution for electronic packages. To enhance the thermal conductivity of SS_PCM, nano-enhanced solid–solid phase change material (NE_SSPCM) samples were prepared by incorporating Neopentyl Glycol (NPG) with 1 wt% of Graphene nanoplatelets (GnP), Copper oxide (CuO) and Aluminium oxide (Al2O3) nanoparticles separately and its thermophysical characterisation study was performed. NE_SSPCM packed heat sink integrated with heat pipe was tested at different power levels from 9 to 13 W and its thermal performance was compared with TMS based on Empty heat sink, PCM-packed heat sink and PCM-packed finned heat sink configurations. TGA and FTIR characterisation techniques revealed good thermal and chemical stability for all NE_SSPCM without affecting the structure of NPG. DSC showed reduction in phase transition enthalpy for NE_SSPCM than SS_PCM. Thermal conductivities of NPG with 1 wt% of GnP, CuO and Al2O3 nanoparticles improved with relative enhancement ratios of 1.8, 1.5 and 0.8, respectively. From the experimental analysis, NE_SSPCM with heat pipe configuration showed outstanding average improvement by 7, 4.3 and 4.2 times at 9–13 W. Additionally, by extending safe operational period, all configurations were more effective at lower heat generation rates. In contrast to three nanoparticles, GnP based NE_SSPCM showed outstanding average improvement of 1.8 over NPG for PCM-based configurations. The study concluded that implementation of GnP in SS_PCM assisted heat sinks with heat pipe exhibited maximum enhancement ratio of 11.3 and demonstrated remarkable efficacy in all aspects.

Microencapsulation study of bioderived phase change material beeswax with ethyl cellulose shell for thermal energy storage applications

ABSTRACT The commercial shape-stabilized phase change material (PCM) products are obtained from synthetic raw materials. These materials are produced from carbon-intensive petroleum-refining processes. The carbon footprint can be minimized by using biobased products. Beeswax is a naturally available PCM with high phase transition enthalpy comparable to synthetic PCMs. In the previous literature studies, beeswax was shape-stabilized with synthetic materials. In the present study, beeswax was shape-stabilized with biopolymer ethyl cellulose by emulsion solvent evaporation method. The study aims to determine optimum microencapsulation process parameter levels for synthesizing microcapsules with high thermal energy storage (TES) capacity. The optimized process parameters for formulating microcapsules were 60:40 core/shell ratio, 2% PVA concentration, ethyl acetate solvent, and 40°C evaporation temperature. The microcapsules prepared with optimized process parameters were characterized using differential scanning calorimeter (DSC), T-history analysis, Fourier transform infrared (FTIR) spectroscope, and scanning electron microscope (SEM). FTIR and SEM analysis confirmed ethyl cellulose shell formation over the beeswax core. The optimized MPCM formulation possesses 115.8 J/g melting enthalpy with peak phase transition temperature of 58.2°C and thermal conductivity of 0.219 W/mK. The porous structure of the shell reduced melting enthalpy of optimized MPCM formulation to 84.6 J/g after 50 thermal cycles. The synthesized microcapsules comprise sustainable materials and have high TES capacity. The fabricated microcapsules can be used as TES additive in composite and coating formulations in food packaging.

Study of Certified Reference Materials for Temperature and Specific Enthalpy of Phase Transitions of Metals and Metal Salts

The development of calibration procedures, as well as the certification of readily available reference materials (RMs) and the improvement of their metrological characteristics, are topical issues for thermal analysis methods. In the course of the work, the necessity of conducting a study in order to expand the range of CRMs for temperature and enthalpy of phase transitions is substantiated. The substantiation of the choice of the measurement procedure and starting materials is given. The conditions for conducting experiments are described in detail, and the choice of these conditions is justified. The developed CRMs passed the metrological examination and were included in the Register of approved types of reference materials FIF EUM as a set of certified reference materials for temperature and specific enthalpy of phase transitions (set SOTSF-2) GSO 11890–2022/GSO 11896–2022. The practical significance of the obtained results is as follows: certified reference materials allow expanding the possibility of establishing and monitoring the stability of the calibration characteristics of thermal analysis installations and measuring instruments; certification of measurement procedures (methods) and accuracy control of the measurement results of the phase transition temperature of metals, metal salts, metal oxides, and polymeric materials, organic and inorganic substances.

Intrinsic photothermal phase change materials with enhanced toughness and flexibility for thermal management in extreme environments

Polymeric solid–solid phase-change materials (SSPCMs) are capable of reversibly absorbing or releasing high latent heat and have been widely studied for thermal energy storage (TES) due to their excellent shape stability and certain mechanical properties. The photothermal fillers were introduced to impart SSPCMs with photo-responsive ability. However, the incompatibility interface between fillers and SSPCMs matrix always causes serious deterioration of mechanical toughness and flexibility. Herein, we report an intrinsic photothermal SSPCM by incorporating a reactive photothermal agent (dihydroxy naphthalene (DN)) into linear polyurethane SSPCMs. The prepared SSPCMs have adjustable phase transition enthalpy and temperature as well as long-term cycle stability. The highest efficiency of SSPCM in near-infrared photothermal conversion including sensible and latent heat is 59.7 %, and the solar photothermal conversion efficiency is 48.1 %. Moreover, SSPCMs exhibit superior mechanical toughness of 193 MJ/m3 and flexibility, which can withstand repeated rotation, folding and stretching. The SSPCMs developed in this work can enable the human body to obtain the heat needed for life through photothermal conversion in extreme environments such as the Arctic, increasing the probability of survival. Therefore, this study provides a facile strategy for fabricating intrinsic photothermal SSPCMs with high toughness and flexibility properties, which have great potential in wearable device for thermal management in extreme environments.

Pressure-induced phase transition in cubic Yb2O3 and phase transition enthalpies

The high pressure structural evolution of cubic Yb2O3 has been studied using in situ synchrotron angle dispersive x-ray diffraction in combination with diamond anvil cell techniques up to 44.1 GPa. The XRD measurements revealed an irreversible reconstructive phase transition from cubic to monoclinic Yb2O3 at 11.2 GPa and extending up to 28.1 GPa with ∼8.1% volume collapse and a subsequent reversible displacive transition from monoclinic to hexagonal phase starting at 22.7 GPa. The monoclinic phase coexists with the hexagonal phase up to 44.1 GPa. After pressure releases, the hexagonal Yb2O3 reverts to the monoclinic structure. The second-order Birch–Murnaghan equation of state fit to the pressure–volume data yields a bulk modulus of 201 (4), 187 (6), and 200 (4) GPa for the cubic, monoclinic, and hexagonal phases, respectively. Furthermore, the effects of the hydrostatic pressure state on the diffraction patterns, bulk modulus, and onset transition pressure of Yb2O3 under high pressure have been discussed. It is concluded that the bulk modulus of the cubic Ln2O3 phase increases with decreasing cation radius due to lanthanide contraction. Another important work in this study is the determination of the enthalpies of the cubic to monoclinic and monoclinic to hexagonal phase transitions of Yb2O3 of 37.0 and 17.4 kJ/mol, respectively, based on the basic thermodynamic equations and using the onset transition pressures and corresponding volume changes obtained from high pressure XRD experiments.

Composition optimization and performance prediction for ultra-stable water-based aerosol based on thermodynamic entropy theory

Water-based aerosol is widely used as an effective strategy in electro-optical countermeasure on the battlefield used to the preponderance of high efficiency, low cost and eco-friendly. Unfortunately, the stability of the water-based aerosol is always unsatisfactory due to the rapid evaporation and sedimentation of the aerosol droplets. Great efforts have been devoted to improve the stability of water-based aerosol by using additives with different composition and proportion. However, the lack of the criterion and principle for screening the effective additives results in excessive experimental time consumption and cost. And the stabilization time of the aerosol is still only 30 min, which could not meet the requirements of the perdurable interference. Herein, to improve the stability of water-based aerosol and optimize the complex formulation efficiently, a theoretical calculation method based on thermodynamic entropy theory is proposed. All the factors that influence the shielding effect, including polyol, stabilizer, propellant, water and cosolvent, are considered within calculation. An ultra-stable water-based aerosol with long duration over 120 min is obtained with the optimal fogging agent composition, providing enough time for fighting the electro-optic weapon. Theoretical design guideline for choosing the additives with high phase transition temperature and low phase transition enthalpy is also proposed, which greatly improves the total entropy change and reduce the absolute entropy change of the aerosol cooling process, and gives rise to an enhanced stability of the water-based aerosol. The theoretical calculation methodology contributes to an abstemious time and space for sieving the water-based aerosol with desirable performance and stability, and provides the powerful guarantee to the homeland security.

Effect of fullerene C60 on phase transition enthalpy of paraffin wax: Calorimetry and structural analysis

In this paper, the effect of minor fullerene С60 admixtures on the phase transitions enthalpy of phase change material (PCM) is studied experimentally. For this purpose, the stable molecular solutions of the paraffin wax (PW) and fullerene С60 were explored in terms of the effective heat capacity and enthalpy of diffuse phase transitions over the (27…65) °С temperature range and C60 mass fraction up to 0.000746 g∙g−1. The choice of C60 as PW admixture was based on the hypothesis that a small amount of C60 contributes to a modification of the PW internal structure and, as a consequence, to a change in its caloric properties. Some factors that may affect the uncertainty for the obtained experimental data were examined. It was shown that the phase transition enthalpy for the PW/C60 in the (40…60) °C temperature range increase from 154.0 J∙g−1 (for pure PW) to 194.7 J∙g−1 (for PW containing 0.000746 g∙g−1 of C60) during cooling and decrease from 233.2 J∙g−1 (pure PW) to 182.3 J∙g−1 (PW containing 0.000746 g∙g−1 of C60) during heating. The results obtained indicate the defining influence of С60 on the PW structure in the liquid and solid states. It was confirmed by an additional structural analysis, which reported that pure PW has a minimal cell volume compared to PW/С60. The C60 addition into PW contributes to the expansion of the cell, indicating that the molecules lose their tight packing. A clear dependence between the enthalpy of melting and unit cell volume for PW/C60 samples was found. It was observed that unit cell expansion of PW due to the addition of C60 reduces the enthalpy hysteresis in the heating-cooling cycle – a key parameter that affects the efficiency of a thermal energy storage material. This positive effect may be due to structural transformation in PW during the melting-solidification cycles.

Robust BNNS/ANF aerogel skeleton-based PEG composite phase change materials with high latent heat for efficient thermal management

In this work, PEG-based phase change materials with high latent heat were fabricated by integrating ANF with two-dimensional BNNS to create a robust hybrid aerogels skeleton with subsequent PEG impregnation. Specifically, BNNS was initially obtained by boric acid-assisted ball milling, and BNNS/ANF hybrid aerogels were then obtained by freeze-drying. The hybrid aerogel had pores uniformly distributed with a size range of 73–190 μm and exhibited a compressive strength of 28.1 kPa with 50 wt% BNNS. The BNNS/ANF porous skeletons were employed as packaging materials for PEG, offering not only a high-load environment and excellent mechanical support, but also outstanding thermal conductivity. The composite phase change material demonstrated a thermal conductivity of 0.48 W/m·K with 40 wt% BNNS, which was 200 % higher than that of pure PEG. In particular, the rigid BNNS/ANF hybrid aerogels skeleton facilitated PEG storage, achieving a maximum loading rate of 98.73 % and an enthalpy efficiency of 99.87 %, respectively. The phase change enthalpy of the composites was as high as 189.19 J/g. The rigid support and adsorption capabilities of the skeleton structure also improve the shape stability and cycle stability during phase transition. Even after 50 thermal cycles, the phase transition temperature and enthalpy of the composites remained largely unchanged.