Microfluidics as a tool to assess and induce emulsion destabilization.
Microfluidics as a tool to assess and induce emulsion destabilization.
复制标题
微流体作为评估和诱导乳液不稳定的工具。
DOI：
10.1039/d1sm01588e
复制
发表时间：
2022
期刊：
影响因子：
3.4
通讯作者：
Porto Santos T
中科院分区：
文献类型：
--
作者：
Porto Santos T
微流体技术能够在小长度范围内明智地控制工艺参数，从而加速微流体装置中乳液液滴界面的不稳定。从这个角度来看，微流体通道可以用作评估乳液稳定性和观察液滴形成后立即行为的有效工具，从而能够确定它们是否易于重新聚结。观察乳化剂吸附后的液滴还可以研究乳液随时间的稳定性。这两项评估都将有助于确定针对食品和制药行业特定应用的乳液稳定性。此外，乳液聚结也可以在微流体装置内的极其受控的条件下进行，以探索乳液液滴作为微反应器（用于受监管的生物和化学测定）。这种微流体程序可以在受限环境或动态流动条件下进行。在密闭环境下，在模拟不同环境条件的固定位置观察液滴。另一方面，通过在动态流动过程中对乳液进行检查，可以确定液滴在受到剪切力时的行为，这与传统乳化技术甚至泵送操作中所经历的行为相当。鉴于上述情况，本文回顾了迄今为止用于使乳液不稳定的不同微流体技术（例如改变通道几何形状或润湿性），主要关注每项研究的特殊性，即液滴是否在受限或动态流动过程中不稳定。因此，通过深入研究这篇综述，读者将能够确定乳液失稳的不同策略（以便了解稳定机制，甚至将这些液滴用作微反应器），因为本文展示了最新研究的特殊性并阐明了这种微流体相关应用的当前最新技术。
Microfluidic technology enables judicious control of the process parameters on a small length scale, which in turn allows speeding up the destabilization of emulsion droplets interface in microfluidic devices. In this light, microfluidic channels can be used as an efficient tool to assess emulsion stability and to observe the behavior of the droplets immediately after their formation, enabling to determine whether or not they are prone to re-coalescence. Observation of the droplets after emulsifier adsorption also allows the investigation of emulsion stability over time. Both evaluations would contribute to determine emulsion stability aiming at specific applications in food and pharmaceutical industries. Furthermore, emulsion coalescence can also be performed under extremely controlled conditions within the microfluidic devices in order to explore emulsion droplets as micro-reactors (for regulated biological and chemical assays). Such microfluidic procedures can be performed either in confined environments or under dynamic flow conditions. Under confined environments, droplets are observed in fixed positions simulating different environmental conditions. On the other hand, with the scrutiny of emulsions under dynamic flow processes, it is possible to determine the behavior of the droplets when subjected to shear forces, comparable to those experienced in conventional emulsification techniques or even in pumping operations. Given the above, this paper reviews different microfluidic techniques (such as changing channel geometry or wettability) hitherto used to destabilize emulsions, mainly focusing on the specificities of each study, whether the droplets are destabilized in confined or dynamic flow processes. Thereby, by going deeper into this review, readers will be able to identify different strategies for emulsion destabilization (in order to understand stabilizing mechanisms or even to apply these droplets as micro-reactors), as this paper shows the particularities of the most recent studies and elucidates the current state-of-the-art of this microfluidic-related application.