TY - JOUR
T1 - Small-angle X-ray scattering study on pectin-chitosan mixed solutions and thermoreversible gels
AU - Ventura, Irit
AU - Bianco-Peled, Havazelet
N1 - Publisher Copyright:
©2015 Elsevier Ltd. All rights reserved.
PY - 2015/6/5
Y1 - 2015/6/5
N2 - Hot solutions containing pectin and chitosan with pectin weight fraction of 0.75, in acidic pH, demonstrate gelation occurring upon cooling to room temperature. This study explores the origin of this gelation using small angle X-ray scattering (SAXS) as the main experimental tool. Modeling SAXS patterns revealed rigid rod conformation in chitosan solutions, whereas pectin formed a self-avoiding chain. In addition, nanometric aggregates were detected in pectin solutions. Pectin and chitosan in mixed solutions adopted a similar semiflexible conformation. The only sample that created a visually stable gel displayed a different pattern, characteristic to polymers gels. Manipulating the composition by adding urea and salts highlighted the important role of hydrogen bonding, which governs the gelation mechanism. Nevertheless, electrostatic interactions were also found to take part in the gelation. To the best of our knowledge, this is the first comprehensive and systematic SAXS study on these pectin-chitosan mixtures.
AB - Hot solutions containing pectin and chitosan with pectin weight fraction of 0.75, in acidic pH, demonstrate gelation occurring upon cooling to room temperature. This study explores the origin of this gelation using small angle X-ray scattering (SAXS) as the main experimental tool. Modeling SAXS patterns revealed rigid rod conformation in chitosan solutions, whereas pectin formed a self-avoiding chain. In addition, nanometric aggregates were detected in pectin solutions. Pectin and chitosan in mixed solutions adopted a similar semiflexible conformation. The only sample that created a visually stable gel displayed a different pattern, characteristic to polymers gels. Manipulating the composition by adding urea and salts highlighted the important role of hydrogen bonding, which governs the gelation mechanism. Nevertheless, electrostatic interactions were also found to take part in the gelation. To the best of our knowledge, this is the first comprehensive and systematic SAXS study on these pectin-chitosan mixtures.
KW - Chitosan
KW - Pectin
KW - Polysaccharides mixtures
KW - SAXS
KW - Thermoreversible gel
UR - http://www.scopus.com/inward/record.url?scp=84949130604&partnerID=8YFLogxK
U2 - 10.1016/j.carbpol.2015.01.025
DO - 10.1016/j.carbpol.2015.01.025
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AN - SCOPUS:84949130604
SN - 0144-8617
VL - 123
SP - 122
EP - 129
JO - Carbohydrate Polymers
JF - Carbohydrate Polymers
ER -