STRUCTURE AND ORDERING IN LOCALIZED ADSORPTION OF PARTICLES
STRUCTURE AND ORDERING IN LOCALIZED ADSORPTION OF PARTICLES
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DOI：
10.1016/0021-9797(90)90329-m
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发表时间：
1990-11-01
影响因子：
9.9
通讯作者：
WARSZYNSKI, P
中科院分区：
文献类型：
--
作者：
ADAMCZYK, Z;ZEMBALA, M;WARSZYNSKI, P
从理论上和实验上分析了胶体粒子通过屏蔽库仑势相互作用的局部顺序吸附。利用蒙特卡罗技术模拟了不同表面浓度θ和不同筛选长度参数κα下的二维对相关函数，表征了粒子-粒子相互作用势的“柔软性”。证实了κα⪢1的硬盘极限行为（最大表面浓度θmx= 55%）。软盘的θmx通常比上述值小得多，它也被确定为κα参数的函数。在接近θmx值的表面浓度中，发现了一种明显的向短程有序的趋势，类似于先前对胶体悬浮液获得的3D结果。采用基于粒子吸附显微镜观察的直接实验方法对理论预测进行了验证。采用单分散聚苯乙烯悬浮液（粒径0.90 μm），吸附表面为云母片。实验结果证明与蒙特卡罗模拟很好地吻合，说明了表面浓度接近预测值θmxvalues时的结构化趋势（二维准液相形成）。
Localized, sequential adsorption of colloid particles interacting via screened Coulomb potential was analyzed theoretically and experimentally. The two-dimensional (2D) pair correlation functions were simulated by using the Monte Carlo technique for various surface concentrations θ and for various screening length parameters κα, characterizing the “softness” of the particle-particle interaction potential. For κα ⪢ 1 the hard-disk limiting behavior was confirmed (maximum surface concentrationθmx= 55%). Theθmxfor soft disks, which is generally much smaller than the above value, was also determined as a function of the κα parameter. A distinctive tendency toward a short-range ordering, analogous to the 3D results obtaining previously for colloid suspensions, was found for surface concentration close to theθmxvalue. Theoretical predictions were tested by applying the direct experimental method based on microscope observations of particle adsorption. A monodisperse polystyrene suspension was used (particle size 0.90 μm) and the adsorbing surface was made of mica sheets. Experimental results proved to be in good agreement with Monte Carlo simulations illustrating well the tendency towards structurization (2D quasi-liquid phase formation) for surface concentrations close to the predictedθmxvalues.