Building Supracolloidal Fibers from Zwitterion-Stabilized Adhesive Emulsions
Building Supracolloidal Fibers from Zwitterion-Stabilized Adhesive Emulsions
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DOI：
10.1002/adfm.201804325
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发表时间：
2018-11-07
影响因子：
19
通讯作者：
Emrick, Todd
中科院分区：
文献类型：
--
作者：
Santa Chalarca, Cristiam F.;Letteri, Rachel A.;Emrick, Todd
用聚合物两性离子稳定的水包油液滴表现出盐响应性聚集-解聚行为。这里，描述了一种将这些液滴成形的方法，从它们的聚集状态开始，通过简单地将它们挤出到水性介质中而将它们成形为超胶体纤维。研究了初始乳液和水性介质中盐浓度对乳液形成纤维的能力的影响。在纤维形成之后，可以简单地通过增加水性环境中的盐浓度来触发从良好限定的宏观结构到无相互作用的液滴分散体的转变。粘附的液滴间能量和乳液流变性与盐浓度定性相关，从而影响乳液通过挤出成形的能力。液滴间粘附力取决于盐浓度和聚合物组成，这允许定制条件以触发纤维解聚。最后，通过连续加载和挤出含有不同密度的油相的乳液，制备沿其长度沿着具有可变组成的纤维。
Oil-in-water droplets stabilized with polymer zwitterions (PZWs) exhibit salt-responsive aggregation-disaggregation behavior. Here, a method to shape these droplets is described, starting from their aggregated state, into supracolloidal fibers by simply extruding them into aqueous media. The effect of salt concentration, in both the initial emulsion and the aqueous medium, on the ability of the emulsions to form fibers is examined. After fiber formation, a transition from well-defined macroscopic structures to noninteracting droplet dispersions can be triggered, simply by increasing the salt concentration of the aqueous environment. The interdroplet energy of adhesion and emulsion rheology correlate qualitatively with salt concentration and thus impact the ability of the emulsions to be shaped by extrusion. The interdroplet adhesion is dependent on both salt concentration and polymer composition, which allows tailoring of conditions to trigger fiber disaggregation. Finally, fibers with variable compositions along their length are prepared by sequential loading and extrusion of emulsions containing oil phases of differing densities.