Study of aggregation in polysaccharides by triple detection HPLC

POSTER

Abstract

It has been observed that various species of the polysaccharide carrageenan undergo a change in conformation under varying conditions of temperature and added salt. The change is from a random coil (under conditions of high temperature or low salt) to a helix (under conditions of low temperature or high salt). It is a point of contention as to whether the helix is formed of one coil wrapping upon itself or two coils wrapping around one another. We present the results of a study of this conformation change using viscometry and multi-angle laser light scattering (MALLS) incorporating size-exclusion chromatography (SEC). In previous research, our batch light scattering results showed a clear increase in molecular weight and radius of gyration when NaCl was added to varying concentrations of iota-carrageenan, which could be interpreted as the conformation change described. However, estimates of persistence length ($\sim $ R$_{G}^{2}$ / M$_{W})$ calculated using MALLS data show no strong variation when increasing added salt. This suggests that the molecular weight increase reflects an aggregation of polymer molecules instead of a change in conformation. However, SEC results show very little variation in molecular weight and radius of gyration, and instead, show behavior typical of linear polyelectrolytes. Resolution of these different results suggests a loose aggregation of polymer molecules that preserves the overall structure rather than a significant change in polymer architecture. We present viscometry and dynamic light scattering results that confirm these conclusions.

Authors

  • David Norwood

    Southeastern Louisiana University

  • R.F. Kelly

    SVT Associates, Department of Material Science and Engineering, Department of Chemistry, University of Florida, Florida International University, WebAssign, North Carolina State University, Broughton High School, Dept.~of Chemistry, Univ.~of Florida, Dept.~of Physics, Univ.~of Florida, National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32306, USA, Center for Superconductivity Research, Dept. of Physics, University of Maryland, College Park, MD, 20742, USA, Dept. of Physics, University of Florida, 32611, USA, Experimentalphysik VI, Center for Electronic Correlations and Magnetism, Institute of Physics, Augsburg, Germany, Physics \& Astronomy, UNC-CH, Chapel Hill, NC, University of North Carolina, Auburn University, University of Virginia, Tech. Univ. Eindhoven, University of Florida, Los Alamos National Labs, University of New Mexico, Advanced Materials Research Institute, University of New Orleans, New Orleans, LA, Department of Physics, University of Florida, UF, NHMFL, FSU / NHMFL, FSU, University of Arkansas, Dept. of Physics and Astronomy, University of Delaware, Newark, DE 19716, USA, Dept. of Physics, University of Florida, Gainesville, FL 32611-8440, USA, Dept. Chemistry Florida State Univeristy, University of Brewen, Tohoku University, Okayama University, Dept of Chemistry, Florida State University, Dept. of Chemistry, Florida State University, National High Magnetic Field Laboratory, Tallahassee, FL, Laboratoire Lois Neel, Grenoble, France, Dept. of Chemistry, Texas A\&M University, Tsinghua Univ., INEL, JINR, Vanderbilt Univ./LBNL, Vanderbilt Univ., SVT Associates, Inc., Department of Chemical Engineering, University of Florida, Department of Materials Science and Engineering, University of Florida, Department of Electrical Engineering, National Central University, Taiwan, University of Miami, North Carolina Central University, University of Missouri Rolla, AB Millimetre, France, Thomas Keating Ltd., UK, Dept. of Physics, Univ. of Florida, Department of Material Science and Engineering University of Florida, Department of Chemistry University of Florida, Department of Chemical Eng. University of Florida, Naval Research Lab, Washington, DC, University of Rajshahi, LENIN All Russian Electrotechnical Institute, Moscow, Russia, Independent Researcher, Argentina

  • R.F. Kelly

    SVT Associates, Department of Material Science and Engineering, Department of Chemistry, University of Florida, Florida International University, WebAssign, North Carolina State University, Broughton High School, Dept.~of Chemistry, Univ.~of Florida, Dept.~of Physics, Univ.~of Florida, National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32306, USA, Center for Superconductivity Research, Dept. of Physics, University of Maryland, College Park, MD, 20742, USA, Dept. of Physics, University of Florida, 32611, USA, Experimentalphysik VI, Center for Electronic Correlations and Magnetism, Institute of Physics, Augsburg, Germany, Physics \& Astronomy, UNC-CH, Chapel Hill, NC, University of North Carolina, Auburn University, University of Virginia, Tech. Univ. Eindhoven, University of Florida, Los Alamos National Labs, University of New Mexico, Advanced Materials Research Institute, University of New Orleans, New Orleans, LA, Department of Physics, University of Florida, UF, NHMFL, FSU / NHMFL, FSU, University of Arkansas, Dept. of Physics and Astronomy, University of Delaware, Newark, DE 19716, USA, Dept. of Physics, University of Florida, Gainesville, FL 32611-8440, USA, Dept. Chemistry Florida State Univeristy, University of Brewen, Tohoku University, Okayama University, Dept of Chemistry, Florida State University, Dept. of Chemistry, Florida State University, National High Magnetic Field Laboratory, Tallahassee, FL, Laboratoire Lois Neel, Grenoble, France, Dept. of Chemistry, Texas A\&M University, Tsinghua Univ., INEL, JINR, Vanderbilt Univ./LBNL, Vanderbilt Univ., SVT Associates, Inc., Department of Chemical Engineering, University of Florida, Department of Materials Science and Engineering, University of Florida, Department of Electrical Engineering, National Central University, Taiwan, University of Miami, North Carolina Central University, University of Missouri Rolla, AB Millimetre, France, Thomas Keating Ltd., UK, Dept. of Physics, Univ. of Florida, Department of Material Science and Engineering University of Florida, Department of Chemistry University of Florida, Department of Chemical Eng. University of Florida, Naval Research Lab, Washington, DC, University of Rajshahi, LENIN All Russian Electrotechnical Institute, Moscow, Russia, Independent Researcher, Argentina