• Energy Research

Abstract Thermosetting polyurethane based on Polyethylene glyol and Polyaryl polymethylene isocyanate was prepared through solvent-free bulk polymerization for solid-solid phase change materials. Chemical structure, crystallization behavior, phase change behavior, thermal reliability and thermal stability of Polyethylene glyol based phase change materials were extensively studied by fourier transform infrared spectroscopy, X-ray diffraction, polarizing optical microscopy, differential scanning calorimetry, thermal cycling testing and thermogravimetric analysis, respectively. The polarizing optical microscopy and X-ray diffraction results indicated that the crystal structure of prepared phase change materials was not affected by the crosslink structure. Differential scanning calorimetry measurements showed that prepared phase change materials possess high latent heat and appropriate phase change temperature for the application of thermal energy storage. The maximum latent heat of phase change materials in melting and freezing process reached 111.7 J/g and 110.4 J/g, respectively. Thermal cycling test and thermogravimetric analysis results demonstrated the good thermal reliability and stability of prepared phase change materials. The prepared phase change materials showed the potential for thermal energy storage application and will make an effective utilization of waste energy.

Abstract Thermosetting polyurethane based on Polyethylene glyol and Polyaryl polymethylene isocyanate was prepared through solvent-free bulk polymerization for solid-solid phase change materials. Chemical structure, crystallization behavior, phase change behavior, thermal reliability and thermal stability of Polyethylene glyol based phase change materials were extensively studied by fourier transform infrared spectroscopy, X-ray diffraction, polarizing optical microscopy, differential scanning calorimetry, thermal cycling testing and thermogravimetric analysis, respectively. The polarizing optical microscopy and X-ray diffraction results indicated that the crystal structure of prepared phase change materials was not affected by the crosslink structure. Differential scanning calorimetry measurements showed that prepared phase change materials possess high latent heat and appropriate phase change temperature for the application of thermal energy storage. The maximum latent heat of phase change materials in melting and freezing process reached 111.7 J/g and 110.4 J/g, respectively. Thermal cycling test and thermogravimetric analysis results demonstrated the good thermal reliability and stability of prepared phase change materials. The prepared phase change materials showed the potential for thermal energy storage application and will make an effective utilization of waste energy.

Abstract To overcome the leakage of phase change materials (PCMs) above melting temperature, PCMs are commonly encapsuled by chemically crosslinked networks, which bring the issues of reparability, reprocess-ability and recyclability making for the environment pollution and resource waste. Herein, a reversible aromatic disulfide is adopted to form dynamic epoxy networks which not only encapsulate polyethylene glycol (PEG) as the shape-stabilized PCMs (SSPCMs) but also address the issues about the un-recyclability of traditional SSPCMs. The PEG was well encapsulated and uniformly dispersed in disulfide-based epoxy due to the elaborate molecular design. The obtained SSPCMs (named EXAP2) shows typical solid–solid phase transitions characteristic and thermal reliability with high latent heat value of 82.7 J/g. Besides, the EXAP2 exhibit dynamic performance and can be reprocessed by hot press via the disulfide bonds exchange reaction above topology freezing temperature (Tv). And the reprocessed EXAP2 exhibits close phase change properties with the original sample, implying the reprocessing does not affect the crystalline structure and encapsuling capability of disulfide crosslinked networks. This strategy prove a significant way for fabricating the novel SSPCM with recyclability, reprocessability and reliability.

Abstract To overcome the leakage of phase change materials (PCMs) above melting temperature, PCMs are commonly encapsuled by chemically crosslinked networks, which bring the issues of reparability, reprocess-ability and recyclability making for the environment pollution and resource waste. Herein, a reversible aromatic disulfide is adopted to form dynamic epoxy networks which not only encapsulate polyethylene glycol (PEG) as the shape-stabilized PCMs (SSPCMs) but also address the issues about the un-recyclability of traditional SSPCMs. The PEG was well encapsulated and uniformly dispersed in disulfide-based epoxy due to the elaborate molecular design. The obtained SSPCMs (named EXAP2) shows typical solid–solid phase transitions characteristic and thermal reliability with high latent heat value of 82.7 J/g. Besides, the EXAP2 exhibit dynamic performance and can be reprocessed by hot press via the disulfide bonds exchange reaction above topology freezing temperature (Tv). And the reprocessed EXAP2 exhibits close phase change properties with the original sample, implying the reprocessing does not affect the crystalline structure and encapsuling capability of disulfide crosslinked networks. This strategy prove a significant way for fabricating the novel SSPCM with recyclability, reprocessability and reliability.

Abstract We fabricated a nanoarray-modified nickel foam utilized as the supporting material for polyethylene glycol (PEG) to prepare a form-stable phase change material (PCM). The nanoarrays on the skeleton of the nickel foam look like flowers and can act as the nucleating agent, giving rise to the heterogeneous nucleation of the material. The nanoarray-modified nickel foam-supported PCM (NAPCM) has high latent heat values, which are 132.1 and 135.8 J·g−1 in the melting and solidification processes respectively, showing outstanding thermal energy storage capacity. The thermal properties including the latent heat values of the NAPCM after 100 times of thermal cycling are almost unchanged compared with the original one. Moreover, the thermal conductivity of the NAPCM increases by 157.4% and the super cooling degree decreases by 35.3% compared with pure PEG. The NAPCM with low super cooling, high latent heat values and thermal conductivity shows great potential for thermal energy utilization.

Abstract We fabricated a nanoarray-modified nickel foam utilized as the supporting material for polyethylene glycol (PEG) to prepare a form-stable phase change material (PCM). The nanoarrays on the skeleton of the nickel foam look like flowers and can act as the nucleating agent, giving rise to the heterogeneous nucleation of the material. The nanoarray-modified nickel foam-supported PCM (NAPCM) has high latent heat values, which are 132.1 and 135.8 J·g−1 in the melting and solidification processes respectively, showing outstanding thermal energy storage capacity. The thermal properties including the latent heat values of the NAPCM after 100 times of thermal cycling are almost unchanged compared with the original one. Moreover, the thermal conductivity of the NAPCM increases by 157.4% and the super cooling degree decreases by 35.3% compared with pure PEG. The NAPCM with low super cooling, high latent heat values and thermal conductivity shows great potential for thermal energy utilization.

In this article, a series of crosslinked polyurethane/lauric acid composites was prepared as form stable phase change materials (FSPCMs) through a brief and solvent-free method.

In this article, a series of crosslinked polyurethane/lauric acid composites was prepared as form stable phase change materials (FSPCMs) through a brief and solvent-free method.

Abstract The solid–solid phase change materials (SSPCMs) have become the preferred materials in thermal energy storage via absorbing latent heat from ambient environment. However, the trade-off between the mechanical properties, stability and recyclability is still the obstacle and barrier for development of SSPCMs. Herein, we proposed a facile and novel strategy to prepare SSPCMs for address above issues by introducing π-π stacking to form physical crosslinking points in linear polyethylene glycol (PEG). The strong intermolecular forces formed by π-π stacking not only prevented leakage of the PEG even at 130 °C but imparted high temperature stability and excellent toughness (172.44 MJ/m3) to fabricated SSPCMs. It is worth mentioning that the prepared PCMs can be added with CNT in a simple process way to improve the photo-thermal conversion ability and thermal conductivity of SSPCMs. Besides, the as-prepared SSPCMs exhibited excellent flexibility, and were expected to be excellent thermal/photo energy storage materials for human thermal management and wearable devices.