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1 – 5 of 5Khaled Mostafa, Khaled Elnagar and Azza El-Sanabary
This study aims to describe the conversion of rice straw (RS) as an agricultural plant waste to high-performance cationic flocculant for kaolin clay suspension in wastewater…
Abstract
Purpose
This study aims to describe the conversion of rice straw (RS) as an agricultural plant waste to high-performance cationic flocculant for kaolin clay suspension in wastewater treatment as an alternative to synthetic ones.
Design/methodology/approach
This was done by grafting rice straw after pretreatment with acrylamide (Aam) using microwave irradiation technique without using an initiator in an open vessel container for wastewater treatment. Radiation time, monomer and rice straw pulp concentration as well as microwave power were scrutinized to examine their impact on maximizing the graft yield %. Application of the resultant copolymers as flocculants for kaolin clay suspension was willful by studying the foremost influences inducing the flocculation process, for instance, flocculent dose, pH, stirring speed and extent of grafting.
Findings
It is seen from the obtained results that both FTIR, SEM, X-Ray diffraction, Thermo gravimetric analysis and Zeta potential confirmed the formation of the cationic amide group onto the graft copolymer chain in comparison with the ungrafted one; the microwave initiation method proved to be a very efficient tool concerning maximizing the graft yield % with no harsh chemicals used for initiating grafting; the flocculation efficiency of the prepared copolymers augmented by increasing the flocculant dose, pH and stirring speed to a maximum value signified at 2.0 g, 6.0 and 75 r/min, respectively, then decreased thereafter while increased by increasing the extent of grafting within the range studied; the flocculant reserved high flocculation efficiency even after five cycles of flocculation/regeneration; preliminary bridging mechanism demonstrating the attraction between the kaolin anionic suspended particles and cationic poly (Aam)-rice straw graft copolymer has been predicted.
Originality/value
The novelty addressed here is undertaken by preparing a very efficient cationic flocculant using rice straw waste with different degrees of grafting for the treatment of wastewater using this kind of microwave irradiation approach as an eco-friendly tool. As far as the authors are aware, no thorough investigation has been done in the literature until now dealing with the above-mentioned preparation process.
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Khaled Mostafa, Nader Abdelaziz and Azza El-Sanabary
The purpose of this study is to undertake surface graft copolymerization of viscose fabric via altering its fibrous properties by using acrylic acid (AA) as a carboxyl-containing…
Abstract
Purpose
The purpose of this study is to undertake surface graft copolymerization of viscose fabric via altering its fibrous properties by using acrylic acid (AA) as a carboxyl-containing monomer and peroxydisulfate (PDS) in presence of ferrous sulfate as a novel redox pair for initiating grafting. The latter process acted as an energy-saving process with respect to the reduction in polymerization temperature and maximizing the graft yield %, in addition to rendering the grafted viscose fabrics dye-able with cationic dye (crystal violet), which has frequently no direct affinity to fix on fabric.
Design/methodology/approach
To make graft copolymerization more efficient and economic, the optimum conditions for graft copolymerization were established. The graft yield % was determined as a function of initiator, catalyst and monomer concentrations and the material to liquor ratio, in addition to polymerization time and temperatures. Metrological characterizations via Fourier transform infrared spectroscopy and scanning electron microscopy of topographic morphological surface change have also been established in comparison with the ungrafted samples.
Findings
The maximum graft yield of 70.6% is obtained at the following optimum conditions: monomer (150 % based on the weight of fabric), PDS (50 m mole), ferrous sulfate (80 m mole) and sulfuric acid (30 m mole) at 40° C for 1.5 h using a liquor ratio of 30. Remarkably, grafting with AA enabled a multifold upsurge in color strength, with improvements in the fastness properties of cationically dyed grafted viscose fabric measured on the blue scale in comparison with untreated viscose fabric.
Originality/value
The novelty addressed here is undertaken with studying the effect of altering the extent of grafting of poly (AA)-viscose graft copolymers expressed as graft yield % in addition to carboxyl contents on cationic dyeing of viscose fabric for the first time in the literature. Moreover, rendering the viscose fabrics after grafting is dye-able with cationic dye with high brilliance of shades, which has regularly no direct affinity to fix on this type of fabrics.
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Khaled Mostafa, Heba Ameen and Ahmed Medhat
The purpose of this paper is to generate nitrogen-containing groups in the cotton fabric surface via low-temperature nitrogen plasma as an eco-friendly physical/zero-effluent…
Abstract
Purpose
The purpose of this paper is to generate nitrogen-containing groups in the cotton fabric surface via low-temperature nitrogen plasma as an eco-friendly physical/zero-effluent process. This was done for rendering cotton dye-able with Acid Blue 284, which in fact does not have any direct affinity to fix on it.
Design/methodology/approach
Dyeing characteristics of the samples such as color strength (K/S), fastness properties to light, rubbing and perspiration and durability, as well as tensile strength, elongation at break, whiteness, weight loss and wettability in addition to zeta potential of the dyed samples, were determined and compared with untreated fabric. Confirmation and characterization of the plasma-treated samples via chemical modifications and zeta potential was also studied using Fourier transform infrared spectroscopy (FTIR) and Malvern Zetasizer instrumental analysis.
Findings
The obtained results of the plasma-treated fabric reflect the following findings: FTIR results indicate the formation of nitrogen-containing groups on cotton fabrics; notable enhancement in the fabric wettability, zeta potential to more positive values and improvement in the dyeability and overall fastness properties of treated cotton fabrics in comparison with untreated fabric; the tensile strength, elongation at break, whiteness and weight % of the plasma treated fabrics are lower than that untreated one; and the durability of the plasma treated fabric decreased with increasing the number of washing cycles.
Originality/value
The novelty addressed here is rendering cotton fabrics dye-able with acid dye via the creation of new cationic nitrogen-containing groups on their surface via nitrogen plasma treatment as an eco-friendly and efficient tool with a physical/zero-effluent process.
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Saima Habib, Zulfiqar Ali Raza, Farzana Kishwar and Sharjeel Abid
This paper aims to develop an indigo-dyed denim fabric treated with a nanosilver colloid in the presence of a natural crosslinker of citric acid for possible surgical gown…
Abstract
Purpose
This paper aims to develop an indigo-dyed denim fabric treated with a nanosilver colloid in the presence of a natural crosslinker of citric acid for possible surgical gown fabrication applications.
Design/methodology/approach
A bleached denim fabric was dyed with the sustainable indigo dye followed by silver nanofinishing through citric acid crosslinking under the pad-dry-cure method. The prepared denim samples were analyzed for chemo-physical, textile, dyeing, antibacterial and finish release properties.
Findings
The results demonstrated that the comfort and textile characteristics of nanosilver-treated/indigo-dyed cellulosic fabric were affected due to the crosslinking, surface amphiphilicity and air permeability. These properties were, still, in the acceptable range for the fabrication of naturally dyed and antibacterial nanofinished denim gowns.
Practical implications
The dyeing of denim with synthetic dyes may cause harmful effects on the skin and health of the wearer, and the authors present an eco-friendly sustainable approach.
Originality/value
The authors used the fabric substrate, natural indigo dye and reducing/crosslinker agent of citric acid, all being bio-based, in the fabrication of antibacterial dyed fabric for health care garments.
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Sally Elkatatny, Lamiaa Zaky, Walaa Abdelaziem and Aliaa Abdelfatah
This study aims to investigate the corrosion behavior of cold-rolled Fe35Ni20Cr12Mn(28-x)Alx high-entropy alloys (HEAs) using the potentiodynamic polarization technique in 1 M H2SO…
Abstract
Purpose
This study aims to investigate the corrosion behavior of cold-rolled Fe35Ni20Cr12Mn(28-x)Alx high-entropy alloys (HEAs) using the potentiodynamic polarization technique in 1 M H2SO4 acid. Additionally, the influence of molybdenum (Mo) additions as inhibitors and the effect of variations in cold rolling reduction ratios and Al content on corrosion behavior are examined.
Design/methodology/approach
Two cold rolling reduction ratios, namely, 50% (R50) and 90% (R90), were examined for the cold-rolled Fe35Ni20Cr12Mn28Al5 (Al5) and Fe35Ni20Cr12Mn23Al10 (Al10) HEAs. Mo inhibitor additions were introduced at varying concentrations of 0.3, 0.6 and 0.9 Wt.%. The potentiodynamic polarization technique was used to evaluate the corrosion rates (CRs) under different experimental conditions.
Findings
The results indicate that the addition of 0.3 Wt.% Mo in 1 M H2SO4 yielded the lowest CR for both R50 and R90, irrespective of the Al content in the HEAs. However, the highest CR was observed at 0.6 Wt.% Mo addition. Furthermore, increasing the concentration of Al resulted in a corresponding rise in the CR. Comparatively, the CR decreased significantly when the cold rolling reduction ratio increased from R50 to R90.
Originality/value
This research provides valuable insights into the intricate relationship between Mo inhibitors, cold rolling reduction ratio, Al content and the resulting corrosion behavior of Fe35Ni20Cr12Mn(28-x)Alx HEAs. The comprehensive analysis of corroded HEAs, including surface morphology, compositions and elemental distribution mapping, contributes to the understanding of the corrosion mechanisms and offers potential strategies for enhancing the corrosion behavior of HEAs.
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