Mehta N K, Grimison A, Block A M
Appl Opt. 1971 Sep 1;10(9):2031-4. doi: 10.1364/AO.10.002031.
The particles in nearly monodisperse sols of polystyrene in water need small amounts of adsorbed emulsifier to combat aggregation tendencies. These sols are used in the calibration of many different types of instrument including instruments capable of measuring angular light scattering functions. Using an IBM 360-40 computer with extended precision on all variables and on machine functions, a calculation has been made of the range of observable effects attributable to an adsorbed layer of emulsifier on the sol particles in water suspension. The calculation of the polarization ratio as a function of angle was based on the formal solution of Maxwell's equations by Aden and Kerker [A. L. Aden and M. Kerker, J. Appl. Phys. 22, 1242 (1951)]. Two model sols were treated for three different commonly used wavelengths of incident light 436 nm, 546 nm, and 632.8 nm. The calculation made use of constituent functions up to the eleventh order. The effect of an adsorbed layer on the light-scattering angular functions was negligible unless the adsorbed layer differed from the medium by about 5% with respect to refractive index. If the layer was not at least 1% of the radius of the particle in thickness there was no observable change in the angular position of the maxima and/or minima of the polarization ratio angular function. For layers thicker than 1% of the particle radius and having a refractive index different from both medium or particle, interesting new maxima and minima are predicted.
水中聚苯乙烯近单分散溶胶中的粒子需要少量吸附乳化剂来对抗聚集趋势。这些溶胶用于校准许多不同类型的仪器，包括能够测量角光散射函数的仪器。使用一台对所有变量和机器功能都具有扩展精度的IBM 360 - 40计算机，已对水悬浮液中溶胶粒子上乳化剂吸附层可观测效应的范围进行了计算。作为角度函数的偏振比计算基于Aden和Kerker对麦克斯韦方程组的形式解[A. L. Aden和M. Kerker，《应用物理杂志》22，1242 (1951)]。针对三种不同的常用入射光波长436纳米、546纳米和632.8纳米处理了两种模型溶胶。计算使用了高达十一阶的组成函数。除非吸附层与介质的折射率相差约5%，否则吸附层对光散射角函数的影响可忽略不计。如果该层厚度不足粒子半径的1%，偏振比角函数的最大值和/或最小值的角位置不会有可观测到的变化。对于厚度大于粒子半径1%且折射率与介质或粒子均不同的层，预测会出现有趣的新的最大值和最小值。
