title: Methodology for the Evaluation of Double-Layered Microcapsule Formability Zone in Compound Nozzle Jetting Based on Growth Rate Ratio.
abstract: Double-layered microcapsules, which usually consist of a core (polymeric) matrix surrounded by a (polymeric) shell, have been used in many industrial and scientific applications, such as microencapsulation of drugs and living cells. Concentric compound nozzle-based jetting has been favored due to its efficiency and precise control of the core-shell compound structure. Thus far, little is known about the underlying formation mechanism of double-layered microcapsules in compound nozzle jetting. This study aims to understand the formability of double-layered microcapsules in compound nozzle jetting by combining a theoretical analysis and numerical simulations. A linear temporal instability analysis is used to define the perturbation growth rates of stretching and squeezing modes and a growth ratio as a function of the wave number, and a computational fluid dynamics (CFD) method is implemented to model the microcapsule formation process in order to determine the good microcapsule forming range based on the growth ratio curve. Using a pseudobisection method, the lower and upper bounds of the good formability range have been determined for a given materials-nozzle system. The proposed formability prediction methodology has been implemented to model a water-poly (lactide-co-glycolide) (PLGA)-air compound jetting system.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: C
authors.initials: C
authors.lastname: Leigh Herran
authors.forename: Nicole
authors.initials: N
authors.lastname: Coutris
authors.forename: Yong
authors.initials: Y
authors.lastname: Huang
authors.forename: Vladimir
authors.initials: V
authors.lastname: Mironov
authors.forename: Roger
authors.initials: R
authors.lastname: Markwald
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