new insight to the effect of calcium concentration on gelation process and physical properties of alginate films

• Published in: Journal of materials science Vol. 51; no. 12; pp. 5791 - 5801
• Main Authors: Li, Jiwei, Wu, Yadong, He, Jinmei, Huang, Yudong
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.06.2016; Springer; Springer Nature B.V
• Subjects: absorption; Alginates; calcium; Calcium chloride; Chain entanglement; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Crosslinked polymers; Crosslinking; Crystallography and Scattering Methods; Density; Elongation; Emission analysis; energy-dispersive X-ray analysis; Entanglement; Fourier transform infrared spectroscopy; Fourier transforms; Gelation; Inductively coupled plasma; Infrared spectroscopy; Materials Science; Molecular chains; Original Paper; Physical properties; Polymer Sciences; Solid Mechanics; spectrometers; Spectrum analysis; Swelling; tensile strength; Alginate; Calcium Alginate; Sodium Alginate; Crosslinking Site; CaCl2 Concentration
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-016-9880-0

A series of alginate films were prepared using constant alginate content (2 % w/v) with various calcium chloride (CaCl₂) concentrations in the crosslinking solution (0.375–6 % w/v). Then, the initial investigation of how the CaCl₂ concentration affected the gelation process and physical properties of alginate films was established. A combination of Fourier transform infrared spectroscopy, swelling test, inductively coupled plasma optical emission spectrometer, and energy-dispersive spectroscopy analysis showed that the gelation process of alginate films evolved with the increase of CaCl₂ concentration, which resulted in different crosslinking density and entanglement of alginate molecular chains. Moreover, the increase of CaCl₂ concentration improved the visual appearance, surface homogeneity, and tensile strength, while the elongation at break and swelling capacity of the film were decreased monotonously. As a compromise between film strength and flexibility, performing effective absorption capability as well as the product appearance, the concentration of 1.5 % w/v CaCl₂ in the crosslinking step was recommended. These various physical properties of obtained alginate films could be attributed to the shaped crosslinking density and molecular entanglement characteristics during crosslinking.