Stock Sebastian, Röhl Susanne, Mirau Luca, Kraume Matthias, von Klitzing Regine
Institute for Condensed Matter Physics, Technische Universität Darmstadt, 64289 Darmstadt, Germany.
Department of Chemical and Process Engineering, Technische Universität Berlin, 10623 Berlin, Germany.
Nanomaterials (Basel). 2022 Aug 1;12(15):2649. doi: 10.3390/nano12152649.
The incorporation of soft hydrophilic particles at the interface of water in non-polar oil emulsion droplets is crucial for several applications. However, the stabilization of water in non-polar oil emulsions with hydrophilic soft material alone is, besides certain exceptions, not possible. In our previous works, we showed that stabilizing the emulsions with well-characterized spherical hydrophobic silica nanospheres (SNs) and soft equally charged microgel particles (MGs) is a robust strategy to stabilize w/o emulsions while still incorporating a large amount of MGs at the interface. In the present study, we address the question of what the maximum amount of MGs at the interface in these kinds of emulsion droplets can be. By using well-characterized mono-disperse SNs, we are able to calculate the fraction of interface covered by the SNs and complementary that of the present MG. We found that it is not possible to decrease the SN coverage below 56% irrespective of MG softness and SN size. The findings elucidate new perspectives to the broader topic of soft/solid stabilized emulsions.
在非极性油乳液滴的水界面处掺入柔软的亲水性颗粒对于多种应用至关重要。然而，除了某些例外情况，仅用亲水性软材料来稳定非极性油中的水乳液是不可能的。在我们之前的工作中，我们表明，用具有良好表征的球形疏水性二氧化硅纳米球（SNs）和带相同电荷的柔软微凝胶颗粒（MGs）来稳定乳液是一种稳健的策略，可在稳定油包水乳液的同时，仍在界面处掺入大量的MGs。在本研究中，我们探讨了在这类乳液滴的界面处MGs的最大量可以是多少这一问题。通过使用具有良好表征的单分散SNs，我们能够计算出被SNs覆盖的界面分数以及当前MGs的互补界面分数。我们发现，无论MG的柔软度和SN的大小如何，都不可能将SN的覆盖率降低到56%以下。这些发现为软/固稳定乳液这一更广泛的主题阐明了新的观点。
