Film squeezing process for generating oblate spheroidal particles with high yield and uniform sizes

• DOI: 10.1007/s00396-016-3838-2
• Publication Date: 2016-02-12T12:14:18Z
• Authors: Sang Jae Ahn; Kyung Hyun Ahn; Seong Jae Lee
• Keywords: Oblate spheroid; Particle (ecology); Ellipsoid

Particle shape is one of the most important parameters that can influence the characteristics and properties of dispersion systems. In this study, we have developed a straightforward and facile method to generate oblate spheroidal particles via a film squeezing process. Representative methods so far developed to prepare oblate spheroidal particles, such as film blowing and mechanical stretching based on a biaxial process, have serious problems, including being difficult methods to adopt, very low yield, and non-uniform particle size. Our film squeezing process involves simply squeezing a sandwiched array comprised of an arbitrarily shaped film with embedded polymer spheres between two identical circular elastomeric sheets, on the basis that homogeneous deformation is possible in the mid-plane of simple squeeze flow. This method utilizes a unified uniaxial process for producing both prolate and oblate spheroidal particles. The advantages of the method are easier access, much higher yield, and more uniform sizes and shapes than previously reported methods. This process can be helpful for the fundamental studies utilizing oblate spheroidal particles with controlled geometries.