bluuebunny/crossref_metadata_2025 huggingface dataset:
Flexible and Versatile Nanoparticle Synthesis By Gas-Diffusion Electrocrystallization
Authors: Dominguez-Benetton Xochitl , Prato-Modestino Rafael , Eggermont Sam , Pozo Guillermo , Fransaer Jan
Published: February 2020

Diverse areas of electrochemistry are greatly impacted by nanoscale materials. In return, electrochemistry is demonstrating a fast-growing impact on their synthesis. This slipstream conveys a vibrant ecosystem for electrochemical breakthroughs that bring about advanced nanomaterials.

Gas-diffusion electrocrystallization (GDEx), a new electrochemical process that we have developed, allows the synthesis of crystalline nanomaterials with well controlled and narrowly distributed properties that relate to specific functionalities. Gas-diffusion electrocrystallization is a one-pot rapid process involving a porous cathode with surface functionalities, an aqueous electrolyte containing metal or metalloid ions, and an oxidant gas, in which colloidal dispersions of nanomaterials or solid nanoparticles are synthesized. The general principles and mechanism through which GDEx operates will be introduced. Furthermore, examples of nanomaterials we have produced and their functionality or industrial relevance will be disclosed.

For instance, cerium oxide nanoparticles with controlled crystallite sizes in the range of 2 to 10 nm as well as varying content of Ce3+ and Ce4+ sites, which result in different degrees of oxygen sorption capacities and kinetics were synthesized using GDEx. Due to this feature, these cerium oxide particles can be tailored for pro-oxidant or anti-oxidant applications of interest for electronic packaging, oxidative stress alleviation, or cancer therapy. Likewise, lanthanum carbonate hydroxides formed by GDEx may find a niche as phosphate scavengers.

GDEx was also used to produce iron oxide nanoparticles in the range of 40 to 100 nm in which the ratio of heamatite (Fe2O3) and magnetite (Fe3O4) can be tweaked, providing the possibility to regulate their magnetic susceptibility. These materials are studied for molecular diagnostics. Solid nanoparticles of herbertsmithite, have been obtained through GDEx when applied to electrolytes containing Cu2+, Zn2+ and Cl– ions, by manipulating the redox potential. These Cu/Zn-based nanoparticles may have applications in data storage, high-temperature superconductors and for so-called ‘‘quantum-entangled’’ batteries.

Finally, when operating GDEx with Mn(III/IV), compositions with birnessite and hausmannite—which may intercalate water and alkali metals— were synthesized, providing promising materials for batteries electrodes or catalysts.

In conclusion, GDEx is revealed as a new route to synthesize a wide range of nanoparticles, flexibly and with versatile control of composition, morphology, and physicochemical parameters such as crystallite size, lattice parameter and particle size, which in turn tailor specific functionalities.

The authors acknowledge the grant from the Flemish SIM MaRes programme for SBO project Get-A-Met.
Analysis of Amorphous Matrices Induced in Nickel Nanowires Due to Kilo-Electron-Volt H+ Ions Beam Irradiation for Application in Spacecrafts
Authors: Honey Shehla , Ahmad Ishaq , Malik Maaza , John Kennedy , Naseem Shahzad
Published: February 2020

This report is based on study of defect clusters or amorphous matrices induced in nickel nanowires (Ni-NWs) due to interaction of a beam of ~ 60 KeV hydrogen (H+) ions. Ni-NWs are exposed to various fluencies of hydrogen (H+) ions ranging between ~ 1014 ions/cm2 to 1017 ions/cm2. The analysis of pristine and hydrogen (H+) ions irradiated Ni-NWs samples has been mainly done using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction (XRD) techniques. SRIM (stopping range of ions in matter) simulation is performed to corroborate the production of defect clusters/amorphous matrices in Ni-NWs theoretically. Moreover, basic insight of defect creation in Ni-NWs due to interaction of low energy in kilo-electron-volt (KeV) range hydrogen (H+) ions has been built using collision cascade theory. The purpose of this analysis is to explore the possibility of application of Ni-NWs based future nanodevices in environment containing plenty of hydrogen (H+) ions such as for use in spacecrafts employed for upper space missions.
The Effect of CVD-Graphene at the Active-Layer/Current-Collector Interface for High-Performance Supercapacitor
Authors: Kwon Younghwi , Shin Junsung , Seo Yongho
Published: February 2020

Supercapacitors, that is to say, electrochemical double-layer capacitors are considered very promising candidates for energy storage device due to their high specific energy and power densities, long cycle life, and fast charge and discharge rates. Typically, the specific capacitance of the ultra-capacitor with high rate capability is much less affected by the charge/discharge rates and thus is particularly attractive for high power applications such as heavy transport and electric vehicles. For such a high performance supercapacitor, it is important to consider the interface of active layer/electrolyte and the interface of the active layer/current collector. In the paper, we report that the presence of graphene layer between the active material and current collector has made it possible to improve the performance of supercapacitor. To demonstrate the advantages of Chemical vapor deposition (CVD) grown graphene, three types of working electrodes were fabricated for comparison by applying graphene films as the active materials in a symmetric two-electrode supercapacitor: 1) without CVD graphene, 2) with transferred CVD graphene on current collector, and 3) with direct-grown CVD graphene on current collector. The effect of graphene on current collector is analyzed by performing cyclic voltammetry (CV), galvanostatic charge/discharge measurement, and electrochemical impedance spectroscopy.
Synthesis and Characterization of Gold Nanoparticle/Boron Nitride Nanotube Composites Toward Hydrogen Generation Reaction
Authors: Huff Clay , Dushatinski Thomas , Abdel-Fattah Tarek M
Published: February 2020

Hydrogen gas is praised for being an environmentally friendly and renewable alternative fuel; however, it is still energy-intensive to produce and is limited in storage due to its gaseous phase. The use of hydrogen feedstock materials (HFMs) is an attempt to address the storage problems of this fuel in which the hydrogen gas is released as needed and stored in HFMs when not being consumed. Many of these materials do not produce hydrogen at a relevant rate for energy applications without the use of a proper catalysts. Gold nanoparticles have displayed impressive catalytic activity for hydrogenation reactions and hydrogen generation reactions. AuMWCNT composites have shown a synergistic relationship where by composites outperform both individual components in these reactions. The recent growth in the field of research of Boron nitride nanotubes (BNNTs) has encouraged many studies of this material, including its capabilities within nanocomposites. BNNTs have demonstrated excellent stability, but are electrically insulating materials. This indicates that the BNNTs will act much differently as a support material for Au nanoparticles as the electrical conductivity of MWCNTs provides stabilization of functionalized materials. The goal of this study is to synthesize and characterize an Au nanoparticle BNNT composite. The synthesis will mimic the technique used in previous works [1]. The produced composites will be characterized via SEM, TEM, and EDS. The materials will also be tested for catalytic activity using a previously described gravimetric water displacement system [1, 2].

References

C. Huff, T. Dushatinski, A. Barzanji, N. Abdel-Fattah, K. Barzanji, and T. Abdel-Fattah, ECS J Solid State, 6, M69-M71 (2017).

T. Dushatinski, C. Huff, and T. Abdel-Fattah, Applied Surface Science, 385, 282 (2016).
Energy from Salinity Gradients
Authors: Chittur Krishnaswamy Subramaniam
Published: February 2020

Osmotic power or salinity
gradient
power (SGP) is the energy available from the difference in the salt concentration between seawater and river water. Two practical methods for this are reverse electrodialysis (RED) and pressure retarded osmosis (PRO). SGP can be generated from reversible mixing of two kinds of water with different salt contents. A process for generating potential from salinity concentration gradient produced in single cell (25 cm2) and multi-cell assembly is presented. The salinity gradient is created using a fuel cell type cell with a micro-porous ion exchange membrane, both anionic (AEM) and cationic (CEM). The study was performed for various gradients.  Salt : Fresh, from 100 : 0 to 16000 : 0 was established using NaCl solution, in the electrode chambers. A potential of 25 mV/cm was realized at ambient temperatures and pressures for a bipolar AEM/CEM cell. The achievable potential is still below theoretical value.  The performance was optimized for various static and dynamic flow rates of the saline and fresh water. For this purpose the cell flow field was simulated using ANSYS and the flow field design was optimized for maximum coverage of the cell area. The cell performance can further be optimized for various Membrane Electrode System (MES) structure. Cyclic Voltammetry (CV) studies were made to understand the redox process.  The electrochemical and electrical efficiency was discussed for various gradients and flow rates. The higher the salinity gradient the larger is the potential generated. This is limited by the membrane characteristics. The membrane characteristics have been studied for optimal ion crossover for various gradients and flow.
Photoelectrochemical Zero Liquid Discharge System for Concentrate Brine Management
Authors: Mubeen Syed
Published: February 2020

There is a substantial amount of value-added chemical products in concentrated brines from desalination plants that is currently wasted or lost in the treatment process. Capturing a portion of these chemical products would provide a new source for producing fuels and industrial chemicals that would also minimize concentrate volume. This talk will discuss our recent efforts to demonstrate and evaluate the feasibility of an integrated sunlight-driven zero liquid discharge system for inland brackish desalination, with concomitant production of fuels and chemicals.
Treatment of Acid Mine Drainage from an Abandoned Coal Mine in a Mcirobial Fuel Cell
Authors: Liu Jia
Published: February 2020

In this study, a microbial fuel cell was used to treat acid mine drainage (AMD) from anabandoned coal mine in the cathode chamber under aerobic condition. Activated sludge from a local wastewater treatment plant was used in the anode chamber of the BES to supply electrons to the treatment. After 7 days, the pH of the cathode solution enhanced from 2.5 to 7.3. More than 99% of Al, Feand Pb were removed, and removal rates of 93%, 91%, 89% and 69% were achieved for Cd, Zn, Mn and Corespectively with biocathode. Energy-dispersive X-ray spectroscopy (EDS) study revealed the depositionof the various types of metals on the cathode surface, and some metals were detected in the precipitatesof the cathode chamber. The bacteria for AMD treatment was identified to be Serratia spp. using 16s rRNAgene amplification and sequencing. Scanning electron microscopy showed attached growth of the bacteria on the cathode. The bioelectrochemical treatment of the AMD was also compared with the biological treatment in a continuously stirred batch reactor (CSBR). Around 30~50 mV of the closed circuit voltage was obtained for different cases in this study.

Figure 1
Conversion of Saline Water and Carbon Dioxide into Value-Added Chemicals By Electrodialysis
Authors: Bonakdarpour Arman , Dara Saad , Ho Meghan , Lam Alfred , Wilkinson David P
Published: February 2020

A multi-compartment electrochemical reactor, which simultaneously converts carbon dioxide (dissolved or gaseous CO2) and high salinity waste-water to value-added chemicals, in the form of inorganic acids, carbonate salts and desalinated water, is demonstrated. The electrocehmical approach operates in electrodialysis or electrolytic mode and uses anion exchange and cation exchange membranes, and a Pt/Ir-coated Ti anode and Ti mesh cathode (for dissolved CO2) or Pt/C-coated gas diffusion cathode electrodes (for gaseous CO2) to produce acid and base products from CO2 (or CO2/O2) and an aqueous NaCl feed. The electrodialysis mode operates with carbonic acid feed while the electrolytic approach electrochemically converts carbon dioxide from the gas phase. With the gaseous conversion of carbon dioxide, a non-selective catalyst (carbon-supported Pt) was used to reduce the oxygen into hydroxyl ions which further reacted with CO2feed to form bicarbonate and carbonate species.

Under an applied voltage (~ 6 V) clear production of inorganic carbon salts and acids was observed. The product fluxes for HCl and NaHCO3 were ~ 0.05 mM cm-2 hr-1 on average for the case of dissolved CO2 and ~ 3.50 mM cm-² hr-1 for the case of gaseous CO2 showing an enhancement factor of about 70x in the flux rates with the use of gaseous CO2.

The bench-top (3.24 cm2 electrodes) cell has been successfully scaled up (1,500x) to a 5,000 cm² NORASCAND® commercial-scale electrolytic cell. Chemicals such as hydrochloric acid and bicarbonate salts have potential uses in many applications including oil and gas exploration and production where the chemicals as well as the desalinated water can be used in resource extraction. Coupling of CO2 removal and water treatment as presented here has potential applications in both conventional and unconventional oil and gas operations. Evolution of the technology from the conceptual bench-top reactor to initial scale up efforts and the current status of technology will be presented during the meeting.

Figure 1
Organic Molecular Catalyst for Electrochemical Production of Hydrogen Peroxide
Authors: Yin Xi , Lin Ling , Martinez Ulises , Chung Hoon T , Zelenay Piotr
Published: February 2020

Hydrogen peroxide (H2O2) as a low cost, safe and clean disinfection agent plays an important role in providing clean water for human society. Compared with complicated industrial anthraquinone process or direct catalytic synthesis from H2 and O2, the distributed production of H2O2 in a polymer electrolyte fuel cell system (PEFC) has numerous merits, including lower financial and energy cost, safer process, use of small-scale, easily deployable device.1,2 For these reasons, there is strong interest in developing electrocatalysts with high activity and selectivity for H2O2 production via the electrochemical reduction of molecular oxygen. Up until now, H2O2 electrocatalysts have been based on precious-metal amalgams, which are costly, scarce, and difficult to handle safely due to the use of Hg.2,3 Carbon-based electrocatalysts have been considered for H2O2 production,4-6 as have been metal-free and nitrogen-containing molecular catalysts known to be selective for two-electron reduction of O2 in various media.7-9

In this presentation, we will demonstrate a new catalyst based on a small organic molecule that enables electrochemical production of H2O2 in an aqueous acidic electrolyte (0.5 M H2SO4). When adsorbed onto glassy carbon this molecular catalyst shows a high onset potential of around 0.6 V vs. RHE, and a specific current density > 1.3 mA/cm2
ECA at 0 V vs. RHE in electrochemical cell test. Rotating ring-disk electrode (RRDE) studies indicate high selectivity for H2O2 production, with H2O2 yield over 80%, and current efficiency over 67%. The durability of this molecule has been evaluated in an electrochemical cell, as well as in a PEFC. Based on experimental data and density functional theory (DFT) calculations, a two electron oxygen reduction mechanism on this molecular catalyst will be proposed.

References

(1) Centi, G.; Perathoner, S.; Abate, S. In Modern Heterogeneous Oxidation Catalysis; Wiley-VCH Verlag GmbH & Co. KGaA: 2009, p 253.

(2) Siahrostami, S.; Verdaguer-Casadevall, A.; Karamad, M.; Deiana, D.; Malacrida, P.; Wickman, B.; Escudero-Escribano, M.; Paoli, E. A.; Frydendal, R.; Hansen, T. W.; Chorkendorff, I.; Stephens, I. E. L.; Rossmeisl, J. Nat. Mater.
2013, 12, 1137.

(3) Verdaguer-Casadevall, A.; Deiana, D.; Karamad, M.; Siahrostami, S.; Malacrida, P.; Hansen, T. W.; Rossmeisl, J.; Chorkendorff, I.; Stephens, I. E. L. Nano Lett.
2014, 14, 1603.

(4) Yamanaka, I.; Onizawa, T.; Takenaka, S.; Otsuka, K. Angew.
Chem. Int. Ed.
2003, 42, 3653.

(5) Yamanaka, I.; Onisawa, T.; Hashimoto, T.; Murayama, T. ChemSusChem
2011, 4, 494.

(6) Fellinger, T.-P.; Hasché, F.; Strasser, P.; Antonietti, M. J. Am. Chem. Soc.
2012, 134, 4072.

(7) Hatay, I.; Su, B.; Méndez, M. A.; Corminboeuf, C.; Khoury, T.; Gros, C. P.; Bourdillon, M.; Meyer, M.; Barbe, J.-M.; Ersoz, M.; Záliš, S.; Samec, Z.; Girault, H. H. J. Am. Chem. Soc.
2010, 132, 13733.

(8) Wu, S.; Su, B. Chem. Eur. J.
2012, 18, 3169.

(9) Savéant, J.-M. Chem. Rev.
2008, 108, 2348.
Three Dimensional Electrodes for Seawater Desalination
Authors: Alsaedi Sattar
Published: February 2020

Surging population and climate change will push society, ever more urgently, to harvest lower quality or impaired water supplies (e.g., sea water or brackish groundwater) for drinking water. For example, membrane based seawater desalination (Reverse Osmosis and Electrodialysis) has become a promising technique for providing additional sources of fresh water along coastal communities. However, their widespread adoption is currently limited due to its energy intensive nature and/or limited membrane lifetime and performance, especially during high operation rates. Here, we report a novel, cost-effective, electrode architecture for improving energy efficiency and desalination rates. Specifically, we have replaced planar electrodes in traditional electrodialysis units with electrodes with three-dimensional complex architecture for improved current utilization, while reducing the iR losses due to ion-transport.
(Invited) Brain Initiative & Biomaterials Research Support at the National Science Foundation
Authors: Simonian Aleksandr
Published: February 2020

In this presentation, the NSF perspective on the BRAIN Initiative research and education, as well as a description of the NSF/DMR/BMAT program perspective on biomaterials research and education will be presented.

The BRAIN Initiative (Brain Research through Advancing Innovative Neurotechnologies) is a collaborative, public-private research initiative with the goal of supporting the development and application of innovative technologies that can create a dynamic understanding of brain function. In support of the BRAIN Initiative, the NSF announced a funding opportunity to support transformative and integrative research to accelerate our understanding of neural and cognitive systems as part of The BRAIN Initiative. NSF Director France Cordova commended the initiative, stating, "The BRAIN Initiative is truly an exciting and potentially game-changing effort to unlock the secrets of one of humankind's most enduring mysteries". The BRAIN Initiative was kicked off with a total of $100 million in initial commitments from NSF, the (U.S.) National Institutes of Health, the Defense Advanced Research Projects Agency, and a number of private research institutes. Since its launch, the initiative has expanded to include the participation of several other federal agencies, scientific societies, and nonprofit organizations.

The Biomaterials program supports fundamental materials researchrelated to (1) biological materials, (2) biomimetic, bioinspired, and bio-enabled materials, (3) synthetic materials intended for applications in contact with biological systems, and (4) the processes through which nature produces biological materials. Projects are typically interdisciplinary and may encompass scales from the nanoscopic to the bulk. They may involve characterization, design, preparation, and modification; studies of structure-property relationships and interfacial behavior; and combinations of experiment, theory, and/or simulation. The emphasis is on novel materials design and development and discovery of new phenomena.

General information on all the programs in DMR can be found on the DMR Web page: http://www.nsf.gov/div/index.jsp?div=DMR. In addition, attendees will have the opportunity to interact “one on one" with NSF BMAT Program Director.
(Invited) Electrochemical Deposition of Conjugated Polymers in the Brain
Authors: Martin David Charles , Ouyang Liangqi , Subramanian Vivek
Published: February 2020

We have been examining the direct electrochemical deposition of conjugated polymers such as poly(3,4-ethylene dioxythiophene) (PEDOT) into living brain tissue. We use a microcannula to deliver the monomer solution, and a microelectrode to deliver the current. By precisely tailoring and controlling the rate of delivery of the reactants and current, we have shown that PEDOT can be grown out and into tissue for hundreds of microns or more. Our hypothesis has been that this may lead to improved long-term communication between implanted electrodes and the surrounding neural tissue, by creating electrically and ionically conductive pathways across the ~150 um thick reactive glial scar that develops after device implantation. We will discuss our work to investigate this method as applied to electrodes implanted into rat hippocampus, where we showed that electrochemically deposited PEDOT does not cause a significant decrease in the ability of the animal to navigate a maze in a forced alternation task. Most recently, we have been examining the electrochemical deposition of PEDOT in the TEM using a in-situ liquid cell. These studies have revealed previously unseen details about the liquid-to-solid phase transition during the electropolymerization reaction, and have provided clues about how to improve the process in the future.
(Invited) Dopamine, Acetylcholine, and Insulin: Modulators of Motivation
Authors: Rice Margaret E
Published: February 2020

Striatal dopamine plays key roles in modulating motor and reward behaviors. Dopamine release from striatal axons is often assumed to be governed exclusively by the firing pattern of midbrain dopamine neurons. However, it is also strongly influenced by local transmitters, especially acetylcholine (ACh), as well as extrinsic factors, like insulin. Indeed, ACh-dopamine interactions are central to the influence of peripherally derived insulin in the striatum. At physiological concentrations, insulin enhances evoked dopamine release in ex vivo striatal slices, monitored with fast-scan cyclic voltammetry (FSCV). This enhancement requires ACh and nAChRs, as the effect is lost in striatal slices from mice with forebrain ACh deletion, or after pharmacological antagonism of nAChRs. Consistent with these results, insulin also enhances evoked ACh release, detected using a carbon-fiber-based enzyme electrode to detect ACh. Further mplicating striatal cholinergic interneurons (ChIs) in this process, insulin ACh increases ChI excitability via insulin receptors on these cells. The amplification of DA release by insulin suggests a role for this neuropeptide as a reward signal, which complements its well-established role in satiety. Companion behavioral studies show that intact insulin signaling conveys the nutritive value of what we ingest, and thereby reinforces preference for high sugar substances. Together, these data reveal the key roles of local modulation of dopamine within the striatum in mediating the influence of insulin on motivation.
(Invited) Carbon Fiber Electrode Array for the Detection of Electrophysiological and Dopaminergic Activity
Authors: Patel Paras R. , Popov Pavlo , Mohebi Ali , Hamid Arif , Pettibone Jeffrey , Roossien Doug , Aragona Brandon , Cai Dawen , Berke Joshua , Chestek Cynthia
Published: February 2020

To better understand how neuromodulators influence information processing we need to be able to monitor both chemical and electrical activity with high spatial and temporal resolution. This holds particularly true for the nucleus accumbens, a critical structure for motivated decision making. Subregions of the nucleus accumbens (including core and shell) have functionally distinct dopamine release characteristics, and sampling from these subregions with multiple electrodes has been difficult due to the size of existing glass or silica- insulated carbon fiber electrodes. To overcome this issue we have developed a high-density carbon fiber electrode array that can alternately monitor electrophysiological and dopaminergic activity in multiple subregions simultaneously. Specifically, we have developed a 16-channel array using a thin (t=50µm) flexible printed circuit board as the underlying substrate. At the end of this extension 16 carbon fibers, at a pitch of 132 um, are secured using silver epoxy. The fibers extend past the edge by 500µm, which is short enough for self-insertion, and are insulated with parylene-c. The tips of the fibers are then laser etched to re-expose a carbon surface and treated with oxygen plasma to remove any remaining debris. The laser and oxygen plasma steps result in a low electrode impedance and eliminate the need to electrodeposit poly(3,4-ethylenedioxythiophene). This array has been implanted in n=3 animals to date. Implanted arrays have exhibited single unit activity, as well as signatures of dopamine activity using cyclic voltammetry while the animal is awake and behaving. Phasic surges in dopamine concentration (i.e. dopamine ‘transients’; indicative of dopamine release from burst firing of dopamine neurons) were also detected using fast scan cyclic voltammetry after the administration of a cocaine and raclopride mixture through a venous port. In n=1 rat, the brain was sliced with the electronics in place after chronic experiments to visual the position of electrode tips, and the neurons immediately surrounding them. Thus, the array allows for sampling of electrical and chemical activity from neighboring, but still distinct, neuronal populations. Increasing the electrode density and count will provide yet further information about the influence of dopamine over microcircuit computations.
(Invited) Modulating and Recording from Peripheral Nerves and End-Organs Using Electricity and Ultrasound
Authors: Lim Hubert
Published: February 2020

There has been a surge of interest and efforts towards modulating peripheral nerves, such as the vagus nerve, to treat various health conditions including tinnitus, rheumatoid arthritis, inflammatory bowel disease, depression and several other diseases. Unfortunately, there is limited understanding of the anatomical and functional organization of these peripheral pathways and their effects on different end-organs in healthy and diseased states. I will present recent results from my lab demonstrating the ability to use electrical and ultrasound stimulation to modulate the vagus nerve pathway and spleen to alter release of specific cytokines and biomolecules within the body, as well as reduce symptoms associated with rheumatoid arthritis in rodents. Ultrasound stimulation can enhance or suppress ongoing nerve activity depending on the selected parameters. These neuromodulatory effects may involve both thermal and mechanical mechanisms. Encouragingly, ultrasound stimulation could serve as a noninvasive method for modulating peripheral nerves and end-organs towards treatment of various diseases. Ultrasound stimulation could also be paired with electrical stimulation to achieve various modulatory and therapeutic effects. Further studies are needed to identify appropriate targets and stimulation patterns for different health conditions.
(Invited) Light up the Brain with Genetically Encoded Indicators of Neural Activity
Authors: Tian Lin
Published: February 2020

To study the neural circuitry, the action of one cells under the context of others, one would precisely measure and perturb specific neuronal populations and molecules in behaving animals who are specifically engaged in performing the computation or function of interest. The dataset of millions of neurons firing together underlying a behavior are required to develop and refine theories (hypotheses) explaining animal behavior in terms of brain physiology. A key challenge has been difficulty of assessing the synaptic transmission with optical methods. My lab has developed a new suite of genetically encoded indicators that would enable one to 1) specifically highlight the structure of single spines and axonal termini in densely labeled neurons and record glutamate activity; 2) simultaneously record synaptic connectivity and glutamate activity to identify active synapses; 3) direct record the release of neuromodulators. We demonstrate the utility of these indicators in cells, rat hippocampal neurons and in vivo. We expect that applications of these imaging tools will contribute to a dynamic and comprehensive view of synaptic transmission in action to decipher the codes for transferring information across neural circuitry and systems.
(Invited) Conjoint Measurement of Brain Electrophysiology and Neurochemistry
Authors: Zaveri Hitten P. , Ganesh Nimisha , Goncharova Irina I , Damisah Eyiyemisi , Ong Caroline , Perez Edgar , Staib Lawrence , Hirsch Lawrence , Petroff Ognen , Spencer Dennis , Eid Tore
Published: February 2020

Purpose: We routinely perform conjoint measurement of intracranial electrophysiology and brain neurochemistry in patients with medically intractable epilepsy undergoing intracranial EEG (icEEG) monitoring for possible epilepsy surgery. The conjoint measurement of these two modalities can be revealing of the presumed neurochemical basis of electrophysiological markers of human brain excitation and inhibition. This study focused on interictal electroencephalography (EEG) spikes. Interictal EEG spikes have traditionally been considered to be a marker of brain excitability in epilepsy, though some recent research has questioned this assumption. Here we correlated co-localized measurements of intracranially recorded interictal EEG spikes and basal extracellular glutamate concentrations, a well-established marker of excitation, in patients with intractable epilepsy.

Methods: Glutamate was quantified from brain microdialysate obtained from 30 combined depth icEEG electrode and microdialysis catheters placed in 15 patients. EEG spikes were counted, at the time when glutamate was documented, in two separate manners: (1) for the two icEEG electrode contacts on either side of the microdialysis membrane, and (2) for all contacts within the brain region where the dialysis probe was located.

Results:We observed the interictal icEEG spike rate was not directly proportional to basal glutamate; rather the icEEG spike rate was low when basal glutamate was high, and vice versa. A joint analysis of brain electrophysiology and neurochemistry thus indicates an inverse, rather than a direct, relationship between interictal icEEG spikes and brain extracellular glutamate.

Discussion: Interictal EEG spikes have traditionally been considered to be a marker of brain excitability. The lack of a direct relation between basal glutamate and icEEG spike rate, however, supports the suggestion that EEG spikes may not be reflective of brain excitability, but rather may be reflective of inhibition. To support the findings of this study and underscore the importance of the conjoint measurement of brain electrophysiology and neurochemistry we discuss observations of other studies of interictal EEG spikes, and observations from other studies of conjoint brain electrophysiology and neurochemistry performed by our group.

Conclusions: This study suggests that there is considerable value for in-vivo co-localized measurement of human brain electrophysiology and neurochemistry to improve our understanding of these two modalities, and for understanding the mechanism underlying medically intractable epilepsy.
(Invited) Scaling Effects on the Electrophysiological Stimulation Capabilities of PEDOT:PSS, Pt, and Au
Authors: Ganji Mehran , Dayeh Shadi
Published: February 2020

Recent clinical successes of neuromodulator devices such as cochlear implants, deep brain stimulation (DBS) and spinal cord stimulation have generated a wide interest in exploiting emerging state-of-the-art biomaterials for therapeutic electrical stimulation of neurological diseases and disorders. Some of these applications require localized stimulation using microelectrodes with a charge injection density beyond 0.5 mC/cm2 that exceeds Pt and Pt alloys charge injection limits (0.3 mC/cm2). This is where IrOx, TiN and conducting polymers (CPs) emerge as potential candidates as materials for next generation microelectrodes.

Here, we present a systematic in-vitro charge injection study to benchmark stimulation performance of PEDOT:PSS on Au, PEDOT:PSS on Pt, and reference Au and Pt electrodes across 20μm to 2000μm electrode diameters. In our study, higher charge injection capacity was measured for PEDOT:PSS/Pt microelectrodes (20 µm to 150 µm diameter size) which was ~3.4 time larger than Pt and ~9 time larger than Au microelectrodes. However, macroscale PEDOT:PSS/Au electrodes (200 µm to 2000 µm diameter size) displayed higher charge injection capacity compare to other electrode materials. Optimal OCP bias voltage was presented at 0.4 V for both PEDOT:PSS/Au and Pt micro/macro electrodes. Particularly, CICs of microelectrodes experienced ~55% and ~135% enhancement compare to zero bias voltage, resulted in maximum 1.88 mC/cm2 and 0.8 mC/cm2 CIC for PEDOT:PSS/Au and Pt microelectrodes respectively. CICs of PEDOT:PSS/Au micro/macro electrodes boosted ~ 13-14% further at 0.5 V OCP bias voltage by pulse engineering (asymmetric pulse injection). Charge injection capacity introduced as frequency-dependent parameter whereas PEDOT:PSS/Au microdots and macrodots demonstrated 40% and 21% larger CIC by pulse width expansion from 200 µs to 2 ms duration; which highlights the importance of accurate regulation of stimulation methodology parameters such as pulse width to make proper balance between safe (higher CIC) and initiative neural stimulation (higher current and frequency). Finally, Charge storage capacity (CSC) evaluation revealed the largest CSC for Pt micro/macro electrodes compare to other electrode materials, whereas PEDOT:PSS/Au micro/macro electrodes offered higher capability to convert those available stored charges into injected electrical pulse (higher CIC/ CSC ratio).

We believe that these results could pave the way toward establishing safe and efficient clinically-relevant stimulation protocol for PEDOT:PSS microelectrodes.
Detection of Foodborne Bacteria based on AlGaN/GaN HEMT DNA Sensors
Authors: Park Minseo , Thapa Resham , Son Ahjeong
Published: February 2020

It is of the utmost importance to rapidly detect and identify bacterial pathogens contained in food. Numerous studies have been performed to develop a biosensor to detect the biopathogens contained in food. Due to its high specificity, hybridization-based DNA sensing mechanisms have of high merit. Among the DNA hybridization biosensors, field effect transistor (FET) based sensors are of interest due to its rapidness in detection and label-free use. AlGaN-based high electron mobility transistor (HEMT) is a special type of a FET which exhibits a high charge sensitivity due to the ample existence of 2 dimensional electron gas (2DEG) in the quantum well transistor channel. In our research, we have fabricated AlGaN-based HEMT DNA sensor and has successfully demonstrated the DNA hybridization. In order to enhance specificity maintaining its sensitivity, an amine-based chemistry was used. A DNA with a sequence which represent that of salmonella were used as a probe. A 3 base-pair mismatched DNA was used as a control. A DNA with a complementary sequence was used as a target. The DNA sensor showed a significant current decrease when a complimentary DNA was applied to the gate well while a substantially small current reduction was observed for the introduction of 3 base pair mismatched DNA. Therefore, it was concluded that the AlGaN-based HEMT DNA sensor with amine-based chemistry exhibits high specificity in detection.

Ref) Resham Thapa, Siddharth Alur, Kyusang Kim, Fei Tong, Yogesh Sharma, Moonil Kim,

Claude Ahyi, Jing Dai, Jong Wook Hong, Michael Bozack, John Williams, Applied Physics Letters 100, 232109 (2012).
Rapid Pathogen detection By Surface Swab Sampling and Wireless Biosensing
Authors: Liu Yuzhe , Du Songtao , Horikawa Shin , Chen I-Hsuan , Wikle Howard Clyde , Lu Xu , Suh Sang-Jin , Davis Edward , Mansoorabadi Steven , Kim Dong-Joo , Nadolnyak Denis , Chin Bryan Allen
Published: February 2020

This paper presents a method that combines surface swab sampling and wireless biosensing for rapid detection of foodborne pathogens on solid surfaces. The method can be applied to any surfaces, including the surface of food processing tables and fresh produce, for improving food safety. Surface swab sampling is an inexpensive and easy-to-use method of collecting pathogens. A desired area or the whole area of a target surface (if needed) can be swabbed to collect pathogens rapidly. In this study, we first investigated the efficiency of capture and release of a model pathogen, Salmonella Typhimurium, in swab sampling. A Salmonella-contaminated surface (2 × 2 cm2 flat polyethylene slab) was prepared by using a spot-inoculation method. Five drops of a Salmonella solution (20 ul/drop at concentrations from 5X108 cfu/ml to 5X103 cfu/ml) were inoculated on the polyethylene surface and allowed to dry in a biosafety cabinet for 2 hours. Swab sampling was then conducted at a controlled temperature and humidity to capture the pathogen. Finally, the swabs used were dipped in a TBS solution for releasing the captured Salmonella cells. Various swab tip materials were tested, including cotton, rayon, and nylon. The effects of swab force and sonication/vortexing on the capture and release efficiency were also investigated. The released Salmonella cells were finally detected and quantified instantaneously by using a wireless phage-based magnetoelastic biosensor. By comparing the quantities of the initially inoculated cells and detected cells, the efficiency of capture and release was calculated.
Detection of Nitrite Pollutant with an Optical Sensor
Authors: Zheng Peng , Wu Nianqiang
Published: February 2020

Nutrient pollution is becoming a most widespread challenging environmental problem with increasing agriculture activities. A high level of nitrite pollutant is harmful to human and animals, especially to infants and pregnant women. Therefore, it is of paramount importance to develop a field-deployable sensor capable of conducting routine nitrite detection in the environment. Traditionally, the Griess reagent is used to treat a nitrite-containing sample and transduce a red pink color. However, the Griess test is vulnerable to false positives in colored sample matrices and limited in its sensitivity. Herein, we have developed a surface-enhanced Raman scattering (SERS) nanostructured device based on a modified Griess test, where nitrite is detected by transducing a SERS signal. The SERS sensor is built based on an optimized electromagnetic field coupling using finite difference time domain (FDTD) simulations. It is demonstrated for nitrite detection in Monongahela River water sample, achieving a linear detection range from down to part-per-trillion up to part-per-million levels.
Novel Low Symmetric Alkyne Terminated Metallophthalocyanine Modified Electrode Via Click Chemistry for Electrochemical Determination of Mercury (II)
Authors: Fomo Gertrude
Published: February 2020

An electrochemical method for the determination of trace levels of mercury(II) ions using metallophthalocyanine (MPc) modified glassy carbon electrode (GCE) via click chemistry by differential pulse stripping voltammetry (DPSV) is described for the first time. In this report, the novel synthesized low symmetry alkyne terminated cobolt Phthalocyanine (CoPc) derivative was prepared and characterized using FTIR, MS, UV-Vis, Elemental Analysis and cyclic voltammetry. Operational parameters such as number of scan for grafting step, concentration of CoPc derivative for clicking solution, and scanning potential range were optimized. Under the optimum experimental conditions, the anodic peak current is proportional to the concentrations of mercury over a wide range of 0.1 to 0.8 mM with the lowest detectable concentration of 440 nM. The selectivity of the CoPc modified GCE via click chemistry towards mercury in the presence of potential interferents such as copper, lead, cadmium and zinc was well studied. The fabricated electrochemical sensor exhibited very good electrocatalytic properties such as good reproducibility, stability and is suitable for the detection of mercury in tap water and seawater.

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Taylor Vortex Reactor: A Scalable Advanced Chemical Reactor for Producing Li-Ion Cathode Precursors
Authors: Kahvecioglu Feridun Ozgenur , Shin Youngho , Krumdick Gregory , Berkland Lisa
Published: February 2020

Although earlier adoption of continuous stirred tank reactors (CSTRs) were successfully employed in the synthesis of cathode precursor to day; there are still engineering challenges with the CSTRs, which makes several manufacturers to seek for alternative reactor systems. Typically, the CSTRs are modified (and still being modified based on the requirement of application) in order to overcome the common issues like: low reproducibility, product efficiency, very long stabilization times due to low mass transfer rate, hard to maintain the stability of the co-precipitation system, particle over growth by time and, etc.

Here, we report an advanced manufacturing system, Taylor Vortex Reactor (TVR), for the cathode precursor synthesis, which overcomes many complexities encountered in CSTRs. The talk will discuss the scalability of TVR as an alternative way of manufacturing cathode precursors and the outcomes of different scales will be compared.

Acknowledgement

Funding for this work from the Office of Vehicle Technologies of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, is gratefully acknowledged. The submitted abstract has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (“Argonne”). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357.
The Importance of Surface Tension Control in Slurry Preparation for Thick Electrode Manufacturing
Authors: Du Zhijia , Wood Marissa , Sheng Yangping , An Seong Jin , Li Jianlin , Daniel Claus , Wood David L
Published: February 2020

Abstract

Aqueous processing of Li-ion battery electrodes promises to reduce cost due to the elimination of the toxic solvent N-Methyl-2-pyrrolidone (NMP) [1]. It has been reported that good rate performance and cycling performance can be achieved by aqueous processing of lithium nickel manganese cobalt oxides (LiNi0.5Mn0.3Co0.2O2, NMC532) at ~2 mAh/cm2 loading [2]. To further increase the energy density of Li-ion cells, the loading needs to be increased to at least ~4 mAh/cm2 [3]. However, loading increases to this level using aqueous processing introduce critical cracking issues leading to poor performance [4].

This work reports the importance of surface tension control in the preparation of slurries for coating manufacturing with high areal loadings. Crack initiation and propagation associated with the build-up of capillary pressure during the drying process will be discussed. The surface tension of the slurry is reduced by the addition of another solvent, which leads to improved wettability and decreased capillary pressure during drying. The critical thickness (areal loading) without cracking increases gradually with decreasing surface tension. The electrochemical performance of pouch cells will also be discussed.

Acknowledgements

This research at Oak Ridge National Laboratory, managed by UT Battelle, LLC, for the U.S. Department of Energy (DOE) under contract DE-AC05-00OR22725, was sponsored by the Office of Energy Efficiency and Renewable Energy (EERE) Vehicle Technologies Office(VTO) (Deputy Director: David Howell) Applied Battery Research subprogram (Program Manager: Peter Faguy).

References:

[1] D. L. Wood, J. Li and C. Daniel, J. Power Sources 275 (2015) 234.

[2] J. Li, D. Mohanty, C. Daniel, and D. L. Wood III, Aqueous Processing of LiNi0.5Mn0.3Co0.2O2 Composite Cathodes for Lithium-Ion Batteries, 225th ECS meeting, May 11-15, 2014.

[3] Z. Du, D.L. Wood, C. Daniel, S. Kalnaus, J. Li, J. Applied Electrochemistry 47 (2017) 405.

[4] Z. Du, K.M. Rollag, J. Li, S.J. An, M. Wood, Y. Sheng, P.P. Mukherjee, C. Daniel, D.L. Wood III, Enabling aqueous processing for crack-free thick electrodes, J. Power Sources, In press.
Tubular TiO2 Structures Towards Biocompatible Microsupercapacitors
Authors: Salari Maryam , Aboutalebi Seyed Hamed , Ekladious Iriny , Jalili Rouhollah , Konstantinov Konstantin , Liu Hua Kun , Grinstaff Mark W
Published: February 2020

Self-organized tubular metal oxide nanostructures, synthesized through straightforward and efficient techniques, have resulted in many breakthroughs yet are underutilized in the energy and microdevice field. Here we demonstrate the fabrication and characterization of unique biocompatible energy storage devices that use self-assembled titanium dioxide (TiO2) and a physiological fluid such as PBS as the electrolyte, without any need of toxic conventional acidic or alkaline electrolytes. Achieving high capacitance through the use of a neutral aqueous electrolyte, combined with the biocompatibility of TiO2 and Ti films opens up new avenues for the investigation of these materials for energy harvesting applications in biological media. We also describe unadulterated anodized TiO2 with higher volumetric capacitance (220 F cm-3) and energy density (5.12 mWh cm-3) values compared to the conventional carbon based micro-supercapacitor devices.

Figure 1. (a) Cyclic performance of TNTA device obtained by CV test at scan rate of 20 mVs-1 along with the 2nd and 2000th cycles of the CV performances in two electrolytes (inset), (b) In-vitro biocompatibility of TNTAs; NIH 3T3 cells exposed to TNTAs for 24 hours did not exhibit a decrease in cell viability compared to untreated cells.

Figure 1