Faculty Profiles

Dr. Walhout's current research interest lies in the area of polyelectrolyte multilayer thin films (PMLs). These films are created by a relatively new self-assembly technique whereby alternating layers of positively and negatively charged polyelectrolytes are deposited onto a substrate from solution. Many variations on this versatile synthetic technique can be employed, including adsorbing charged small molecules such as dyes into the thin film structure or creating discrete layers of non-charged conducting polymers by assembling a layer of the charged monomers followed by in situ polymerization.

Several projects related to fundamental properties of PMLs are underway. One project involves investigating whether a glass transition temperature can be found for typical PMLs using phase-modulated ellipsometry to track thickness changes as a function of temperature. Other projects relate to measuring the rotational and translational diffusion of small charged molecules embedded in the thin films using FRAP methods (fluorescence recovery after photobleaching). These diffusion measurements will be useful for PML applications that involve small molecules, but they are also useful on a more fundamental level as a probe of the polymer dynamics in the thin film. Lastly, a project has just started in which electron transfer dynamics will be examined between donor and acceptor layers within a PML. This study will be undertaken using transient absorption and time-correlated single photon counting techniques employing a Ti:sapphire ultrafast laser.

This research combines Dr. Walhout's interest in spectroscopy and polymers. His ultrafast thesis work at Minnesota under Paul Barbara was titled "Ultrafast Studies of Radical Anions in Solution." This was followed by a post-doctoral appointment at the University of Wisconsin working with Mark Ediger in the area of polymer dynamics.

Dr. Walhout married his wife Jenna in 1992 and they now have four children. Both are Wheaton alums and enjoy being back in the Chicagoland area where they are close to their kids' four grandparents and 2 great-grandparents. They are active in their local church where Dr. Walhout sings in the choir. He also enjoys watching and playing many sports and is happy to be close to the Chicago sports teams again after too long an exposure to Vikings and Packers fans.

University of Minnesota
Ph.D., Physical Chemistry, 1997

Wheaton College
B.S., Chemistry, 1991

• Spectroscopy
• Physical Chemistry
• Chemistry
• Laser

• American Chemical Society
• Midwest Association of Chemistry Teachers at Liberal Arts Colleges (MACTLAC)

• General Chemistry
• Physical Chemistry I and II
• Methods in Physical Chemistry

The Beautiful and the Sublime in Natural Science, Zygon
Walhout, Peter K., 2009

Heterogeneous Translational Dynamics of Rhodamine B in Polyelectrolyte Multilayer Thin Films, Langmuir
Carr, Joshua K.; Himes, Ryan D.; Keung, Connie; Burden, Daniel L.; Walhout, Peter K., 2009

Measuring Diffusion in Nanoscale Environments with Single-Molecule Confocal Fluorescence Microscopy, Spectroscopy Letters
Burden, D.L., Walhout, P.K., Elliott, J.T, Chandler, E.L., Scharf, R.G., Culbertson, M.J., Stults, D.A., Rupp, E.L., Poppen, S.D., 2004

Detailed Investigation of the Femtosecond Pump-Probe Spectroscopy of the Hydrated Electron, The Journal of Physical Chemistry
A Yokoyama, K., Silva, C., Son, D., Walhout, P.K., Barbara, P.F., 1998

Detailed Investigations of the Pump-Probe Spectroscopy of the Equilibrated Solvated Electron in Alcohols, The Journal of Physical Chemistry
A Silva, C., Walhout, P.K., Reid, P.J., Barbara, P.F., 1998