Silk-Cellulose Acetate Biocomposite Materials Regenerated from Ionic Liquid

Abstract

The novel use of ionic liquid as a solvent for biodegradable and natural organic biomaterials has increasingly sparked interest in the biomedical field. As compared to more volatile traditional solvents that rapidly degrade the protein molecular weight, the capability of polysaccharides and proteins to dissolve seamlessly in ionic liquid and form fine and tunable biomaterials after regeneration is the key interest of this study. Here, a blended system consisting of Bombyx Mori silk fibroin protein and a cellulose derivative, cellulose acetate (CA), in the ionic liquid 1-ethyl-3-methylimidazolium acetate (EMIMAc) was regenerated and underwent characterization to understand the structure and physical properties of the films. The change in the morphology of the biocomposites (by scanning electron microscope, SEM) and their secondary structure analysis (by Fourier-transform infrared spectroscopy, FTIR) showed that the samples underwent a wavering conformational change on a microscopic level, resulting in strong interactions and changes in their crystalline structures such as the CA crystalline and silk beta-pleated sheets once the different ratios were applied. Differential scanning calorimetry (DSC) results demonstrated that strong molecular interactions were generated between CA and silk chains, providing the blended films lower glass transitions than those of the pure silk or cellulose acetate. All films that were blended had higher thermal stability than the pure cellulose acetate sample but presented gradual changes amongst the changing of ratios, as demonstrated by thermogravimetric analysis (TGA). This study provides the basis for the comprehension of the protein-polysaccharide composites for various biomedical applications.

Valorization of chicken feathers using aqueous solutions of ionic liquids

“…The ILs selected comprise a combination of different cations and anions, taking into consideration the ILs that have been reported in the literature for the effective dissolution of different biopolymers from biomass. 29,31,[34][35][36][37] Nevertheless, to the best of our knowledge, the selected ILs have so far not been evaluated for chicken feather dissolution. The dissolution assays were carried out at 100 °C for 4 h in a solid : liquid (chicken feathers : solvent) ratio of 1 : 20 w/w in a carrousel (Carousel Tech, Radleys).…”

Application of Thermal Analysis to Evaluate Pharmaceutical Preparations Containing Theophylline

“…This is evidenced by a small peak on the DTG curves with the maximum mass loss at 351.8 °C and 355 °C for 300 mg and 200 mg dose of drug, respectively ( Figure 5 ). The maximum mass loss compared in literature for microcrystalline cellulose is 357 °C [ 29 ], methyl cellulose is 359 °C [ 30 ], cellulose acetate is 220 °C [ 31 ], and carboxymethyl cellulose is 280 °C [ 32 ]. Analysis indicates that microcrystalline cellulose and methyl cellulose make up the largest contribution to this peak due to the value of the maximum mass loss temperature.…”

Strength Enhancement of Regenerated Cellulose Fibers by Adjustment of Hydrogen Bond Distribution in Ionic Liquid

“…The temperature of beginning of weight loss, maximum rate of weight loss and glass transition was obtained. The glass transition temperature was calculated according to the literature method [ 30 ].…”