Determination of the Failure Stresses for Fluid-filled Microcapsules that Rupture Near the Elastic Regime

Research output: Contribution to journalArticlepeer-review

Authors

Colleges, School and Institutes

External organisations

  • Procter and Gamble
  • ENCAPSYS

Abstract

The encapsulation of liquids within an external wall or shell is an important technology often utilized in the production of many commercial products. The mechanical characterization of such microcapsules is paramount in order to fully understand their performance in their target environment. Some microcapsules, with wall materials such as inorganic based compounds, rupture at small deformations, commonly near the elastic regime. The study herein presents a general methodology that enables calculation of the failure stresses leading to the elastic-like rupture of microcapsules under parallel compression testing. Two scenarios of failure, brittle and ductile, were considered. Analyses of the critical stresses present within the microcapsule wall during different degrees of fractional deformation were obtained using finite element modelling, resulting in similar values for both the brittle and ductile scenarios. The correlations presented were used to determine the failure stresses of tetraethoxyorthosilane-methyltrimethoxysilane (TEOS-MTMS) microcapsules with a model core oil, which are 11-14 ± 10 MPa. The data were further analyzed using Weibull distributions.

Details

Original languageEnglish
Pages (from-to)1435-1445
Number of pages11
JournalExperimental Mechanics
Volume52
Issue number9
Early online date8 Mar 2012
Publication statusPublished - Nov 2012

Keywords

  • Elastic behaviour, Finite element modelling (FEM), Fracture stress, Microcapsule, Micromanipulation