When concentrated particle suspensions flow into a constricting channel, the suspended particles may either smoothly flow through the constriction or jam and clog the channel. These clogging events are typically detrimental to technological processes, such as in the printing of dense pastes or in filtration, but can also be exploited in micro-separation applications. Many studies have to date focused on important parameters influencing the occurrence of clogs, such as flow velocity, particle concentration, and channel geometry. However, the investigation of the role played by the particle surface properties has surprisingly received little attention so far. Here, we study the effect of surface roughness on the clogging of suspensions of silica particles under pressure-driven flows along a microchannel presenting a constriction. We synthesize micron-sized particles with uniform surface chemistry and tunable roughness and determine the occurrence of clogging events as a function of velocity and volume fraction for a given surface topography. Our results show that there is a clear correlation between surface roughness and flow rate, indicating that rougher particles are more likely to jam at the constriction for slower flows. These findings identify surface roughness as an essential parameter to consider in the formulation of particulate suspensions for applications where clogging plays an important role.

中文翻译：

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颗粒悬浮液流入狭窄处的粗糙度相关堵塞

当浓缩颗粒悬浮液流入收缩通道时，悬浮颗粒可能平稳地流过收缩通道或堵塞通道。这些堵塞事件通常对技术过程有害，例如在稠密糊状物的印刷或过滤中，但也可用于微分离应用。迄今为止，许多研究都集中在影响堵塞发生的重要参数上，例如流速、颗粒浓度和通道几何形状。然而，迄今为止，对颗粒表面特性所起的作用的研究令人惊讶地很少受到关注。在这里，我们研究了表面粗糙度对在压力驱动下沿着呈现收缩的微通道的二氧化硅颗粒悬浮液堵塞的影响。我们合成具有均匀表面化学和可调粗糙度的微米级颗粒，并确定堵塞事件的发生作为给定表面形貌的速度和体积分数的函数。我们的结果表明，表面粗糙度和流速之间存在明显的相关性，表明较粗糙的颗粒更容易堵塞在较慢流动的收缩处。这些发现将表面粗糙度确定为在颗粒悬浮液配方中需要考虑的基本参数，用于堵塞起着重要作用的应用。我们的结果表明，表面粗糙度和流速之间存在明显的相关性，表明较粗糙的颗粒更容易堵塞在较慢流动的收缩处。这些发现将表面粗糙度确定为在颗粒悬浮液配方中需要考虑的基本参数，用于堵塞起着重要作用的应用。我们的结果表明，表面粗糙度和流速之间存在明显的相关性，表明较粗糙的颗粒更容易堵塞在较慢流动的收缩处。这些发现将表面粗糙度确定为在颗粒悬浮液配方中需要考虑的基本参数，用于堵塞起着重要作用的应用。