Investigating the Diffusive Behavior of HPC with DLS and FPR

ORAL

Abstract

Hydroxypropylcellulose (HPC) polymer chains were dissolved in aqueous solution in order to explore their diffusive qualities. Two fundamentally different methods: FPR (Fluorescence Photo-bleaching and Recovery) and DLS (Dynamic Light Scattering) were employed to study the structure and dynamics of HPC chains. FPR requires polymer to be chemically tagged by fluorescent molecules. FPR captures diffusion by establishing a photo-bleached boundary, observing only tagged particles diffusing back into the bleached area, yielding a contrast decay function. DLS auto-correlates scattered light intensity from particles, calculating a decay function which yields information about the self diffusion of particles at chemical equilibrium. An Inverse Laplace Transform Algorithm (CONTIN) and stretch exponential line shape analysis (LSA) quantitatively decomposed spectral decays into diffusion processes or modes. The LSA and CONTIN analysis on the same FPR decay spectra resulted in roughly similar modal distribution and mode intensity results. The modal distributions for FPR and DLS spectra on the same sample have shown consistent dissimilarities which may indicate a comparative limitation and/or sensitivity to a particular range of diffusive speeds or processes. The tag and/or tagging process appear to alter samples in a way that is quantifiable and consistent. The nature of diffusive processes in HPC appears to be complex, but analysis reveals a reproducible picture.

–

Authors

  • Doug Petkie

    AFRL/RX, AFRL/RX, Systran Systems Inc, UCSD, Los Alamos National Laboratory, Ohio Northern University, BFS, Germany, Florida State University, Monmouth College, Ohio Wesleyan University, Department of Chemical and Biomolecular Engineering, The University of Akron, Physics Department, John Carroll University, Department of Chemistry, Knight Chemical Laboratories, The University of Akron, Australian National University, Miami University, Oxford, OH, University of Cincinnati, University of Findlay, Naval Research Laboratory, Washington, DC 20375, Cleveland State University, Health Sciences Dept, Cleveland State University, Physics Dept, Cleveland State University, Bucknell University, Wright State University, Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, Wright State University, Department of Physics, University of Puerto Rico, Department of Mechanical Engineer, Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB and UES, Inc., Department of Environmental Science and Policy, School of Science, Marist College, Poughkeepsie, NY 12601, USA, AFRL/711 HPW, EPA Sustainable Technology Division, University of Akron, Rose-Hulman Institute of Technology, Harvard University, LSU, Ohio University, Wittenberg University, Student

  • Kiril Streletzky

    Cleveland State University, CSU

  • Doug Petkie

    AFRL/RX, AFRL/RX, Systran Systems Inc, UCSD, Los Alamos National Laboratory, Ohio Northern University, BFS, Germany, Florida State University, Monmouth College, Ohio Wesleyan University, Department of Chemical and Biomolecular Engineering, The University of Akron, Physics Department, John Carroll University, Department of Chemistry, Knight Chemical Laboratories, The University of Akron, Australian National University, Miami University, Oxford, OH, University of Cincinnati, University of Findlay, Naval Research Laboratory, Washington, DC 20375, Cleveland State University, Health Sciences Dept, Cleveland State University, Physics Dept, Cleveland State University, Bucknell University, Wright State University, Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, Wright State University, Department of Physics, University of Puerto Rico, Department of Mechanical Engineer, Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB and UES, Inc., Department of Environmental Science and Policy, School of Science, Marist College, Poughkeepsie, NY 12601, USA, AFRL/711 HPW, EPA Sustainable Technology Division, University of Akron, Rose-Hulman Institute of Technology, Harvard University, LSU, Ohio University, Wittenberg University, Student