物理化学学报 >> 2006, Vol. 22 >> Issue (11): 1427-1430.doi: 10.3866/PKU.WHXB20061124

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纳米铁的低温热容和热力学性质研究

岳丹婷;谭志诚;李彦生   

  1. 大连海事大学轮机学院, 辽宁 大连 116026; 中国科学院大连化学物理研究所热化学实验室, 辽宁 大连 116023; 大连交通大学环境科学与工程学院, 辽宁 大连 116028
  • 收稿日期:2006-04-03 修回日期:2006-07-05 发布日期:2006-11-06
  • 通讯作者: 谭志诚 E-mail:tzc@dicp.ac.cn

Low-Temperature Heat Capacity and Thermodynamic Functions of Nano Fe

YUE Dan-Ting;TAN Zhi-Cheng;LI Yan-Sheng   

  1. (Dalian Maritime University, Dalian 116026， P. R. China; Thermochemistry Laboratory,
  • Received:2006-04-03 Revised:2006-07-05 Published:2006-11-06
  • Contact: TAN Zhi-Cheng E-mail:tzc@dicp.ac.cn

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摘要： 用扫描电子显微镜(SEM)测定了纳米铁试样的粒径, SEM结果表明Fe试样平均粒径d为25 nm. 在84～350 K温区, 用精密低温绝热量热计测定了该纳米铁试样的等压摩尔热容, 拟合出其等压摩尔热容与热力学温度的函数关系式: Cp=36.831+14.772x−5.4968x2−0.7099x3−1.3188x4, 其中x=(T−234)/156. 根据热容与热力学函数关系, 计算了以298.15 K为基准的纳米Fe(d=25 nm)热力学函数, 并与文献报导的粗晶Fe及粒径87 nm Fe的热容进行了比较, 从能量角度分析了不同粒径Fe热容曲线差别产生的原因.

关键词: 纳米铁, 低温热容, 热容增强, 热力学函数, 绝热量热法

Abstract: The size of nano Fe powders was determined to be 25 nm in diameter by SEM. The isobaric molar heat capacity Cp of the nano Fe was measured with the high precision adiabatic low-temperature calorimeter in the temperature range from 84 K to 350 K. The relationship of Cp with temperature T was established as: Cp=36.831+14.772 x−5.4968x2−0.7099x3−1.3188x4, where x=(T−234)/156. The thermodynamic functions of the nano Fe, 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 powders and 87 nm Fe powders cited from literature and the difference between the Cp curves was analyzed

Key words: Nano Fe, Low-temperature heat capacity, Heat capacity enhance, Thermodynamic functions, Adiabatic calorimetry