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1 – 10 of 685Mudasir Peerzada, Khan Adnan, Basrah Bilal, Riyaz Janees, Bazila Qazi and Naqash Ahmed Javed
The purpose of this paper is to study the effect of nano alumina (Al2O3) on the properties of fresh concrete, hardened concrete and microstructure of concrete incorporated with…
Abstract
Purpose
The purpose of this paper is to study the effect of nano alumina (Al2O3) on the properties of fresh concrete, hardened concrete and microstructure of concrete incorporated with high range water reducer (HRWR). This initiative was taken to improve characteristic properties of concrete using nano alumina because nano alumina can be easily be manufactured from a scrap of industrial aluminum products, so its incorporation in concrete will not only reduce industrial aluminum waste but will also change the morphology of concrete at the microstructural level.
Design/methodology/approach
To accomplish the objectives of the research, four different concrete mixes with the constant water–cement ratio (W/C) and superplasticizer (SP) content 0.4 and 0.6% by weight of cement, respectively, were prepared, whereas nano alumina content was altered by 0.3% and 0.4% by weight of cement. Fresh property of concrete was analyzed by using slump cone test, whereas hardened properties of concrete were analyzed through compression test and flexural strength test. The interaction of nano alumina with concrete composite was evaluated using an X-ray diffraction test.
Findings
It was observed that 0.6% superplasticizer by weight of cement increased workability by 22% but with the addition of 0.3%, nano alumina by weight of cement workability decreased by 31%. Compressive strength increased by 4.88% with the addition of 0.6% superplasticizer but with the addition of 0.3% nano alumina by weight of cement compressive strength increased by 18.60%. Also, flexural strength increased by 1.21% with the addition of 0.6% superplasticizer by weight of cement but with the addition of 0.3% nano alumina by weight of cement flexural strength increased by 8.76%. With the addition of superplasticizer, alite and belite phases remained un-hydrated but with the addition of nano alumina alite phase was hydrated while belite phase was un-hydrated. The size of belite crystals in mixes having nano alumina was less than that of mix having 0.6% superplasticizer. Also with the addition of nano alumina, a calcium aluminum silicate phase was formed which was responsible for the increment of strength in mixes having nano alumina.
Originality/value
Incorporation nano alumina (Al2O3) in concrete will not only reduce industrial aluminum waste but will also reduce CO2 emission. Nano alumina (Al2O3) also changes morphology of concrete at micro structural level.
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Rania Abdel Gwad Eloriby and Hamdy Mohamed Mohamed
This study aims to assess the efficacy of nano-alumina (nano-Al2O3) in improving the performance of epoxy adhesives used to assemble archaeological glass. The conservators face a…
Abstract
Purpose
This study aims to assess the efficacy of nano-alumina (nano-Al2O3) in improving the performance of epoxy adhesives used to assemble archaeological glass. The conservators face a significant problem in assembling this type of artifact. Therefore, the assembling process is considered one of the important stages that must be taken care of to preserve these artifacts from damage and loss.
Design/methodology/approach
To evaluate the stability of adhesives, the samples were subjected to artificial aging under varying environmental conditions. Some investigative techniques and mechanical testing were used in this study to evaluate the selected materials. It includes a transmission electron microscope, X-ray diffraction, visual assessment, digital microscope, scanning electron microscopy (SEM), color change and tensile strength test.
Findings
The visual evaluation and the digital microscope results showed that the epoxy/nano-Al2O3 greatly resisted artificial aging. Although slight yellowing was present, it did not significantly affect the general appearance of the samples. On the other hand, the pure epoxy sample showed cracks of different sizes on its surface due to aging, as evidenced by SEM examination. Furthermore, epoxy/nano-Al2O3 has a better tensile strength (11.27 MPa) and slight color change (ΔE = 2.06).
Originality/value
The main objective of the experimental study was to identify appropriate adhesive materials that possess key properties such as non-yellowing and improved tensile strength by conducting various tests and evaluations. Ultimately, the goal was to identify materials that could serve as effective adhesives for assembling the archaeological glass.
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Refaie Omar, Elsayed Oraby, Yasser Abdelrhman and Mohammed Aboraia
The ability to produce a uniform composition, high corrosion resistance with a hard coating layer during the electroless coating techniques are mainly based on the plating bath…
Abstract
Purpose
The ability to produce a uniform composition, high corrosion resistance with a hard coating layer during the electroless coating techniques are mainly based on the plating bath composition. The complexing agent is one of the most important components that control the coating layer properties. This paper aims to investigate the effect of the glycine as a complex agent on the surface and corrosion properties of Ni-P and Ni-P/Al2O3 electroless coating.
Design/methodology/approach
In this study, the effect of glycine as a complexing agent on the final surface and corrosion properties of the Ni-P and Ni-P/Al2O3 coatings has been investigated. The surface morphology and composition of the coated samples were investigated by scanning electron microscope (SEM) imaging and energy dispersive x-ray spectroscopy (EDS) analysis. Linear polarization scan and electrochemical impedance spectroscopy techniques were used to investigate the corrosion properties of the coating layer.
Findings
The results clarify that, glycine has a remarkable effect on the porosity content of Ni-P and Ni-P/Al2O3. It was found that increasing of glycine concentration results in higher porosity content in the coating layers. Also, the porosity in the coating layers minimizes the protectability of the coating against corrosion. The results also show that adding nano-alumina (Al2O3) to the coating path has improved the corrosion properties by decreasing the porosity in the coating layer. The scanning electron microscope (SEM) images showed that the concentration of glycine affects the content and distribution of alumina nanoparticles embedded in the coating layer. Also, it was observed that using a high concentration of glycine (0.4 M glycine), the alumina tends to agglomerate and the final alumina content in the coating was decreased.
Originality/value
The present study reveals that the quality of the final coating plays a major role in the corrosion performance of the steel substrate. The coating quality can by improve remarkably by optimization of the complexing agent used in the plating bath, to minimize the porosity involve in the coating layer.
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Xiaoxuan Lin, Xiong Sang, Yuyan Zhu and Yichen Zhang
This paper aims to investigate the preparation of AlN and Al2O3, as well as the effect of nano-AlN and nano-Al2O3, on friction and wear properties of copper-steel clad plate…
Abstract
Purpose
This paper aims to investigate the preparation of AlN and Al2O3, as well as the effect of nano-AlN and nano-Al2O3, on friction and wear properties of copper-steel clad plate immersed in the lubricants.
Design/methodology/approach
Nano-AlN or nano-Al2O3 (0.1, 0.2, 0.3, 0.4 and 0.5 Wt.%) functional fluids were prepared. Their tribological properties were tested by an MRS-10A four-ball friction tester and a ball-on-plate configuration, and scanning electron microscope observed the worn surface of the plate.
Findings
An increase in nano-AlN and Al2O3 content enhances the extreme pressure and anti-wear performance of the lubricant. The best performance is achieved at 0.5 Wt.% of nano-AlN and 0.3 Wt.% of nano-Al2O3 with PB of 834 N and 883 N, a coefficient of friction (COF) of approximately 0.07 and 0.06, respectively. Furthermore, the inclusion of nano-AlN and nano-Al2O3 particles in the lubricant enhances its extreme pressure performance and reduces wear, leading to decreased wear spot depth. The lubricating effect of the nano-Al2O3 lubricant on the surface of the copper-steel composite plate is slightly superior to that of the nano-AlN lubricant, with a COF reaching 0.07. Both lubricants effectively fill and lubricate the holes on the surface of the copper-steel composite plate.
Originality/value
AlN and Al2O3 as water-based lubricants have excellent lubrication performance and can reduce the COF. It can provide some reference for the practical application of nano-water-based lubricants.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2023-0255/
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This contribution aims to introduce an effective low cost polymer-nanocomposite for possible application to achieve a super protection for highly damaged ancient Egyptian wall…
Abstract
Purpose
This contribution aims to introduce an effective low cost polymer-nanocomposite for possible application to achieve a super protection for highly damaged ancient Egyptian wall paintings.
Design/methodology/approach
SiO2 and Al2O3 nanoparticles were synthesized by the sol-gel method. Then, the polymer-nanocomposite was prepared by simple mixing and dispersing the nanoparticles into the tetraethoxysilane polymer solution, with the aid of an ultrasonic dismembrator. The application of the polymer-nanocomposite and other polymeric nanodispersions, on laboratory models, was performed by the brushing technique. Next, the materials stability was evaluated by means of digital optical microscope, colorimetry, FE-scanning electron microscope, measuring the static contact angle and water absorption rates.
Findings
The results were promising in creating a superhydrophobicity and the static contact angle (?S) measured for the polymer-nanocomposite reached 135o. An average of three measurements of the water absorption rate after polymer-nanocomposite treatment was 0.66 g/m2 s, compared to 2.60 g/m2 s for the control model (untreated). Further, an average of color difference (?E*) for the treated surface was 2.78, and after the accelerated thermal aging was 3.6. Observing the surface morphology, the polymer-nanocomposite enhanced the roughness of the treated surface and showed a high resistance to laboratory salt weathering.
Practical implications
Preparation of a polymer-nanocomposite by adding SiO2 and Al2O3 NPs to tetraethoxysilane polymer has been proposed. As a promising conservation material, the produced polymer-nanocomposite helped to form an efficient protective film.
Originality/value
This paper attains to develop an economic polymer-nanocomposite to maintain a high protection to damaged ancient Egyptian wall paintings and similar objects.
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Bahareh Nikmehr, Bidur Kafle and Riyadh Al-Ameri
This study aimed to review various existing methods for improving the quality of recycled concrete aggregates (RCAs) as a possible substitution for natural aggregates (NAs) in…
Abstract
Purpose
This study aimed to review various existing methods for improving the quality of recycled concrete aggregates (RCAs) as a possible substitution for natural aggregates (NAs) in concrete. It is vital as the old paste attached to the RCA weakens its structure. It is due to the porous structure of the RCA with cracks, weakening the interfacial transition zone (ITZ) between the RCA and binding material, negatively impacting the concrete's properties. To this end, various methods for reinforcement of the RCA, cleaning the RCA's old paste and enhancing the quality of the RCA-based concrete without RCA modification are studied in terms of environmental effects, cost and technical matters. Furthermore, this research sought to identify gaps in knowledge and future research directions.
Design/methodology/approach
The review of the relevant journal papers revealed that various methods exist for improving the properties of RCAs and RCA-based concrete. A decision matrix was developed and implemented for ranking these techniques based on environmental, economic and technical criteria.
Findings
The identified methods for reinforcement of the RCA include accelerated carbonation, bio deposition, soaking in polymer emulsions, soaking in waterproofing admixture, soaking in sodium silicate, soaking in nanoparticles and coating with geopolymer slurry. Moreover, cleaning the RCA's old paste is possible using acid, water, heating, thermal and mechanical treatment, thermo-mechanical and electro-dynamic treatment. Added to these treatment techniques, using RCA in saturated surface dry (SSD) mixing approaches and adding fibres or pozzolana enhance the quality of the RCA-based concrete without RCA modification. The study ranked these techniques based on environmental, economic and technical criteria. Ultimately, adding fibres, pozzolana and coating RCA with geopolymer slurry were introduced as the best techniques based on the nominated criteria.
Practical implications
The study supported the need for better knowledge regarding the existing treatment techniques for RCA improvement. The outcomes of this research offer an understanding of each RCA enrichment technique's importance in environmental, economic and technical criteria.
Originality/value
The practicality of the RCA treatment techniques is based on economic, environmental and technical specifications for rating the existing treatment techniques.
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Xinlong Wei, Erguang Fu, Aolin Ban, Wy Zhu, Dl Wu, N. Li and C. Zhang
The purpose of this paper is to investigate the effect of nano-alumina sealant sealing treatment on corrosion behavior of the Fe-based amorphous coatings deposited on 304…
Abstract
Purpose
The purpose of this paper is to investigate the effect of nano-alumina sealant sealing treatment on corrosion behavior of the Fe-based amorphous coatings deposited on 304 stainless steel plates by atmospheric plasma spraying (APS) with different hydrogen flow rates.
Design/methodology/approach
The surface morphology and microstructure of the unsealed and sealed coatings were characterized by scanning electron microscopy and X-ray diffraction. The corrosion resistance of the coatings was investigated by potentiodynamic polarization test and electrochemical impedance spectroscopy experiment in 3.5 Wt.% NaCl solution.
Findings
Results show that a few microcracks and pores exist in the as-sprayed Fe-based amorphous coatings. The pores on the surface of the coatings after sealing treatment have been filled with nano-alumina sealant, which can effectively prevent corrosive medium from entering into coatings. Electrochemical tests results show that the corrosion resistance of the coatings before sealing treatment decreases with the increase of hydrogen flow rate and is significantly improved by sealing treatment.
Originality/value
The effect of nano-alumina sealant sealing treatment on corrosion resistance of APS-sprayed Fe-based amorphous coatings is revealed. The corrosion resistance of the as-sprayed Fe-based amorphous coating can be significantly improved by nano-alumina sealant sealing treatment because of the blocking effect of nano-alumina sealant on corrosive medium, which confirms that the application of nano-alumina sealant sealing treatment is of a practical option to improve corrosion resistance of as-sprayed thermal sprayed coatings.
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Ebrahim Yousefi, Morteza Adineh and Mohammad Bagher Askari
The purpose of this paper is to fabricate zirconia-nano alumina porous nanocomposites with different amount of alumina (0-30 Wt.%). Specimens were prepared by solid state…
Abstract
Purpose
The purpose of this paper is to fabricate zirconia-nano alumina porous nanocomposites with different amount of alumina (0-30 Wt.%). Specimens were prepared by solid state sintering method at different temperature (1,400-1,700°C).
Design/methodology/approach
Effects of processing temperature and amount of alumina on microstructure, distribution of nanoparticles, flexural and compressive strengths, micro-hardness and densification were investigated.
Findings
Results indicated that interpenetration of particles and their contacts increased by increasing sintering temperature. As a consequence of better particles contacts and microstructure coarsening, the porosity decreased. As alumina nanoparticles content increased, the amount of porosity decreased conversely and distribution of pores become more uniform. Simultaneous enhancement of temperature and alumina nanoparticles content caused an improvement of flexural and compressive strengths because of an improvement of sintering process resulted from porosity reduction. Increase in hardness and density were observed as porosity values diminished and alumina nanoparticles were distributed well at micro zirconia grain boundaries as a result of increasing the process temperature.
Originality/value
This article contains original research.
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Abstract
Purpose
The purpose of this paper is to synthesise and characterise nano‐alumina hybrid polyimide (PI) films.
Design/methodology/approach
PI nano‐composite films containing definitive contents of Al2O3 were prepared by the sol‐gel process of aluminum isopropoxide in the N, N′‐dimethylacetamide solution of polyamide acid. The films were characterised by Fourier transform infrared spectroscope, atomic forced microscope, and X‐ray fluorescent spectroscope (XRF). The thermal stability of the composite films was tested by TG.
Findings
PI nano‐Al2O3 films were prepared by the sol‐gel method. The XRF is an effective way to detect the inorganic phase of the composite films and measure the content of nano‐Al2O3.
Research limitations/implications
There are seldom reports about the PI composites containing Al2O3 through sol‐gel process.
Practical implications
PI has been widely used in the fields of aviation micro‐electron and less costly dyes.
Originality/value
Improved electricity insulation property of the PI films. Al2O3 particles were distributed homogeneously in the PI in nano‐scale by means of sol‐gel process.
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Banu Sugözü, Behcet Dağhan and Ahmet Akdemir
The purpose of this paper is to study the potential of alumina (Al2O3) in nanometer size in automotive brake friction materials.
Abstract
Purpose
The purpose of this paper is to study the potential of alumina (Al2O3) in nanometer size in automotive brake friction materials.
Design/methodology/approach
Four brake linings containing alumina differing in particle size (355 µm and 80 nm) and various amount (5 and 10 Wt.%) were designed and produced. The hardness, density and porosity of the samples were measured. All samples were tested on a full-scale brake dynamometer with gray cast iron disc to determine the tribological properties. Detailed examinations on the worn surface were analyzed using a scanning electron microscopy.
Findings
It was concluded that all performance parameters were beneficially affected because of nano alumina.
Originality/value
This paper emphasizes the importance of nano-composites in the automotive industry and helps industrial firms and academicians working on wear of materials.
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