John F. Oliver

Evaporation from a microemulsion in the water-aerosol OT-cyclohexanone system

Abstract Evaporation from microemulsions was investigated at room temperature in the system water-Aerosol OT-cyclohexanone. The water/cyclohexanone weight ratio was varied and a minimum amount of surfactant was used to obtain a microemulsion in the samples used for the evaporation studies. Evaporation to 70 wt.% of the original weight took place with an approximately constant water/cyclohexanone ratio in the vapor, independent of the original water/cyclohexanone ratio. When the samples approached a water content of a few percent by weight, the cyclohexanone/water ratio was strongly increased in the vapor phase. These changes were assigned to differences in colloidal association structures and strong binding of the water molecules to the surfactant at low water content.

A diffusion approach for modelling penetration of aqueous liquids into paper

Abstract Theoretical and experimental approaches have been developed for predicting drying rates of aqueous ink images printed on paper by ink jet printing technology. The predictive aspect of the model requires that the diffusion constant be known for each ink—paper system as a function of concentration and temperature, and that evaporation rates be measured. Experimental data input to the theoretical model is obtained via a dynamic sorption apparatus which enables the in situ study of individual microscopic ink jet drops as they spread and penetrate into a porous structure. Simultaneous plan- and side-view video recording coupled with an image analyser enables rapid data acquisition and processing of the drop profile and developing contact line. Smooth, non-porous, transparent polymer films and a range of papers with different absorptivity have been investigated. The salient features of the diffusion model and its applicability are discussed in light of the experimental results.

A dynamic liquid sorption apparatus for studying interactions of microscopic drops in situ on porous substrates

Abstract A novel dynamic sorption apparatus is described which has been developed to study spreading and penetration of microscopic-sized liquid drops on rough and porous surfaces. The apparatus is capable of observing localized wetting phenomena at microscopic resolutions. Among its essential features are: a video/optical system which enables simultaneous plan and side-view observations of sorption phenomena; automated data acquisition via interacting a VCR with an image analyzer; and in the present design, a liquid drop generator which ejects reproducibly-sized drops. Several applications of the apparatus are illustrated. These include: in situ studies on the interaction of ink jet inks with various paper substrates; developing a more realistic understanding of liquid penetration in porous media; and extending the present range of application to time resolutions

The Inter-Relationship Between Paper Structure and Print Quality in Ink Jet Printing

This article describes a print quality evaluation of laboratory designed ink jet papers prepared on a dynamic former. A comparison with various plain and coated papers serves to illustrate the potential opportunity for papermakers to exploit novel types of paper structures in the future. The article will also briefly focus on some of the fundamental issues and key paper properties which perturb print quality and govern the capillary absorption of aqueous inks.