Kinetic theory of polymeric liquids
Kinetic theory of polymeric liquids
复制标题
聚合物液体的动力学理论
DOI：
10.1021/ar00120a002
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发表时间：
1985
影响因子：
18.3
通讯作者：
R. Bird
中科院分区：
文献类型：
--
作者：
R. Bird
大多数化学家在大学学习中都遇到过稀气体的基本动力学理论.在许多物理学或物理化学教科书中，关于动量转移的简单动力学理论论证导致了稀气体粘度μ的表达式1，2，其中分子被建模为质量为m且直径为μ~ VmkT/2的刚性球（这里kT是玻尔兹曼常数乘以绝对温度）。也就是说，相对粗糙的参数导致气体粘度依赖于温度和分子质量和直径。当然，一个更精确的动力学理论已经发展出来，其中的偏差是从上面引用的简单关系式中发现的。[1]分子的模型也变得更加真实，包括了货车德瓦耳斯吸引力、偶极和四极矩之间的相互作用以及非中心分子间力。不幸的是，稀聚合物溶液的简单动力学理论还没有进入教科书，因为它提供了相当深入的结构-性质关系。当聚合物分子被粗略地建模为弹性哑铃时，可以在短短几页中开发动力学理论方程;早在40年前，物理和化学研究文献中就已经给出了3个这样的推导，尽管不是以适合教科书使用的形式。
Most chemists have encountered intheir university study some kind of elementary kinetic theory of dilute gases. In many textbooks of physics or physical chem-istry, simple kinetic theory arguments about momen-tum transfer lead to an expression1, 2 for the viscosity µ of a dilute gas, in which the molecules are modeled as rigid spheres of mass m and diameter: µ~ VmkT/2 (here kT is the Boltzmann constant times the absolute temperature). That is, relatively crude arguments lead to the dependence of the gas viscosity on the temperature and on the molecular mass and diameter. Of course, a much more refined kinetic theory has been developed, in which the deviations are found from the simple relation cited above. 1 Also the modeling of the molecules has become more realistic, with the inclusion of van der Waals attractive forces, interactions among dipole and quadrupole moments, and noncentralintermolecular forces. It is unfortunate that the simple kinetic theory for dilute polymer solutions has not found its way into the textbooks, since it gives considerable insight into structure-property relationships. When the polymer molecules are modeled crudely as elastic dumbbells, it is possible to develop the kinetic theory equations in just a few pages; 3 such derivations have been given in the physics and chemistry research literature as early as 40 years ago, although not in suitable form for textbook use.