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1 – 8 of 8This study aims to embed anatase, rutile and brookite TiO2 nanoparticles (NPs) with different crystal phases into cotton fabrics by epoxy silane and to examine the effect of these…
Abstract
Purpose
This study aims to embed anatase, rutile and brookite TiO2 nanoparticles (NPs) with different crystal phases into cotton fabrics by epoxy silane and to examine the effect of these applications on the photocatalytic and mechanical properties of the fabric.
Design/methodology/approach
Different aqueous dispersions which contain anatase, rutile and brookite were prepared at three different concentrations (5%, 10% and 15%). These NPs were embedded in cotton fabrics by using GPTS [(3-glycidyloxypropyl) trimethoxysilane]. Characterization tests were performed by scanning electron microscopy (SEM), Raman and Fourier-transform infrared spectroscopy (FT/IR). Samples were stained with methylene blue (MB) and then exposed to solar light for different periods. Color changes of the samples were examined with a spectrophotometer. Air permeability, abrasion and tear strength tests were applied to all samples.
Findings
According to SEM images, the NPs were successfully attached to the cotton fabrics, and epoxy silane coating surrounded the fiber surfaces. The presence of the coating was also confirmed by Raman spectroscopy and FT/IR. The treatments reduced the stainability of the samples. The most effective applications for ensuring photocatalytic activity in cotton fabrics were suspensions as 10% brookite, 10% anatase and 5% anatase, in descending order. The applied coating slightly reduced the samples’ air permeability, and wear and tear strength.
Originality/value
The importance of this study is to determine the optimal crystal phase and its concentration by using epoxy silane to ensure self-cleaning properties on cotton fabrics. The sample treated with 10% brookite is the most approached its original white color by 99.65% as a result of degradation of MB (after 120 min). On the other hand, using the pure rutile with epoxy silane was not suitable for removing MB from the fabric.
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Youssef L. Nashed, Fouad Zahran, Mohamed Adel Youssef, Manal G. Mohamed and Azza M. Mazrouaa
The purpose of this study is to examine how well reinforced concrete structures can be shielded against concrete carbonation using anti-carbonation coatings based on synthetic…
Abstract
Purpose
The purpose of this study is to examine how well reinforced concrete structures can be shielded against concrete carbonation using anti-carbonation coatings based on synthetic polymer.
Design/methodology/approach
Applying free radical polymerization, an acrylate terpolymer emulsion that a surfactant had stabilized was created. A thermogravimetric analysis, minimum film-forming temperature, Fourier transform infrared spectroscopy and particle size distribution are used to characterize the prepared eco-friendly water base acrylate terpolymer emulsion. Using three different percentages of the acrylate terpolymer emulsion produced, 35%, 45% and 55%, the anti-carbonation coating was formed. Tensile strength, tensile strain, elongation, crack-bridging ability, carbon dioxide permeability, chloride ion diffusion, average pull-off adhesion strength, water vapor transmission, gloss, wet scrub resistance, QUV/weathering and storage stability are the characteristics of the anti-carbonation coating.
Findings
The formulated acrylate terpolymer emulsion enhances anti-carbonation coating performance in CO2 permeability, Cl-diffusion, crack bridging, pull-off adhesion strength and water vapor transmission. The formed coating based on the formulated acrylate terpolymer emulsion performed better than its commercial counterpart.
Practical implications
To protect the steel embedded in concrete from corrosion and increase the life span of concrete, the surface of cement is treated with an anti-carbonation coating based on synthetic acrylate terpolymer emulsion.
Social implications
In addition to saving lives from building collapse, it maintains the infrastructure for the long run.
Originality/value
The anti-carbonation coating, which is based on the synthetic acrylate terpolymer emulsion, is environmentally benign and stops the entry of carbon dioxide and chlorides, which are the main causes of steel corrosion in concrete.
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Sampson Kofi Kyei, William Iheanyi Eke, Godfred Darko and Onyewuchi Akaranta
This study aims to synthesize pigment and resin from agro-wastes and use them in the formulation of eco-friendly surface coatings.
Abstract
Purpose
This study aims to synthesize pigment and resin from agro-wastes and use them in the formulation of eco-friendly surface coatings.
Design/methodology/approach
The pigments and resin were synthesized through a chemical modification of agro-wastes. The pigments were characterized by infrared spectroscopy (FTIR) and were screened for their antimicrobial activities. The physicochemical characteristics of the cashew nutshell liquid (CNSL)-modified resin were evaluated. These precursors and other natural additives were used to formulate surface coatings, and their drying and adhesive properties were evaluated using international testing methods.
Findings
It was observed that the curing of the CNSL-modified resin depended on time and temperature. The pigments exhibited antimicrobial activity against E. coli and S. aureus and had high melting points, affirming their stability. The chemically modified precursors successfully yielded surface coatings with acceptable drying times and adhesion to the base substrate.
Practical implications
The use of agro-wastes as the main components of the surface coatings implies waste valorization, a reduction in production costs and the creation of job opportunities for sustainable development. To increase the chemical, physical, corrosion resistance and antimicrobial qualities of paint compositions, chemically modified peanut skin extracts and CNSL can be used as pigments and resins, respectively. This could be a green approach to achieving the targets of Sustainable development goals 11 and 12.
Originality/value
The paper outlines a prospective approach to use unwanted waste (peanut skin, cashew nutshells) and other natural additives as industrial raw materials. These novel surface coating precursors are cost-effective, readily available, eco-friendly and could replace conventional precursors.
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H. Abd El-Wahab and Raafat A. El-Eisawy
This paper aims to prepare new modified alkyd resins and use it as an antimicrobial binder for surface coating applications.
Abstract
Purpose
This paper aims to prepare new modified alkyd resins and use it as an antimicrobial binder for surface coating applications.
Design/methodology/approach
Various modified alkyd resins were prepared by partial replacement of 3,6-dichloro benzo[b]thiophene-2-carbonyl bis-(2-hydroxy ethyl)-amide as a source of polyol with glycerol and confirmed by acid value, FT-IR, 1H-NMR. The modified alkyd resins were covering a wide range of oil lengths and hydroxyl content (0%, 10%, 20% and 30% excess-OH). The antimicrobial activity of the prepared alkyds was also investigated. The coatings of 60 ± 5 µm thickness were applied to the surface of glass panels and mild steel strips by means of a brush. Physico-mechanical tests, chemical resistance and antimicrobial activities were investigated.
Findings
The obtained results illustrate that the introduction of benzo[b]thiophene derivative as a modifier polyol within the resin structure improved the film performance and enhanced the physico-mechanical characteristics, chemical resistance and the antimicrobial activities.
Practical implications
The modified alkyd resins can be employed as antimicrobial binders in paint compositions for a variety of surfaces, particularly those that are susceptible to a high number of bacteria.
Originality/value
Modified alkyd resins based on antimicrobial heterocyclic compounds have the potential to be promising in the manufacturing of antimicrobial coatings and development of paints, allowing them to function to prevent the spread of microbial infection, which is exactly what the world requires at this time. Also, they can be applied in different substrates for industrial applications.
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Yang Liu, Qian Zhang, Jialing Wang, Yawei Shao, Zhengyi Xu, Yanqiu Wang and Junyi Wang
The purpose of this paper is to enhance the compatibility of titanium dioxide in epoxy resins and thus the corrosion resistance of the coatings.
Abstract
Purpose
The purpose of this paper is to enhance the compatibility of titanium dioxide in epoxy resins and thus the corrosion resistance of the coatings.
Design/methodology/approach
In this work, TiO2 was modified by the mechanochemistry method where mechanical energy was combined with thermal energy to complete the modification. The stability of modified TiO2 in epoxy was analyzed by sedimentation experiment. The modified TiO2-epoxy coating was prepared, and the corrosion resistance of the coating was analyzed by open circuit potential, electrochemical impedance spectroscopy and neutral salt spray test.
Findings
High-temperature mechanical modification can improve the compatibility of TiO2 in epoxy resin. At the same time, the modified TiO2-epoxy coating showed better corrosion resistance. Compared to the unmodified TiO2-epoxy coating, the coating improved the dry adhesion force by 61.7% and the adhesion drop by 33.3%. After 2,300 h of immersion in 3.5 Wt.% NaCl solution, the coating resistance of the modified TiO2 coating was enhanced by nearly two orders of magnitude compared to the unmodified coating.
Originality/value
The authors have grafted epoxy molecules onto TiO2 surfaces using a high-temperature mechanical force modification method. The compatibility of TiO2 with epoxy resin is enhanced, resulting in improved adhesion of the coating to the substrate and corrosion resistance of the coating.
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Roma G. Elfadel, Hala M. Refat, H. Abdelwahab, Salem S. Salem, Mohamed A. Awad and M.A.M. Abdel Reheim
This paper aims to investigate the prepared modified alkyd and poly(ester-amide) (PEA) resins as antimicrobial and insecticide binders for surface coating applications.
Abstract
Purpose
This paper aims to investigate the prepared modified alkyd and poly(ester-amide) (PEA) resins as antimicrobial and insecticide binders for surface coating applications.
Design/methodology/approach
Salicylic diethanolamine and 4-(N, N-dimethylamino) benzylidene glutamic acid were prepared and used as new sources of polyol and dibasic acid for PEA and alkyd resins, then confirmed by: acid value, FT-IR and 1H-NMR. The coating performance of the resins was determined using measurements of physico-mechanical properties. The biological and insecticide activities of the prepared resins were investigated.
Findings
The tests carried out revealed that the modified PEA and alkyd enhanced both phyisco-mechanical and chemical properties in addition to the biological and insecticide activities. The results of this paper illustrate that the introduction of salicylic diethanolamine and 4-(N, N-dimethylamino) benzylidene glutamic acid within the resin structure improved the film performance and enhanced the antimicrobial activity performance of PEA and alkyd resins.
Research limitations/implications
The modified alkyd and PEA organic resins can be used as biocidal binders when incorporated into paint formulations for multiple surface applications, especially those that are exposed to several organisms.
Originality/value
Modified alkyd and PEA resins based on newly synthesized modifiers have a significant potential to be promising in the production and development of antimicrobial and insecticide paints, allowing them to function to restrict the spread of insects and microbial infection.
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Xingxing Li, Shixi You, Zengchang Fan, Guangjun Li and Li Fu
This review provides an overview of recent advances in electrochemical sensors for analyte detection in saliva, highlighting their potential applications in diagnostics and health…
Abstract
Purpose
This review provides an overview of recent advances in electrochemical sensors for analyte detection in saliva, highlighting their potential applications in diagnostics and health care. The purpose of this paper is to summarize the current state of the field, identify challenges and limitations and discuss future prospects for the development of saliva-based electrochemical sensors.
Design/methodology/approach
The paper reviews relevant literature and research articles to examine the latest developments in electrochemical sensing technologies for saliva analysis. It explores the use of various electrode materials, including carbon nanomaterial, metal nanoparticles and conducting polymers, as well as the integration of microfluidics, lab-on-a-chip (LOC) devices and wearable/implantable technologies. The design and fabrication methodologies used in these sensors are discussed, along with sample preparation techniques and biorecognition elements for enhancing sensor performance.
Findings
Electrochemical sensors for salivary analyte detection have demonstrated excellent potential for noninvasive, rapid and cost-effective diagnostics. Recent advancements have resulted in improved sensor selectivity, stability, sensitivity and compatibility with complex saliva samples. Integration with microfluidics and LOC technologies has shown promise in enhancing sensor efficiency and accuracy. In addition, wearable and implantable sensors enable continuous, real-time monitoring of salivary analytes, opening new avenues for personalized health care and disease management.
Originality/value
This review presents an up-to-date overview of electrochemical sensors for analyte detection in saliva, offering insights into their design, fabrication and performance. It highlights the originality and value of integrating electrochemical sensing with microfluidics, wearable/implantable technologies and point-of-care testing platforms. The review also identifies challenges and limitations, such as interference from other saliva components and the need for improved stability and reproducibility. Future prospects include the development of novel microfluidic devices, advanced materials and user-friendly diagnostic devices to unlock the full potential of saliva-based electrochemical sensing in clinical practice.
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Hakan Karaosman, Donna Marshall and Verónica H. Villena
The purpose of this paper is to understand how supply chain actors in an Italian cashmere supply chain reacted to dependence and power use during the Covid-19 crisis and how this…
Abstract
Purpose
The purpose of this paper is to understand how supply chain actors in an Italian cashmere supply chain reacted to dependence and power use during the Covid-19 crisis and how this affected their perceptions of justice.
Design/methodology/approach
The research took a case study approach exploring issues of dependence, power and justice in a multi-tier luxury cashmere supply chain.
Findings
The authors found two types of dependence: Craftmanship-induced buyer dependence and Market-position-induced supplier dependence. The authors also identified four key archetypes emerging from the dynamics of dependence, power and justice during Covid-19. In the repressive archetype, buying firms perceive their suppliers as dependent and use mediated power through coercive tactics, leading the suppliers to perceive interactional, procedural and distributive injustice and use reciprocal coercive tactics against the buying firms in the form of coopetition. In the restrictive archetype, buying firms that are aware of their dependence on their suppliers use mediated power through contracts, with suppliers perceiving distributive injustice and developing ways to circumvent the brands. In the relational archetype, the awareness of craftmanship-induced buyer dependence leads buying firms to use non-mediated power through collaboration, but suppliers still do not perceive distributive justice, as there is no business security or future orders. In the resilient archetype, buying firms are aware of their own craftmanship-induced dependence and combine mediated and non-mediated power by giving the suppliers sustainable orders, which leads suppliers to perceive each justice type positively.
Originality/value
This paper shows how the actors in a specific supply chain react to and cope with one of the worst health crises in living memory, thereby providing advice for supply chain management in future crises.
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