Van't Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute for NanoMaterials Science, Padualaan 8, 3584 CH Utrecht, The Netherlands.
J Phys Chem B. 2010 Aug 19;114(32):10347-56. doi: 10.1021/jp102659b.
Particular types of solid-stabilized emulsions can be thermodynamically stable as evidenced by their spontaneous formation and monodisperse droplet size, which only depends on system parameters. Here, we investigate the generality of these equilibrium solid-stabilized emulsions with respect to the basic constituents: aqueous phase with ions, oil, and stabilizing particles. From systematic variations of these constituents, we identify general conditions for the spontaneous formation of monodisperse solid-stabilized emulsions droplets. We conclude that emulsion stability is achieved by a combination of solid particles as well as amphiphilic ions adsorbed at the droplet surface, and low interfacial tensions of the bare oil-water interface of order 10 mN/m or below. Furthermore, preferential wetting of the colloidal particles by the oil phase is necessary for thermodynamic stability. We demonstrate the sufficiency of these basic requirements by extending the observed thermodynamic stability to emulsions of different compositions. Our findings point to a new class of colloid-stabilized meso-emulsions with a potentially high impact on industrial emulsification processes due to the associated large energy savings.
特定类型的固体稳定乳液在热力学上是稳定的，这可以从它们的自发形成和单分散液滴尺寸得到证明，而这仅取决于系统参数。在这里，我们研究了这些平衡的固体稳定乳液对于基本成分的通用性：含离子的水相、油相和稳定颗粒。通过对这些成分的系统变化，我们确定了单分散固体稳定乳液液滴自发形成的一般条件。我们得出的结论是，乳液稳定性是通过固体颗粒以及吸附在液滴表面的两亲离子的组合以及裸油水界面的低界面张力（约 10 mN/m 或更低）来实现的。此外，胶体颗粒对油相的优先润湿对于热力学稳定性是必要的。我们通过将观察到的热力学稳定性扩展到不同组成的乳液中来证明这些基本要求的充分性。我们的发现指向了一类新的胶体稳定中间乳液，由于其相关的大量节能，可能会对工业乳化过程产生重大影响。
