Yale University, New Haven, Connecticut 06520, USA.
AMOREPACIFIC Co., Gyeonggi-do, Seoul 446-729, South Korea.
Phys Rev E. 2017 Jan;95(1-1):012805. doi: 10.1103/PhysRevE.95.012805. Epub 2017 Jan 17.
We investigate the mechanical behavior of particle-stabilized droplets using micropipette aspiration. We observe that droplets stabilized with amphiphilic dumbbell-shaped particles exhibit a two-stage response to increasing suction pressure. Droplets first drip, then wrinkle and buckle like an elastic shell. While particles have a dramatic impact on the mechanism of failure, the mechanical strength of the droplets is only modestly increased. On the other hand, droplets coated with the molecular surfactant sodium dodecyl sulfate are even weaker than bare droplets. In all cases, the magnitude of the critical pressure for the onset of instabilities is set by the fluid surface tension.
我们使用微吸管吸液法研究了颗粒稳定液滴的力学行为。我们观察到，用两亲性哑铃形粒子稳定的液滴在逐渐增加吸力时表现出两阶段的响应。液滴先滴落，然后像弹性壳一样起皱和弯曲。虽然粒子对失效机制有显著影响，但液滴的机械强度仅略有增加。另一方面，用十二烷基硫酸钠这种分子表面活性剂包裹的液滴甚至比裸液滴还弱。在所有情况下，不稳定性开始时的临界压力大小都由流体的表面张力决定。
