Department of Physics and Astronomy, University of California, Irvine, California 92697, United States.
Langmuir. 2012 Oct 2;28(39):13976-83. doi: 10.1021/la301543y. Epub 2012 Sep 19.
We report on the impact of differently sized particles on the collapse of a Langmuir monolayer. We use an SDS-DODAB monolayer because it is known to collapse reversibly under compression and expansion cycles. Particles with diameters of 1 μm, 0.5 μm, 0.1 μm, and 20 nm are deposited on the SDS-DODAB monolayer. We find a critical particle size range of 0.1 to 0.5 μm that produces a transition from reversible to irreversible collapse. The nature of the collapse is determined through optical observations and surface pressure measurements. In addition, although 20 nm particles do not cause irreversible collapse in the monolayer, they significantly decrease the collapse pressure relative to the other systems. Therefore, we observe three distinct collapse behaviors-reversible, irreversible, and reversible at a reduced surface pressure.
我们研究了不同粒径的颗粒对朗缪尔单层压缩和扩张循环中坍塌的影响。我们使用 SDS-DODAB 单层，因为它已知在压缩和扩张循环中可以可逆地坍塌。直径为 1 μm、0.5 μm、0.1 μm 和 20 nm 的颗粒被沉积在 SDS-DODAB 单层上。我们发现一个临界粒径范围为 0.1 到 0.5 μm，它导致从可逆到不可逆坍塌的转变。坍塌的性质通过光学观察和表面压力测量来确定。此外，尽管 20nm 颗粒在单层中不会导致不可逆坍塌，但它们相对于其他体系显著降低了坍塌压力。因此，我们观察到三种不同的坍塌行为——可逆、不可逆和在降低的表面压力下的可逆。
