School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK.
J Phys Condens Matter. 2013 Oct 16;25(41):415101. doi: 10.1088/0953-8984/25/41/415101. Epub 2013 Aug 27.
The instability of a polyisoprene (PI) thin film on a silicon substrate at room temperature in an aqueous environment was investigated by atomic force microscopy and optical microscopy. The instability mechanism changes from spinodal dewetting to hole nucleation with increasing film thickness, with the transitional thickness found to be around 46-50 nm. For PI films ≥50 nm, the dewetting was observed to proceed via successive stages of hole nucleation and growth, hole coalescence, cellular pattern formation and droplet formation. There is also a slowing down in the rate of the PI dewetting process and an increase in the pattern size as the film thickness is increased. In those films with observable holes, we also observed the coexistence of fine cellular cracking that is on a much smaller scale of hundreds of nanometres and extends only a few nanometres in depth from the film surface.
通过原子力显微镜和光学显微镜研究了聚异戊二烯（PI）薄膜在室温下的水溶液环境中的不稳定性。随着薄膜厚度的增加，不稳定性机制从旋节分解转变为孔成核，过渡厚度约为 46-50nm。对于厚度≥50nm 的 PI 薄膜，观察到的去湿过程是通过孔成核和生长、孔合并、细胞图案形成和液滴形成的连续阶段进行的。随着薄膜厚度的增加，PI 去湿过程的速率也会减慢，图案尺寸会增大。在那些有可观察到的孔的薄膜中，我们还观察到了细小的细胞裂纹的共存，其尺度要小得多，只有几百纳米，并且从薄膜表面深度仅延伸几纳米。
