APS Logo

The local environment of pentylphosphonic acid molecular layers with mixed azide and OH terminations, examined by X-ray photoemission spectroscopy

ORAL

Abstract

The surface termination of pentylphosphonic acid (PA-C5-R) molecular films with different ratios of PA-C5-N3 (azide termination) and PA-C5-OH (OH termination) was studied by angle resolved X-ray photoemission spectroscopy. Angle resolved X-ray photoemission spectroscopy suggests that the azide, N3, headgroup surface termination decreases with respect to the OH surface termination, as the PA-C5-N3 and PA-C5-OH ratio decreases, very much as is expected. Surprisingly, it is found that the chemical environment around the N3 headgroup changes with changing PA-C5-N3 and PA-C5-OH ratio. We infer from the shift in intensity of the N 1s core level photoemission features to higher binding energies, and away from the N3 photoemission component with the least binding energy, that the N3 is donating more electron charge with higher OH end group concentrations. This tends to suggestion that during the self-assembly growth process, there is weak ordering of the different species rather than strong clustering among the species with different surface terminal groups.

–

Presenters

  • Esha Mishra

    Department of Physics and Astronomy, University of Nebraska - Lincoln, Department of Physics and Astronomy, University of Nebraska-Lincoln

Authors

  • Esha Mishra

    Department of Physics and Astronomy, University of Nebraska - Lincoln, Department of Physics and Astronomy, University of Nebraska-Lincoln

  • Kenneth Hipp

    Department of Chemistry, University of Nebraska-Lincoln

  • Andrew S. Olson

    Department of Chemistry, University of Nebraska-Lincoln

  • Peter A Dowben

    Physics and Astronomy, University of Nebraska - Lincoln, Department of Physics and Astronomy, University of Nebraska - Lincoln, Department of Physics and Astronomy, University of Nebraska-Lincoln, University of Nebraska - Lincoln

  • Patrick H. Dussault

    Department of Chemistry, University of Nebraska-Lincoln

  • Rebecca Y. Lai

    Department of Chemistry, University of Nebraska-Lincoln