MECHANISM OF FORMATION OF 2-DIMENSIONAL CRYSTALS FROM LATEX-PARTICLES ON SUBSTRATES
MECHANISM OF FORMATION OF 2-DIMENSIONAL CRYSTALS FROM LATEX-PARTICLES ON SUBSTRATES
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DOI：
10.1021/la00048a054
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发表时间：
1992-12-01
期刊：
影响因子：
3.9
通讯作者：
NAGAYAMA, K
中科院分区：
文献类型：
--
作者：
DENKOV, ND;VELEV, OD;NAGAYAMA, K
用光学显微镜直接观察了聚苯乙烯乳胶微球在水平玻璃基底上的二维有序化动力学。结果表明，当含有颗粒的水层的厚度变得近似等于颗粒直径时，有序化开始。通过改变电解质浓度、粒子的电荷和体积分数，证明了粒子间的静电斥力和货车范德华吸引力都不是二维晶体形成的原因。直接观察揭示了控制有序化的主要因素--吸引毛细力（由于颗粒周围形成的毛细作用力）和颗粒向有序区域的对流输送。水蒸发速率的控制结果是允许获得良好有序的单层或由多层（双层、三层等）组成的良好有序域。
The dynamics of two-dimensional ordering of micrometer-size polystyrene latex spheres on a horizontal glass substrate has been directly observed by means of optical microscopy. It turns out that the ordering starts when the thickness of the water layer containing particles becomes approximately equal to the particle diameter. By variation of the electrolyte concentration, the charge of the particles, and their volume fraction, it is proven that neither the electrostatic repulsion nor the van der Waals attraction between the particles is responsible for the formation of two-dimensional crystals. The direct observations revealed the main factors governing the ordering-the attractive capillary forces (due to the menisci formed around the particles) and the convective transport of particles toward the ordered region. The control of the water evaporation rate turns out to allow obtaining either well-ordered monolayers or well-ordered domains consisting of multilayers (bilayers, trilayers, etc.).