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Start Over Author "Salwa Mowafi" Journal journal of natural fibers
5 results on '"Salwa Mowafi"'

1. Benign Felt-proofing of Wool Fibers Using a Keratinolytic Thermophilic Alkaline Protease

Author

Shaymaa A. Ismail, Marwa Abou Taleb, Mohamed A. Emran, Salwa Mowafi, Amal M. Hashem, and Hosam El-Sayed

Subjects
wool, thermophilic protease, keratinolytic activity, scales, felting, dyeing, Science, Textile bleaching, dyeing, printing, etc., TP890-933
Abstract

Felting shrinkage of wool is a major problem which has negative impacts on its performance attributes. Traditional chemical methods used for shrink-resist finishing are suffering from some drawbacks. Therefore, this work aimed at the utilization of microbial protease in wet processing of wool. The bacterial strain Bacillus licheniformis ALW1 produced 52.1 U/mL enzyme activity that was thermophilic with optimum activity at pH 9. Additionally, the enzyme possessed a keratinolytic activity of 4.1 U/mL, suggesting its applicability in wool processing. Therefore, the effects of different treatment conditions; Viz. concentration of the enzyme, temperature, treatment period and pH on some of the physical and chemical characteristics of wool were studied. The felting shrinkage of wool fibers was determined using the Aachener 3-D felting machine. The influence of the enzymatic modification of wool on its dyeability with anionic dye was assessed. Chemical, physical, and mechanical properties of treated samples were evaluated using amino acid analysis, alkali solubility, Fourier Transform Infrared spectroscopy, whiteness index, and tensile properties. Scanning electron microscopy was applied for the examination of wool fibers’ surface. The results proved that the modification of wool fibers with the produced enzyme highly improved their felting resistance and dyeability with acid dye without adverse effects on its inherent properties.

Published
2022
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2. A Novel Approach towards Removal of Lipid Barrier from Wool Fibers’ Surface Using Thermophilic Lipase

Author

Hosam El-Sayed, A. F. El-Fiky, E. M. Khalil, R. A. Zaki, and Salwa Mowafi

Subjects
genetic structures, biology, Chemical engineering, Wool, Chemistry, Materials Science (miscellaneous), Thermophile, biology.protein, lipids (amino acids, peptides, and proteins), chemical and pharmacologic phenomena, Lipase, Lipid bilayer, eye diseases
Abstract

The hydrophobic nature of wool caused by the surface lipid barrier impedes any wet processes of wool fibers. The conventional methods that utilize alkaline solutions for removing this lipid layer a...

Published
2021

3. Benign Felt-proofing of Wool Fibers Using a Keratinolytic Thermophilic Alkaline Protease

Author

Hosam El-Sayed, Mohamed A. Emran, Marwa Abou Taleb, Amal M. Hashem, Salwa Mowafi, and Shaymaa A. Ismail

Subjects
Wool, Chemistry, Materials Science (miscellaneous), Thermophile, Alkaline protease, 02 engineering and technology, 010501 environmental sciences, 021001 nanoscience & nanotechnology, 0210 nano-technology, Pulp and paper industry, 01 natural sciences, 0105 earth and related environmental sciences, Shrinkage
Abstract

Felting shrinkage of wool is a major problem which has negative impacts on its performance attributes. Traditional chemical methods used for shrink-resist finishing are suffering from some drawback...

Published
2020

4. Microwave-Assisted Bleaching of Wool Fabrics

Author

Amira Abou El-Kheir, Hosam El-Sayed, Karima Haggag, and Salwa Mowafi

Subjects
Materials science, genetic structures, Scanning electron microscope, Materials Science (miscellaneous), chemical and pharmacologic phenomena, eye diseases, chemistry.chemical_compound, chemistry, Wool, Ultimate tensile strength, sense organs, Irradiation, Wetting, Solubility, Elongation, Composite material, Hydrogen peroxide
Abstract

Microwave irradiation was used to reduce consumption of energy and time during bleaching of wool fabrics with hydrogen peroxide. The effect of some reaction conditions; viz. hydrogen peroxide concentration, treatment time, presence of stabilizer, on degree of whiteness imparted to bleached wool, was studied systematically. Comparative study between bleaching of wool using microwave irradiation and conventional heating was undergone. The effect of bleaching of wool on its morphological structure was assigned by scanning electron microscopy. The change in some chemical and physicomechanical characteristics of bleached wool was monitored; namely whiteness index, alkali solubility, wettability, critical surface area, tensile strength, and elongation at break, of the treated as well as untreated fabrics were measured. The microwave-assisted bleaching of wool resulted in improved degree of whiteness comparable to that is obtained using conventional heating method. However, the microwave-assisted bleached wool s...

Published
2014

5. Electrospun Keratin/Polyvinyl Alcohol Regenerated Fibers Part 1: Preliminary Study

Author

Salwa Mowafi, Amira Abou El-Kheir, Hosam El-Sayed, and M. Abou Taleb

Subjects
chemistry.chemical_classification, Materials science, integumentary system, Materials Science (miscellaneous), Substrate (chemistry), Polyvinyl alcohol, Electrospinning, chemistry.chemical_compound, chemistry, Keratin, Polymer chemistry, medicine, Hydroxide, Triol, Swelling, medicine.symptom, Bradford protein assay, Nuclear chemistry
Abstract

Keratinous materials, namely, coarse wool or feather, were dissolved in mixture of alkali metal hydroxide or alkaline earth metal hydroxide in the presence of swelling and reducing agents. The obtained soluble keratin was mixed with polyvinyl alcohol (PVA) before being electro-spun into fibers. The protein content of the obtained composite was determined using Bradford method. Keratin/PVA (K/PVA) fibers were plasticized using aliphatic triol and cross-linked using bi-functional aldehyde. The amino acid composition in K/PVA regenerated fibers was determined. The change in the morphological structure of the said fibers relative to the starting native substrate was assigned using scanning electron microscopy. Results of this investigation clarify that the proposed method of dissolution and regeneration of keratin is suitable to obtain regenerated keratinous fibers with outstanding resistance to moth larvae attack.

Published
2013

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