Stabilization of Liquid Foams through the Synergistic Action of Particles and an Immiscible Liquid
Stabilization of Liquid Foams through the Synergistic Action of Particles and an Immiscible Liquid
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DOI：
10.1002/anie.201405816
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发表时间：
2014-12-01
影响因子：
16.6
通讯作者：
Behrens, Sven H.
中科院分区：
文献类型：
--
作者：
Zhang, Yi;Wu, Jie;Behrens, Sven H.
啤酒、起泡牛奶或泡泡浴中常见的液体泡沫；一般来说，泡沫在采油、轻量化包装和绝缘方面也发挥着重要作用。这里报道了一种新型泡沫，它是在少量不混溶的二次液体存在的情况下使胶体颗粒悬浮液起泡而得到的。这些泡沫的一个独特的方面，被称为毛细管泡沫，是少数液体在气泡周围的颗粒介导的扩散。由此产生的混合颗粒/液体涂层可以稳定气泡，防止合并，即使颗粒本身不能。包覆的气泡被困在由少数液体桥连接的多余颗粒网络中，从而进一步固定。毛细管泡沫是用不同的颗粒/液体组合来制备的，以证明这种现象的普遍性。观察到的泡沫稳定性与颗粒对气泡表面扩散形成的液体界面的亲和力有关。
Liquid foams are familiar from beer, frothed milk, or bubble baths; foams in general also play important roles in oil recovery, lightweight packaging, and insulation. Here a new class of foams is reported, obtained by frothing a suspension of colloidal particles in the presence of a small amount of an immiscible secondary liquid. A unique aspect of these foams, termed capillary foams, is the particle-mediated spreading of the minority liquid around the gas bubbles. The resulting mixed particle/liquid coating can stabilize bubbles against coalescence even when the particles alone cannot. The coated bubbles are further immobilized by entrapment in a network of excess particles connected by bridges of the minority liquid. Capillary foams were prepared with a diverse set of particle/liquid combinations to demonstrate the generality of the phenomenon. The observed foam stability correlates with the particle affinity for the liquid interface formed by spreading the minority liquid at the bubble surface.