El Mertahi C, Grandmaison N, Dupont C, Jellali R, Brancherie D, Salsac A-V
Université de Technologie de Compiègne, CNRS, Biomechanics and Bioengineering, Compiégne, France.
Université de Technologie de Compiègne, Roberval, Compiégne, France.
J Fluid Mech. 2024 Dec 3;1000. doi: 10.1017/jfm.2024.952. eCollection 2024 Dec 10.
Capsules, which are potentially-active fluid droplets enclosed in a thin elastic membrane, experience large deformations when placed in suspension. The induced fluid-structure interaction stresses can potentially lead to rupture of the capsule membrane. While numerous experimental studies have focused on the rheological behavior of capsules until rupture, there remains a gap in understanding the evolution of their mechanical properties and the underlying mechanisms of damage and breakup under flow. We here investigate the damage and rupture of bioartificial microcapsules made of ovalbumin reticulated with terephthaloyl chloride and placed in simple shear flow. We characterize damage by identifying how the surface shear modulus of the capsule membrane changes over time. Rupture is then characterized by comparing the number and size distribution of capsules before and after exposure to shear, while varying the shear rates and time during which capsules are sheared. Our findings reveal how the percentage of ruptured capsules increases with their size, exposure time to shear, and the ratio of viscous to elastic forces at rupture.
微胶囊是包裹在薄弹性膜中的具有潜在活性的液滴，当置于悬浮液中时会发生大变形。由此产生的流固相互作用应力可能导致微胶囊膜破裂。虽然许多实验研究都聚焦于微胶囊直至破裂时的流变行为，但在理解其力学性能的演变以及流动条件下损伤和破裂的潜在机制方面仍存在差距。我们在此研究由对苯二甲酰氯交联的卵清蛋白制成并置于简单剪切流中的生物人工微胶囊的损伤和破裂情况。我们通过确定微胶囊膜的表面剪切模量如何随时间变化来表征损伤。然后通过比较微胶囊在剪切前后的数量和尺寸分布来表征破裂情况，同时改变微胶囊的剪切速率和剪切时间。我们的研究结果揭示了破裂微胶囊的百分比如何随着其尺寸、剪切暴露时间以及破裂时粘性力与弹性力的比值而增加。
