Monodisperse ellipsoidal polystyrene latex particles: Preparation and characterisation

Abstract

An improved version of a novel method first employed by Nagy & Keller for the preparation of monodisperse ellipsoidal polystyrene latex particles is described. The method involves embedding monodisperse spherical polystyrene latex particles as starting material in a deformable polymer matrix such as poly(vinyl alcohol) and deforming these mechanically to various predetermined macroscopic draw ratios to give ellipsoids of various axial ratios. Ellipsoids with lengths ranging from about 350 to 12250nm were prepared. Stable aqueous dispersions of these were recovered and characterised with respect to particle size and axial ratio distributions and surface morphology using electron microscopy. Axial ratios ranging from 2.0 to 5.65 were obtained for the resulting ellipsoids. Various factors influencing the monodispersity of the resulting ellipsoids in the preparation method are discussed.

Flow-induced orientation of non-spherical particles: Effect of aspect ratio and medium rheology

“…Monodisperse polystyrene spheres with a diameter 1.9 m were synthesized by a dispersion polymerization process [30]. These particles were embedded in a polyvinyl alcohol film [31][32][33]. The film with the latex particles was immersed in hot oil at a temperature above the glass transition temperature of the two polymers and deformed uniaxially.…”

Shape-tunable wax microparticle synthesis via microfluidics and droplet impact

“…In particular, microfluidic-assisted techniques can tailor-design particles with unique sizes and shapes that are difficult to achieve by using conventional techniques such as template molding, 12,13 seeded emulsion polymerization, 14 selfassembly of colloids through liquid protrusions, 15 and stretching of soft spherical particles. 16,17 In this regard, microfluidic techniques are highly desirable to generate particles with homogeneous morphologies and monodispersed sizes due to their consistent and reproducible behavior.…”

Nanopressing: Toward Tailored Polymer Microstructures and Nanostructures

“…Among these approaches, the stretching method is commonly used to prepare ellipsoidal polymer particles through the uniform deformation of polymer microspheres in a matrix of another polymer. For example, Ho et al embedded monodisperse spherical polystyrene (PS) particles in a deformable poly(vinyl alcohol) (PVA) matrix. The samples were then stretched above their glass transition temperatures to various predetermined macroscopic draw ratios.…”