Preparation and modification of novel phase change material Na₂SO₄·10H₂O-Na₂HPO₄·12H₂O binary eutectic hydrate salt

ABSTRACT

A novel composite phase change material was prepared by compounding Na₂SO₄ 10H₂O-Na₂HPO₄ 12H₂O binary eutectic hydrate salt (BEHS) and modifying it. The optimum ratio of nucleating agent (nanometer AlN, borax) and thickening agent (hydroxyethyl cellulose, sodium alginate and sodium polyacrylate) was determined by uniform design test, so as to eliminate phase separation and reduce supercooling degree of BEHS. The prepared composite BEHS was microscopically analyzed by scanning electron microscopy (SEM) and X-ray energy spectroscopy (EDS) and its thermal stability of the composite BEHS was analyzed by melt-freezing cycle and Fourier transform infrared spectroscopy (FTIR). The results showed that the best composite BEHS was prepared by adding 1.8wt% nano-AlN, 1.5wt% borax, 4.8wt% hydroxyethyl cellulose, 4wt% sodium alginate and 1.5wt% sodium polyacrylate in the 80%Na₂SO₄ 10H₂O-20% Na₂HPO₄ 12H₂O system, which subcooling degree was 3.1°C, and phase change enthalpy was 180.2J/g. After 50 times and 100 times of melt-freeze cycle experiments, the phase change enthalpy of composite BEHS decreased by 2.72% and 3.61% respectively, and the material composition remains unchanged, the thermal properties are relatively stable

KEYWORDS:

• Nano-AlN
• eutectic hydrated salt
• supercooling
• phase separation
• uniform design experimentation

Additional information

Notes on contributors

Wang Xin

Wang Xin, Master, Army Logistics Unversity of PLA. Research direction is synthesis and application of phase change energy storage materials.

Jianhua Fang

Jianhua Fang, Ph.D. supervisor, Army Logistics Unversity of PLA. Research direction is the development and application of new energy materials and the study of friction and lubrication mechanism.

Wu Jiang

Wu Jiang, Ph.D., Army Logistics Unversity of PLA. Research direction is efficient collection and utilization of solar energy and development of its products.

Liu Ping

Liu Ping, Master, Army Logistics Unversity of PLA. Research direction is efficient collection and utilization of solar energy and development of its products

Liu Na

Liu Na, Ph.D., Army Logistics Unversity of PLA. Research direction is the synthesis process of phase change microcapsules.

Feng Yanhan

Feng Yanhan, Master, Army Logistics Unversity of PLA. Research direction is the synthesis and application of high melting point paraffins.

Lin Wang

Lin Wang, Master, Army Logistics Unversity of PLA. Research direction is synthesis and application of phase change energy storage materials.