相关论文: Nucleation Induced Undulative Instability in Thin …
A transient surface instability is reported in thin nematic films of 5CB and 8CB, occurring near the nematic-isotropic phase transition. Although this instability leads to patterns reminiscent of spinodal dewetting, we show that it is…
The instability, dynamics and morphological transitions of patterns in thin liquid films on periodic striped surfaces (consisting of alternating less and more wettable stripes) are investigated based on 3-D nonlinear simulations that…
The stability of thin liquid coatings is of fundamental interest in every- day life. Homogeneous and non-volatile liquid coatings may dewet either by heterogeneous nucleation, thermal nucleation, or spinodal dewetting. Wetting and dewetting…
The behavior as a function of temperature of very thin films (10 to 200 nm) of pentylcyanobiphenyl (5CB) on silicon substrates is reported. In the vicinity of the nematic/isotropic transition we observe a coexistence of two regions of…
Partially wetting nematic liquid crystal (NLC) films on substrates are unstable to dewetting-type instabilities due to destablizing solid/NLC interaction forces. These instabilities are modified by the nematic nature of the films, which…
We study dewetting of thin polymer films with built-in topographical fluctuations produced by rubbing the film surface with a rayon cloth. By varying the density of imposed surface defects, we unambiguously distinguish spinodal dewetting,…
We report the observation of a doubly-periodic surface defect-pattern in the liquid crystal 8CB, formed during the nematic--smectic A phase transition. The pattern results from the antagonistic alignment of the 8CB molecules, which is…
Motivated by recent experimental observations [U. Delabre et al, Langmuir 24, 3998, 2008] we reconsider an instability of ultrathin nematic films, spread on liquid substrates. Within a continuum elastic theory of liquid crystals, in the…
We consider a mathematical model that describes the flow of a Nematic Liquid Crystal (NLC) film placed on a flat substrate, across which a spatially-varying electric potential is applied. Due to their polar nature, NLC molecules interact…
We discuss instabilities of fluid films of nanoscale thickness, with a particular focus on films where the destabilising mechanism allows for linear instability, metastability, and absolute stability. Our study is motivated by nematic…
In this Letter we investigate the rupture instability of thin liquid films by means of a bifurcation analysis in the vicinity of the short-scale instability threshold. The rupture time estimate obtained in closed form as a function of the…
A confined incompressible elastic film does not deform uniformly when subjected to adhesive interfacial stresses but with undulations which have a characteristic wavelength scaling linearly with the thickness of the film. In the classical…
Confinement in the nanochannels of porous silicon strongly affects the phase behavior of the archetype liquid-crystal 4-n-octyl-4-cyanobiphenyl (8CB). A very striking phenom- enon is the development of a short-range smectic order, which…
Starting from a three-dimensional description of an active nematic layer, we employ an asymptotic theory to derive a series of low-dimensional continuum models that capture the coupled dynamics of flat and curved films, including variations…
The nucleation mechanisms during solution deposition of organic semiconductor thin films determine the grain morphology and may influence the crystalline packing in some cases. Here, in-situ optical spectromicroscopy in reflection mode is…
Recent theoretical analysis of spatially-nonuniform modes of the thermomagnetic instability in superconductors [Phys. Rev. B 70, 224502 (2004)] is generalized to the case of a thin film in a perpendicular applied field. We solve the thermal…
Dynamic simulations of the isotropic-nematic phase transformation of liquid crystal droplets under homeotropic anchoring are found to predict chiral symmetry-breaking dynamics. These observations occur when using material parameters for…
The stability of thin liquid films on a surface depends on the excess free energy of the system involving various short-range and long-range interactions. In an unstable condition, thin liquid films may dewet into multiple small-sized…
The interplay between thin film hydrodynamics and solidification produces formidably intricate geophysical structures, such as stalactites and icicles, whose shape is a testimony of their long growth. In simpler settings, liquid films can…
Wrinkles commonly develop in a thin film deposited on a soft elastomer substrate when the film is subject to compression. Motivated by recent experiments [Agrawal et al., Soft Matter 8, 7138 (2012)] that show how wrinkle morphology can be…