https://doi.org/10.1007/s100510051188
Morphology transition and slow dynamics in the collapse of amphiphilic monolayers at the air-water interface
1
Nanoelectronics Laboratory, Graduate School of Engineering,
Hokkaido University, Sapporo 060 - 0813, Japan
2
Materials Division, Hokkaido National Industrial Research Institute, AIST, MITI, Sapporo 062 - 8517, Japan
Corresponding author: a hatta@nano.eng.hokudai.ac.jp
Received:
11
January
1999
Published online: 15 October 1999
The morphology on collapsed monolayers at the air-water interface has been studied using phase contrast microscopy. It is found that the transition from randomly distributed to quasi-one dimensional crack pattern takes place, depending on the pH value of the subphase and the presence of specific divalent metal ions. In these macroscopic patterns, the former exhibits a surface roughening due to a monolayer buckling while the latter becomes more smooth and uniform. The occurrence of the former is instantaneous and the latter follows a slow dynamics, i.e., the crack propagation in monolayers occurs with a delay for crack nucleation. Thus the change of pattern indicates the existence of a dynamic transition. The transition is discussed with the scenario of a crack instability in brittle materials. The changes of viscous nature and of ion binding, and the compression direction probably operate for the observed behavior effectively.
PACS: 68.18.+p – Langmuir-Blodgett films / 46.50.+a – Fracture mechanics, fatigue and cracks / 81.40.Np – Fatigue, corrosion fatigue, embrittlement, cracking, fracture and failure
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999