Louise Diane Farrand

Poly(dimethylsiloxane)-Stabilized Polymer Particles from Radical Dispersion Polymerization in Nonpolar Solvent: Influence of Stabilizer Properties and Monomer Type

Particles used in electrophoretic display applications (EPD) must possess a number of specific properties ranging from stability in a nonaqueous solvent, high reflectivity, low polydispersity, and high charge density to name but a few. The manufacture of such particles is best carried out in the solvent of choice for the EPD. This opens up new interests in the study of nonaqueous dispersion polymerization methods, which deliver polymer particles suspended in low dielectric constant solvents. We explore in this article the use of a poly(dimethylsiloxane) macromonomer for the stabilization of poly(methyl methacrylate) polymer particles in dodecane, a typical solvent of choice for EPDs. The use of this stabilizer is significant for this method as it is directly soluble in the reaction medium as opposed to traditionally used poly(12-hydroxystearic acid)-based stabilizers. Additionally, the present study serves as a baseline for subsequent work, where nonaqueous dispersion polymerization will be used to create polymer particles encapsulating liquid droplets and solid pigment particles. In this article, the influence of the macromonomer molecular weight and concentration on the properties of the synthesized particles is studied. In addition, we investigate the possibility of synthesizing polymer particles from other monomers both as a comonomer for methyl methacrylate and as the only monomer in the process. The influence of macromonomer concentration is also studied throughout all experiments.

40.1: Invited Paper: Dyed Polymeric Microparticles for Colour Rendering in Electrophoretic Displays

Realising bright and vivid full colour performance in electrophoretic displays presents a significant challenge to display architects and material designers. A range of dyed polymeric microparticles with tunable size, charge and colour have been developed. When formulated as colloidal dispersions in low dielectric constant media, the particles are electrophoretically active and are suitable for use in full colour or monochrome electrophoretic displays.

Liquid Crystals Spanning the Globe

Abstract Liquid crystal research is increasingly an international activity, often involving collabrations between groups and laboratories separated by great distances and cultures. Bridging these gaps is an importanta part of scientific activity and below we report the experiences of two young scientists from the UK who travelled to Japan to further their research.