Controlled Dissolution of Organosilica Sol−Gels as a Means for Water-Regulated Release/Delivery of Actives in Fabric Care Applications

Organosilica sol−gels functionalized with amino groups are used for the controlled release of encapsulated molecules including biomolecules. These gels prepared by hydrolysis of aminosilane precursors are characterized by water-induced changes in network formation and dissolution and as a result can be used as controlled release matrixes on the basis of the water content of the medium. The gels were initially evaluated for release of simple organic dyes such as Congo red as a result of the water-induced dissolution of gels. These gels can also be used as a means for controlled release of encapsulated entities including enzymes such as proteases that are used in fabric care applications. The rapid dissolution of these gels when placed in water-rich media provides an effective strategy for release and/or delivery of actives with potential utility in fabric care applications. The encapsulated enzymes are able to retain their activity and remain stable for extended periods. The gels were characterized by FTIR spectroscopy, which indicates the formation of a loosely held network of hydrogen-bonded particles in these gels. The results indicate potential utility of these materials as versatile delivery matrixes where the release of actives can be initiated by facile water-induced dissolution of these organosilica sol−gels.