Intraparticle Transport and Release of Dextran in Silica Spheres with Cylindrical Mesopores
2010 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 6, no 1, 466-470 p.Article in journal (Refereed) Published
The transport of oligomeric molecules in silica spheres with cylindrical mesopores has been quantified and related to the features of the internal structures in the spherical particles and the interactions at the polymer-pore interface. An emulsion-solvent-evaporation method was used to produce silica spheres having cylindrical mesopores with an average pore diameter of 6.5 nm. The transport of dextran molecules (fluorescently tagged) with molecular weights of 3000 and 10000 g/mol were quantified using confocal laser scanning microscopy (CLSM). The intraparticle concentrations profiles in the dextran-containing spheres were flat at all times, suggesting that the underpinning diffusion is not fully isotropic and the release is controlled by the pores close to the external surface of the spheres. The release of dextran into the solution is characterized by an initial burst, followed by a long-term sustained release. This behaviour cannot be described by a spherical model with a single diffusion constant (or a surface-induced mass transfer resistance). The release follows a logarithmic time-dependency that can be described by a Temkin model.
Place, publisher, year, edition, pages
2010. Vol. 6, no 1, 466-470 p.
Mesoporous particles, controlled release, dextran, CLSM, molecular transport
Research subject Materials Science
IdentifiersURN: urn:nbn:se:su:diva-27800DOI: 10.1021/la902092eOAI: oai:DiVA.org:su-27800DiVA: diva2:218352
ProjectsSynthesis, functionalisation and controlled release of mesoporous materials