Hydrothermal Carbon‐Doped Polyethylene Glycol as Phase‐Change Materials with Good Thermal Conductivity and Shape‐Stability

Abstract

Polyethylene glycol (PEG) is limited by the low thermal‐conductivity and poor shape‐stability in practical applications. In our work, the thermal conductivity and shape‐stable phase change Materials (SSPCMs) doped with hydrothermal carbon (HTC) was successfully prepared. HTC with ‐ OH and ‐ COOH groups on the surface was prepared by hydrothermal carbonization of glucose. The hydrogen bonds were formed between functional groups on HTC surface and PEG to obtain the network structure. When the HTC doping ratio is 6 wt%, good shape‐stability can be achieved. Besides, the thermal conductivity of the HTC/PEG SSPCMs with the HTC doping ratio of 9 wt% is 0.6121 W/(m⋅K), which is 134.7% higher than PEG. The DSC results show that the melting enthalpy (ΔHm) of PEG and HTC/PEG SSPCMs is almost the same, as is the crystallization enthalpy (ΔHc). It indicates that doping HTC does not substantially affect the heat storage capacity of PEG.

Copolymerization of Phase Change Materials with Water Resistance Poly(Acrylamide‐Co‐Polyacrylic Acid) Copolymer Encapsulation: Photothermal Conversion and Storage Performance Under Solar Conditions

“…For PRP, the major peaks of RHTC, PAAAM, and PEG all existed in PRP composites. [ 36,46 ] The location of diffraction peaks were basically the same, indicating that PRP was successfully prepared. In addition, the intensity of the diffraction peak of PRP at 23.4° was significantly enhanced due to the presence of the RHTC diffraction peak at 23.1°.…”

Polyethylene glycol with dual three-dimensional porous carbon nanotube/diamond: a high thermal conductivity of composite PCM

“…Undoubtedly, the shape-stability and leakage proof performance of PCM was one of the essential criteria for evaluating in thermal applications. However, pure PEG had leakproof properties, weak intermolecular interaction, which cannot be maintained during phase change process [37]. It is demonstrated that the skeleton can preserve shape stability and avoid leaking for PEG.…”

Development and Laboratory Scale Characterization of a New Hybrid Nano‐enhanced Phase Change Material for Solar Thermal Energy Storage

“…[8][9][10] The previous studies show that the presence of nanoparticles is capable of enhancing the thermal conductivity up to a large extent without changing the properties of the phase change materials significantly. [11][12][13] Nanoparticles are usually less than 100 nm and they have high surface to volume ratio. The nanoparticles being lighter in weight do not make the system bulky.…”

“…There is a possibility to enhance the thermal conductivity by some techniques such as insertion of metallic structure, formation of form stable PCMs, encapsulation, and addition of nanoparticles in the base PCMs [8–10] . The previous studies show that the presence of nanoparticles is capable of enhancing the thermal conductivity up to a large extent without changing the properties of the phase change materials significantly [11–13] . Nanoparticles are usually less than 100 nm and they have high surface to volume ratio.…”