利用微流体Y型交叉点进行动态界面张力测量。

Dynamic interfacial tension measurements with microfluidic Y-junctions.

作者信息

Steegmans Maartje L J, Warmerdam Anja, Schroën Karin G P H, Boom Remko M

机构信息

Food Engineering Group, Department ATV, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands.

出版信息

Langmuir. 2009 Sep 1;25(17):9751-8. doi: 10.1021/la901103r.

DOI:10.1021/la901103r

PMID:19583180

Abstract

Emulsification in microdevices (microfluidic emulsification) involves micrometer-sized droplets and fast interface expansion rates. In addition, droplets are formed in less than milliseconds, and therefore traditional tensiometric techniques cannot be used to quantify the actual interfacial tension. In this paper, monodisperse droplets formed at flat microfluidic Y-junctions were used to quantify the apparent dynamic interfacial tension during (microfluidic) emulsification. Hexadecane droplets were formed in ethanol-water solutions with a range of static interfacial tensions to derive a calibration curve, which was subsequently used to access the dynamic interfacial tension of hexadecane droplets formed in surfactant solutions. For SDS and Synperonic PEF108, various continuous- and disperse-phase (hexadecane) flow rates were studied, and these conditions were linked to interfacial tension effects, which also allowed convective transport of surfactants to be investiagted. On the basis of these findings, various strategies for the formation of emulsion droplets can be followed and are discussed.

摘要

微器件中的乳化（微流控乳化）涉及微米级液滴和快速的界面扩展速率。此外，液滴在不到一毫秒的时间内形成，因此传统的张力测量技术无法用于量化实际的界面张力。在本文中，利用在扁平微流控Y型结处形成的单分散液滴来量化（微流控）乳化过程中的表观动态界面张力。在具有一系列静态界面张力的乙醇-水溶液中形成十六烷液滴，以得出校准曲线，随后用该校准曲线来测定在表面活性剂溶液中形成的十六烷液滴的动态界面张力。对于十二烷基硫酸钠（SDS）和月桂醇聚醚（Synperonic PEF108），研究了各种连续相和分散相（十六烷）流速，这些条件与界面张力效应相关联，这也使得能够研究表面活性剂的对流传输。基于这些发现，可以采用并讨论形成乳液液滴的各种策略。