Effect of Surfactants on Stability of Colloidal Sols as Precursors in Sol-Gel Encapsulation
This paper aims to study the effect of three alkyl quaternary salts on stability of colloidal sols further used as water-insoluble oligomers for encapsulation of an active flavonoid compound – quercitin. The preparation procedure is described and practical remarks on silica-based sol-gels are included. It is also demonstrated how to exploit the sol-gel preparation route in order to improve the thermal resistance of quercitin and to increase an optical function - fluorescence. The evolution in time of competitive hydrolysis and condensation processes has been observed by dynamic light scattering measurements. The sol-gel materials with entrapped quercitin molecule have been characterised by spectral methods (FT-IR, UV-VIS-NIR), fluorescence and by thermal analysis as well. Sol-gel materials doped with active flavonoid compound may be used in preparation of some functional materials with bioactive properties.
I. Lacatusu et al., "Effect of Surfactants on Stability of Colloidal Sols as Precursors in Sol-Gel Encapsulation", Key Engineering Materials, Vol. 415, pp. 57-60, 2009