The 1 H NMR spectroscopy is used to study the kinetics of gelation in the aqueous mixtures of κ-carrageenan with gelatin. The time dependence of NMR signals intensities shows that the kinetics of gel formation consists of classical ‘fast’ (rate constant k ≈ 6 h −1 ) and ‘slow’ (k ≈ 1 h −1 ) periods, corresponding to a coil → helix transition and subsequent aggregation of helices. Upon increase of the κ-carrageenan/gelatin (w/w) ratio Z the rate of the fast process slows down by a factor of 1.6–2.4. Further analysis was done by studying the dependence of spin-spin relaxation times of protons of gelatin on Z in the aqueous phase. A qualitative scheme describing hydrogel formation in the complex solution is given. It is hypothesized that at higher concentration of PECs the hydrogel structure network is stabilized by three types of nodes: triple helices of gelatin and intra-/inter-molecular double helices of κ-carrageenan.

Original languageEnglish
Pages (from-to)117-126
Number of pages10
JournalCarbohydrate Polymers
Volume169
DOIs
StatePublished - 1 Aug 2017

    Research areas

  • Gelatin, High-resolution H NMR spectra, Kinetics of gelation, Polyelectrolyte complexes, Spin-spin relaxation times, κ-Carrageenan

    Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Materials Chemistry

ID: 9327697