液晶分子的抗弯刚度和分子间位致排斥势

The Bending Strength of Molecule and the Steric Repulsive Potential between Molecules of Liquid Crystals

定义了反映分子刚性的物理量，称为抗夸刚度K。给出了用具体的化学键结构及键的力常数计算的K方法。计算得PAA，anisaldehyde azine及BA的K分别为3．17×10^6，2．93×10^3，4．17×10^5λkK，导出了分子阃位致弹性排斥势。提出了处理弹性棒分子体系的统计物理方法。对PAA作了具体的数值计算，并讲座了向列序形成的微观机制；吸引势是主要的，但位致排斥势起十分重要的作用。

A new concept called the bending strength K of molecule is introduced, which can be calculated from the concret structure of molecular chemical bonds and thd force constants of the bonds, and the method of calculation is given. For example for PAA, anisaldehydeazine and BA, K. is 3. 17 × 105,2. 93× 105. 4. 17× 105 AkK , respectively, from calculations. The elastic repulsive potential between two molecules is deduced and the statistical method for the system of elastic rod-like molecules is presented by means of cell model. A detailed calculation is made for PAA. The microcosmic mechanism for forming nematic order is discussed and it is concluded that the attractive potential is primary bgtit the effect of steric repulsive potential is important.