title: Shear-induced solvent release from gel particles: application to drug-delivery systems.
abstract: The behaviour of a swollen-in-water hydrogel particle and of a chitosan-alginate micro-capsule immersed in a silicon oil under shear is studied by the rheo-optical method. Both gel and capsule quantitatively behave in a same way. Shear stress leads to a solvent release from a particle and a further increase of shear stress induces the solvent detachment from the released areas. Particle deformation and solvent release are reversible: when stopping the shear, the particle recovers its initial shape and volume. But when some solvent is detached, it flows separately as would do low-viscosity droplets immersed in a high-viscosity matrix.
authors.affiliation: Ecole des Mines de Paris, Centre de Mise en Forme des Matériaux, UMR CNRS/Ecole des Mines de Paris 7635, BP 207, 06904, Sophia-Antipolis, France.
authors.forename: Anna
authors.initials: A
authors.lastname: Zanina
authors.forename: Alexander
authors.initials: A
authors.lastname: Vilesov
authors.forename: Tatiana
authors.initials: T
authors.lastname: Budtova
mesh_terms: D000464:Alginates; D000465:Algorithms; D002686:Chitin / Q000031:analogs & derivatives; D048271:Chitosan; D016503:Drug Delivery Systems; D005782:Gels / Q000737:chemistry*; D020100:Hydrogels; D007700:Kinetics; D010316:Particle Size; D012212:Rheology; D012997:Solvents
chemical_list: D000464:Alginates; D005782:Gels; D020100:Hydrogels; D012997:Solvents; D002686:Chitin; D048271:Chitosan