Paraffin/diatomite/multi-wall carbon nanotubes composite phase change material tailor-made for thermal energy storage cement-based composites

• Published in: Energy (Oxford) Vol. 72; pp. 371 - 380
• Main Authors: Xu, Biwan, Li, Zongjin
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.08.2014; Elsevier
• Subjects: Applied sciences; Cement-based Composites; Cements; Composite materials; Composite PCM; Diatomite; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fourier transforms; Materials selection; MWCNTs; Paraffin; Paraffins; Phase change materials; Thermal properties; Thermal stability; Transport and storage of energy; Diatomite; MWCNTs; Composite PCM; Paraffin; Cement-based Composites; Wall; Cement; Carbon nanotubes; Thermal energy storage; PCM material
• ISSN: 0360-5442
• DOI: 10.1016/j.energy.2014.05.049

In this study, a paraffin/diatomite/MWCNTs (multi-wall carbon nanotubes) composite PCM (phase change material) was tailor-made for further applications in producing thermal energy storage cement-based composites. For the purpose of selecting an optimum diatomite as the supporting matrix for the new composite PCM, the pozzolanic reactivity and paraffin absorption capacity of various diatomite materials were evaluated. It was shown that the diatomite material calcined at 600°C for 2h has the best pozzolanic reactivity and comparable paraffin absorption capacity compared to other diatomite candidates. It, therefore, was used as the supporting matrix of the new paraffin/diatomite/MWCNTs composite PCM. The thermal properties of this fabricated composite PCM were determined by the DSC (differential scanning calorimetry) method. It was revealed that the composite PCM has a melting temperature of 27.12°C and latent heat of 89.40J/g. In addition, experimental results from FTIR (Fourier transform infrared) and TGA (thermogravimetric analysis) on this composite PCM showed that it has good chemical compatibility and thermal stability. Moreover, compared to paraffin/diatomite composite PCM, the use of MWCNTs was found to have clear beneficial effects for improving the thermal conductivity and heat storage/release rates, without affecting the thermal properties, chemical compatibility and thermal stability. •Diatomite calcined at 600°C for 2h has the best pozzolanic reactivity.•The fabricated paraffin/diatomite/MWCNTs composite PCM is form-stable.•The composite PCM has a melting temperature of 27.12°C and enthalpy of 89.40J/g.•The 0.26% MWCNTs in composite PCM causes 42.45% thermal conductivity enhancement.