Autophobing on liquid subphases driven by the interfacial transport of amphiphilic molecules.
Autophobing on liquid subphases driven by the interfacial transport of amphiphilic molecules.
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DOI：
10.1021/la303639w
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发表时间：
2012-10-30
期刊：
影响因子：
--
通讯作者：
Tilton RD
中科院分区：
文献类型：
--
作者：
Sharma R;Kalita R;Swanson ER;Corcoran TE;Garoff S;Przybycien TM;Tilton RD
我们研究了不完全润湿的现象的高能液体亚相的纯两亲分子的滴，以及滴的两亲溶液是不混溶的亚相。我们发现，两亲物逃逸的接触线的下降，移动的亚相/蒸汽界面上，并形成一个亚单层或完整的单层外部的下降。如果该单层足够致密，则其可以降低亚相的表面张力，提高液滴的接触角并防止液滴完全润湿亚相。这种现象被称为自聚焦，并已在固体基质上进行了广泛的研究。对于这里研究的液体亚相，我们测量了三个相关界面的表面张力之前和之后的下降沉积。所测量的液滴外部的表面张力表明，两亲物可以移动穿过接触线并在液滴外部形成单层。在某些情况下，在平衡时，单层处于充分堆积的状态以产生非润湿条件。在其他情况下，在平衡时，单层密度不足以将表面张力降低到足以实现非润湿条件。不像在固体基底上，其中在液滴外部的单层的形成受到动力学阻碍，两亲物可以通过Marangoni驱动的表面运输快速移动穿过液体亚相，并且实现局部平衡。然而，由于两亲物库存和亚相面积是有限的，在液体亚相上实现自憎不仅取决于固有的亚相/两亲物相互作用，而且取决于总的两亲物库存和液体亚相的面积。
We investigated the phenomenon of incomplete wetting of a high energy liquid subphase by drops of pure amphiphilic molecules as well as drops of amphiphile solutions which are immiscible with the subphase. We show that amphiphiles escape across the contact line of the drop, move on the subphase/vapor interface and form a submonolayer or full monolayer external to the drop. If this monolayer is sufficiently dense, it can reduce the surface tension of the subphase, raise the contact angle of the drop and prevent the drop from fully wetting the subphase. This phenomenon is called autophobing and has been extensively studied on solid substrates. For the liquid subphase studied here, we measure the surface tensions of the three relevant interfaces before and after the drop is deposited. The measured surface tension external to the drop shows that amphiphiles can move across the contact line and form a monolayer outside of the drop. In some cases, at equilibrium, the monolayer is in a sufficiently packed state to create the nonwetting condition. In other cases, at equilibrium the monolayer density is insufficient to lower the surface tension enough to achieve the nonwetting condition. Unlike on solid substrates where the formation of the monolayer external to the drop is kinetically hindered, the amphiphiles can move rapidly across the liquid subphase by Marangoni driven surface transport and local equilbirum is achieved. However, because the amphiphile inventory and subphase area are limited, the achievement of autophobing on a liquid subphase depends not only on the instrinsic subphase/amphiphile interaction but also on the total amphiphile inventory and area of the liquid subphase.
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影响因子：
3.7
作者：
Dussaud, AD;Matar, OK;Troian, SM
通讯作者：
Troian, SM
DOI：
10.1016/0927-7757(96)03622-9
发表时间：
1996-09-16
影响因子：
5.2
作者：
Frank, B;Garoff, S
通讯作者：
Garoff, S
影响因子：
2.9
作者：
Cappa, Christopher D.;Lovejoy, Edward R.;Ravishankara, A. R.
通讯作者：
Ravishankara, A. R.
影响因子：
2.4
作者：
CHURAEV, NV;MARTYNOV, GA;ZORIN, ZM
通讯作者：
ZORIN, ZM
影响因子：
4.6
作者：
Dussaud, AD;Troian, SM
通讯作者：
Troian, SM