Acta Phys. -Chim. Sin. ›› 2005, Vol. 21 ›› Issue (04): 446-449.doi: 10.3866/PKU.WHXB20050421

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Low-temperature Heat Capacity and Thermodynamic Functions of Nano ZnO

YUE Dan-Ting; TAN Zhi-Cheng; DONG Li-Na; SUN Li-Xian; ZHANG Tao   

  1. Thermochemistry Laboratory. Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023; Marine Engineering College, Dialian Maritime University, Dalian 116026
  • Received:2004-09-29 Revised:2004-11-23 Published:2005-04-15
  • Contact: TAN Zhi-Cheng

Abstract: The size of nano ZnO powders was determined to be 30 nm in diameter by SEM. The isobaric molar heat capacity Cp of the nano ZnO was measured with high precision adiabatic low-temperature calorimeter in temperature range from 83 K to 350 K. The relationship of Cp with temperature T was established as: Cp=-3.249+0.2400T-3.413×10-4T 2+4.485×10-7T 3. The thermodynamic functions of the nano ZnO, relative to the standard temperature of 298.15 K, were derived based on the heat capacity data through thermodynamic relationship. The measured Cp values were compared with those of coarse crystal and 18 nm ZnO powders cited from literature and the difference between the Cp curves was analyzed.

Key words: Nano ZnO, Low-temperature heat capacity, Thermodynamic functions