Green and Highly Efficient Wool Keratin Extraction by Microwave Induction Method

Abstract

Keratin is a plentiful and renewable fibrous protein resource found in nature, but a great deal of keratin-containing waste causes environmental problems, especially wool waste, which accounts for the majority. A green and efficient extraction method of keratin based on microwave induction method was studied. Compared with traditional thermal induction, the extraction time was shortened by half, and the dissolution rate of the wool was improved. The effects of the above two methods on the size, structure, crystallinity, and thermal stability of wool keratin were studied by a series of analysis methods [e.g., attenuated total reflectance Fourier transform infrared spectrometry (ATR-FTIR), Raman spectroscopy, X-ray diffraction spectroscopy (XRD), dynamic light scattering (DLS), thermogravimetric analysis (TG), and so on]. The results showed that under microwave irradiation, the disulfide bonds were destroyed greatly, and the secondary structure changed significantly, which was beneficial to obtain wool keratin with low crystallinity and small particle size.

Physico-Chemical Characterization of Keratin from Wool and Chicken Feathers Extracted Using Refined Chemical Methods

“…Stretching vibrations of C=O bonds appear from 1600 to 1700 cm −1 and they are typical of the amide I band, that contains information about the secondary structure of keratin [ 27 ]. At 1520 cm −1 , the bending vibration of N-H of amide II is visible [ 28 ]. The stretching vibrations of C-N and C–H and bending vibrations of N-H and C=O at around 1220–1300 cm −1 are related to amide III.…”

Sustainable keratin recovery process using a bio-based ionic liquid aqueous solution and its techno-economic assessment

“…The diffraction peak at 10° corresponds to the protein α-helix structure, while the diffraction peak at 20° is related to the β-sheet structure of keratin, being in accordance with the literature. 50,51…”

“…The diffraction peak at 10°corresponds to the protein α-helix structure, while the diffraction peak at 20°is related to the β-sheet structure of keratin, being in accordance with the literature. 50,51 Ionic liquid recovery Regardless of the feasibility of the keratin recovery process using an aqueous solution of IL, [N 111(2OH) ][C 1 CO 2 ] recovery and reuse is as a prerequisite condition for developing a sustainable process. Accordingly, this work attempted the IL reuse in 4 cycles of dissolution with fresh biomass.…”

Biocompatible Reduced Graphene Oxide Ink Hybridized by Wool Keratin for Flexible Strain Sensor Electronics

“…According to statistics, about one million tons of coarse and short wool is directly discarded every year by the textile carding and animal husbandry processing industries, leading to a serious waste of resources and secondary pollution. As a result, the efficient and efficient utilization of waste wool has gradually become a research hotspot. − Keratin is considered a type of ideal active material in many fields because of its unique biocompatibility and biodegradability. , It is worth noting that in the field of electronic devices, unique properties of keratin have recently been revealed, indicating that keratin has great potential as a stabilizer and biocompatible agent for graphene-based ink. But at present, keratin is mostly prepared by the reduction method in this field, and the keratin prepared by this method has poor water solubility; it is difficult to prepare water-based ink without other organic additives and with high concentrations of carbon conductive materials. ,, …”