Control of Particle Shape by Adjusting Solidification Rates in Aggregation of Dispersed Gels
Abstract:This paper reports a chemical method, phase-separation/aggregation (PSA), to prepare CPT particles with surface morphology tuned by adjusting the process parameters during aggregation and coalescence of the particles. It is shown a highly hydrophilic organic solvent favors the formation of spherical particles due to the facile gel formation and expeditious solidification. Deviations of spherical particle shape can be achieved by inclusion of a less aqueous-soluble organic solvent in which the viscosity of gel colloids is increased gradually, allowing shear force of the non-solvent phase to apply its effect on the particle shape. The particles can be made potato-shaped or elliptically shaped by adjustments of the aqueous solubility of the organic solvent. The effect of shear force can also be magnified by increasing the speed of stirring during particle coalescence, with a finding showing a distorted, elliptical shape as a result of increasing agitation speed. The viscosity or the solid content values of the aqueous non-solvent phase solution are also found to have effects on the particle shape. It is found a dilute aqueous phase solution is prone to forming spherical particles, whereas a concentrated aqueous phase allows the particles to become non-spherical. These parameters are studied to elucidate the interplay of viscosity and surface tension, and to understand their effects on the particle shape. The results of this paper show that the particle shape obtained from the PSA method can be fine tuned by modulating the process parameters.
Document Type: Research Article
Publication date: 2007-01-01
For more than 25 years, NIP has been the leading forum for discussion of advances and new directions in non-impact and digital printing technologies. A comprehensive, industry-wide conference, this meeting includes all aspects of the hardware, materials, software, images, and applications associated with digital printing systems, including drop-on-demand ink jet, wide format ink jet, desktop and continuous ink jet, toner-based electrophotographic printers, production digital printing systems, and thermal printing systems, as well as the engineering capability, optimization, and science involved in these fields.
Since 2005, NIP has been held in conjunction with the Digital Fabrication Conference.
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Terms & Conditions
- Ingenta Connect is not responsible for the content or availability of external websites