The Centre for Nanomaterials Applications in Construction

Efficient encapsulation of different compounds is an important research area for many industrial sectors such as food, cosmetic, medical and pharmaceutical industries. Usually organic materials are used to obtain the capsules. However, in the last years there has been an increase in the synthesis of inorganic capsules, in particular silica capsules by sol-gel process due to their great chemical resistance, thermal stability, biocompatibility and their non-toxic quality for the environment.

As part of an ongoing research project at Nanoc, several technologically interesting organic compounds have been encapsulated based on the synthesis reported by Ahn et al. (B.Y. Ahn, S.I. Seok, I.C. Baek, S.I: Hong, Chem. Commun., 2, 189 (2006)) and their morphology, size and shell characteristics have been characterized (Fig.1). Part of the study was presented as a poster in the conference Trends in Nanotechnology 2009 and has been accepted to be published in the journal Physica Status Solidi. The microcapsules are made of silica and the synthesis is based in a sol-gel reaction followed by an emulsion process. The characteristics of the microcapsules vary depending on the parameters of the reaction such as the pH, stirring speed and even the material to be encapsulated. The synthesized capsules can have a wide size range that could go from 100 nm to 100 µm.

The capsules shown above were synthesised by Idurre Kaltzakorta, who is doing her PhD studies under the supervision of Dr. Edurne Erkizia (eerkizia@labein.es). If you are interested in knowing more about this issue, please contact them !!!