Biography:

Elod L Gyenge is a Professor in the Department of Chemical and Biological Engineering and Clean Energy Research Centre at the University of British Columbia, Vancouver, Canada. His research is focused on electrocatalysis and electrochemical engineering for improving the performance of electrochemical power sources and electrosynthetic processes. His research led to many innovations for a variety of electrochemical systems including diverse fuel cells and rechargeable batteries, and electrosynthesis of hydrogen peroxide. The research materialized in over 75 refereed research publications in peer reviewed journals, over 40 invited presentations and 10 patents and patent applications. He has received a number of awards and recognitions, among them the Japanese Society for Promotion of Science (JSPS) Fellowship at Osaka University and Elisabeth and Leslie Gould Endowed Professorship at UBC (2007-2014). Since 2016 he is also cross-appointed Professor in the Graduate School of Engineering at Osaka University, Japan. He is a Co-Founder of two companies: Catalyst Square Materials Ltd. and Agora Energy Technologies Ltd.

Abstract:

Development of highly active, durable and cost-efficient bifunctional electrocatalysts for the oxygen reduction and evolution reactions (ORR and OER) is of outmost importance for commercialization of rechargeable metal-air batteries (e.g., Zn-air, Al-air, Mg-air, Li-air) and regenerative H₂-O₂ fuel cells. Manganese dioxide (MnO₂), a low cost and abundant material, has been intensely studied as ORR electrocatalyst in alkaline media. Regarding the bifunctional ORR and OER electrocatalytic performance, however, enhancement of the activity (e.g., lower surface overpotential at practical current densities above 100 mA cm^-2) and improvement of the long-term stability are required for potential implementation in commercial systems. The purpose of this study is to present novel approaches for tuning the MnO₂ performance with co-catalyst addition, potassium ion doping and support effect (e.g., graphene and graphitized carbon). The combination of MnO₂ with structurally different oxide co-catalysts such as perovskite (LaCoO₃) or fluorite-type oxide (Nd₃IrO₇) produces a synergistic catalytic effect improving the bifunctional (ORR and OER) activity compared to the individual oxides. Doping of the oxide catalyst with potassium ions, either by long-term exposure to 6 M KOH or potential driven insertion (PDI), increases further the activity and durability as revealed in accelerated degradation experiments. Optimizing the MnO₂ electrodeposition conditions can produce nanostructured morphologies that are favorable for ORR and OER activity. The electrochemical studies are supported by extensive surface analysis (SEM, TEM, XPS, EDX, EELS). This work reveals new oxygen electrode catalyst formulations for rechargeable metal-air batteries and regenerative fuel cells.

Biography:

Peggy Gunkel Grillon is an Environmental Chemist having expertise in heavy metals and their contamination, bioavailability and mobility in the environment. She is an Assistant Professor since 2008 and Deputy Director of ISEA laboratory (Institut des Sciences Exactes et Appliquées) at the University of New Caledonia. She has a keen interest in understanding heavy metals behavior in the environment for a modern society concerned with sustainable development. Recently, her activities also include the development of remediation techniques. With her colleagues she’s been working for 4 years on the electrochemical precipitation of heavy metals in seawater to trap dissolved metallic contaminants.

Abstract:

The contamination of coastal waters by trace metals is an important worldwide concern since they may significantly affect marine ecosystems. A novel use of the calcareous deposit formed on a metallic structure is proposed to trap metallic contaminants in seawater. It is the same deposit that builds up in many tea kettles or water pipes in areas where calcium-rich water is the norm. Whereas the calcareous deposition is a common problem for many people, we transformed this problem into a solution to trap metals. The calcareous deposit is formed in seawater by imposing a current on a galvanized steel electrode. The working electrode’s potential reaches potential in the water reduction range. This reaction causes pH increase at the seawater/metal interface, inducing calcium and magnesium precipitation. A voluminous calcareous deposit composed of CaCO₃ and Mg(OH)₂ grows with polarization time. Experiments conducted in situ revealed that many metals can also be trapped. In order to better control and understand the mechanisms, lab-experiments were performed in artificial seawater. We first decided to study nickel trapping since nickel mining activities in New Caledonia are causing the subsequent pollution of local coastal waters. Artificial seawater was doped with NiCl_2(s) and analysis revealed that Ni is trapped mainly as β-Ni(OH)₂. Ni content increases with the initial Ni concentration in the electrolyte. Up to 24% in weight of Ni is trapped in the deposit after seven days of polarization. The calcareous deposit appears like a simple implementation with just a metallic structure immerged in seawater and connected to an electrical circuit which can be charged by renewable energy. This electrochemical method is thus a promising and cheap clean-up device for remediation of contaminated seawater.

Biography:

Peggy Gunkel Grillon is an Environmental Chemist having expertise in heavy metals and their contamination, bioavailability and mobility in the environment. She is an Assistant Professor since 2008 and Deputy Director of ISEA laboratory (Institut des Sciences Exactes et Appliquées) at the University of New Caledonia. She has a keen interest in understanding heavy metals behavior in the environment for a modern society concerned with sustainable development. Recently, her activities also include the development of remediation techniques. With her colleagues she’s been working for 4 years on the electrochemical precipitation of heavy metals in seawater to trap dissolved metallic contaminants.

Abstract:

Biography:

Roman Korobko received his BA in Chemistry and BSc in Materials Engineering in Technion – Israel Institute of Technology in 2003. He continued his studies in the Faculty of Chemistry of the Weizmann Institute of Science. He earned an MSc in the theme of Molecular Electronics in 2009 and PhD on controlling the elastic properties of ceramics with an external electric field in 2014. Until 2017 he was conducting a Postdoctoral Research in ETH Zurich in the field of Memristive Materials. Now he holds the position of Senior Intern in Inharmonicity of Functional Materials group at Weizmann Institute of Science. His research interests include the elastic, electronic, electromechanical and memristive properties of dielectrics, focusing on solid oxide ionic conductors. He was a recipient of the 2012 Acta student award and E-MRS 2013 graduate student award.

Abstract:

Electrochemical resistive switches operating on ionic carriers, sometimes named memristors, may revolutionize the future electronics as the next generation building blocks of non-volatile memory and neuromorphic computing replacing electronically operated classic transistor structures. Despite an extensive research performed on solid oxide materials, the technology is still immature. Therefore, the exploration in the direction of understanding the mechanisms and adaptation of novel materials systems is ongoing. In this presentation, we show a study of memristive properties of Ce_0.8Gd_0.2O_1.9/VO₂ thin film system (Gd-doped ceria (GDC), and V⁴⁺ vanadia). Ceria is a well-studied ionic conductor that tolerates high percentage of mobile oxygen vacancies. Vanadia, as VO₂ is famous for its metal-insulator transition, an ability to switch the resistance by several orders of magnitude by change of temperature, electromagnetic fields or mechanical strain beyond a sufficient transition level. Furthermore, ceria is a wide bandgap (~3 eV) and vanadia is a narrow bandgap n-type semiconductor (0.7 eV). Combination of these materials in one device seems incompatible for the conventional electronic materials strategy due to the dissimilar electric/dielectric properties. We show that integrating both oxides in the double layer device yields to synergetic memristive results, which are uncharacteristic neither for GDC nor for VO₂ as oxide constituents. It was experimentally found that the conduction and the resistive switching are governed by the mass transport kinetics, which is a function of the applied voltage, the electric field and the voltage application rate. We suppose that the field-induced transport of oxygen vacancies to and from the ceria-vanadia interface modifies the electrically variable energy barrier, which tunability is responsible for the enhanced memristance effect.

Biography:

Yan Sun has his research interests mainly focus on the theatrical study of topological materials. Through the analysis of the relationship between Berry curvature and band structure, we revealed strong spin Hall effect (SHE) and anomalous Hall effect (AHE) in WSMs and nodal line semimetals. The generalized relation between SHE/AHE and topological band structure suggests a way of the application of topological semimetals in spintronics. Fundamentally, the intrinsic AHE just depends on the symmetry of Berry curvature, but not the magnitude of net magnetic moments. Guiding by this principle, we have deeply studied two ideal strong AHE systems with vanishing net magnetic moment, non-collinear antiferromagnets (Mn3Ge) and compensated ferrimagnetic WSM (Ti2MnAl).

Abstract:

Topological insulators have been expected to be ideal spintronic materials due to the spin currents carried by the surface states with spin-momentum locking. However, the bulk doping problem still remains to be an obstacle that hinders such application. While this kind of problem is naturally avoided in topological semimetals due to the large anomalous Hall and spin Hall effect originated from the intrinsic bulk band structures. We have found that the strong spin Hall effect in TaAs is mainly dominated from the Weyl points and nodal-line-like Fermi surface, which implying a strong interplay between the topological band structure and Berry curvature in topological semimetals. With this guiding principle, we have successfully understood the strong spin Hall effect in IrO₂ and found the nodal line band structures in it. Generalizing this principle to time reversal symmetry breaking system, we have predicted strong anomalous Hall effect in magnetic Weyl semimetal Co₃Sn₂S₂, which was verified by our experimental collaborators. Owing to the low charge carrier density and large Berry curvature from the nodal line band structure, the anomalous Hall conductivity and anomalous Hall angle experimentally reach up to 1130 S/cm and 20% respectively. Further, the anomalous Hall effect can even exist with zero net moments in the absence of the symmetry operation that changes the sign of Berry curvature. And the anomalous Hall effect can be strongly enhanced by the special band structures of Weyl points and nodal lines. Following this guiding direction, we have predicted a strong anomalous Hall effect in the compensated ferrimagnetic Weyl semimetal Ti₂MnAl with vanishing magnetic net moments. Our work is helpful for the comprehensive understanding of the linear response effect in topological materials and their future applications.

Biography:

Mackenzie Honikel is a current PhD student in the School of Biological and Health Systems Engineering at Arizona State University, mentored by Dr. Jeffrey LaBelle. She graduated from Binghamton University in May 2016 with a Bachelor’s degree in Biomedical Engineering, with a concentration in biomedical devices. Her research background is in point-of-care diagnostics and she aims to continue this work during her doctoral training. Her current research focuses on the development of a continuous, implantable sensor platform for continuous monitoring throughout the episode of care for breast cancer patients.

Abstract:

Statement of the Problem: Breast cancer remains the second leading cause of cancer related death among women and accounts for nearly one in three cancer diagnoses. Advances in mammography have helped improve the early detection rate; however, noninvasive imaging modalities are unable to accurately identify the molecular subtype of the disease, therefore delaying treatment until further validation. In addition, technological advancements have increased annual screening costs, segregating lower income populations from proper preventative care. To facilitate earlier diagnosis and treatment, a point-of-care (POC) electrochemical biosensor is currently being pursued to provide immediate, sensitive and specific diagnostic information.

Methodology & Theoretical Orientation: Using electrochemical impedance spectroscopy (EIS) and a novel imaginary impedance algorithm a panel of biomarkers can be detected, simultaneously. Through the identification of a biomarker’s respective optimal binding frequency rapid signal acquisition is achievable, permitting signal deconvolution and robust characteristics.

Findings: Currently we have validated detection of a previously FDA approved biomarker on a benchtop electrode platform revealing low limits of quantification. Upon the characterization of other breast cancer indicative biomarkers, a multiplexed POC sensor will be developed and validated in complex media and clinical samples. Additionally, a screen-printed electrode platform and novel immobilization protocol will be adopted for increased feasibility in clinical use.

Conclusion & Significance: We propose that the developed technology in conjunction with electrochemical detection methodologies has profound applications in other medical conditions where a rapid diagnostic test could be useful in supplementing clinical diagnosis.

Biography:

Atiweena Krittayavathananon PhD has her expertise in Applied Electrochemistry, Electro-Analysis and Functional Materials. After years of experience in the research, she found new pathways for observing aggregation of 2D materials in colloids and suspensions using an electrochemical “nano-impacts” based on bridging impacts. The “nano-impacts” has proved to be an effective approach for investigating single nanoparticle behavior in solution phase. By using this technique, she creates a simple idea for minimizing contact resistance between catalysts and supporting electrode in the solution phase as presented in her talk.     

Abstract:

Carbon nanotubes (CNTs) and their derivatives are commonly applied as both catalyst supports and catalysts in many electronic devices. To achieve high-performance electronics, researchers have focused intensive efforts into developing the chemical and physical properties of new materials but largely ignore the potentially fundamental problem of forming a high-quality contact with the electrochemical substrate. When two materials are brought into contact, the junction causes a potential drop in the system resulting from a contact resistance. To understand the junction properties of metal/CNT interfaces, the nano-impact methodology has been developed as a route to measuring the resistance across individual CNT−electrode contacts. In these experiments, some of the CNTs in the solution phase form a bridge across two adjacent gold electrode contacts. An average bridging resistance for individual CNTs contact is 1.1±0.1×108 Ω. To improve the CNT-Au contact, we report the use of an electroactive species, acetaminophen, to modify the electrical connection between a carbon nanotube (CNT) and an electrode. By measuring the current signal across the bridge of single acetaminophen-modified CNT contact between the two microbands of the IDE-Au, the current response of acetaminophen modified on CNT is significant higher than the bare CNT, indicating that the electronic properties of the single CNT-Au contact are improved by modifying CNT with acetaminophen. It investigates that the adsorbed acetaminophen molecules contribute to promoting the electron transfer processes between the junctions of two materials.

Biography:

Vinita has her expertise in synthesis of nanosized metal coordination polymers and metal nanoparticles for sensing application. Her system based on metal organic framework. She has built this system after 2 years of experience in research institutions. Her established system has potential for fabrication of high performance electrochemical sensors, biosensors and colorimetric sensors for the detection of biologically important drug and biomolecules. Her successful effort in the area of silver and palladium based coordination polymers synthesis and their sensing application has been recently recognized.

Abstract:

The advancement in the chemistry of the coordination polymers having designable architectures fabricated from functionalized building blocks is an emerging area from last two decades. The further challenges are the construction of coordination network assembly having electro-active nano-pores. We are first time exploring a nanocrystalline coordination polymer (NCCP) framework resulting from 2–amino–5–mercapto–1,3,4–thiadiazole (AMT)  and silver nitrate. In the infinite polymer arrangement of AMT–Ag, silver (I) centers are bridged by tecton AMT through the amino linkage and exocyclic thiol. The grasped nano–sized granules of AMT–Ag are investigated by FE-SEM. The crystalline nature along with the oxidation state of silver is studied through XRD, TEM and XPS respectively. Additionally, the thermal stability and activation energy for thermal decomposition of NCCP are scrutinized by thermo–gravimetric analysis. Furthermore, the efficient electron transfer kinetics is probed by using Fe (II)/Fe (III) redox couple in phosphate buffer pH 7 via cyclic voltammetry. The excellent electroactivity is employed in the electro-detection of a biologically active drug molecule ciprofloxacin hydrochloride (CFX). The anodic peak current revealed a linear dependence with CFX concentration with sensitivity and limit of detection as 0.001 μA/μM and 5.0 nM, respectively. The effective assay of the drug is caused by the excellent electron channeling through the pores of polymeric nano–crystallites. Further, the concept is extended and established in the voltammetric detection of CFX in biological fluid and pharmaceutical formulation by a considerably high sensitivity (0.002 mA/mM and 0.007 mA/mM) and the detection limit (22 nM and 60 nM) respectively. Our established system has potential for fabrication of high performance electro-chemical sensors for assay of biologically significant drug molecule.

Biography:

Preeti Tiwari has completed MSc in Chemistry and has her expertise in electro-chemical sensing, conducting polymers and nanomaterials. She is developing sensors for drugs (especially anti-cancerous and anti-HIV drugs). She is also working for the development of the handheld devices for drug detection.

Abstract:

Azidothymidine (AZT) is an anti-HIV drug used against the treatment of HIV-1 (human immunodeficiency virus-1) infections. HIV-1 is the major cause of AIDS in humans. This drug is used for the treatment of this immunosuppressive disease since 1987 and still it is one of the drugs of choice either given alone or in combination of some other drugs. This drug has a major disadvantage that its concentration more than 10 µM in human serum causes several side effects. So, its concentration has to be maintained in human serum at very low level. Various methods are evolved for the detection of this drug using various techniques like HPLC, HPTLC etc. Electro-chemical detection of this drug is highly advantageous as it takes less time and quick response. Various modifications are utilized for electro-chemical detection of AZT. We first time developed handheld device for the detection of this drug using modified screen printed graphite electrode (SPGE). For modification we synthesized chitosan capped silver nanoparticles (Ch@AgNPs) using one pot, facile chemical reduction method. This material is utilized for the fabrication of screen printed graphite electrode (SPGE) and modified SPGE nanostructures platform is further used for estimation of AZT using simple cyclic voltammetric techniques in phosphate buffer solution at pH 7.6. This method is the most advanced as it is helpful for the development of portable sensing probes.                      

Biography:

Richa Mishra has her expertise in self-assembly and processing of various organic materials for large area film formation via various techniques such as spin coating, Langmuir-Blodgett and Langmuir-Schaeffer. Her successful effort in the area of ordered film fabrication of non-alkyl chain conducting polymers and other п- conjugated materials has been recently recognized.

Abstract:

Tailoring of physical properties of π-framework containing organic molecules by tuning their non-covalent interactions is an intensive research area. Non-covalent interactions among organic molecules can be intervened to assemble them preferably via solution based processing methods. These solution processable materials can then be assembled with varying morphology thus procuring appropriate physical properties requisite for the application desired. We are more interested in processing organic synthetic metals for large area thin film based device applications. Organic charge transfer materials particularly those containing 7,7,8,8-tetracyano-p-quinodimethane (TCNQ) as one precursor are in current scientific interest due to its intrinsic (TCNQ֗¯) radical anion formation and astonishing electrical properties when complexed with strong donors like tetrathiafulvalene (TTF), phenothiazine (PTZ), etc. Besides these gains, these complexes carry a limitation of not forming flexible, uniform and ordered large area film in their pristine state thus restricting themselves in electronic device applications. Here, it is a motivation to investigate morphology controlled assembly of donor-acceptor PTZ-TCNQ charge transport complex on solid (hard) and liquid (soft) surfaces and their film formation. We have studied their surface (liquid and solid) induced assembly via spin casting and Langmuir technique. Films fabricated from both soft and hard surfaces depicted variation in crystalline morphology and surface topography that has been studied via SEM, TEM and AFM characterizations. These assembled large area films have also shown variation in electrochemical properties and charge transport characteristics as per their molecular arrangement and their stacking/orientation on the substrate. The main purpose of this study was to substantiate the significant effect of surface induced processing methodology on the assembly of the PTZ-TCNQ complex and its charge transport characteristics. We believe this study may open new dimension towards large area based organic electronics device application of TCNQ based organic metals.

Biography:

Alay Patel is pursuing his graduation in Mechanical Engineering at Pandit Deendayal Petroleum University, Gandhinagar, Gujarat, India. He has been appointed as an Undergraduate Research Assistant to a PhD scholar and has been working on the topic of Electrochemical Deburring for the past two and half years. Based on his passion and the opportunities provided at the institution, he has gained a good amount of knowledge base and research experience in manufacturing division of mechanical engineering. Other than that, he had participated in an industrial innovation competition organized by Larsen & Toubro (L&T) Technological Services, in which he secured a position in top 20 participants out of 7000, at the national level.

Abstract:

Statement of the Problem: Electrochemical deburring (ECD) is a widely popular process among industries to manufacture miniature parts and intricate components. Hence, it is important to optimize its process parameters to obtain high material removal rates and cost efficiencies. The domain of this paper focuses on the electrolyte types and control over the variation of its concentration during ECD operations. Here, a technique is developed to maintain a set value of electrolyte concentration based on its relation with the electrical conductivity of electrolytes.

Methodology & Theoretical Orientation: Sample testing solutions were prepared in laboratory for the electrolytes, sodium chloride and sodium nitrate. Conductivity and total dissolved solids (TDS) measurements were taken for each sample and recorded. Standard conductivity and TDS versus concentration charts were prepared corresponding to the measurements. Then the charts are trend-fitted to obtain certain empirical relations for the concerned parameters. These relations are then used to identify the value of conductivity by substituting the desired amount of concentration.

Conclusion & Significance: The measured values of conductivity and TDS for various concentrations of sodium chloride and sodium nitrate show a proportionate growth with respect to the concentrations. The interpolation models obtained from the plots can be utilized in industrial ECD operations to control and manipulate concentration of electrolytes. As it is a difficult task to maintain a set value of concentration in such applications, this technique can simplify it by monitoring the corresponding value of conductivity for the required concentration.

Biography:

Dina U Alshimbayeva is pursuing her PhD with specialization in Project Management. Her major is Oil and Gas Business. She is the Executor of research projects in alternative energy sources, geology and oil and gas industry, metallurgy fields. She has experience of commercialization of results of scientific research and technologies.

Abstract:

Biography:

Meet Oza is pursuing his graduation in Mechanical Engineering from Pandit Deendayal Petroleum University, Gandhinagar, Gujarat, India. He had participated in an industrial innovation competition organized by Larsen & Toubro (L&T) Technological Services, in which he secured a position in top 20 participants out of 7000, at the national level.

Abstract:

Statement of the Problem: Electrochemical deburring (ECD) appears to be very promising in the field of precision manufacturing. High precision and machining rates of this micro-machining technique has led to a wide variety of industrial applications, especially in mass production cycles. The study in this paper focuses on the application of combination of different electrolytes and control over the variation of its composition during ECD operations. In this study, various combinations of sodium chloride and sodium nitrate solutions are used as electrolytes and the performance of ECD has been evaluated.

Methodology & Theoretical Orientation: Testing solutions, with various percentage combinations were prepared in laboratory for various combinations of electrolytes, sodium chloride and sodium nitrate, with individual concentrations providing maximum machining rates. Conductivity was measured for each sample and recorded. Standard conductivity versus composition charts and equations were prepared corresponding to the measurements. Experimental trials were conducted on the available setup. The material removal rates and current densities were calculated and compared.

Conclusion & Significance: The measured values of conductivity for these combinations show a growth with respective increment in sodium chloride proportions. The interpolation models obtained from the plots can be utilized in industrial ECD operations to control and manipulate concentration of electrolytes. The MRR and current densities also are proportionate to the percentage of sodium chloride in the solution. Hence, it can be concluded that the effect of sodium chloride in the combination is more dominant. At the same time more stray cuts are observed with higher NaCl values.

Biography:

Harsh Thakkar is pursuing graduation in Mechanical Engineering at Pandit Deendayal Petroleum University, Gandhinagar, Gujarat, India. He has been working on topic of Electrochemical Deburring for the past two and half years. He was the Member and Vice President of Team INDEAGLES who participated in SUPRA SAEINDIA, in which the team secured 56^th rank for the first time out of 250 teams at national level.

Abstract:

Statement of the Problem: A rapid increment in demand of highly accurate, repeatable finishing process for high value added applications, like aerospace and automotive, has led to the development of technologies like electrochemical deburring (ECD). Thus, it is of utmost importance to evaluate and optimize the performance of ECD process. This study is focused on evaluation of ECD process by comparison of material removal rates and maximum current obtained by variation in process parameters like machining time, electrolyte concentration.

Methodology & Theoretical Orientation: The paper mainly aims to evaluate the performance of electrochemical deburring process by varying certain process parameters during the deburring of internal holes. These parameters include the cycle time, electrolyte type, electrolyte concentrations. The results are obtained by a comparative study of several experimentations and characterization of the deburred area.

Conclusion & Significance: The analysis of ECD process helps to obtain the optimum value of parameters that is essential to increase the productivity of industries that require deburring of components. Deburring of internal geometries can be done by various processes like hand deburring, honing, abrasive jet machining etc. but all these processes do not ascertain specific spatial control over the deburred area, which is possible with electrochemical deburring. Hence, it is important to evaluate the performance of ECD and also to check the economic viability of the process.