bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of Morphological Variation on SiO2/Nafion Composite Membrane Under Different Hydration Condition
Authors: Kwon Osung , Son ByungRak , Kim Joogon , Lee Dong Ha 
Published: February 2020

Passive air breathing proton exchange membranes fuel cells (AB-PEMFC) have a unique advantage such as remarkably reducing stack weight by minimizing balance of plant (BOP). However, the performance of the AB-PEMFC is worse than general PEMFC because it is difficult to controlling humidification and stack temperature. Thus, the proton exchange membranes (PEMs) which are used to AB-PEMFC have to stably work under various humidification and temperature. A lot of research groups are reported that inorganic fillers (SiO2, TiO2, ZrO2) and Nafion composite membrane show high performance under low relative humidity by increasing water retention on the membrane. In this study, we synthesize SiO2/Nafion composite membrane for compensating the weakness of AB-PEMFC.
The performance of membrane electrode assembly (MEA) with SiO2/Nafion composite membrane is tested under different hydration and temperature conditions. For more detailed characterization, morphological variations of the composite membrane under hydration conditions are studied by using dynamic mode atomic force microscopy (DMAFM). DMAFM can map amplitude and phase distribution on the specimen surface. The phase lag, which is mechanical vibration changing of a cantilever, is resulting of tip-sample interaction, which is induced by microscopic mechanical property of sample. Thus, the DMAFM is best tool for characterizing heterogeneous materials such as composite membrane. The morphological structure variation on the composite membrane by water retention elevation is systematically studied by using phase lag changing under different humidification condition.

References

C. A. Hayden, and G. R. Goward, Proton Dynamics of Nafion and Nafion/SiO2 Composites by Solid tate NMR and Pulse Field Gradient NMR Macromolecules 40, (2007), 1529-1537

Bella Nicotera, Apostolos Enotiadis, Kristina Angjeli, Luigi Coppola, Giuseppe A. Ranieri, and imitrios Gournis, Effective Improvement of Water-Retention in Nanocomposite embranes Using Novel Organo-Modified Clays as Fillers or High Temperature PEMFCs, Journal of Physical Chemistry B 115, (2011), 9087–9097

Figure 1
Aptamer-Based Electrochemical Biosensors for Marine Toxins
Authors: Eissa Shimaa , Siaj Mohamed , Zourob Mohammed 
Published: February 2020

Marine toxins are naturally occurring chemicals that can contaminate certain seafood. They are usually tasteless, odourless and have no toxic effect on shellfish. However, they exhibit toxicity towards marine mammals, birds, fish and humans. The ethical problems as well as the technical difficulties associated with the currently employed analysis methods for marine toxins are encouraging the research for suitable alternatives to be applied in a regulatory monitoring regime. Here, we report electrochemical biosensing platforms for okadiac acid (OA) as well as brevetoxin-2 (BTX-2) detection using aptamers as specific receptors. Using in vitro selection, high affinity DNA aptamers to OA and BTX-2 were successfully selected for the first time from a large pool of random sequences. The binding of the toxins to aptamer pools/clones was monitored using fluorescence and electrochemical impedance spectroscopy (EIS). Most of the selected aptamers exhibited high binding affinity to their target toxins with a dissociation constants in the nanomolar range. The effects of the incubation time, pH and metal ions concentrations on the aptamers-toxins binding were studied. The highest affinity aptamers were then used to construct label-free impedimetric biosensors for both OA and BTX-2 detection showing good sensitivity. A high degree of cross reactivity of the selected BTX aptamers to the two similar congeners, BTX-2 and BTX-3 was observed, whereas no cross reactivity to other marine toxins was obtained. Moreover, the aptasensors were applied for the detection of OA and BTX-2 in spiked shellfish extracts showing very good recovery percentages. We believe that the continual emergence of novel, high-affinity aptamers will open the way to a variety of biosensing architectures, particularly for small-molecule toxin detection in complex samples.
(Invited) Graphene and 2d Crystals for Energy Devices
Authors: Pellegrini Vittorio , Bonaccorso Francesco 
Published: February 2020

Energy conversion and storage are two of the grand challenges that our society is facing. New materials and processes [1] can improve the performance of existing devices or enable new ones [2] that are also environmentally benign. In this talk we will start by reviewing recent progress on the application of graphene, related two-dimensional crystals, and hybrid systems for energy conversion and storage [3]. The versatility of graphene and related materials can lead to new power management solutions for portable and flexible devices, as well as integration in living environments. In this context we will present our latest results on the development of solar module based on graphene ink deposited by spray coating on large area (~50cm2), a promising starting point for façade applications. We will then focus on our recent development of graphene-based ink battery that displays an estimated energy density of about 200 Whkg-1 and a stable operation for over 80 charge-discharge cycles [4]. These properties are linked to the graphene nanoflake anode displaying crystalline order and high uptake of lithium at the edges. Our approach, compatible with any printing technologies, is cheap and scalable and opens up new opportunities for the development of high-capacity Li-ion batteries.

References

F. Bonaccorso, et al., Production and processing of graphene and 2d crystals.
Materials Today
, 15, (2012), 564-589.

F. Bonaccorso, Z. Sun, Solution processing of graphene, topological insulators and other 2d crystals for ultrafast photonics.
Opt. Mater. Express
4, (2014) 63-78.

F. Bonaccorso, et. al., Graphene, 2d crystal and hybrid structures for energy conversion and storage.
Science
in press (2014).

J. Hassoun, et al. An advanced lithium-ion battery based on a graphene anode and a lithium iron phosphate cathode.
Nano Lett
. 14, 4901-4906 (2014).

* Work done in collaboration with A. Di Carlo, E. Kymakis, B. Scrosati,
A Miniature Sensor Integrating Multiple Detection Technologies for Evaluating Water Pollution
Authors: Poorahong Sujittra , Lefèvre Florent , Perron Marie-Claude , Juneau Philippe , Izquierdo Ricardo 
Published: February 2020

A portable system to monitor water quality in both developed and developing countries is highly required. Currently, there is no commercial test available to satisfy this demand, as only accredited laboratories can perform such evaluations. Miniaturization of analytical instrumentation is one of the dominant trends within the chemical and biological sciences. Miniaturization of diagnostic devices not only affords portability and significant cost reductions but also performance gains in terms of speed, analytical efficiency, automation and reproducibility.
To address this issue, a phytoplankton (alga and cyanobacteria) based detection system implemented in a micro-fluidic platform was developed. As change of the environment of algae induced by toxic compound can affect their metabolism, this makes phytoplankton ideal natural biosensors. Their response can be measured in real time by various detection mechanisms i.e., optical, chemical or electrical. The innovation of the system presented in this study, is to integrate both electrochemical and fluorescence detection in a single chamber. The system is shown in Fig.1.
In general, photosynthesis process of algae is inhibited in presence of toxic compound, in our case, Diuron. Electrochemical detection is based on the measurement of oxygen produced by algae under such conditions. It was carried out using transparent silver nanowires electrode. The size distribution of the Ag nanowires is ~ 80 nm in length and the transparency of the electrode is 80%. Fluorescence detection is based on the activity of photosystem II in the presence and absence of Diuron. The concentration of Diuron can be detected by electrochemical detection between 50 and 1000 nM. (Fig. 2A) and 0.50 to 1000 nM using fluoresecense detection (Fig. 2B). The two detection systems were integrated into a single chamber in a way which enables for more reliable and sensitive detection of water pollutant.
Figure 1 Edge view of the opto-electrochemical sensing device: a transparent oxygen sensor is integrated with a fluorescence sensor into the same chamber.
Figure 2 response curves of electrochemical and fluorescense detections of algae to the herbicide, Diuron

Figure 1
(Invited) Nanobiosensors for Healthcare and Environmental Monitoring
Authors: Aguilar Zoraida Pascual 
Published: February 2020

Nanobiosensors applications are among the most promising commercial products developments involving nanotechnology. It was predicted that in 2017[i], the global market for biosensors in medical diagnostics would reach US$16.5 billion. Various entities working on new product developments focus on health, food, water, pharmaceuticals, industrial, and environmental monitoring. Nanobiosensors which are robust, sensitive, inexpensive, and have ultra-low limits of detection are revolutionizing the various areas of sensing with advances beyond conventional science and technology. The preliminary developments of nanobiosensor platforms that are potentially applicable across all fields of science, engineering, technology, and medicine will be presented. The unique attributes of nanobiosensors for healthcare and environmental applications that harness the unique properties and attributes of nanomaterials will be discussed.

[i] Global Industry Analysts, Inc., accessed on February 3, 2014. http://www.prweb.com/releases/medical_biosensors/environmental_biosensors/prweb9242715.htm
Electrochemical and Electrocatalytic Properties of Platinum Electrode Modified With Gold-CNT Nanocomposite
Authors: Adekunle Abolanle Saheed , Ayenimo J. G. , Fang X. -Y. , Doherty W. O. , Arotiba A. O. , Mamba B. B. , Ebenso Eno E 
Published: February 2020

Dopamine (DA) is an important neurotransmitter in the mammalian central nervous, hormonal and renal system [1]. It can cause Parkinson’s disease (when in low amount) and other similar diseases [2]. Epinephrine, (EP) on the other hand belongs to the group of substances known as catecholamine neurotransmitters which include norepinephrine and dopamine [3]. They are mainly important for message transfer in the mammalian central nervous system (CNS). Changes in concentration of epinephrine in the body can result in many diseases such as Alzheimer’s disease and aging effect. Therefore, various analytical methods to detect these analytes have been developed in the past. Some examples of these methods are the liquid chromatography, mass spectrometry, gas chromatography methods, and capillary electrophoresis mass spectrometry method. These methods require several derivatization procedures which are time consuming and very expensive. It is also known that with a bare electrode the oxidation peaks of DA and AA are at nearly same potential, which results in the overlapped voltammetric responses making their discrimination very difficult. Thus, motivation to this work is to fabricate sensitive, specific and selective sensors that would discriminately detect DA and EP in the presence of other interfering species such as ascorbic and uric acids. An electrochemical method was employed since it provides a simple, cost effective and quick way of analyzing biologically and environmentally important molecules.
In this study, the electron transfer and electrocatalytic properties of gold nanoparticle catalysts supported on MWCNTs/platinum modified electrode were described. The Pt-MWCNT-Au and Pt-MWCNT-AuO and the other modified electrodes were successfully characterised with FESEM, HRTEM, XRD, EDX, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The MWCNT-Au based electrodes demonstrated fastest electron transport and current response towards DA and EP compared to the other electrodes studied, with a relatively high catalytic rate constant, high sensitivity and nano molar (10-9 M) limit of detection. The electrode can detect DA and EP without interference from ascorbic acid (AA) signal. The electrode demonstrated good potential towards DA detection in real drug sample analysis.

REFERENCES:

1. N.Q. Jia, Z.Y. Wang, G.F. Yang, H.B. Shen and L.Z. Zhu, Electrochem. Commun., 9, pp 233, 2007
2. Q. Wang, N. Jiang and N. Li, Microchemical Journal, 68, pp 77, 2001
3. P. Hernandez, O. Sanchez, F. Paton and L. Hernandez, Talanta, 46, pp 985, 1998
Gas Sensing on Oxidized Bronze
Authors: Banerjee Sriya , Myung Yoon , Banerjee Parag 
Published: February 2020

We perform oxidation and phase segregation of bronze (an alloy of Cu: Sn = 95: 5) and demonstrate that the heterogeneous oxide formed is suitable for oxygen sensing. Tin oxide (SnO2) is an n-type semiconductor whereas, cupric oxide (CuO) is a p-type semiconductor. Both oxides have shown sensitivity to detecting gas molecules. Therefore, the presence of both n and p-type oxide on the same substrate can lead to a sensory platform with a wide array of gas sensing capabilities.
Thermally oxidized bronze forms a CuO layer on top, underneath which exists a mixed, CuO-SnO2 layer. It is found that Sn segregates to the grain boundaries whereas Cu exists mostly on grain surfaces. This happens due to the differences in the diffusion constants of the Cu and Sn atoms. Further, the oxidation process creates a variety of nanostructures including CuO nanowires and SnO2 plates. Supporting characterization data is provided via SEM, HRTEM, Raman and x-ray diffraction.
The oxidized samples are then prepared as conductometric sensors for testing various gasses. As an example, on the introduction of dry air into a vacuum chamber (maintained at 2 mTorr), the devices showed a 10% resistance change at 400 K and a 6% resistance change at 373 K. This indicates that facile thermal oxidation of low-cost alloy substrates can lead to the formation of effective, ‘on-skin’ sensors.
a New Bifunctional Electrochemical Sensor for Hydrogen Peroxide and Nitrite Based on Bimetallic Porphyrin MOF
Authors: Zhou Bo , Shi Li-Mei 
Published: February 2020

Metalloporphyrin molecules are excellent candidates to act as molecular building blocks for the construction of MOFs, because of various functional group substituents in the periphery of the molecule and the huge variety of available derivatives incorporating different centre-coordinated metals.[1] in this work, a new bimetallic porphyrin MOF, [Cu2(Co-TCPP)(H2O)2]·0.5DMF·5H2O (Cu-CoTCPP), consisting of [5,10,15,20-(4-carboxy-phenyl)porphyrin]Co(II) (CoTCPP) struts which were bound by Cu(II)-carboxylate clusters (Cu2(COO)4), was prepared solvothermally and characterized by various techniques, including XRD, IR, elemental analysis, TG, and TEM. Cu-CoTCPP showed novel bifunctional electrocatalytic ability toward both the reduction of H2O2 and the oxidation of NaNO2 which might be due to Cu and Co, respectively. With the assistance of multi-walled carbon nanotubes (MWNTs), Cu-CoTCPP showed greatly improved sensing performance in the determination of H2O2 and NaNO2. Cu-CoTCPP/MWNTs/GCE also showed fast response, and high selectivity, steadiness and reproducibility. Excellent determination performance and high biocompatibility make the metalloporphyrin functionalized MOFs promising in electrochemical biosensing.

Keywords: porphyrin

MOF

, bimetallic, electrochemical sensing

[1] LI, Q. W., ZHANG, W. Y., MILJANIC, O. S., SUE, C. H., ZHAO, Y. L., LIU, L. H., KNOBLER, C. B., STODDART, J. F. & YAGHI, O. M. 2009. Docking in Metal-Organic Frameworks. Science, 325, 855-859.
The authors thank National Natural Science Foundation of China (Grant No. 21175068) for the financial support.
Characterization of the Double Layer By Time Resolved Surface Enhanced FTIR Spectroscopy
Authors: Parr Daniel , Zibart Christina , Egan Bryce , Malik Kasim , Shadley Tyler , Haverhals Luke M. 
Published: February 2020

The utilization of ionic liquids (ILs) for future electrochemical applications shows great promise. Recently ILs have been investigated for many electrochemical systems however, further characterization and development of ILs remains to be done before they are applied to devices such as batteries, capacitors, and fuel cells. For example, data that yield understanding of the interfacial structure and dynamics of ILs at electrode surfaces are vital since these interactions ultimately allude to electrochemical device efficiency. We will present time resolved (TRS) FTIR spectroscopy data as a means to characterize IL-based electrolytes. In particular, we will exhibit two modes of TRS: step scanning and rapid scanning during simultaneous electrochemical perturbation to better understand IL interactions at metal electrode surfaces.
Pit Initiation in Aluminum and Aluminum Alloys
Authors: Pinkowitz Ainsley , Straub Sarah , Duquette David , Hull Robert 
Published: February 2020

The growth of pits in passive metals and alloys exposed to chloride solutions is reasonably well understood and has generally been attributed to chemistry changes in occluded cavities in the metal surfaces. The initiation of pits, however, is still a matter of some conjecture. In particular the processes associated with the propagation of stable pits, versus pits that initiate but then apparently re-passivate are not particularly well understood. It is well known that, many passive metals and alloys exhibit well-established relationship between the onset of stable pitting (as measured by an irreversible pitting potential) and chloride concentration [1]. The goal of this program is to study the local breakdown of passive films by onset of pitting in dilute chloride solutions where it is presumed that the pitting processes will be delayed and the specific interactions between chloride and passive films can be examined in more detail. Pitting potential experiments on A1100 aluminum and A2024 aluminum alloys were performed in aqueous chloride solution, as a function of pH, from 10-6 M to 3 M chloride, using conventional potentiodynamic techniques. The results obtained for both alloys, in solutions ranging from 10-3 M to 3 M chloride replicate those of McCafferty [1] that showed a specific relationship between pitting potential and chloride concentration. However, the sensitivity of the pitting potential to chloride concentration shows a well defined inflection at chloride concentration of approximately 10-3M. Data will be presented comparing the pit distributions and morphologies at low, intermediate and high chloride concentrations. The results will be discussed in terms of the specific interactions of chloride with passive films, transport of the chloride through the passive films, and the reaction of the chloride with the underlying metal surfaces.

1. McCafferty, E. (2003). Sequence of steps in the pitting of aluminum by chloride ions. Corrosion Science, 1421-1438.
This project was supported by the National Science Foundation under grant #NSF-DMR 1309509
Lithium Ion Battery Energy Storage System for Grid Applications
Authors: Moss Eugene Newton , Nelson Ruben , Weatherspoon Mark H , Moss Pedro L. 
Published: February 2020

Due to the increasing demand for lower energy costs for the supplier and the consumer, using energy storage devices can offer a number of high-value benefits, provided that lower costs can be gained from using this method. Using rechargeable lithium batteries as a storage device in tandem with the power grid can be viewed as a viable way to reduce costs of generation and distribution by the power company and also as a way to drive down electricity bills for consumers. Possible grid applications with energy storage devices can range from frequency regulation and load following, for which short response times are needed, to peak shave and load shift, both of which can lead to improvements in grid reliability, stability, and cost [1].
Energy storage systems (ESS) are becoming widely used as a compliment to the power grid (need a citation to prove this). Large scale ESS are often used due to the advancement of the technology but smaller scale technologies such as compressed air, thermal (thermal what?) and batteries, are also being used more. The smaller scale application can be used more often because there is not a need for specific geographical requirements such a remote location [2]. The ESS that will be discussed is one composed of lithium-ion batteries. There are many advantages of using this specific device, including a high energy-to-weight ratio, no memory effect, and a little self-discharge[3]. Common applications include portable equipment, mobile telephones, and plug-in hybrid and electric vehicles.
In this study, an overview of a proposed ESS organization and simulation of the response of both parallel and series lithium-ion battery ESS configurations will be compared to determine the most efficient method of powering a load. Factors that determine the better response include capacity fade and useful life. From these results, it can be concluded which may be a better design to incorporate into an ESS based on cost.
Figure 1: Flowchart of Energy Storage System Design

Acknowledgment

This work was supported by the FREEDM ERC program of the National Science Foundation under award number EEC-08212121.

References

B. Dunn, H. Kamath and J. Tarascom. Electrical Energy Storage for the Grid: A Battery of Choice. American Association for the Advancement of Science. 2011

M. Arifujjaman, A comprehensive power loss, efficiency, reliability and cost calculation of a 1 MW/500 kWh battery based energy storage system for frequency regulation application, Science Direct. 2013

S. Vazquez, S. M. Lukic, E. Galvan, L. Franquelo, J.M. Carrasaco. Energy Storage Systems for Transport and Grid Applications

Figure 1
Laterally Assembled Ga2Te3/In2Te3 Hetero-Nanostructures for Thermoelectric Applications
Authors: Hung Yu-Ting , Chen Taung-Han , Chang Hsiu-Cheng , Chen Chun-Hua 
Published: February 2020

Hetero-nanostructuring has been theoretically and experimentally proven as a practical strategy to enhance the thermoelectric figure of merit, ZT (defined as σS2T /κ) via largely creating various nanoscaled heterogeneous interfaces which could not only effectively scatter phonons to have a much lower thermal conductivity, but potentially activate the electron filtering phenomenon for simultaneously improving the Seebeck coefficient and electrical conductivity. In this presentation, a series of laterally- and periodically-assembled Ga2Te3/In and Ga2Te3/In2Te3 hetero- nanocomposite films were successfully fabricated using pulsed laser deposition (PLD) with subsequent various annealing processes. The distinct interfacial structures as well as the corresponding enhanced thermoelectric properties will be discussed.
Keywords: thermoelectric, heterostructure, assembly, nanocomposite, pulsed laser deposition
Evaluation of Nanocarbon Material Dispersions
Authors: Okazaki Toshiya 
Published: February 2020

Nanocarbon materials such as fullerenes, carbon nanotubes and graphenes have attracted considerable attention due to their inherent superior properties. Indeed, the nanocarbon-based materials have been extensively studied for voltaic cells, electrodes, capacitors, reinforced rubbers and the other applications. Researchers have usually discussed the physical properties of the produced materials based on the intrinsic properties of the nanocarbons themselves. Even through the dispersion of the nanocarbons into solution or matrix is one of the most important issues for fabricating advanced composites, the effective evaluation technique of the dispersion states has so far been limited. In this talk, we will show effective evaluation methods for the nanocarbon dispersions for obtaining desired properties of the composite materials.

This paper is based on results obtained from a project commissioned by the New Energy and Industrial Technology Development Organization (NEDO).