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Item Microstructure and microhardness characterization of Cp- Ti/SiAlON composite Coatings on Ti-6Al-4V by laser cladding.(Elsevier B.V, 2019-03-08) Sibisi, P.N.; Popoola, A.P.I.; Kanyane, L.R.; Fatoba, O.S.; Adesina, O.S.; Arthur, N.K.K.; Pityana, S.L.Failure of engineering components on application is mainly a result of poor surface behavior of materials under certain conditions. Titanium and its alloys have numerous beneficial properties including light weight, high strength and excellent corrosion resistance which have made them desirable in various industries. However, due to low hardness and poor wear resistance their industrial applications are restricted in harsh conditions. In this study Commercially Pure Titanium and SiAlON powders admixed at varied composition (98%Ti/2%SiAlON and 95%Ti/5%SiAlON) were used to fabricate composite coating on Ti6Al4V substrate by Laser cladding at altered scanning speed (0.6 and 1.2 m/min). The microstructures were examined using SEM/EDS and the phase evolutions were identified using XRD. The cross-section microhardness measurements were carried out by means of a Vickers hardness tester. The results revealed improvement in the hardness property as compared to the unconditioned substrate. The coating average surface hardness values were about twice that of the as-received substrate which was attributed to the presence of hard phases such as Si3N4, TiN and SiO2 as revealed on XRD.Item Effect of MgO/MnO2 additives on the structural properties of zinc electroplated mild steel.(Elsevier B.V., 2019-04) Kanyane, L.R.; Fayomi, O.S.I.; Popoola, A.P.I.; Sibisi, P.N.Low carbon steel is widely used in engineering applications due to its availability, physical properties and reasonable cost. Regardless of the massive use of mild steel in engineering applications, their application is limited to high tribology and corrosive environment are limited due to low corrosion resistance properties, low microhardness and poor tribological properties. The increase in service life and exceptional properties of reinforcement composite coatings for advanced engineering application has attracted many researchers world-wide. In this study, the effect of manganese oxide (MnO2) on Zn-MgO chloride bath coating by co-deposition route on mild steel is studied. The coating micrographs and surface thickness were examined by means of scanning electron microscope (SEM) coupled with energy dispersive spectroscopy (EDS) and PosiTector (SPG) respectively. The thermal stability of the synthesized composite coatings studied in isothermal furnace at 350°C. The findings of the studies are discussed in this paper. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the organizing committee of SMPM 2019.Item Assessment of the performance of osmotically driven polymeric membrane processes.(IOP Publishing, 2019-12-01) Agboola, O.; Sanni, S.E.; Oyekunle, D.T.; Ayeni, A.O.; Oni, B.A.; Ayoola, A.; Popoola, A.P.I.The universal water scarceness and the extensive ordeals with energy cost in conjunction with the undesirable ecological effects have advanced the improvement of novel osmotically driven membrane processes. Membrane processes which are osmotically driven are developing type of membrane separation procedures that apply concentrated brines to separate liquid streams. They are adaptable in various applications; hence, allow them to be an attractive substitute for drug release, wastewater treatment and the production and recovery of energy. Although, internal concentration polarization (ICP) occurs in membrane practices which are osmotically driven as a consequence of hindered diffusion of solute in a porous stratum, their interest has even increased. Here we review two natural membrane processes that are osmotically driven; Forward osmosis (FO) and Pressure retarded osmosis (PRO). Thus, the major points are as follows: 1) it was highlighted in this review, that the major developments in FO process, important for the process efficiency is to choose a suitable membrane and draw solution. 2) The recent evaluation, understanding and optimizing the activities of fouling throughout the osmotic dilution of seawater employing FO was discussed. 3) Recent advancements of FO in the application of food processing was reviewed. 4) It was highlighted that the main concept of PRO for power generation is the energy of mixing that offers great assessment of the nonexpansion work which could be generated from mixing; nonetheless, the development of effective membranes with appropriate arrangement and performance is needed for the advancement of PRO process for power generation. 5) One major challenge of osmotically driven membrane processes, most recent developments and model development to predict their performances were discussed.Item Influence of zirconium diboride (ZrB2) on the physio- mechanical behavior of AA8011 alloy base.(IOP Publishing, 2019-12-18) Fayomi, J.; Popoola, A.P.I.; Popoola, O.M.; Fayomi, O.S.I.The AA8011 reinforced with 5 to 20 weight percent of zirconium diboride (ZrB2) were developed via stir casting route. In this current research work, characterization evaluation was conducted on the AA8011 alloy and its composites with the varying composition to investigate the physical and mechanical properties. The results of the mechanical properties obtained revealed an enhanced hardness and strengthening mechanism propagation of the composite in comparison to the base alloy AA8011. The experimental studies show that the addition of ceramic particles into the molten metal alloy resulted in improved properties. Also, an increase in the percentage composition of the particles leads to an increase in the strength value of the composite. Generally, the improvement in the hardening mechanical behavior of the composites can be attributed to the intrinsic properties of the incorporated particulates.Item Influence of zirconium diboride (ZrB2) on the physio- mechanical behavior of AA8011 alloy base.(IOP Publishing, 2019-12-18) Fayomi, J.; Popoola, A.P.I.; Popoola, O.M.; Fayomi, O.S.I.The AA8011 reinforced with 5 to 20 weight percent of zirconium diboride (ZrB2) were developed via stir casting route. In this current research work, characterization evaluation was conducted on the AA8011 alloy and its composites with the varying composition to investigate the physical and mechanical properties. The results of the mechanical properties obtained revealed an enhanced hardness and strengthening mechanism propagation of the composite in comparison to the base alloy AA8011. The experimental studies show that the addition of ceramic particles into the molten metal alloy resulted in improved properties. Also, an increase in the percentage composition of the particles leads to an increase in the strength value of the composite. Generally, the improvement in the hardening mechanical behavior of the composites can be attributed to the intrinsic properties of the incorporated particulates.Item Synthesis and characterization of tantalum oxide deposited by metal-organic chemical vapour deposition (MOCVD).(IOP Publishing, 2018-10-23) Jeje, S.O.; Jeje, S.O.; Akinwunmi, O.O.; Akinwunmi, O.O.; Shongwe, M.B.; Shongwe, M.B.Tantalum oxide thin films have rapidly evolved as a potentially important film material in a wide range of industrial applications such as optical coatings, dielectric films, corrosion and heat-resistant coatings, dental implants and coronary stents, or prosthesis. The preparation of an improved liquid source metal-organic precursor suitable for the deposition of high-quality tantalum oxide thin films on soda lime glass using Metal-organic Chemical Vapour Deposition (MOCVD) was reported. Peroxo–hydroxyl–amino tantalum complex precursor was prepared by a method of ligand-exchange reactions between hydroxo–peroxo tantalum complexes and traditional chelating reagents. Preparation of the thin films was achieved by the pyrolysis of the precursor at four different temperatures (380 °C, 400 °C, 420 °C, 450 °C) with a flow rate of 1.5 dm3/min for 2 hours deposition period. The deposited films were characterized using Ultraviolet-Visible spectroscopy, Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDX). A direct optical band gap of 4.16 eV – 4.70 eV was obtained from the analysis of the absorption spectrum of the thin-films. SEM micrographs revealed that the deposited film had no regular structure, and the layers could be described as amorphous. The EDX results confirmed the presence of Tantalum and Oxygen in the thin films.Item Composite materials on the manufacturing of metallic surface alloys.(Elsevier Ltd., 2020-07-31) Fayomi, O.S.I.; Babaremu, K. O.; Akande, I.G.; Popoola, A.P.I.This study focused on the influence of composite materials on electrodeposition process. The exploit of composite materials due to their exceptional characteristics such as, aesthetic beauty, mechanical performance or electrochemical stability can never be over emphasized. While electrodeposition is seen a unique method for surface improvement development of right bath framework and particle infringement are major concern. Therefore, there is a need to adequately highlight the uniqueness of composite material development, their application using deposition route.Item Development of bacterial resistant acrylamide-polyvinylpyrrolidonemetal oxide hydrogel nanocomposites.(Elsevier Ltd., 2020-05-16) Owonubi, Shesan John; Agwuncha, S.C.; Malima, Nyemaga Masanje; Sadiku, Rotimi E.; Revaprasadu, NeerishFabrication of polymer-based nanocomposites for numerous biomedical applications represents a predominant form of therapeutics for combating microbial and bacterial infections. Herein, we firstly synthesized metal oxide nanoparticles (MONPs) by previously reported precipitation methods. Hydrogel nanocomposites were then prepared by free radical polymerization of a combination of the synthesized MONPs, polyvinylpyrrolidone (PVP) and acrylamide. The hydrogel nanocomposites were characterized by FTIR, XRD and investigated for potential antibacterial protection. FTIR spectra of the prepared hydrogel nanocomposites revealed significant characteristic peaks of the distinctive MONPs within the polymer matrix. XRD micrographs revealed slight shifting of peak positions in nanocomposites; the change in peak intensity, coupled with the observed slight shift in the diffraction peaks of both CuO and ZnO nanoparticles confirmed the successful incorporation of the MONPs into the polymer matrix. The presence of the MONPs, in combination with PVP, displayed a synergistic antibacterial activity, with increasing concentration of the MONPs. The treatment against S.pneumoniae, revealed a zone of inhibition phenomenon which showed zones of PVP-5 > PVP-8 > PVP-6 > PVP-9 > PVP-7. PVP-1, PVP-2, PVP-3, PVP-4 did not show any significant zone of inhibition on treatment due to the quantity of MONPs present. The findings show that the hydrogel nanocomposites are potential topical wound dressing materials for the management of bacterial infections.