Effects of the evaporation rate on the segregation in drying bimodal colloidal suspensions
Effects of the evaporation rate on the segregation in drying bimodal colloidal suspensions
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DOI：
10.1063/1.5013194
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发表时间：
2018-01
影响因子：
4
通讯作者：
R. Tatsumi;T. Iwao;O. Koike;Y. Yamaguchi;Y. Tsuji
中科院分区：
文献类型：
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作者：
R. Tatsumi;T. Iwao;O. Koike;Y. Yamaguchi;Y. Tsuji
当含有两种不同大小的胶体颗粒的悬浮液被涂覆在基材上，通过蒸发主体流体形成薄膜时，较小的颗粒可以分离到薄膜的上表面。利用朗之万动力学模拟研究了蒸发速率对分凝的影响。蒸发率通过颗粒的布朗扩散速率来衡量，产生一个无量纲数，我们将其定义为颗粒干燥Peclet数。我们证明了存在一个Peclet数，在该数处偏析最强。当含有两种不同尺寸胶体粒子的悬浮液被涂覆在基片上，通过蒸发主体流体形成薄膜时，较小的粒子可以分离到薄膜的上表面。利用朗之万动力学模拟研究了蒸发速率对分凝的影响。蒸发率通过颗粒的布朗扩散速率来衡量，产生一个无量纲数，我们将其定义为颗粒干燥Peclet数。我们证明了存在一个Peclet数，在该数处偏析最强。我们的结果表明，需要调节蒸发速率来控制偏析。
When suspensions containing colloidal particles of two different sizes are coated on substrates to form films by evaporating the host fluids, the smaller particles can segregate to the top surface of the films. We investigate the effects of the evaporation rate on the segregation by use of Langevin dynamics simulations. The evaporation rate is scaled by the Brownian diffusion rate of the particles, yielding a dimensionless number which we define as the particle drying Peclet number. We show that there is a Peclet number at which the segregation is the most enhanced. Our result indicates the need for the regulation of the evaporation rate to control the segregation.When suspensions containing colloidal particles of two different sizes are coated on substrates to form films by evaporating the host fluids, the smaller particles can segregate to the top surface of the films. We investigate the effects of the evaporation rate on the segregation by use of Langevin dynamics simulations. The evaporation rate is scaled by the Brownian diffusion rate of the particles, yielding a dimensionless number which we define as the particle drying Peclet number. We show that there is a Peclet number at which the segregation is the most enhanced. Our result indicates the need for the regulation of the evaporation rate to control the segregation.