Hope College Physics Department
Research Experiences for Undergraduates
Summer 2007
Project Summary

 

Project Title:

RBS Analysis as a Technique for Electropolymer Thickness Determination

Student Name: Daniel Tobert
Student's Home Institution: Hope College
Research Advisor: Dr. Paul DeYoung/Dr. Graham Peaslee
Source of Support: This material is based upon work supported by the National Science Foundation under Grant Numbers 0354920 and 031923.

A glassy carbon electrode electropolymerized with ruthenium bis(1,10-phenanthroline)(4-methyl-4’-vinyl-2,2’-bipyridine) monomers using cyclic voltammetry is capable of detecting hydrazine in groundwater. A thickness measurement is necessary to complete the development of these electrodes and to understand their structure, and a method was developed to determine the thickness using Hope’s Ion Beam Analysis Laboratory (HIBAL). The technique involves electroplating a lead layer on the electrode surface followed by electroplating the ruthenium polymer and using the traditional Rutherford Back-Scattering (RBS) analysis to determine thickness. HIBAL accelerates high energy helium cations towards the electrode and the energy of the back-scattered particles was measured to determine thickness of the layers. It was concluded that the uniformity of the plated layers plays a role in the consistency of the results. Measurements of uniformly plated electrodes do show a correlation between the number of cycles of the ruthenium polymer and the measured thickness.