Electro "Dynamic" Interaction in charged Polymer Particle Systems

在胶体晶体关系中，发现盐浓度-粒间距存在一个极大值。通过超小角X射线散射，我们详细研究了这种现象的本质和胶体晶体形成的真实的起源。结果表明：（1）该关系式中的极大值对应于固-液相转变点。(2)在高盐条件下的液相行为可以用经典的DLVO理论很好地解释。(3)在最大点处，胶体晶体中的粒子间距离是物理上可能的最大距离。因此，在比最大点低的盐条件下，对流云的异常重叠发生。(4)这种不规则的重叠在粒子之间产生吸引力，导致胶体晶体的形成。(5)当反离子是质子时，这种吸引力很强。当钠或钾离子是抗衡离子时，吸引力较弱。这表明反离子的运动是粒子相互作用的一个重要因素。(6)在不同粒径和/或不同电荷数的乳胶粒子的混合分散体中，在一定条件下可形成胶体合金结构。超小角中子散射可以很好地研究胶体合金的结构。这种新结构将被应用于开发新型功能材料。

We have found a maximum in salt concentration-interparticle distance in colloidal crystal relationship. By ultra-small-angle X-ray scattering, we have investigated in detail the nature of this phenomena and the real origin of the colloidal crystal formation. The results obtained can be surmmarized as follows ;(1) The maximum in the relationship corresponds to solid-liquid phase transiton point.(2) The behavior at liquid phase at high salt condition can be well explaine by classical DLVO theory.(3) At the maximum point, the interparticle distance in colloid crystal is the physically possible maximum distance. Hence, at lower salt condition than maximum point, an anomalous overlap of counterion cloud occurs.(4) This anomalous overlap generates an attractive force between paticles, which results in colloidal crystal formation.(5) This attractive interaction is strong when the counterions are protons. When sodium or pottasium ions are counterions, the attractive force is weaker. This clealy means that the motion of the counterions is an important factor for particle interaction.(6) In the mixed dispersions of latex particles which is different in size and/or charge number, a colloidal alloy structure can be formed at certain condition. The structure of colloidal alloy can be well studied by ultra-small-angle neutron scattering. This kind of new structure will be applied to develop a novel functinal materials.