Project Description: |
The fabrication and characterization of ruthenium-based polymeric structures on three-dimensional ordered macroporous electrode (3DOM) surfaces is an exciting new area of electrochemistry. The motivation for this research is the subsequent use of these modified 3DOM surfaces in design of electrochemical sensors for hydrazine detection in the environment. 3DOM electrodes have well-configured interconnected pore structures ranging from 100 nm - 300 nm and wall structures ranging from 10 nm - 30 nm in thickness. Using a resorcinol-formaldehyde system, students will synthesize (poly)-methyl methacrylate templates with opalescence-type properties. The templates will be used in a carbonization process for the formation of 3DOM structures. These structures have increased surface area, enhanced charge-transfer properties and conductivity, and a significantly large energy density for heterogeneous and homogeneous electrochemical-chemical reactions compared to other electrode surfaces such as glassy carbon. During the first five weeks of research, students will focus on both electro-polymerizing several ruthenium complexes such as [(bpy)3-nRu(5-phenNH2)n]2+ (5-phenNH2=5-amino-1,10-phenanthroline, n=1-3) onto 3DOM structures and characterizing the structures using cyclic voltammetry. The objective during this time is to correlate electropolymerization conditions to the overall properties of the modified 3DOM structures and to study how the structure of the ruthenium complexes modulate redox potentials and changes the properties of the 3DOM. Additional information on polymeric structures will be determined using ion beam analysis techniques such as Rutherford Backscattering in the research lab of Professor Graham Peaslee. Weeks 6-8 will be used to evaluate the apparent charge transfer diffusion coefficient within the 3DOM structures since rates of charge transfer reactions are enhanced by the nanometer diffusional pathways within the well-interconnected porous structures. The last two weeks of research will focus on using cyclic voltammetry to characterize the 3DOM electrodes, and will involve kinetic modeling of the system to include identifying the rate determining step in the overall reaction between hydrazine and the 3DOM ruthenium polymeric structures. Such information will be critical in the development of sensors and probe units for the detection of hydrazine under static and dynamic-convective flow conditions. |
