Abstract
The dynamics of single droplets containing non-Brownian particles are studied. The particle over droplet size ratio (r/R) is changed by using different particle sizes (r/R = 0.02–0.4). Additionally, the effect of particle concentration (5–20 vol%) is investigated. The dynamics of droplets with r/R = 0.02 show good agreement with the corresponding particle-free reference system which has a comparable viscosity ratio. Hence, this droplet phase can be considered as a homogenous medium characterized by its bulk viscosity which is governed by the particle concentration. However, droplets with r/R ≥ 0.1 show a more suppressed deformation and slower transient dynamics and, therefore, behave as a slightly more viscous medium than expected based on their bulk viscosity. These effects become more pronounced at higher particle concentrations and higher r/R. Moreover, local particle effects like asymmetric droplet shapes, oscillating droplet shapes, and tip streaming start to influence the droplet dynamics at particle concentrations around 15 vol%.
Highlights
Polymer blends are used in many everyday products and materials to achieve superior properties as compared with their single polymer counterparts
We expect to observe a reduced droplet deformation, slower transient dynamics, and droplet breakup at higher critical capillary numbers compared with reference systems (RS)-1.4 as a consequence of the increased viscosity ratio
The droplet dynamics are compared with those of reference systems with a comparable viscosity ratio in order to verify the hypothesis that particle-filled droplets behave as a homogeneous medium characterized by the bulk viscosity of the suspension
Summary
Polymer blends are used in many everyday products and materials to achieve superior properties as compared with their single polymer counterparts. The relationships between the applied flow and the single droplet dynamics of systems consisting of two Newtonian fluids have been studied extensively (Taylor 1934; Torza et al 1972; Rallison 1984; Kennedy et al 1994; Janssen and Anderson 2007). Maffettone and Minale (1998) developed a phenomenological model which is able to describe the droplet dynamics of ellipsoidal Newtonian droplets in a Newtonian matrix in various flow fields and shows good agreement between model predictions and experimental data (Maffettone and Minale 1998; Vananroye et al 2007; Vananroye et al 2008)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
