Raymond W. Wong

The effect ofn-decanol on solubilization of water-in-oil microemulsions and stability of lamellar liquid crystals of alkylphenol ethoxylates

Addition of n-decanol at appropriate concentrations is beneficial to increasing the solubilization amount of water in a water-in-oil microemulsion in the system of nonylphenol ethoxylate/olive oil/water, but it destabilized the lamellar liquid crystal and reduced the solubilization of olive oil in the lamellar liquid crystal.

Material and physicochemical properties of electrostatically-based liquid developers

Abstract During the last decade, liquid immersion development (LID) of a latent electrostatic image has become established as an important alternative to dry toning. In this development method, charged, colloidally stable pigment particles dispersed in a dielectric liquid undergo electrophoresis under the influence of an applied field. These particles thus neutralize a latent electrostatic image of opposite sign, which resides on either a photoreceptor drum or on dielectric paper and results in a hard copy of the latent image being obtained. This paper is concerned with the materials and physicochemical properties of LID developers and has been organized into three parts. In Part 1, the criteria pertaining to selection of the materials for such developers is reviewed. In Part 2, a discussion of the physicochemical properties of the materials is given, while in Part 3 we report some of the results of a systematic study that has been undertaken in order to understand the behavior and limitations of LID toners. The materials package considered in detail in this paper consisted of a dispersion of a laked carbon black in Isopar G that was colloidally stabilized by a soluble alkyl methacrylate based copolymer, Goodyear Pliolite OMS. The developer was electrostatically charged using a variety of heavy metal soaps. Experimental results concerning the colloidal stability, charge-to-mass ratio and evaluation of the final image properties of this developer are discussed. It is concluded that only by making a systematic investigation of the complex interactions that occur in such LID inks will a materials package with optimal shelf life and imaging properties be obtained.

Hydrocarbon Based Inks for Electronic Printing

Electrostatically assisted liquid inks have firmly established themselves as a viable developer option for certain printer applications. In this process a particle, either a pigment or a latex particle, is dispersed and electrostatically charged in a dielectric fluid. Under the influence of an electrostatic field within a development housing the particles undergo electrophoresis to neutralise a latent image that resides on the surface of a dielectric substrate. This results in a hard copy of the latent image being obtained. In this paper we review the properties demanded of a liquid toner, methods of preparing such inks, their colloidal behaviour and their electrical and imaging characteristics. The trade-offs that need to be made when optimising such developers is also discussed. Some conclusions are drawn regarding future materials directions for this toning technology.