title: Mechanical properties of liquid-filled shellac composite capsules.
abstract: This paper describes the mechanical properties of thin-walled, liquid-filled composite capsules consisting of calcium pectinate and shellac. In a series of experiments we measured the deformation of these particles in a spinning drop apparatus. For different pH-values we studied the elastic properties of these particles and compared the obtained results with the mechanical response measured by squeezing capsule experiments. In analogy to these experiments, we also investigated liquid-filled unloaded calcium pectinate capsules without the addition of shellac. The deformation properties of these experiments and the surface Young moduli were in good agreement. Furthermore we investigated the liquid-filled calcium pectinate and the composite capsules by NMR microscopy. These experiments allowed investigations of the membrane thickness and the kinetics of membrane growing. Additional characterizations by stress controlled small amplitude surface shear experiments of similar composed gel layers provided coherent results for the surface Young modulus.
authors.affiliation: Department of Physical Chemistry II, Technische Universität Dortmund, 44227 Dortmund, Otto-Hahn-Straße 6, Germany. sabine.leick@tu-dortmund.de
authors.forename: Sabine
authors.initials: S
authors.lastname: Leick
authors.forename: Maureen
authors.initials: M
authors.lastname: Kott
authors.forename: Patrick
authors.initials: P
authors.lastname: Degen
authors.forename: Stefan
authors.initials: S
authors.lastname: Henning
authors.forename: Tobias
authors.initials: T
authors.lastname: Päsler
authors.forename: Dieter
authors.initials: D
authors.lastname: Suter
authors.forename: Heinz
authors.initials: H
authors.lastname: Rehage
mesh_terms: D002214:Capsules; D006863:Hydrogen-Ion Concentration; D055595:Mechanical Phenomena; D008567:Membranes, Artificial; D008853:Microscopy; D010368:Pectins / Q000737:chemistry; D012116:Resins, Plant / Q000737:chemistry*; D012212:Rheology
chemical_list: D002214:Capsules; D008567:Membranes, Artificial; D012116:Resins, Plant; C003934:shellac; D010368:Pectins