(636g) Self Assembly of Silk Fibroin/Metal Composite Nanomaterials

Authors: 
Nagelli, E., United States Military Academy
Mitropoulos, A., United States Military Academy
Milanesa, G., United States Military Academy
Wang, J., United States Military Academy
Woronowicz, K., United States Military Academy
Burpo, F. J., United States Military Academy
Methods to develop light weight energy storage devices made from biomaterials has been challenging but can enhance properties to normally insulating materials. High surface area composites offer unique properties for electrode materials to provide faster ion transport and larger ion storage capacity. However, generating controlled structures in composite biomaterials can be difficult which, if wanting to generate a material with high surface area, self-assembly of molecules with different static charges in liquid solutions offers one of the fastest and scalable processes. The self-assembly of proteins benefits bottom assembly that can be easily mixed in liquid solutions with metals ions. Upon reduction of the metal salts, composite metallic devices can merge biology with electronics to generate new capacitors, energy storage, or catalytic materials. Silk fibroin from the Bombyx mori silk worm is a structural protein used for its potential in textile, biomedical, photonic, and electronic applications. It has shown great potential as a structural support in unique sensing devices to merge biotic systems with abiotic systems. In aqueous environments, silk fibroin is negatively charged allowing for protein molecules to interact with positive ions. Here, mixtures of silk fibroin and positive and metal ions are combined to develop free standing gel composites. Changing the order of mixture combination (positive vs. negative) and the concentration of each mixture, different composite nanoscale structures are created. Therefore, composites of silk fibroin can be bonded to metals, such as platinum and palladium, to provide a new structure for a self-assembled biomaterial. Previous work with platinum and graphene oxide mixtures produces high surface area controlled rectangular platinum prisms coated in graphene oxide. Here, the silk fibroin acts as the biomaterial coating the platinum rectangular prisms. Capitalizing on the self-assembly and stabilizing effects of silk fibroin, additional enzymes are applied to enhance the capabilities of these nanomaterials to produce a new generation of biomaterial composites. In addition, due to the bottom-up assembly process, these composites are easily synthesized and have the possibility to be scaled up for industrial and consumer applications. Furthermore, silk fibroin can be generated into several forms capitalizing on the function of these composites.