ABSTRACT
Boron nitride nanosheet (BNNS) and graphene oxide (GO) as a single filler can effectively improve the thermal conductivity of the composites, and the synergistic mechanism of BNNS and GO was investigated in this paper. In this study, BNNS was first surface-functionalized and the multi-sized (50 nm, 200 nm, 500 nm) modified BNNS (A-BN) were attached to GO through non-covalent bonding interactions to form a cross-linked structure. Then, A-BN and GO were used as thermal fillers and support material adsorption eutectic phase change materials (PCMs) to prepare composite phase change material (CPCM). Characterization results show that small-size A-BN was more likely to form dense thermal networks with good compatibility and interface connectivity between PCMs, A-BN, and GO, ensuring that PCMs can be stored in the network without leaking. When the size of the BNNS was greater than 200 nm, the advantage of thermal conductivity obtained by A-BN was no longer obvious, and the phase change behavior of CPCM was inhibited. In general, the prepared CPCM has the ideal thermal response and thermal stability, which is very suitable for energy storage and thermal management applications.
ABSTRACT
[This corrects the article DOI: 10.1021/acsomega.1c03344.].
ABSTRACT
As an important method to effectively improve energy efficiency, the study of thermal energy storage is particularly important. In this study, six types of clay mineral-based form-stable phase-change materials (FSPCMs) were prepared by the vacuum adsorption method. The adsorption capacity of vermiculite and diatomite was satisfactory, and sepiolite showed the worst adsorption capacity. Clay minerals can delay the thermal decomposition rate of capric-palmitic acid (CA-PA), and the specific surface area and pore capacity of clay minerals all decrease dramatically after the clay minerals have absorbed CA-PA. FSPCMs exhibited a higher heat storage and release efficiency and reflects a certain temperature control performance. In addition, only physical adsorption between the CA-PA and the clay material occurred, and no chemical reaction occurred. Finally, FSPCMs still have high latent heat of phase transition, and they can be used for low-temperature thermal energy storage.
ABSTRACT
In this study, a capric acid (CA)-stearic acid (SA)/expanded graphite (EG) composite phase change material (PCM) was prepared, and the optimum mass ratio of CA-SA is 0.84:0.16. The composite PCM was characterized by scanning electron microscopy, differential scanning calorimetry, and X-ray diffraction. It can be concluded that the CA-SA mixture was found to possess good compatibility with EG, the thermal conductivity of the CA-SA/10 wt % EG composite PCM was 3.28 times higher than that of the CA-SA mixture, and the PCM thermal stability was satisfactory; no leakage occurred in the CA-SA/10 wt % EG composite PCM. The PCM has good thermal reliability after 500 thermal cycles. Finally, it is shown that the CA-SA/10 wt % EG composite PCM showed excellent performance, and therefore, it can be used for low-temperature thermal energy storage.