Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · cond-mat/0111117

Solvent evaporation of spin cast films: crust effects

Pierre-Gilles de Gennes
View original source ↗Read source document ↗Export metadata ↓

Abstract

When a glassy polymer film is formed by evaporation, the region near the free surface is polymer rich and becomes glassy first, as noticed long ago by Scriven et al. We discuss the thickness of this "crust" and the time interval where it is present -before freezing of the whole film. We argue that the crust is under mechanical tension, nd should form some cracks. This may be the source of the roughness observed on the final, dry films, when the solvent vapor pressure is high (and leads to thin crusts).

Explore related subjects

cond-mat.soft

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Pierre-Gilles de Gennes. 2001-11-07. Solvent evaporation of spin cast films: crust effects. https://doi.org/10.1140/epje%2Fi200101169

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Reciprocal theorem for ion-releasing colloidal particles

We describe a generalization of the reciprocal theorem for particles suspended in electrolyte solutions and subjected to an electric field that could be either applied or emerged spontaneously. Attention is focused on catalytic colloids that release ions. The power of the generalization is to capture the effect of formation of a secondary cloud around a catalytic particle, which is equivalent to accounting for an excess charge $Q$ of a system. Our results show that the propulsion speed of catalytic particles has an extra contribution proportional to $Q$ and an external field $E_{\infty}$. The derived equation for $Q$ reveals that its sign is defined by the difference in the ion diffusivity and the magnitude is controlled by the average flux of ions from the surface. We demonstrate the application of the generalized theorem to electro- and diffusiophoresis of homogeneously releasing ions passive particles, as well as to a self-propulsion of inhomogeneous active particles (microswimmers). It is shown that whilst in some situations the extra term in the reciprocal theorem vanishes or has a little effect on the particle mobility, in many others it may dramatically change its magnitude, and even sign. In addition, the relevance of our results for microswimmer interactions is discussed briefly.

cond-mat.soft↗
arXiv2026

Multigeometric Breathing Mode Framework for viruses

The estimation of the breathing mode frequency for viral capsids remains a persistent challenge across literature which spawned various frameworks and methodologies. However, discrepancies were observed between the experimental Low Frequency Raman Scattering (LFRS) and calculated pre-existing values. To solve this discrepancy, we propose a framework which is developed to determine the breathing-mode frequency by modelling the virus as a macroscopic coupled harmonic oscillator. By integrating mass-loading directly into the classical elastodynamic equations, this model yields an analytical expression that couples the system's total inertia with its specific geometry. Moreover, the viruses are segregated according to their geometries into three coordinates to acquire their respective geometric eigen values. Here we illustrate how the proposed Multigeometric Breathing mode Framework for Virus (MBFV) outperforms prior models by yielding closer values than the pre-existing frameworks upon validating against LFRS.

cond-mat.soft↗
arXiv2026

Insight into ordering at nematic twist-bend interfaces

Twist-bend nematics formed by achiral particles support heliconical domains of opposite handedness. Using Monte Carlo and molecular dynamics simulations of repulsive bent particles, we study the interface between two such domains. Rather than a gradually untwisting texture, we find a density-modulated splay-bend-twist structure. The density modulation is along the helix axis with a period of approximately half the bulk pitch, while the twist is locally enhanced in magnitude, alternates in sign, and vanishes only on an undulating surface. An explicit director interpolation shows how gradients along the helix axis and across the interface combine to produce an undulating zero-twist surface.

cond-mat.soft↗