Abkarian Manouk, Subramaniam Anand Bala, Kim Shin-Hyun, Larsen Ryan J, Yang Seung-Man, Stone Howard A
School of Engineering and Applied Sciences, Harvard University, Pierce Hall, 29 Oxford Street, Cambridge, Massachusetts 02138, USA.
Phys Rev Lett. 2007 Nov 2;99(18):188301. doi: 10.1103/PhysRevLett.99.188301. Epub 2007 Oct 31.
Experiments show that bubbles covered with monodisperse polystyrene particles, with particle to bubble radius ratios of about 0.1, evolve to form faceted polyhedral shapes that are stable to dissolution in air-saturated water. We perform Surface Evolver simulations and find that the faceted particle-covered bubble represents a local minimum of energy. At the faceted state, the Laplace overpressure vanishes, which together with the positive slope of the bubble pressure-volume curve, ensures phase stability. The repulsive interactions between the particles cause a reduction of the curvature of the gas-liquid interface, which is the mechanism that arrests dissolution and stabilizes the bubbles.
实验表明,覆盖有单分散聚苯乙烯颗粒、颗粒与气泡半径比约为0.1的气泡,会演变成多面体形状,在空气饱和水中稳定不溶解。我们进行了表面演化器模拟,发现有颗粒覆盖的多面体气泡代表了能量的局部最小值。在多面体状态下,拉普拉斯超压消失,这与气泡压力-体积曲线的正斜率一起确保了相稳定性。颗粒之间的排斥相互作用导致气液界面曲率减小,这就是阻止溶解并使气泡稳定的机制。