Abstract
This work investigates a direct transfer of dispersed particles into another dispersion medium. The transfer is realized by layering the suspension above a second, non-miscible liquid. The particles are then transferred by centrifugation or mere sedimentation. The transfer is, unlike a liquid-liquid extraction, not only driven by thermodynamic effects such as favorable solubility, but is based on an additional mechanical work input. Here the transfer of a colloidal particle system is discussed on the example of SiO2 particle dispersions with regards to the influence of particle size, viscosity, density and an emphasis on the effects of interfacial forces. For small particles it was found that hydrophilic and hydrophobic forces dominate and hinder the transfer as particles adsorb to the interface, which can be countered by an increase of centrifugation forces or reduction of surface forces with surfactants. The transfer is described in detail with a model to lay out the influence of all parameters, revealing a threshold size for a successful transfer at given conditions. The model is applied and tested on different SiO2 suspensions for verification.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have