Elasticity of particle assemblies as a measure of the surface energy of solids
Elasticity of particle assemblies as a measure of the surface energy of solids
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颗粒集合体的弹性作为固体表面能的量度
DOI：
10.1098/rspa.1987.0089
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
J. Birchall
中科院分区：
文献类型：
--
作者：
K. Kendall;N. Alford;J. Birchall
提出了一种理论来解释粒子集合体的弹性。结果表明，球体的规则立方堆积具有有效杨氏模量，该模量取决于单个颗粒之间的接触。特别值得注意的是，有效模量取决于球体之间的界面吸引力能，因此提供了测量固体表面能的直接方法。然而，大多数粒子集合既不是立方体也不是规则的。问题是根据颗粒的堆积来描述这些真实系统的特性。理论上，粉末压块的模量应随颗粒堆积分数的四次方变化。该结果已通过实验验证，并已用于测定氧化锆、二氧化钛、氧化铝和二氧化硅粉末的表面能。测量值有时远低于表面能理论计算的预期值。实验表明，这种差异是由固体表面的污染造成的。
A theory is suggested to explain the elasticity of particle assemblies. It is shown that a regular cubic packing of spheres has an effective Young’s modulus that depends on the contacts between individual particles. In particular, it is noted that the effective modulus depends on the interfacial attractive energy between the spheres, and thus provides a direct method for measuring the surface energy of solids. However, most particle assemblies are neither cubic nor regular. The problem is to describe the properties of these real systems in terms of the packing of the grains. Theoretically, it is shown that the modulus of a powder compact should vary as the fourth power of the particle packing fraction. This result has been verified experimentally and has been used to determine the surface energies of zirconia, titania, alumina, and silica powders. The measured values were sometimes much lower than expected from theoretical calculations of surface energy. Experiment has shown that such discrepancies result from contamination of the solid surfaces.