Gómez-Guzmán O, Ruiz-Garcia J
Instituto de Física, Universidad Autónoma de San Luis Potosí, Alvaro Obregón 64, 78000 San Luis Potosí, Mexico.
J Colloid Interface Sci. 2005 Nov 1;291(1):1-6. doi: 10.1016/j.jcis.2005.04.100. Epub 2005 Jun 23.
In the past few years, measurements of the pair interaction potential have shown evidence of micrometer-range attractive interactions between colloidal particles trapped between glass plates. In these experiments it is believed that the glass walls play an important role in the observed attractions. Colloidal particles trapped at the air/water interface show the formation of different 2-D colloidal patterns such as foams, clusters, and chains, whose formation has been taken as evidence of micrometer-range attractive interaction. Here, we present measurements of the pair interaction potential between 0.5-microm colloidal particles at the air/water interface. Indeed, the pair potential shows an attractive secondary minimum at about 1.9sigma, where sigma is the particle's diameter. Surprisingly, the position and depth of the secondary well are similar to those found in colloidal systems trapped between glass plates. However, we do not have a clear explanation on the origin of the attractive component of the interaction potential.
在过去几年中，对粒子间相互作用势的测量显示，被困在玻璃板之间的胶体颗粒之间存在微米级范围的吸引相互作用迹象。在这些实验中，人们认为玻璃壁在观察到的吸引力中起着重要作用。被困在空气/水界面的胶体颗粒会形成不同的二维胶体图案，如泡沫、团簇和链，其形成被视为微米级范围吸引相互作用的证据。在此，我们展示了空气/水界面处0.5微米胶体颗粒之间的粒子间相互作用势的测量结果。实际上，该粒子间势在约1.9σ处显示出一个吸引性的次级最小值，其中σ为粒子直径。令人惊讶的是，次级阱的位置和深度与被困在玻璃板之间的胶体系统中的情况相似。然而，我们对相互作用势的吸引成分的起源尚无明确解释。
