Breakup Criteria for Confined Droplets: Effects of Compatibilization and Component Viscoelasticity

Abstract

The breakup of confined droplets was studied systematically for systems with either interfacial or component viscoelasticity. The former was obtained by adding a compatibilizer, the latter by using a viscoelastic fluid as the droplet or as the matrix phase. The critical capillary numbers of Newtonian and compatibilized droplets showed a similar increase with increasing confinement ratio. However, a decrease in breakup length was observed in the compatibilized case, caused by the viscoelastic interface. Viscoelastic droplets experienced more stabilization by confinement compared to Newtonian droplets. Matrix viscoelasticity, on the other hand, induced a destabilization with a minimum in critical capillary number as a function of confinement ratio, resulting from a complex interplay of viscoelastic stresses. magnified image

Understanding the Morphological Changes in the Polypropylene/Polyamide 6 Fifty/Fifty Blends by Interfacial Modifiers Based on Grafted Atactic Polypropylenes: Microscopic, Mechanical, and Thermal Characterization

“…From an applied perspective, the polyamide/polyolefin binary systems have been a study matter for several years because of their potential in many industrial applications, mostly related to the decrease in the water absorption of polyamides by blending with polyolefins and the improvements in their impact resistance [48][49][50][51][52][52][53][54][55][56][57][58][59][60][61][62][63].…”

Rheology, Mixing, and Flow of Polymeric Materials

“…''Competition between Viscoelasticity and Surfactant Dynamics in Flow Focusing Microfluidics'' by Shelley L. Anna et al [1] ''Breakup Criteria for Confined Droplets: Effects of Compatibilization and Component Viscoelasticity'' by Peter Van Puyvelde et al [2] ''Micromechanics of Soft Particles'' by Hans M. Wyss et al [3] ''Phase Sensitive Constant Temperature Anemometry'' by Detlef Lohse et al [4] Multiple Drop Dynamics ''Modeling film drainage and coalescence of drops in a viscous fluid'' by Patrick D. Anderson et al [5] ''Emulsion Drops with Complex Interfaces: Globular versus Flexible Proteins'' by Peter Fischer et al [6] ''Effects of viscosity-controlled interfacial mobility on the coalescence of immiscible polymer blends'' by Nino Grizzuti et al [7] ''Bubble Behaviour in Fluidised Beds at Elevated Pressures'' by Niels G. Deen et al [8] Granular Flow ''Rheology and mixing of granular materials'' by Devang V. Khakhar [9] ''Computational approaches for studying the granular dynamics of continuous blending processes -Part 1: DEM based methods'' by Fernando J. Muzzio et al [10] Structured Flows ''The Use of Microfluidics in Rheology'' by L. James Lee et al [11] ''Structure Formation of NonColloidal Particles in Viscoelastic Fluids Subjected to Simple Shear Flow'' by Martien A. Hulsen et al [12] ''Assessment of the dispersion quality in polymer nanocomposites by rheological methods'' by Jan Vermant et al [13] ''Morphology and rheology of polypropylene/polystyrene/clay nanocomposites in batch and continuous melt mixing processes'' by Kyung Hyun Ahn et al [14] Structuring Flows ''Compact Mixing using Multiple Splitting, Stretching and Recombining Flows'' by Peter E. Neerincx et al [15] ''A Particulate Method for Determining Residence Time in Viscous Flow Processes'' by Mourad Heniche et al [16] ''Towards Gradient Formation in Microfluidics Devices by using Slanted Ridges'' by Jaap M.J. den Toonder et al [17] We are convinced that you will, like us, enjoy reading this collection of papers that give a broad, and good, overview of recent results in this intriguing interconnected research area, where polymer rheology meets polymer physics -and where polymer fluids meet the walls! …”

Formation and stability of string phase in polyamide 6/polystyrene blends in confined flow: Effects of nanoparticles and blend ratio

“…Conversely, more complex interactions between confinement conditions and component viscoelasticity on the shape relaxation of fibrils were explored . It was shown that viscoelastic droplets are more stabilized by confinement compared with Newtonian droplets; matrix viscoelasticity, conversely, induced a destabilization, thereby shifting the of confined droplets to smaller values . For example, in systems with either a viscoelastic matrix or droplet in the confined shear flow, the of a viscoelastic droplet was found to be similar to a Newtonian one, whereas matrix viscoelasticity caused breakup at a much lower , which affected the breakup mode.…”

“…Usually, to improve the poor interfacial adhesion of immiscible blends, additives (such as nanoparticles or copolymers) are added . So one of the challenge is to predict how the additives affect the morphology development (such as droplet breakup, coalescence, and deformation) in the confined flow . For instance, Moldenaers and coworkers found that in the presence of an interfacially active block polymer in Newtonian systems, the breakup of confined droplets was inhibited for the , and compared with the bulk behavior, the droplet length at the breakup of confined droplets was reduced.…”

“…So one of the challenge is to predict how the additives affect the morphology development (such as droplet breakup, coalescence, and deformation) in the confined flow . For instance, Moldenaers and coworkers found that in the presence of an interfacially active block polymer in Newtonian systems, the breakup of confined droplets was inhibited for the , and compared with the bulk behavior, the droplet length at the breakup of confined droplets was reduced. Moreover, both the deformation and orientation of polydimethylsiloxane (PDMS) droplets in polyisobutylene (PIB) matrix is suppressed by the addition of the PIB‐PDMS block copolymer .…”