Laboratoire Réactions et Génie des Procédés, UMR 7274 CNRS, Université de Lorraine, 1 rue Grandville, 54001 Nancy, France.
J Colloid Interface Sci. 2021 May;589:286-297. doi: 10.1016/j.jcis.2021.01.005. Epub 2021 Jan 5.
The distribution of particles in Pickering emulsions can be estimated through a percolation-type approach coupled to the evolution of their rheological features with the dispersed phase volume fraction ϕ.
The rheological behavior of water-in-dodecane Pickering emulsions stabilized with hydrophobic silica nanoparticles is addressed. The emulsions viscosity and elastic modulus are investigated at ϕ varying from 0.1 to 0.75. Various rheological models are adjusted to the experimental data.
The comparison of the elastic modulus evolution of the Pickering emulsions with those of emulsions stabilized with surfactants confirms a major contribution of the particles to the rheological behavior of Pickering emulsions and supports the existence of a three-dimensional network between the droplets. The applied percolation approach allows to quantitively estimate a nanoparticles viscoelastic link between the droplets and opposes the classic vision of interfacial monolayers stabilizing the Pickering emulsions. This network of interconnected particles and droplets contributes significantly to the viscosity as well as the elastic modulus of these emulsions. To our knowledge, the applied percolation-based model is the only one capable of providing a structural explanation while describing the abrupt viscosity and elastic modulus growth of Pickering emulsions across the range of ϕ.
可以通过与分散相体积分数 ϕ 相关的渗流型方法来估计 Pickering 乳液中颗粒的分布，同时结合其流变特性的演变。
研究了由疏水性二氧化硅纳米颗粒稳定的水/正十二烷 Pickering 乳液的流变行为。在 ϕ 从 0.1 到 0.75 的范围内，研究了乳液的粘度和弹性模量。调整了各种流变模型以适应实验数据。
Pickering 乳液的弹性模量演变与用表面活性剂稳定的乳液的弹性模量演变的比较，证实了颗粒对 Pickering 乳液流变行为的主要贡献，并支持了液滴之间存在三维网络的存在。所应用的渗流方法允许定量估计液滴之间纳米颗粒的粘弹性连接，并反对界面单层稳定 Pickering 乳液的经典观点。这些相互连接的颗粒和液滴的网络对这些乳液的粘度以及弹性模量有很大的贡献。据我们所知，所应用的基于渗流的模型是唯一能够在描述 Pickering 乳液在 ϕ 范围内的粘度和弹性模量突然增长时提供结构解释的模型。
