Metal oxide nanoparticles incorporated mesoporous silica nanospheres for oxygen scavenging

Abstract

To avoid foodborne illness, maintaining the prolonged food freshness and real-time food quality/health monitoring are the challenges to be addressed in this era. Development of active food packaging is an advancing research for real-time food health monitoring. In this study, mesoporous silica nanospheres (MSNs) have been synthesized with controlled size (>100nm) and porosity by using modified Stöber method. These MSNs are capable of adsorbing oxygen by physisorption thus can be used as oxygen scavengers for food packaging materials to extend shelf life of the food products. Furthermore, this study aims to incorporate active metal oxide nanoparticles (MNPs) in the pores of synthesized MSNs to extend its applications as oxygen scavenging and detection to avoid oxygen produced food degradation. The MNPs with an average size of <10 nm were successfully synthesized with stable dispersions. The active MNPs including SnO₂, Fe₂O₃, ZnO and TiO₂ (<10 nm) have been incorporated in the pores of MSNs. The MNPs were incorporated in the MSNs using i) Synthesis of MNPs followed by in-situ synthesis of MSNs, ii) synthesis of MSNs first followed by in-situ synthesis of MNPs in the pores of MSNs and, (iii) Synthesis of MSNs and MNPs separately and mixing of stable suspension of both MSNs and MNPs to achieve the best results for oxygen scavenging. The results indicated that first route was more successful for embedding the MNPs in the pores of MSNs. The oxygen scavenging efficiency of the MNPs incorporated MSNs were evaluated.