| Popis: |
This chapter presents a brief overview of the use of surfactants in inks for ink-jet printing. It aims to provide the reader with a short, self-consistent and pedagogically balanced introduction to this highly technical but, at the same time, largely empirical subject. The adsorption of surfactant at the liquid/vapour interface leads to a reduction in the surface tension of the solution in accordance with the Gibbs law. However, the Gibbs law applies to equilibrium systems. The dynamics of surface tension relaxation can be described in the framework of a diffusion-controlled adsorption model. The model uses the so-called surface-subsurface concept, assuming that the adsorbate is transported by diffusion to a thin interfacial region, called the subsurface, which constantly is in equilibrium with the surface. To describe this equilibrium, an appropriate adsorption isotherm should be used. Different surfactants have different surface tension relaxation dynamics. |
