Now showing items 1-3 of 3

  • Comparison of cation effects on phase transitions of kappa and iota carrageenan 

    Authors:Tari, Özlem; Pekcan, Önder
    Publisher and Date:(European Polymer Federation, 2010)
    Phase transitions of kappa and iota carrageenan in KCl NaCl and CaCl2 solutions were separately studied during heating and cooling processes by using fluorescence technique. Scattered light I-SC and fluorescence intensity I was monitored against temperature to determine the critical transition temperatures and exponents. Kappa and iota carrageenans with monovalent (KCl NaCl) salt system presented only coil to double helix (c-h) and double helix to coil (h-c) transitions upon cooling and heating ...

  • Fluorescence study on drying of iota-carrageenan gels at different temperatures prepared with various CaCl2 content 

    Authors:Tari, Özlem; Pekcan, Önder
    Publisher and Date:(Springer, 2011)
    The influence of temperature and salt content on drying was investigated by using steady-state fluorescence (SSF) technique. Supporting gravimetric and volumetric measurements were also carried out during drying of gels at various temperatures. iota-Carrageenan gels were prepared with various CaCl2 content. Pyranine was introduced as a fluorescence probe during gel preparation. Apparent fluorescence intensity I was measured during in situ drying process at each temperature and it was observed that ...

  • Modelling of Swelling by the Fluorescence Technique in Kappa Carrageenan Gels 

    Authors:Tari, Özlem; Pekcan, Önder
    Publisher and Date:(Amer Inst Physics, 2011)
    Kappa (-kappa) carrageenan gels prepared with various carrageenan concentrations in pure water were completely dried and then swelled in water vapor. Steady state fluorescence measurements were performed using a spectrometer equipped with temperature controller. Pyranine was embedded in kappa-carrageenan gels as a fluorescence probe during gel preparation. The fluorescence intensity I increased exponentially as swelling time is increased for all gel samples. The increase in I was modelled using ...