Effect of channel structure on microchannel emulsification
Effect of channel structure on microchannel emulsification
复制标题
DOI：
10.1021/la025813a
复制
发表时间：
2002-07-23
期刊：
影响因子：
3.9
通讯作者：
Seki, M
中科院分区：
文献类型：
--
作者：
Sugiura, S;Nakajima, M;Seki, M
微通道乳化是一种利用界面张力自发转化形成单分散乳液的新技术。MC结构由一条狭窄的河道和一个狭长的阶地组成。在这项研究中，调查从MC液滴形成的动态行为的通道结构的影响，我们进行MC乳化使用不同的通道宽度和长度的MC和观察乳化行为，使用配备有高速摄像机的显微镜。所形成的液滴直径是独立的通道的宽度和长度，是恒定的低于临界流速，超过该液滴直径急剧增加。超过临界速度后，液滴脱离的时间也急剧增加。结果表明，窄长通道的临界流速较高。这意味着液滴的形成是基于使用窄长通道在高流速下由界面张力引起的自发转变。窄而长的通道在通道中产生大的压降。通道中的大的压降可能干扰分离期间通道中的分散相通过阶地流入井中。因此，阶地上的分散相使用窄而长的通道在更短的时间内分离。因此，具有较窄和较长通道的MC结构对于高乳液生产速率更好。
Microchannel (MC) emulsification is a novel technique for producing monodispersed emulsions in which droplets are formed by spontaneous transformation caused by interfacial tension. An MC structure consists of a narrow channel and a slitlike terrace. In this study, to investigate the effect of the channel structure on the dynamic behavior of droplet formation from an MC, we performed MC emulsification using MCs with different channel widths and lengths and observed emulsification behaviors using a microscope equipped with a high-speed camera. The formed droplet diameter was independent of the channel width and length and was constant below the critical flow velocity, over which the droplet diameter drastically increased. The time for droplet detachment also drastically increased above the critical velocity. It was found that the critical velocity was high for narrow and long channels. It means that droplet formation is based on the spontaneous transformation caused by interfacial tension at high flow velocity using narrow and long channels. Narrow and long channels produce a large pressure drop in the channel. The large pressure drop in the channel may disturb the flow of the dispersed phase in the channel into the well through the terrace during detachment. Therefore, the dispersed phase on the terrace detaches in less time using narrow and long channels. As a result, an MC structure with narrower and longer channels is better for high emulsion production rates.