Multiple Emulsion Templating of Hybrid Ag/SiO2 Capsules for Antibacterial Applications. (29th November 2014)

• Record Type: Journal Article
• Authors: Sousa, Filipa L.; Almeida, Adelaide; Girão, Ana V.; Fateixa, Sara; Trindade, Tito
• Is Part Of: Particle and particle systems characterization. Volume 32:Number 5(2015:May)
• Page Start: 561
• Page End: 566
• Publication Date: 2014-11-29
• Subjects: Particles -- Periodicals; 620.43
• DOI: 10.1002/ppsc.201400168
• Languages: English
• ISSNs: 0934-0866

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Silver nanoparticles (NPs) encapsulated in amorphous silica shells are synthesized and evaluated for their antibacterial action using the Gram‐negative <italic>Escherichia coli</italic> bacterium. These inorganic capsules are synthesized using a new approach that comprises the use of oil‐in‐water‐in‐oil (O/W/O) multiple emulsions to fabricate SiO₂ capsules incorporating organically capped Ag NPs. This strategy is explored as a mean to promote the bioadhesion of the microorganisms to the silica rough surfaces while still keeping the system with a high surface area for the active metal. The results have shown that the hybrid capsules enable a slow release of cationic silver from the interior of the silica microsphere to the external medium probably through the pore channels in the shell. The antibacterial activity against <italic>E. coli</italic> is mainly determined by the Ag⁺ ion release rate, suggesting that these particulates can be employed as a robust system for prolonged used as an antimicrobial material.</p> </abstract>