Oluwaseun John Dada- Professorial Chair
- Managing Director at Signature EcoSystems Technologies
Oluwaseun John Dada
- Professorial Chair
- Managing Director at Signature EcoSystems Technologies
About
82
Publications
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163
Citations
Introduction
Prof. Dr. Oluwaseun John Dada has worked over the past 8 years on NanoScale materials, electrochemistry, advanced materials manufacturing and applications, and over 10 years in Metallurgy and Aluminium Manufacturing.
Current institution
Signature EcoSystems Technologies
Current position
- Managing Director
Publications
Publications (82)
Extrusion press is not a new phenomena but the synthesis of a reasonable lab prototype, at low cost using available materials requires a lot of innovation and development. Comprehensive literature search and consultations preceded design calculations, Computer-Aided design (Autodesk Inventor) and materials selection that steered the trajectory of f...
Frictie roerlassen (FSW) is de snelst evoluerende verbindingstechnologie en de belangrijkste prospectieve techniek voor de implementatie van een integrale rompstructuur in de vliegtuigbouw. De levensvatbaarheid van FS-lassen is afhankelijk van de mechanische eigenschappen en de productieomzetten, die afhankelijk zijn van de lassnelheid en het ontwe...
Friction stir welding (FSW) é a tecnologia de junção mais rápida em evolução e a principal técnica prospectiva para implementação de uma estrutura de fuselagem integral na fabricação de aeronaves. A viabilidade das soldas FS depende das propriedades mecânicas e do volume de produção, que dependem das taxas de soldagem e do projeto da ferramenta. Po...
Spawanie steru ciernego (FSW) jest najszybciej rozwijającą się technologią łączenia i najważniejszą perspektywiczną techniką wdrażania zintegrowanej struktury kadłuba w konstrukcji samolotu. Żywotność spawania FSW zależy od właściwości mechanicznych i konwersji produkcji, które zależą od prędkości spawania i konstrukcji narzędzi. W związku z tym w...
Rührreibschweißen (Friction Stir Welding, FSW) ist die sich am schnellsten entwickelnde Verbindungstechnologie und die wichtigste prospektive Technik zur Implementierung einer integralen Rumpfstruktur im Flugzeugbau. Die Durchführbarkeit von FS-Schweißungen hängt von den mechanischen Eigenschaften und den Produktionsumsätzen ab, die von den Schweiß...
La saldatura a frizione (FSW) è la tecnologia di giunzione in più rapida evoluzione e la principale
tecnica prospettica per l'implementazione di una struttura integrale della fusoliera nella produzione
aeronautica. La fattibilità delle saldature FS dipende dalle proprietà meccaniche e dai cambi di
produzione, che dipendono dalle velocità di saldatu...
Le soudage par friction-malaxage (FSW) est la technologie d'assemblage qui évolue le plus rapidement et la principale technique prospective pour la mise en œuvre d'une structure de fuselage intégrale dans la construction aéronautique. La viabilité des soudures FS dépend des propriétés mécaniques et des chiffres d'affaires de production, qui dépende...
Lithium battery anode plates were made from sugar processed into hard carbon by high temperature carbonization in an autoclave. Sucrose was dissolved in water at 60 ⁰C, mixed thereafter with naphthalene. The hard carbon is purifies with HCl and distilled water. Nano-hard carbons1,2 are 3-dimensional and notably larger than the 2-dimensional graphen...
This is an exceptional process on low cost, low defect and high-quality graphene which is produced by sonication in PPC and microwaving for just 5sec. Low energy arc-discharging process expands electrolytic graphite rods into hierarchical-like 3D-graphene retaining the basal plane carbon crystalline order and chemical purity [1-2]. Sonication in Po...
Wrinkled Graphene Oxide has been produced from both glow electrolytic thermal arc discharging of graphite rods combined with hummer's process. Wrinkling in GO was enhanced by low defects, multilayer clusters, and variegated-edge interaction amongst graphene clusters. The composition of GO was confirmed by XPS, while the low defect level clearly mar...
High performance lithium battery anode plates were made from processed arc discharge graphene. Arc discharge graphene has been produced from glow electrolytic thermal arc discharging of graphite rods [1-3], different from graphene or reduced graphene prepared through other means [4-11], because it maintains high crystallinity and planar characteris...
Low cost, low defect and high-quality graphene have been produced in three simple exfoliation steps as a fully tested commercial concept. Low energy thermal arc-discharging expands the electrolytic graphite rod electrodes into hierarchical-like 3D graphene retaining the graphite structural order on a basal plane and chemical purity. Multi-size ball...
Free Standing Porous Graphene and Reduced Graphene Papers manufactured from Sedimentation of Arc Discharge of Graphite Rods. At SignEcoTech, novel and newer nano-carbons such as hard carbons, homogenized graphene, low defect highly crystalline graphene's, and wrinkled graphene [1-14]. Here, Graphene Oxide papers have been synthesized previously by...
Friction stir welding (FSW) is the fastest evolving joining technology and the principal prospective technique for implementing integral fuselage structure in aircraft manufacturing. The viability of FS welds is dependent upon mechanical properties and production turnovers, which are dependent on welding rates and tool design. Hence this review pap...
Low cost, low defect and high-quality graphene have been produced in three simple exfoliation steps as a fully tested commercial concept. Low energy thermal arc-discharging expands the electrolytic graphite rod electrodes into hierarchical-like 3D graphene retaining the graphite structural order on a basal plane and chemical purity. Multi-size ball...
Free Standing Porous Graphene and Reduced Graphene Papers manufactured from Sedimentation of Arc Discharge of Graphite Rods. At SignEcoTech, novel and newer nano-carbons such as hard carbons, homogenized graphene, low defect highly crystalline graphene’s, and wrinkled graphene [1-14]. Here, Graphene Oxide papers have been synthesized previously by...
This is an exceptional process on low cost, low defect and high-quality graphene which is produced by sonication in PPC and microwaving for just 5sec. Low energy arc-discharging process expands electrolytic graphite rods into hierarchical-like 3D-graphene retaining the basal plane carbon crystalline order and chemical purity [1-2]. Sonication in Po...
High performance lithium battery anode plates were made from processed arc discharge graphene. Arc discharge graphene has been produced from glow electrolytic thermal arc discharging of graphite rods [1-3], different from graphene or reduced graphene prepared through other means [4-11], because it maintains high crystallinity and planar characteris...
Utilization of Hard Carbon As a Substitute for Graphite As Efficient Lithium Battery Anode Material
Lithium battery anode plates were made from sugar processed into hard carbon by high temperature carbonization in an autoclave. Sucrose was dissolved in water at 60 ⁰C, mixed thereafter with naphthalene. The hard carbon is purifies with HCl and dist...
Wrinkled Graphene Oxide has been produced from both glow electrolytic thermal arc discharging of graphite rods combined with hummer’s process. Wrinkling in GO was enhanced by low defects, multilayer clusters, and variegated-edge interaction amongst graphene clusters. The composition of GO was confirmed by XPS, while the low defect level clearly mar...
Friction stir welding (FSW) is the fastest evolving joining technology and the principal prospective technique for implementing an integral fuselage structure in aircraft manufacturing. The viability of FS welds is dependent upon mechanical properties and production turnovers, which are dependent on welding rates and tool design. Hence this review...
Este trabalho estabelece que as propriedades eletrônicas e dielétricas dependentes da freqüência e temperatura do grafeno reduzido eletroquimicamente (ERGO) são superiores aos papéis de óxido de grafeno (GO) em 2 ordens de grandeza. Há uma polarização mais forte como resultado do aumento da concentração de grupos reduzidos e do desbaste de folhas d...
Ce travail établit que les propriétés électroniques et diélectriques du graphène électrochimiquement réduit (ERGO), qui dépendent de la fréquence et de la température, sont supérieures de deux ordres de grandeur à celles des papiers à base d'oxyde de graphène (GO). La polarisation est plus forte en raison de la concentration accrue des grappes rédu...
Dit werk stelt vast dat de frequentie- en temperatuurafhankelijke elektronische en diëlektrische eigenschappen van elektrochemisch gereduceerd grafeen (ERGO) 2 orden van grootte hoger zijn dan die van grafeenoxide (GO). Er is een sterkere polarisatie als gevolg van een verhoogde concentratie van gereduceerde clusters en het uitdunnen van grafeenvel...
Questo lavoro stabilisce che le proprietà elettroniche e dielettriche dipendenti dalla frequenza e dalla temperatura del grafene elettrochimicamente ridotto (ERGO) sono superiori di 2 ordini di grandezza rispetto alle carte di ossido di grafene (GO). C'è una polarizzazione più forte come risultato di una maggiore concentrazione di cluster ridotti e...
Diese Arbeit stellt fest, dass die frequenz- und temperaturabhängigen elektronischen und dielektrischen Eigenschaften von elektrochemisch reduziertem Graphen (ERGO) um 2 Größenordnungen höher sind als die von Graphenoxidpapieren (GO). Es gibt eine stärkere Polarisierung als Folge einer erhöhten Konzentration von reduzierten Clustern und einer Verdü...
Gel - Kristaltheorie Oplossingsmechanisme voor neerslagVerbeteringen aan de grafiek-NanoSheetEffect van Grootte en Vermindering van GrapheneSchuifgeïnduceerde fragmentatie van grafeen Interconductiviteit en elektro-smotische verschijnselenNieuwe strategieën voor het gebruik en de capaciteitsverbetering van loodaccu's De technologische eisen in hybr...
Gel - Teoria dos Cristais Mecanismo de Precipitação de DissoluçãoMelhorias na Nanofolha GrapheneEfeito do Tamanho e Redução do GrafenoFragmentação de Grafeno Induzida por Cisalhamento InterCondutividade e Fenômenos Eletro-OsmóticosNovas Estratégias de Utilização e Melhoria da Capacidade da Bateria de Ácido Chumbo As exigências tecnológicas em veícu...
Żel - Teoria Kryształowa Mechanizm rozpuszczania opadówUlepszenia nano arkuszy Graphene'aWpływ wielkości i redukcji grafenuFragmentacja indukowana ścinaniem grafenu Zjawiska międzyprzewodzące i elektroosmotyczneNowe strategie wykorzystania i poprawy wydajności akumulatorów kwasowo-ołowiowych Zapotrzebowanie technologiczne w hybrydowych pojazdach el...
Théorie du gel - cristal Mécanisme de dissolution et de précipitationAméliorations des nanofeuilles de graphèneEffet de la taille et de la réduction du graphèneFragmentation du graphène induite par le cisaillement Interconductivité et phénomènes électro-osmotiquesNouvelles stratégies pour l'utilisation et l'amélioration de la capacité des batteries...
Gel-Kristalltheorie Auflösungs-Niederschlags-MechanismusGraphen-Nano-Blatt-VerbesserungenAuswirkung von Größe und Verkleinerung von GraphenScher-induzierte Fragmentierung von Graphen Interleitfähigkeit und elektro-osmotische PhänomeneNeue Strategien für die Nutzung und Kapazitätsverbesserung von Blei-Säure-Batterien Die technologischen Anforderunge...
Gel - Teoria del cristallo Meccanismo di precipitazione di dissoluzioneMiglioramenti dei nanofogli di grafeneEffetto delle dimensioni e riduzione del grafeneFrammentazione indotta da taglio del grafene Interconduttività e fenomeni elettro-osmoticiNuove strategie per l'utilizzo e il miglioramento della capacità delle batterie al piombo acido Le rich...
Graphene nano-sheets such as graphene oxide, chemically converted graphene and pristine graphene improve the capacity utilization of the positive active material of the lead acid battery. At 0.2C, graphene oxide in positive active material produces the best capacity (41% increase over the control), and improves the high-rate performance due to high...
Gel – Crystal Theory Dissolution Precipitation MechanismGraphene Nano-Sheet EnhancementsEffect of Size and Reduction of GrapheneShear Induced Fragmentation of Graphene InterConductivity and Electro-Osmotic PhenomenaNovel Strategies for Utilization and Capacity improvement in Lead Acid Battery Technological demands in hybrid electric vehicles, large...
Friction stir welding (FSW) is the fastest evolving joining technology and the principal prospective technique for implementing an integral fuselage structure in aircraft manufacturing. The viability of FS welds is dependent upon mechanical properties and production turnovers, which are dependent on welding rates and tool design. Hence this review...
This work establishes that the frequency and temperature-dependent electronic and dielectric properties of electrochemically reduced graphene (ERGO) are higher than graphene oxide (GO) papers by 2 orders of magnitude. There is stronger polarization as a result of increased concentration of reduced clusters and thinning of graphene sheets in ERGO pa...
Rührreibschweißnähte (Friction Stir Weldings, FSW), ein neuartiges Schweißverfahren für alle Metalllegierungen und Polymere, hat bessere mechanische Eigenschaften als ältere Schweiß- und Fügetechniken gezeigt, insbesondere für integrale Aluminiumstrukturen von Flugzeugzellen, um die Gewichtsbelastung und das Versagen zu reduzieren. Diese parametris...
Le saldature a frizione (FSW), una nuova tecnica di saldatura per tutte le leghe metalliche e i polimeri, ha mostrato migliori proprietà meccaniche rispetto alle vecchie tecnologie di saldatura e di giunzione, specialmente per la struttura integrale in alluminio della cellula per ridurre il peso e i guasti. Questo studio parametrico è importante pe...
Les soudures par friction-malaxage (FSW), une nouvelle technique de soudage pour tous les alliages métalliques et les polymères, ont montré de meilleures propriétés mécaniques que les anciennes technologies de soudage et d'assemblage, en particulier pour la structure intégrale en aluminium de la cellule afin de réduire la charge de poids et la défa...
As soldaduras por fricção (FSW), uma nova técnica de soldadura para todas as ligas metálicas e polímeros, mostrou melhores propriedades mecânicas do que as tecnologias mais antigas de soldadura e união, especialmente para a estrutura integral de alumínio da fuselagem para reduzir a carga de peso e as falhas. Este estudo paramétrico é importante par...
Spawy tarciowe z przemieszaniem (FSW), nowa technika spawania wszystkich stopów metali i polimerów, wykazała lepsze właściwości mechaniczne niż starsze technologie spawania i łączenia, szczególnie w przypadku integralnej konstrukcji aluminiowej płatowca, w celu zmniejszenia ciężaru i uszkodzenia. To badanie parametryczne jest ważne dla symulacji i...
Wrijvingsroerlassen (FSW), een nieuwe lastechniek voor alle metaallegeringen en polymeren, heeft betere mechanische eigenschappen dan oudere las- en verbindingstechnologieën, met name voor de integrale casco-aluminiumstructuur, om de gewichtsbelasting en het falen te verminderen. Deze parametrische studie is belangrijk voor simulaties en automatisc...
Friction stir welds (FSW), a novel welding technique for all metal alloys and polymers, has shown better mechanical properties than older welding and joining technologies, especially for integral airframe aluminium structure to reduce weight burden and failure. This parametric study is important for simulations and automatic programming for manufac...
Friction stir welds (FSW), a novel welding technique for all metal alloys and polymers, has shown better mechanical properties than older welding and joining technologies, especially for integral airframe aluminium structure to reduce weight burden and failure. This parametric study is important for simulations and automatic programming for manufac...
Technological demands in HEVs, large scale storage and portable power stations has furthered more research interests in Lead Acid Batteries (LAB), in addition to the advantage of power rating per cost. The LAB positive active materials (PAM), due to low utilization and life cycle, severely limits the competitiveness of the traditional battery. The...
This work establishes that the frequency and temperature-dependent electronic and dielectric properties of electrochemically reduced graphene (ERGO) are higher than graphene oxide (GO) papers by 2 orders of magnitude. There is stronger polarization as a result of increased concentration of reduced clusters and thinning of graphene sheets in ERGO pa...
![Figure 1. Schematic diagram of the FSW process and forces on the tool [6].](publication/339358780/figure/fig1/AS:868721899888646@1584130849576/Schematic-diagram-of-the-FSW-process-and-forces-on-the-tool-6_Q320.jpg)
Friction Stir Welding (FSW) is one of the fastest developing welding technologies being implemented in the transport industry today. Fracture surfaces of AA5083-H111 specimens, which were friction-stir-welded using different parameters, were studied with a scanning electron microscope (SEM). The changes in the microstructure of the weld, the locati...
Free Standing Porous Graphene and Reduced Graphene Papers manufactured from Sedimentation of Arc Discharge of Graphite Rods. At SignEcoTech, novel and newer nano-carbons such as hard carbons, homogenized graphene, low defect highly crystalline graphene’s, and wrinkled graphene [1-14]. Here, Graphene Oxide papers have been synthesized previously by...
Friction stir welding (FSW) is a fast-evolving joining technology with a superior advantage over other welding technologies. The viability of FS welds is dependent upon mechanical properties and production turnovers, which are dependent on welding parameters and tool design. This book does not only contain a comprehensive FSW process-structure-prop...
Lead Oxide/Graphene Interfacial Characteristics
Graphene Oxide Electrochemical Reductions
Dielectric and Electronic Properties
Capacity Optimization in Lead Acid Batteries
Graphene-based nanosheets have gained prominence in batteries and super-capacitors owing to their high aspect ratio, tunable transport properties, diverse ionic function...
Graphene additives [1-13] have been rightly used in enhancing the capacity and cyclic performance of lead acid battery. However, the fundamental mechanisms of the enhancements in terms of electrochemical characteristics is still unclear. This study focuses on the mechanistic understanding of graphene enhancements within the interphase of the lead a...
In recent times, it is found that energy has received quite an appreciable attention around the world. This is partly due to the gradual transition from centralized to distributed energy generation technology brought about by the widespread application of renewable energy resources. However, while this is a welcome development, it is also found tha...
Highlights
• Highest reported optimization for positive active material.
• 1 wt% GO additive results in 57% Capacity utilization increase at 0.2 C.
• Lower Peukert dependencies, excellent rate performance and high current rate stability.
• GO/PbO2 interfacial interaction caused increased electrochemical activity.
• Increased utilization of lead...
oluwaseundd@yahoo.com; ojdada@connect.ust.hk (852) 5362 1400 (852) 6709 8309
HIGHLIGHTS
1. This is the first study to exfoliate and synthesize 2D planar graphene from graphite with conformable with flat surfaces for electronic applications.
2. Also the first study to synthesize low defect Graphene with smaller domain size, unobtainable by labor...
oluwaseundd@yahoo.com; ojdada@connect.ust.hk (852) 5362 1400 (852) 6709 8309 Low cost, low defect and high-quality graphene have been produced in three simple exfoliation steps as a fully tested commercial concept. Low energy thermal arc-discharging expands the electrolytic graphite rod electrodes into hierarchical-like 3D graphene retaining the gr...
Compared with the matrix alloy, Al6061 reinforced with nano-fillers possesses higher strength, stiffness, damage tolerance properties, and wear and creep resistance in a wide temperature range hence, suitable for automotive, aerospace structures, marine and medicine. This research work entails the enhancement of the structural properties of Al6061...
Technological demands in HEVs, renewable systems, and electrical storage systems coupled with its mature industrial process, recyclability and low cost has furthered the interests in Lead acid (LAB) systems. The LAB Positive active materials, due to low utilization and life cycle, severely limits the competitiveness of the traditional battery.
This work establishes that the frequency and temperature-dependent electronic and dielectric properties of electrochemically reduced graphene (ERGO) are higher than graphene oxide (GO) papers by 2 orders of magnitude. There is stronger polarization as a result of increased concentration of reduced clusters and thinning of graphene sheets in ERGO pa...
Wrinkled Graphene Oxide has been produced from both glow electrolytic thermal arc discharging of graphite rods [1,2] combined with hummer’s process [3-5]. Wrinkling in GO was enhanced by low defects, multilayer clusters, and variegated-edge interaction amongst graphene clusters. The composition of GO was confirmed by XPS, while the low defect level...
Reduced graphene fillers were integrated into epoxy nanocomposites by solvent exchange of GO solution to acetone, ethanol and DMF, and subsequent in-situ thermal reduction and curing. The comparative fracture specimens of neat epoxy, acetone-rGO/epoxy, and DMF-rGO/epoxy showed ethanol-rGO/epoxy had greater load transfer by bonding and functionaliza...
Graphene nano-sheets such as graphene oxide, chemically converted graphene and pristine graphene improve the capacity utilization of the positive active material of the lead acid battery. At 0.2C, graphene oxide in positive active material produces the best capacity (41% increase over the control), and improves the high-rate performance due to high...
Nano-carbons Based Optimization of Lead Acid Battery and Electrochemical Reduction of Graphene Oxide Paper
Reduced graphene and graphene oxide sheets have been in-situ functionalized during electrochemical reactions in lead-acid cathode system. This research investigated the comparative differences in surface chemistry of reduced graphene and graphene oxide sheets, and their influence on electrochemical activity within the lead acid charge and discharge...
Developments in graphene based batteries, supercapacitors transistors, or energy harvesting applied as additives, electrodes, current collectors or even electrolytes have necessitated the importance of understanding its evolution. High electrical conductivity, tunable and functional surface and interfacial characteristics, super-ionic transportatio...
Technological demands in HEVs, renewable systems, and electrical storage systems coupled with its mature industrial process, recyclability and low cost has furthered the interests in Lead acid (LAB) systems. The LAB Positive active materials, due to low utilization and life cycle, severely limits the competitiveness of the traditional battery.
Repo...
The effect of reduced graphene electro-catalysts and their the agglomerate sizes, the case in lead acid battery positive active material was done. Reduced graphene size distributions were achieved via shear induced fragmentation of graphene oxide paper followed by hydrazine reduction. Increased size of agglomerates were beneficial when conductive r...
Interconnected graphene/PbO composites appearing sand-wish was developed for lead acid battery cathode. Facile processing technique which is solution based, enabled the interaction between graphene oxide nano-sheets and PbO submicron particles under mechanical stirring producing sand-wish-like structures containing graphene nano-sheets. The affinit...
Graphene based nano-sheets have gained prominence in batteries and super capacitors owing to their high aspect ratio, exceptional transport properties, ionic functionalities, and surface properties. Variants like pristine graphene, graphene oxide, or chemically/thermally reduced graphene are not equal in ionic and transport properties owing to the...
Friction stir welding (FSW) is the fastest evolving joining technology and the principal prospective technique for implementing integral fuselage structure in aircraft manufacturing. The viability of FS welds is dependent upon mechanical properties and production turnovers, which are dependent on welding rates and tool design. This dissertation is...
Self-aligned in-situ reduced graphene oxide (rGO)/waterborne epoxy (EP) nanocomposite were prepared using an all aqueous method. The nanocomposites delivered a very low percolation threshold of 0.26 wt% as a result of the fine dispersion of monolayer rGO sheets and their ultralarge size. The rGO/EP nanocomposites exhibited exceptionally high dielec...
Friction Stir Welding (FSW) is the leading joining technique in the aeronautical industry for producing integral airframe structures, because of the advantages of lower cost and weight, and reduction in widespread fatigue damage compared to standard riveting.
FSW is a solid state process that involves the plunging of a rotating tool, comprising a...
This paper reports the relationship between residual stress distribution and key friction stir welding parameters, transverse and rotational speeds, on 6056-T4 aeronautical aluminium alloy. Standard electric strain gauge based destructive technique was used to measure residual stresses at the top of the weld in the longitudinal direction. Residual...
This work examined the role of defects and microstructure on the fast fracture mechanism in welded 5083-H111 aluminum alloy. The sample was welded at 400rpm tool rotation speed and 50mm/minute transverse speed. Optical microscopy images across the weld were taken. After welding, the sample was tensile tested and the fracture surfaces were viewed wi...
Friction Stir Welding (FSW) is one of the fastest developing welding technologies being implemented in the transport industry today. Fracture surfaces of AA5083-H111 specimens, which were friction-stir-welded using different parameters, were studied with a scanning electron microscope (SEM). The changes in the microstructure of the weld, the locati...
Friction Stir Welding (FSW) is a solid state process that utilizes a rotating tool, comprising a shoulder and pin, pushed in to stir the material while the tool moves along the jointline. Better mechanical properties, environmental friendliness and lower cost make it the fastest evolving welding technology. AA5083 was selected owing to its enhanced...
Friction Stir Welding (FSW) has become the most important evolving welding technology for the proposed integral aluminium structures for aerospace fuselage to avoid high cost, excessive weight. The fatigue performances of FSW parts are superior to riveting. FSW entails a nonconsumable rotating cylindrical tool, consisting of a shoulder and pin, bei...
