摘要
从单元系的液滴和蒸汽两相共存的热力学平衡条件出发,在视液滴表面张力引起的压强相对于共存时蒸汽相压强为一级小量的情况下,分析了热力学平衡状态时的温度、压强和化学势三个重要参量随熵变值变化的行为,导出了液滴蒸发温度与其半径大小之间的定量关系式。该定量关系式表明液滴半径越小越容易蒸发,亦可解释半径越小的水滴越容易蒸发的这一实际生活中遇到的现象。对该式适当加以推广,可以解释纳米颗粒材料的熔化温度为什么小于其块材熔化温度,即可阐明材料做成纳米尺度后,其熔融烧结温度将明显低于相应的固体大块材料的实验事实。
Based on the thermodynamic equilibrium condition of the coexistence of droplet and vapor in single-component system,when the pressure caused by droplet surface tension is a first-order small quantity relative to the vapor phase pressure,the quantitative relationship between droplet evaporation temperature and its radius can be derived.It is found that the smaller the droplet radius is,the easier it is to be evaporated.The relationship can explain the phenomenon that the smaller the radius of water droplets is,the easier it is to evaporate in real life.It can be generalized to explain that the melting temperature of nanoparticle materials is less than that of bulk materials.That is,after the materials are made into nanoscale,the melting and sintering temperature will be significantly lower than that of corresponding solid bulk materials.
作者
李广
左学勤
杨群
丁宗玲
郑赣鸿
LI Guang;ZUO Xueqin;YANG Qun;DING Zongling;ZHENG Ganhong(School of Physics & Optoelectronic Engineering, Anhui University, Hefei 230601, China;School of Materials Science & Engineering, Anhui University, Hefei 230601, China)
出处
《合肥师范学院学报》
2021年第6期1-3,共3页
Journal of Hefei Normal University
基金
安徽省高等学校省级质量工程项目“材料类专业物理基础课程群教学团队”(2019jxtd017)
安徽省省级精品线下开放课程“材料物理性能”(2019kfkc020)
安徽省高等学校省级质量工程项目“点圆式工作法在材料物理专业课程改革和一流人才培养中的发展与应用”(2019jyxm0066)。
关键词
气液两相共存
液滴半径
蒸发温度
liquid and vapor phases
radius of droplet
vaporization temperature
