In the quest to find approaches to prepare food grade Pickering emulsions, we studied the formation and stability to coalescence of colloidal lipid particle (CLP)-stabilized emulsions within a cross-flow microfluidic device. We show that the particles can either stabilize or destabilize the emulsions depending on the particle adsorption rate versus droplet formation rate, and on the resulting surface coverage when the droplet is formed. At low surface coverage, when droplet formation is significantly faster than adsorption, CLPs have a destabilizing effect as incomplete surface coverage leads to droplet-droplet bridging. At high surface coverage, the dense particle layer results in an effective barrier against droplet coalescence, resulting in physically stable emulsions. The observed non-monotonic dependency of emulsion droplet stability on surface coverage of CLP-stabilized emulsions is in stark contrast to what is observed for conventional surfactant-stabilized emulsions, and thus should be taken into account for the rational design of Pickering emulsions.

为了寻找制备食品级Pickering乳液的方法，我们研究了在交叉流微流控设备中胶体脂质颗粒（CLP）稳定的乳液的形成和聚结稳定性。我们表明，取决于颗粒吸附速率与液滴形成速率之间的关系，以及取决于形成液滴时所产生的表面覆盖率，颗粒可以使乳液稳定或不稳定。在低表面覆盖率下，当液滴的形成速度明显快于吸附时，CLP具有不稳定的作用，因为不完全的表面覆盖率会导致液滴与液滴的桥接。在高表面覆盖率下，致密的颗粒层可有效防止液滴聚结，从而形成物理稳定的乳液。