Tailoring Multi-Level Structural and Practical Features of Gelatin Films by Varying Konjac Glucomannan Content and Drying Temperature

Abstract

Here, we tailored the multi-level structural and practical (mechanical/hydrophilic) features of gelatin films by varying the konjac glucomannan (KGM) content and the film-forming temperatures (25 and 40 • C). The addition of KGM apparently improved the mechanical properties and properly increased the hydrophilicity. With the lower temperature (25 • C), the increase in KGM reduced the gelatin crystallites of films, with detectable KGM-gelatin interactions, nanostructures, and micron-scale cracks. These structural features, with increased KGM and negligibly-occurred derivatizations, caused initially an insignificant decrease and then an increase in the strength, with a generally-increased elongation. The higher temperature (40 • C) could reduce the strength and slightly increase the elongation, related to the reduced crystallites of especially gelatin. With this higher temperature, the increase in KGM concurrently increased the strength and the elongation, mainly associated with the increased KGM and crystallites. Additionally, the increase in KGM made the film more hydrophilic; the multi-scale structural changes of films did not dominantly affect the changing trend of hydrophilicity.

Sound absorption, structure and mechanical behavior of konjac glucomannan-based aerogels with addition of gelatin and wheat straw

“…For gelatin aerogel, the characteristic peak at 1632 cm − 1 is attributed to the amide I extension of C--O and the peak situated at 1538 cm − 1 can be assigned to the amide II stretching of C -N and bending of the N -H ligation. Spectral peak at 1236 cm − 1 results from the amide III (the plane vibration of C-N and N -H bond) [47]. Compared with spectrum of gelatin aerogel, some peaks of KGM/gelatin aerogels become slightly stronger and the peaks for amide I, II, and III of KGM/gelatin aerogels shift to the higher wavenumbers due to the addition of KGM.…”