ChBE Seminar Series: Integrated Synthesis-Capture Strategies...
Speaker: Hyunmin Yi, ChBE Associate Professor, Tufts University
Title: Integrated Synthesis-Capture Strategies for Viral Templated and Catalytically Active Palladium Nanoparticles Toward Multifunctional Membranes
Controlled and programmable fabrication of functional materials at the nano to micro scales under mild aqueous conditions remains an unmet challenge. Our approach to addressing these challenges is biofabrication, that is to understand and utilize the programmable functionalities of biologically derived materials and interactions for facile fabrication of functional materials.
Viral assemblies have attracted substantial attention as templates for materials synthesis due to their precisely controlled dimensions, chemical functionalities and the ability to impart additional modalities through genetic modification. We harnessed several unique properties of tobacco mosaic virus (TMV) for facile synthesis of catalytically active palladium (Pd) nanoparticles; such advantages include robust nanotubular structure providing large surface area, high stability in a wide range of conditions, easy mass production and biological safety. We have demonstrated size-controlled synthesis of small palladium nanoparticles under mild aqueous conditions via spontaneous reduction of precursors. High catalytic activity and stability of TMV-templated Pd nanoparticles are examined via dichromate reduction reaction. The results show that the TMV-templated Pd nanoparticle synthesis offers attractive routes to highly active, controlled and stable catalyst systems.
Polymeric hydrogels offer attractive platforms for a large range of applications including bioassays, separation and catalysis. We exploit simple photo-induced radical polymerization of poly(ethylene glycol) diacrylate and related hydrogel materials to capture the as-prepared viral-nanoparticle complexes for facile catalytic reaction applications via replica molding and interfacially initiated hydrogel layer synthesis. This simple, robust and readily tunable scheme allows the large nanocomplexes to be captured and utilized without aggregation or leaching in a stable fashion while small molecule reactants can access the catalytic sites with minimal mass transfer limitation. Combined, our facile synthesis-capture strategy integrates potent viral nanotemplates, high catalytic activity and stability of the small nanocatalysts, and robust polymerization schemes. We thus believe that our strategy can be readily extended to programmable manufacturing of a large array of multifunctional materials.
In this presentation, our recent progress on the fabrication of multifunctional membranes via interfacially initiated radical polymerization offering controlled macroporous structures for size-selective protein purification as well as catalytic remediation of toxic compounds will be highlighted.