Phase change material impregnated wood for passive thermal management of timber buildings

The Scots pine (Pinus sylvestris L.) sapwood was impregnated with the eutectic mixture of capric acid (CA) and stearic acid (SA) as phase change material (PCM) via vacuum process for passive thermoregulation in timber buildings. The hygroscopic properties, mechanical properties, thermal energy storage (TES) characteristics and lab-scale thermo-regulative performance of wood/CA-SA composite were evaluated. The produced composite from PCM was morphologically and physico-chemically characterized by SEM, FT-IR and XRD analysis. Thermal energy storage (TES) properties, cycling chemical/thermal reliability, and thermal degradation stability of the produced composite were determined by TG/DTA and DSC analysis. The hygroscopic tests revealed that the wood/CA-SA composite showed low water absorption (WA) and high anti-swelling efficiency (ASE) after 264 hours in water. Wood treatment with CA-SA increased the bending and compression strength of wood. TG/DTA data demonstrated that the wood/CA-SA composite left higher residue of 10.31% at 800°C than that of wood with 6.87%. The DSC measurements showed that the obtained wood/CA-SA composite had a good TES capacity of about 94 J/g at 23.94°C. The cycling DSC results confirmed the eutectic PCM in wood indicated high chemical stability and storage/release reliability even though it was run 600 times melt/freeze. According to thermal performance test, the wood/CA-SA composite has ability of storing excess heat in the environment and preventing the heat flow to the environment. It can be concluded that the fabricated wood/CA-SA composite can be used for indoor temperature regulation and energy saving in timber buildings.     

Stearic acid/polymethylmethacrylate composite as form-stable phase change materials for latent heat thermal energy storage

The aim of this research is to prepare of a novel form-stable composite phase change material (PCM) for the latent heat thermal energy storage (LHTES) in buildings, passive solar space heating or functional fluid by entrapping of SA into PMMA cell through ultraviolet curing dispersion polymerization. The composite PCM was characterized using scanning electron microscope (SEM) and Fourier transformation infrared (FT-IR) analysis technique. The results show that the form-stable microencapsulated PCM with core/shell structure was formed and the maximum encapsulated proportion of SA in the composite was 51.8 wt.% without melted PCM seepage from the composite. In the shape stabilized microencapsulated PCM, the polymer acts as supporting material to form the microcapsule cell preventing the leakage of PCM from the composite and the SA acts as a PCM encapsulated in the cell of PMMA resin. The oxygen atom of carbonyl group of skeleton is interacted with the hydrogen atom of hydroxyl group of SA. Thermal properties, thermal reliability and heat storage/release performance of the composite PCM were determined by differential scanning calorimetry (DSC), FT-IR and thermal cycling test analysis. The melting and freezing temperatures and the latent heats of the composite PCM were measured as 60.4 °C, 50.6 °C and 92.1 J/g, 95.9 J/g, respectively. The results of DSC, FT-IR and thermal cycling test are all show that the thermal reliability of the composite PCM has an imperceptible change. This conclusion indicates that the composite has a good thermal and chemical stability.     

Polyethylene glycol (PEG)/diatomite composite as a novel form-stable phase change material for thermal energy storage

This paper deals with the preparation, characterization, and determination of thermal energy storage properties of polyethylene glycol (PEG)/diatomite composite as a novel form-stable composite phase change material (PCM). The composite PCM was prepared by incorporating PEG in the pores of diatomite. The PEG could be retained by 50 wt% into pores of the diatomite without the leakage of melted PEG from the composite. The composite PCM was characterized by using SEM and FT-IR analysis technique. Thermal properties of the composite PCM were determined by DSC analysis. DSC results showed that the melting temperature and latent heat of the composite PCM are 27.70 °C and 87.09 J/g, respectively. Thermal cycling test was conducted to determine the thermal reliability of the composite PCM and the results showed that the composite PCM had good thermal reliability and chemical stability. TG analysis showed that the impregnated PEG into the diatomite had good thermal stability. Thermal conductivity of the composite PCM was improved by adding expanded graphite in different mass fractions. Thermal energy storage performance of the composite PCM was also tested.     

Preparation of stearic acid/halloysite nanotube composite as form‐stable PCM for thermal energy storage

A novel form‐stable composite as phase change material (PCM) for thermal energy storage was prepared by absorbing stearic acid (SA) into halloysite nanotube (HNT). The composite PCM was characterized by TEM, FT‐IR and DSC analysis techniques. The composite can contain SA as high as 60 wt% and maintain its original shape perfectly without any SA leakage after subjected to 50 melt–freeze cycles. The melting temperature and latent heat of composite (SA/HNT: 60/40 wt%) were determined as 53.46°C and 93.97 J g^?1 by DSC. Graphite was added into the SA/HNT composite to improve thermal storage performance, and the melting time and freezing time of the composite were reduced by 65.3 and 63.9%, respectively. Because of its high adsorption capacity of SA, high heat storage capacity, good thermal stability, low cost and simple preparation method, the composite can be considered as cost‐effective latent heat storage material for practical application. Copyright © 2011 John Wiley & Sons, Ltd.     

Thermal properties and characterization of palmitic acid/nano silicon dioxide/graphene nanoplatelet for thermal energy storage

Palmitic acid (PA), nano silicon dioxide (nano SiO₂), and graphene nanoplatelets (GNPs) were fabricated to composite phase change materials (PCMs) for thermal energy storage. PA acted as PCM, nano SiO₂ was used as supporting material. GNP as thermal conductivity promoter was added to modify composite PCM. Nano SiO₂ has good adsorption property and can adsorb liquid PCM to prevent leakage. Leakage measurement indicated that PA maximum content in composite PCM is 70 wt%. Chemical and crystal structures, and microstructure of composite PCM were tested by Fourier transformation infrared spectroscope, X-ray diffractometer and scanning electronic microscope, which showed that the raw materials are well mixed by physical action. Differential scanning calorimeter result presented that composite PCM possess phase change temperature at about 60°C and latent heat of 128.42 kJ/kg. Thermogravimetric analyzer and thermal cycle experiment showed that composite PCM have outstanding thermal stability and durability. Thermal conductivity apparatus measurement results indicated that thermal conductivity of composite PCM with 5 wt% GNP is 1.65 times that of composite PCM without GNP. Therefore, this composite PCM are potential materials for thermal energy storage.     

High Density Polyethylene/Paraffin Composites as Form-stable Phase Change Material for Thermal Energy Storage

Abstract

This article focuses on the preparation and thermo-physical properties of paraffin/high density polyethylene (HDPE) composites as form-stable solid-liquid phase change material (PCM) for thermal energy storage. In the paraffin/HDPE blend, the paraffin (P) dispersed into the HDPE serves as a latent heat storage material when the HDPE, as a supporting material, prevents the melted paraffin leakage thanks to its structural strength. Therefore, this type composite is form-stable and can be used as a PCM without encapsulation for thermal energy storage. In this study, two paraffins with melting temperatures of 48°C–50°C and 63°C–65°C were used. The mass percentages of paraffins in the composites could go high as 76% without any seepage of the paraffin in melted state. The dispersion of the paraffin into the network of the solid HDPE was investigated using scanning electronic microscope (SEM). The melting temperatures and latent heats of the form-stable P1/HDPE and P2/HDPE composite PCMs were determined as 44.32°C and 61.66°C, and 179.63 and 198.14 Jg^?1, by the technique of differential scanning calorimetry (DSC), respectively. Furthermore, the thermal conductivity of the composite PCMs were improved as about 33.3% for the P1/HDPE and 52.3% for the P2/HDPE by introducing the expanded and exfoliated graphite to the samples in the ratio of 3 wt%. The results reveal that the prepared form-stable composite PCMs have great potential for thermal energy storage applications in terms of their satisfactory thermal properties, improved thermal conductivity and cost-efficiency because of no encapsulation for enhancing heat transfer in paraffin.     

Development of pentadecane/diatomite and pentadecane/sepiolite nanocomposites fabricated by different compounding methods for thermal energy storage

Global warming is one of the most important consequences of excess energy consumption. Phase change materials (PCMs) have prominent advantages in thermal energy storage owing to their high latent heat capacities and small temperature variations during the phase change process. However, leakage is a major problem that limits the use of PCMs. Leakage may occur in encapsulated PCMs or in composites where the PCM is attached to the surface of a supporting material or within the pores of that material. In this study, pentadecane/diatomite and pentadecane/sepiolite nanocomposites were fabricated by using unmodified and microwave‐irradiated diatomite and sepiolite samples and by using different compounding processes, such as direct impregnation, vacuum impregnation, and ultrasonic‐assisted impregnation methods. The microstructures and the chemical and thermal properties of the composites were characterized by scanning electron microscopy, Fourier‐transform infrared spectroscopy, and differential scanning calorimetry. Subsequently, the thermal reliability and stability and the thermal conductivity of the PCM composites were also investigated. A melting temperature of 9.25°C and a latent heat capacity of 58.73 J/g were determined for the pentadecane/diatomite composite that was prepared with the direct impregnation method using a microwave‐treated diatomite sample. The pentadecane/sepiolite composite prepared in the melting temperature range 7.98°C to 8.53°C and latent heat capacity range 41.05 to 46.02 J/g. The results of the thermal analysis indicate that fabricated diatomite‐based or sepiolite‐based PCM composites have good potential as thermal energy storage materials.     

Preparation and properties of caprylic‐nonanoic acid mixture/expanded graphite composite as phase change material for thermal energy storage

To satisfy the application demands for latent heat storage in the temperature range from 5°C to 15°C, an original composite phase change material (PCM), CA‐NA/EG (caprylic‐nonanoic acid/expanded graphite), was prepared and characterized. For CA‐NA/EG, the mass ratio of CA and NA was 8:2, and the mass percentage of the CA‐NA in CA‐NA/EG composite PCM was determined as 90% by leakage test. The melting and freezing points of the CA‐NA/EG were 6.84°C and 9.34°C, and corresponding latent heats were 108.75 kJ/kg and 107.67 kJ/kg. In addition, its thermal conductivity, thermal stability and reliability were investigated by thermal conductivity apparatus (TCA), thermal gravimetric analyzer (TGA), and accelerated thermal cycle test for 100 melt/freeze cycles, respectively. The results showed that the CA‐NA/EG had a good thermal stability and an excellent thermal reliability. Moreover, the thermal conductivity of CA‐NA/EG had an improvement of 25% than that of the CA‐NA. On the other hand, the accelerated thermal cycle test also indicated that the CA‐NA/EG had no supercooling during all melt/freeze cycles. Therefore, the prepared composite PCM, CA‐NA/EG, can be applied for low‐temperature thermal energy storage owing to its proper melting temperature, acceptable latent heat and thermal conductivity, excellent thermal stability and reliability.     

Preparation of capric acid/halloysite nanotube composite as form-stable phase change material for thermal energy storage

A novel form-stable composite as phase change material (PCM) for thermal energy storage was prepared by absorbing capric acid (CA) into halloysite nanotube (HNT). The composite PCM was characterized by TEM, FT-IR and DSC analysis techniques. The composite can contain capric acid as high as 60 wt% and maintain its original shape perfectly without any CA leakage after subjected to 50 melt-freeze cycles. The melting temperature and latent heat of composite (CA/HNT: 60/40 wt%) were determined as 29.34 °C and 75.52 J/g by DSC. Graphite (G) was added into the composite to improve thermal storage performance and the thermal storage and release rates were increased by 1.8 times and 1.7 times compared with the composite without graphite, respectively. Due to its high adsorption capacity of CA, high heat storage capacity, good thermal stability, low cost and simple preparation method, the composite can be considered as cost-effective latent heat storage material for practical applications such as solar energy storage, building energy conservation and agricultural greenhouse in the near future.     

Liquid metal gallium laden organic phase change material for energy storage: An experimental study

This paper presents the experimental study on the thermophysical behavior, thermal cyclic characteristics and energy storage performance of liquid metal (LM) laden in organic solid-liquid phase change material (PCM) for energy storage. In this view, Gallium (Ga) is added into D-Mannitol (DM) with a weight fraction of 0.1% and 0.5% by dispersion technique using a ball mill. Repeated melting/freezing cycle was carried out for 350 cycles and the samples were characterized using Differential Scanning Calorimetry (DSC), Thermogravimetry Analysis (TGA) and Fourier Transform Infrared (FTIR). The DM/Ga composite PCM showed enhanced thermal conductivity of ～8.4%, ～27.8% for 0.1 and 0.5 wt % Ga as compared to pure DM. XRD studies reveal that the pure DM exhibited β polymorphic phase while TGA and FTIR analysis confirm the thermal reliability and chemical stability of composites in the temperature range of 50–200 °C. Non isothermal crystal kinetic study proved that the addition of Ga increased the crystallization rate due to heterogeneous nucleation effect and leads to the reduction in subcooling temperature of the PCM. The experimental setup results to test the charging and discharging performance of the composite PCM revealed that the total time for one complete cycle reduced from 97.48 min for pure DM to 84.73 min and 63.92 min for DM-Ga composite with 0.1 wt % and 0.5 wt % respectively. Based on the results obtained, D-Mannitol based composites could be recommended as potential PCM candidates for solar heat and industrial waste heat recovery application due to its high energy density capacity, thermal/chemical stability and good heat transfer performance.     

Theoretical study on a novel phase change process

This paper mainly deals with a novel homogeneous phase change process in materials (HPCP). The HPCP is analysed in detail and the expressions for one‐dimensional HPCPs are derived. It is concluded that, compared with the conventional phase change processes, the complete phase change time of HPCPs can be decreased by 60% for a spherical phase change material (PCM), 50% for a cylindrical PCM and 33% for a flat plate PCM, respectively, and the application of HPCPs to thermal energy storage systems can charge or discharge thermal energy with constant rates. Possible applications of HPCPs to thermal energy storage are simulated and further discussed using composite flat plate PCMs. Copyright © 1999 John Wiley & Sons, Ltd.     

Capric-myristic acid/vermiculite composite as form-stable phase change material for thermal energy storage

Phase change materials (PCMs) can be incorporated with building materials to obtain novel form-stable composite PCM which has effective energy storage performance in latent heat thermal energy storage (LHTES) systems. In this study, capric acid (CA)-myristic acid (MA) eutectic mixture/vermiculite (VMT) composite was prepared as a novel form-stable PCM using vacuum impregnation method. The composite PCM was characterized using scanning electron microscope (SEM) and Fourier transformation infrared (FT-IR) analysis technique. Thermal properties and thermal reliability of the composite PCM were determined by differential scanning calorimetry (DSC) analysis. The CA-MA eutectic mixture could be retained by 20 wt% into pores of the VMT without melted PCM seepage from the composite and therefore, this mixture was described as form-stable composite PCM. Thermal cycling test showed that the form-stable composite PCM has good thermal reliability and chemical stability although it was subjected to 3000 melting/freezing cycling. Thermal conductivity of the form-stable CA-MA/VMT composite PCM was increased by about 85% by introducing 2 wt% expanded graphite (EG) into the composite. The increase in thermal conductivity was confirmed by comparison of the melting and freezing times of the CA-MA/VMT composite with that of CA-MA/VMT/EG composite. The form-stable PCM including EG can be used as energy absorbing building material such as lightweight aggregate for plaster, concrete compounds, fire stop mortar, and component of interior fill for wallboards or hollow bricks because of its good thermal properties, thermal and chemical reliability and thermal conductivity.     

Impact of the Relationship between Phase Change Temperature and Boundary Temperature on the Thermal Performance of a PCM Wall and the Presentation of PCM Thermal Performance Indexes

In the composite phase change material (PCM) building envelope, the matching relationship between the phase change temperature of the PCM and the wall's boundary temperature significantly affects the energy storage performance of the PCM building envelope. In this paper, a type of concrete hollow block with a typical structure and a common PCM were adopted to produce multiform composite PCM hollow blocks, and the temperature changing hot chamber method was performed to test the thermal performance of the hollow block walls under different temperature conditions. New indexes were proposed for the thermal performance evaluation of the PCM wall. Meanwhile, combined with experimental data, the effective heat capacity model and the enthalpy model were used to analyze the effect of correlations concerning how the relationship between phase change temperature and wall's boundary temperature influenced the thermal performance of PCM wall. Three main impact factors related to temperature were obtained through the analysis. In addition, approaches for improving the thermal performance of a composite PCM wall were put forward. This paper provides the theoretical basis, data reference and practical instruction for the proper use of a PCM wall and ways for improving the thermal performance of a composite PCM wall.     

Synthesis and Characterization of Disodium Hydrogen Phosphate Dodecahydrate-Lauric-Palmitic Acid Used for Indoor Energy Storage Floor Units

Organic and inorganic phase change materials(PCMs) are considered potential materials for thermal energy storage(TES) with different phase change characteristics. In this study, a novel organic-inorganic composite phase change material(PCM) called disodium hydrogen phosphate dodecahydrate-lauric-palmitic acid(D-LA-PACM) was prepared. Expanded graphite(EG) was selected as the support material, and the novel organic-inorganic form-stable PCM called D-LA-PAPCM/EG was prepared using the vacuum adsorption method. Differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, leakage testing, melting and solidification cycle testing, thermal conductivity testing, scanning electron microscopy observation of the micromorphology, and other characterization methods were used to study the microstructure and morphology, thermal physical parameters, thermal conductivity, stability of the PCMs, and the comprehensive material properties of D-LA-PAPCM under the composite action of EG. Results indicated that the melting and freezing temperatures and latent heats of D-LA-PAPCM/EG were measured to be 31.6℃ and 34.3℃ and 142.9 and 142.8 J/g, respectively. Although some of the lauric-palmitic acid(LA-PA) and disodium hydrogen phosphate dodecahydrate(DHPD) separated in the multiple porous structures of EG after 1000 cycles, they could still absorb and release latent heats independently, with D-LA-PAPCM/EG still exhibiting good thermal stability. The thermal conductivity of D-LA-PAPCM/EG was 1.361 W/(m·K). Therefore, the material and thermal properties of the prepared D-LA-PAPCM/EG indicate that it could be well used as a feasible material for energy-saving phase change floor units in indoor TES systems.     

Eutectic compound (KNO3/NaNO3 : PCM) quasi‐encapsulated into SiC‐honeycomb for suppressing natural convection of melted PCM

The phase change eutectic compound, KNO₃/NaNO₃ (50/50 mol%) (phase change material (PCM)), which is used as the thermal energy storage material in the solar thermal power plant, was quasi‐encapsulated into the SiC‐honeycomb (SCH) for suppressing the natural convection occurring at the liquid state of PCM. The performance of the SCH as the material suppressing natural convection of PCM was investigated experimentally. PCM with three kinds of mixing ratios of SCH of 10%, 20%, and 30%, was prepared and packed in their respective stainless can with oil‐flowing pipe in the center, which is called thermal energy storage unit (TESU). Three units were linked together and stacked vertically by the connector at the inlet/outlet oil pipe. The time variation of temperature at the fixed positions inside the TESU in charging/discharging process and temperature gradient in the radial direction inside TESU when PCM was liquid state were investigated. It is concluded that the natural convection is suppressed by mixing the SCH with PCM up to around 30% in weight, because the PCM is quasi‐encapsulated into cell holes and porous structures of SCHs. And thus, the heat transfer of the PCM + 30%SCH composite is controlled mainly by its thermal conduction, which is also supported through comparison of simulation result with experimental one. And so, we conclude that SCH has a function as the quasi‐encapsulating material for suppressing the natural convection of PCM. Copyright © 2015 John Wiley & Sons, Ltd.     

Lauric and myristic acids eutectic mixture as phase change material for low‐temperature heating applications

Lauric acid (m.p.: 42.6°C) and myristic acid (m.p.: 52.2°C) are phase change materials (PCM) having quite high melting points which can limit their use in low‐temperature solar applications such as solar space heating and greenhouse heating. However, their melting temperatures can be tailored to appropriate value by preparing a eutectic mixture of lauric acid (LA) and myristic acid (MA). In the present study, the thermal analysis based on differential scanning calorimetry (DSC) technique shows that the mixture of 66.0 wt% LA forms a eutectic mixture having melting temperature of 34.2°C and the latent heat of fusion of 166.8 J g^?1. This study also considers the experimental establishment of thermal characteristics of the eutectic PCM in a vertical concentric pipe‐in‐pipe heat storage system. Thermal performance of the PCM was evaluated with respect to the effect of inlet temperature and mass flow rate of the heat transfer fluid on those characteristics during the heat charging and discharging processes. The DSC thermal analysis and the experimental results indicate that the LA–MA eutectic PCM can be potential material for low‐temperature solar energy storage applications in terms of its thermo‐physical and thermal characteristics. Copyright © 2005 John Wiley & Sons, Ltd.     

Design of three-dimensional interconnected porous hydroxyapatite ceramic-based composite phase change materials for thermal energy storage

In this article, three-dimensional connected porous hydroxyapatite ceramics (PHCs) were prepared by using the Pickering emulsion template, which possessing controlled pore structure simply by adjusting the solid content from 35 to 55 wt%. The polyethylene glycol (PEG) and PHCs were compounded by vacuum impregnation to acquire composite phase change materials (CPCMs) with admirable shape stability. The SEM and EDS images showed that PEG was successfully adsorbed in the pore, and the results of FT-IR, XRD, TGA, and thermal cycles test, demonstrated the CPCMs possessed satisfactory chemical stability, favorable thermal stability, and wonderful thermal reliability. The maximum package ratio obtained was 66 wt%, which was supported by the PHC sample prepared with a solid content of 40 wt%. Moreover, the phase transition temperature and latent heat during melting and solidification were 53.41°C and 117.5 J/g, 36.49°C and 111.1 J/g, respectively. Therefore, the prepared PCM composites had a controlled pore structure, stable chemical properties, high latent heat, and excellent thermal reliability, making it a reliable application of thermal energy storage.     

石墨泡沫/共晶盐复合相变材料制备

选择KNO3/NaNO3二元体系按照质量比4∶6制备共晶盐,对共晶盐进行了熔点及熔化潜热的测量;将石墨泡沫这一新型材料作为强化基体,共晶盐作为相变材料（PCM）,采用熔融浸渗法制备了适用于太阳能热发电系统储能装置的石墨泡沫/共晶盐复合相变材料。采用扫描电镜对复合相变材料表面的微观结构进行了表征,并对其熔点、潜热、等效导热系数等热物性参数进行了测试。结果表明：共晶盐与石墨泡沫复合效果比较理想;复合前后共晶盐的熔点和潜热几乎没有发生变化;复合相变材料的等效导热系数得到了显著提升,石墨泡沫对相变材料起到了导热强化作用,满足高温蓄热的要求。     

Improved heating floor thermal performance by adding PCM microcapsules enhanced by single and hybrid nanoparticles

A heating floor is a low-temperature emitter consisting of pipelines in which a fluid circulates between 35°C and 45°C. To ensure energy efficiency, occupant comfort, and building material durability, proper heat management is crucial in buildings. By using phase change materials (PCMs) in building envelopes, the indoor temperature can be regulated through the storage and release of thermal energy, which reduces energy consumption and enhances occupant comfort. In this study, we evaluated numerically a heating floor that incorporates a PCM enhanced by nanoparticles (NePCM). The aim of the numerical analysis is to assess the impact of the addition of single and hybrid nanoparticles in different proportions to the PCM layer on the thermal performance of the PCM-based floor. Therefore, two main objectives are defined. The primary is to take advantage of the storage capacity of a PCM layer by integrating it into the ground; second, to evaluate the hot water temperature levels effect on the floor's performance. Additionally, we address the low thermal conductivity of PCM by enhancing PCM microcapsules with single and hybrid nanoparticles and comparing them to pure PCM. The numerical results obtained show that positioning the PCM microcapsules above the heating tubes (upper position) provides an optimum improvement in thermal performance. Moreover, the addition of hybrid nanoparticles within the base PCM, 1% of Cu mixed with 4% of Al₂O₃, allows an increase of 4°C, which relates to a reduction of 18% in the internal temperature amplitude and a phase shift of 6 h 30 min compared with the conventional heated floor in which there is no PCM.     

Fabrication and characterization of electrospun fatty acid form-stable phase change materials in the presence of copper nanoparticles

Latent heat storage system using phase change materials (PCMs) has been recognized as one of the most useful technologies for energy conservation. In this study, a novel type of fatty acid eutectic of methyl palmitate (MP) and lauric acid (LA)/polyacrylonitrile (PAN) composite phase change fiber is prepared by single electrospinning method. Additionally, copper nanoparticles (CNPs) with different mass ratio are combined for improving the thermal conductivity of the PCM. The structure and morphology of the fabricated composite PCMs are observed by scanning electron microscopy (SEM), and the thermal properties and performance are also characterized. SEM results show that the liquid fatty acid has been fully stabled by the three-dimensional structure of the fibers. Good compatibility among the components of the composites is also demonstrated. Besides, the addition of nanoparticles leads to an improved thermal conductivity by over 115.2% and a phase transition temperature 21.24 °C as well as a high latent heat of 85.07 J/g. Moreover, excellent thermal reliability of the phase change fiber is confirmed by multiple thermal cycles. Hence, the composite PCM prepared in this study shows a promising potential for thermal energy system such as building insulating and thermal mass regulating textiles.