Structure and physical properties of silk fibroin/polyacrylamide blend films

Abstract

This article deals with the characterization of blend films obtained by mixing silk fibroin (SF) and polyacrylamide (PAAm). The DSC curves of SF/PAAm blend films showed overlapping of the main thermal transitions characteristic of the individual polymers. The exothermic peak at 218°C, assigned to the ␤-sheet crystallization of silk fibroin, slightly shifted to a lower temperature by blending. The weightretention properties (TG) of the blend films were intermediate between those of the two constituents. The TMA response was indicative of a higher thermal stability of the blend films, even at low PAAm content (Յ25%), the final breaking occurring at about 300°C (100°C higher than pure SF film). The peak of dynamic loss modulus of silk fibroin at 193°C gradually shifted to lower temperature in the blend films, suggesting an enhancement of the molecular motion of the fibroin chains induced by the presence of PAAm. Changes in the NH stretching region of silk fibroin were detected by FTIR analysis of blend films. These are attributable to disturbance of the hydrogen bond pattern of silk fibroin and formation of new hydrogen bonds with PAAm. The values of strength and elongation at break of blend films slightly improved at 20 -25% PAAm content. A sea-island structure was observed by examining the air surface of the blend films by scanning electron microscopy.

Characterization of silk fibroin/hyaluronic acid polyelectrolyte complex (PEC) films

“…In amide I and II regions of the IR spectra of the films, instead of a single characteristic peak, bands were observed. In literature, amide I (-CO-and -CN-stretching) appeared to be in the region of 1655-1660 cm [26,33,35,36]. The appearance of strong and broad peak of SF-HA complex film (Fig.…”

“…1. In other words, the films displayed so-called sea-island morphology, which was also met in the SEM photographs of chitosan-alginate polyelectrolyte complexes [26].…”

Surface Morphology and Properties of Bombyx mori Silk Fibroin Fiber Treated with I 2-KI Aqueous Solution

“…A second large weight loss takes place in the temperature range from 270 to 400 °C. This is associated with the degradation of side chain groups of amino acid residues and the cleavage of peptide bonds [34]. After iodine treatment, the onset temperature of the second weight loss was shifted to approximately 220 °C.…”

Characterization and functions of Nano-Wool crystallites

“…Powdered silk fibroin is considered effective as an additive for cosmetic and pharmaceutical preparations because of its moderate moisture absorption and retention properties, and its high affinity for human skin and silk; actually, wool powder also preserve these virtues. Silk powder is one of the useful physical forms of silk fibroin protein, as well as fiber and film, for biomaterial applications [7,8].…”