1. Liquid-liquid and liquid-solid separation in self-assembled chitosan-alginate and chitosan-pectin complexes.
- Author
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García-Jiménez, Abraham, Román-Guerrero, Angélica, Pérez-Alonso, César, and Fouconnier, Benoit
- Subjects
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MOLECULAR weights , *PECTINS , *VIRIAL coefficients , *IONIC strength , *PHASE separation , *PHASE transitions - Abstract
The complexation between two oppositely charged polyelectrolytes (PE) can lead liquid-liquid (complex coacervates, CC) or liquid-solid (solid precipitates, SP) phase separations. Herein, the effect of pH (2−11) and ionic strength (I , 0.05–1.0 M KCl) on the associative interactions between chitosan (QL)-alginate (SA) and QL-Pectin (Pec), polysaccharides widely used in biotechnology field, is described. pH and I , exhibited significant effect on the structure and phase transitions by modifying the ionization degree (α), pk a , and associative interactions between PE. Onset of binding was established at pH c 9, while continued acidification (pH τ 5.8) led to simultaneous CC and SP exhibiting a maximum turbidity in both systems. At pH δ 4.0, QL-Pec showed preferably CC structures whereas QL-SA maintained the CC and SP structures. At pH ω 2, the associative interactions were suppressed due to the low ionization of Pec and SA. I (1.0 M) significantly diminished the interactions in QL-Pec due to charge screening. Molecular weight, second virial coefficient, hydrodynamic size, ionizable groups, and persistence length of polyion, influenced on the phase behavior of QL-Pec and QL-SA systems. Therefore, CC and SP are found simultaneously in both systems, their transitions can be modulated by intrinsic and environmental conditions, expanding the functional properties of complexed polysaccharides. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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