bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carbon Dots Based Fluorescence Nanoprobe for Cell Imaging and Single Particle Tracking
Authors: Song Yang , Du Dan , Lin Yuehe 
Published: February 2020

School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164
Advances in real-time imaging in living cells have enabled tracking of individual molecules over time and space. Single particle tracking (SPT) technique enables the imaging and mapping of functional biomolecules directly in living cells at unprecedented spatial and temporal resolution [1-4]. This technique has provided a powerful tool to reveal the dynamic structure-function relationships in complex biological systems and dramatically advanced the fundamental understanding of biological systems and medical diagnose [5-7]. The fluorescent probe, which tags the molecules of interest and allows the fluorescent emission, is crucial for intercellular imaging. The considerable interest in intercellular trafficking sparked sustained research efforts on developing of fluorescent probes with high quantum yield, excellent stability and biocompatibility.
Carbon dots (CDs) exhibit controlling size and shape, surface heteroatom doping, tunable photoluminescence (PL) and efficient multiphoton up-conversion. These CDs exhibit excellent biocompatibility, high photostability, enhanced brightness and high quantum yields [8]. Therefore, CDs will provide a new platform as versatile probes for single particle tracking (SPT) in various biological and medical areas. In our previous studies [9-10], we synthesis the CDs with optimized remarkable quantum confinement effect, surface effect and surface defect state are expected to present (1) low cytotoxicity and excellent biocompatibility. (2) Capability of precisely controlling the functional-group and feasible labeling of biomolecule for enhanced specificity. (3) Enhanced optical properties. (4) High stability. The CDs are highly chemically and thermally stable. We found that the endosome escape most probably because that the untreated surface group of CDs could provide high buffering capacity to trigger the osmotic swelling and physical rupture of the lysosomes in acid vesicle [9]. This technology can be easily extended to the mobility of molecules and proteins in the cell membrane with the same principle. This new technology will be a major breakthrough of real-time, high resolution of intercellular imaging.
Influence on the Porous Silicon Photoluminescence By Magnetic Nanostructures
Authors: Granitzer Petra , Rumpf Klemens , Poelt Peter , Reissner Michael 
Published: February 2020

In this framework luminescent porous silicon (PSi) is filled with a magnetic metal (e.g. Ni) to influence the photoluminescence due to the presence of metal deposits. This happens in two ways. On the one hand the surface plasmon of the metal deposits is exploited to modify the luminescence and on the other hand it is influenced by an external magnetic field. Due to the metal filling of the porous silicon the photoluminescence is blue-shifted and furthermore an increase of the intensity is observed. The influence of the magnetic metal filling on the optical properties is discussed and the magnetic characterization of the nanocomposits is presented.
The porous silicon is fabricated by anodization of a moderately doped p-silicon wafer. The electrolyte consists of hydrofluoric acid, Ethanol and distilled water (1:2:1). The metal deposition has been performed by pulsed electrodeposition in using a NiCl2 and NiSO4 solution.
First the optical properties of the luminescent PSi are investigated, second Ni is deposited within the porous silicon samples and subsequently the nanocomposite specimens are characterized optically again and also magnetically. The samples are structurally characterized by SEM, EDX and TEM.
The optical properties are investigated with respect to the shift of the photoluminescence due to the metal filling. Photoluminescence spectra of bare PSi show a maximum around 620 nm whereas in the case of Ni filled samples the peak is blue-shifted to around 580 nm and the luminescence intensity is increased. Figure 1 shows the comparison of the photoluminescence of two Ni-filled samples with different metal deposition time.
Concerning the magnetic properties of the nanocomposite the embedded Ni structures can be superparamagnetic from the size of the pore diameters but due to the branched morphology the achieved deposits tend to be interconnected and thus do not offer necessarily a superparamagnetic behavior. Also temperature dependent magnetization measurements give no hint for a superparamagnetic behavior. Field dependent magnetization measurements performed with the magnetic field applied perpendicular and parallel to the sample surface show a high magnetic anisotropy. It can be clearly seen that the samples offer a film-like behavior due to the interconnected Ni structures which is represented by the easy axis parallel to the surface. In the frame of this work the optical characterization of luminescent PSi with respect to its photoluminescence compared with Ni filled samples is discussed in detail as well as the corresponding magnetic properties of the nanocomposites. Furthermore the influence of an external magnetic field on the optical properties is elucidated. The presented systems are promising candidates for applications in optoelectronics and also for magneto optical integrated devices.
Figure 1. Photoluminescence spectra of porous silicon with incorporated Ni for two different deposition times.

Figure 1
(Invited) Fundamentals and Applications of Directional and Isotropic Atomic Layer Etching
Authors: Vahedi Vahid , Lill Thorsten 
Published: February 2020

Atomic Layer Etching (ALE) is a cyclic process comprised of a self-limited surface modification step followed by a self-limited step to remove the modified layer. Based on this definition, there are several approaches to realize and classify ALE. For instance, one can distinguish between directional and isotropic ALE depending on whether the removal of the activated layer is accomplished by ion bombardment or thermal energy.
Thanks to such salient performance benefits as uniformity across all length scales and selectivity, atomic layer etching is being proliferated in production. Directional ALE was the first process to go into production because most critical etch applications require directionality. Isotropic ALE is an emerging branch based on chemical reactions akin to those uses in thermal ALD. The term “isotropic” means that the etch proceeds in all directions. This property is particularly valued in vertical device integration where materials need to be removed from vertical and concealed surfaces.
In this talk, a conceptual framework for directional and isotropic ALE will be introduced to explain the performance benefits and limitations of both technologies. Experimental and theoretical results as well as applications examples will be presented to illustrate the concepts.
Heat to H2
Authors: Skilbred Ellen Synnøve , Krakhella Kjersti Wergeland , Haga Ida Johanne Molvik , Hillestad Magne , Serrano Gonzalo del Alamo , Pharoah Jon G. , Burheim Odne Stokke 
Published: February 2020

Renewable energy sources are often intermittent or unavailable for the end user, making energy storage vital. One way to store the energy is in hydrogen, and our aim is to produce hydrogen through reverse electrodialysis (RED) [1, 2, 3]. RED is a technology that uses concentration differences to create electrical energy. This is achieved through the use of ion-conducting membranes, where the membranes separate two solutions while producing an electric potential. Moreover, RED can be used to produce hydrogen in addition to electric energy. An illustration of the RED-cell is given in Figure 1.

Any salt can be used for this purpose, as the potential is dependent on concentration differences only, not the specific solution used. This project utilises waste heat of low quality to build up and maintain the concentration differences (see Figure 2). The whole process is carried out in a closed system, where heat will be the only external input (in addition to electricity used for pumps). The closed energy storage system can easily be installed in connection with industrial processes where waste heat is available.
As ions are transported from the concentrated to the diluted solution, the potential will decrease. Two separation techniques are evaluated for increasing the concetration difference, namely evaporation at high temperature or precipitation at low temperature. The respective process sketches are shown in Figure 2.

This research investigates the suggested system with either NaCl or KNO3 as active solutions and temperature levels. Parts of the experiments include an end goal of creating sufficient potentials for hydrogen evolution, hence creating a technology where low-grade waste heat is converted to hydrogen.

[1] O. S. Burheim, J. G. Pharoah, D. Vermaas, B. B. Sales, K. Nijmeijer, and H. V. Hamelers, "Reverse electrodialysis," Encyclopedia of Membrane Science and Technology, 2013.
[2] M. F. M. Bijmans, O. S. Burheim, M. Bryjak, A. Delgado, P. Hack, F. Mantegazza, S. Tenisson, and H. V. M. Hamelers, "CAPMIX - Deploying capacitors for salt gradient power extraction," Energy Procedia, vol. 20, pp. 108-115, 2012.
[3] O. S. Burheim, Engineering Energy Storage. Academic Press 2018, 2017.

Figure 1
Probing the Size-Exclusion Properties of Redox Flow Battery Separator Membranes Using Metal-Ligand Complexes
Authors: Kushner Douglas I. , Tucker Michael C , Kusoglu Ahmet , Weber Adam Z. 
Published: February 2020

Redox flow batteries (RFBs) are among one of the most promising technologies being explored for grid-scale energy storage from discontinuous power sources such as wind and solar.1 This has resulted in a need for continued development and understanding of electrolytes and membranes employed in RFBs as a means of improving performance while reducing cost. New approaches in membrane design rely on size-exclusion to reduce parasitic losses resulting from water and electrolyte crossover that presently plagues ionomer membranes within the perfluorosulfonic acid (PFSA) family (e.g. Nafion, Aquivion, and 3M PFSA).2 The structure-property relationships of PFSAs are well-known and studied,3 providing the initial framework for utilization of ligands to understand transport through next-generation membranes.
In this work, we discuss our efforts in developing a systematic approach towards probing the effective size-exclusion properties of the polymeric membranes by employing iron-ligand complexes. A series of aminopolycarboxylic acid ligands, shown in Figure 1, that strongly complex with iron were selected to explore the effect of molecule size on crossover in PFSAs with varying domain sizes, controlled via side chain length. We show decreases in permeability with increased size of the iron-ligand complex, providing information regarding the hydrophilic domain network of these ionomer membranes. By measuring the crossover of these complexes using diffusion cells, we explore the size-exclusion properties of PFSAs using relevant molecules for future iron RFB applications.

Acknowledgements

This work was funded as a sub-contract under the Integration and Optimization of Novel Ion-Conducting Solids program (IONICS), by the Advanced Research Projects Agency-Energy (ARPA-E), of the US Department of Energy under award number DE-AR0000773.

Perry, M. L.; Weber, A. Z., Advanced Redox-Flow Batteries: A Perspective. J Electrochem Soc
2016,
163 (1), A5064-A5067.

Darling, R.; Gallagher, K.; Xie, W.; Su, L.; Brushett, F., Transport Property Requirements for Flow Battery Separators. J Electrochem Soc
2015,
163 (1), A5029-A5040.

Kusoglu, A.; Weber, A. Z., New Insights into Perfluorinated Sulfonic-Acid Ionomers. Chem Rev
2017,
117 (3), 987-1104.

Figure 1
Highly Ion Selective Membranes for Aqueous Redox Flow Batteries
Authors: Gigli Matteo , Mecheri Barbara , Branchi Mario , Tizzoni Anna Chiara , Licoccia Silvia , D'Epifanio Alessandra 
Published: February 2020

Redox flow batteries (RFB) are one of the most promising energy storage systems used to overcome the intermittence limitations of renewable energies. In RFB, electrical energy production is supplied by two electrolytes that undergo redox reactions in two half cells. These latter are separated by a membrane, whose primary function is to allow the proton flow, while preventing the transport of the active species to avoid battery self discharge.
Traditional aqueous RFBs, such as all-vanadium (redox battery, VRB) [1], or more innovative anthraquinone-disulphonic acid (AQDS) combined with the Br2/Br- redox couple [2], used Nafion membranes as separator because of the high ion conductivity and chemical stability of this polymer. However, its low selectivity causes a significant drop of battery performances over time.
In this work, several ionic exchange membranes (CEM) have been investigated and their performances have been compared to Nafion. Hydrocarbon-based membranes have been tested because highly rigid aromatic macromolecular chains and tinier ionic clusters are expected to decrease electrolyte crossover. In this framework, the use of sulfonated poly(phenylene sulfide sulfone) polymers (sPSS) as chemically stable ion-conducting membranes for aqueous RFB is proposed [3].
To further increase membrane selectivity, sPSS has been loaded with sufonated hypercrosslinked polystyrene nanoparticles (sHCP). sHCP have been synthesized through Friedel-Craft alkylation to obtain HCP, followed by post-functionalization to attach sulfonic groups. sHCP structure and morphology has been assessed by TGA, FT-IR, SEM and BET.
Composite (sPSS-sHCP) and pristine (sPSS) membranes have been characterized ex situ and in operando for all vanadium Redox Flow Battery applications, through galvanostatic cyclation at a current density of 150 mA/cm2.
The results evidenced the higher performances of the composite membranes with respect to sPSS and Nafion, resulting in a self-discharging time over 3.5x higher and capacity fading about 33% lower.

Acknowledgements

The present work was carried out with the support of the “European Union's Horizon 2020 research and innovation programme”, under H2020-FTIPilot-2015-1 (Grant Agreement n. 720367-GREENERNET) and GREENERSYS project supported by Provincia Autonoma di Trento ITALY

References

[1] M. Skyllas-Kazacos, M. Rychcik, R.G. Robins, A.G. Fane, M.A. Green, New all-vanadium redox flow cell, J. Electrochem. Soc. 133, 1057-1058 (1986)
[2] B. Huskinson, M. P. Marshak, C. Suh, S. Er, M. R. Gerhardt, C. J. Galvin, X. Chen, A. Aspuru-Guzik, R. G. Gordon, and M. J. Aziz, Nature, 505, 195 (2014).
[3] M.Branchi, M. Gigli, B. Mecheri, D. de Porcellinis, S. Licoccia and A. D'Epifanio
J. Mater. Chem. A, 5, 18845 (2017)
Disinfection of Seawater and Its Neutralization Using Seawater Battery
Authors: Park Jeong-Sun , Park Jehee , Hwang Soo Min , Kim Youngsik 
Published: February 2020

Seawater disinfection is a commonly used technology in many functional systems operated in the seawater environment to prevent biofouling due to the formation of biofilms by microorganism growth, which induces an operational problem in the long-term. there are three kinds of conventional disinfection technologies, physical (UV), chemical (ozone and Cl), and electrochemical ones with no use of chemical additive. Conventional disinfection methods have many issues to be resolved, such as high energy consumption, low disinfection efficiency, and an additional neutralization process before discharging the treated water. Therefore, it is highly required to develop an energy-efficient disinfection technology which enables a high disinfection efficiency, as well as simple neutralization process to remove toxic disinfectants, such as total residual oxidant (TRO) in the treated water.
In this work, we introduce a new type of electrochemical disinfection system, which functions both seawater disinfection and neutralization without any chemical treatments, named as the combined system for disinfection and neutralization (CSDN). By employing a rechargeable seawater battery system[1-3], the CSDN conducts seawater disinfection and the neutralization of remained TRO during charge and discharge processes, respectively. The disinfection efficiency of total chlorine (TC), such as HOCl and OCl, produced during charging is evaluated by using Escherichia coli and Enterococcus aquamarines. The remained TRO in disinfected seawater is removed by discharging, where the TRO (TC) are reduced into chloride ions, while providing electricity to external loads. The mechanisms behind the generation and neutralization of TRO are discussed. The proposed CSDN would provide an effective solution to lower energy consumption for seawater disinfection through the battery technology and an interdisciplinary approach to connect between the disinfection and electrochemical energy storage technologies.
References :
[1] Kim, J.-K.; Mueller, F.; Kim, H.; Bresser, D.; Park, J.-S.; Lim, D.-H.; Kim, G.-T.; Passerini, S.; Kim, Y. Rechargeable-Hybrid-Seawater Fuel Cell. NPG Asia Mater. 2014, 6, e144.
[2] Kim, H.; Park, J.-S.; Sahgong, S. H.; Park, S.; Kim, J.-K.; Kim, Y. Metal-Free Hybrid Seawater Fuel Cell with an Ether-Based Electrolyte. J. Mater. Chem. A 2014, 2, 19584−19588.
[3] Kim, J.-K.; Mueller, F.; Kim, H.; Jeong, S.; Park, J.-S.; Passerini, S.; Kim, Y. Eco-friendly Energy Storage System: Seawater and Ionic Liquid Electrolyte. ChemSusChem 2016, 9, 42−49.
In-Situ De-Aeration Towards Performance Stability of Capacitive Deionization Cells
Authors: Caudill Landon , Omosebi A. , Gao X. , Landon James , Liu K. 
Published: February 2020

Carbon-based Capacitive Deionization (CDI) is an emerging treatment method for saline waters with ion concentration at or below brackish levels. This technology works similarly to a parallel plate aqueous capacitor in that the dissolved ions are removed from solution through an applied electric potential and adsorbed onto the active surface of the electrodes. Upon removal or reversal of the applied potential, the ions re-dissolve, creating a concentrated stream (1). One setback in the commercialization of CDI technology is performance stability, which has mainly been attributed to a combination of carbon oxidation at the anode (positive electrode) and oxygen reduction at the cathode (negative electrode)(2-4). This work explores an in-situ method for evacuating trapped air from the electrode’s pores towards mitigating Faradaic reactions and increasing the long-term stability of CDI systems.
The flow through CDI cell used in this study utilized symmetric, pristine, carbon electrodes obtained from Kynol®. The CDI system, fitted with a pressure regulator and gauge, allows for operation at elevated pressures, up to 60 psi, within the cell. Figure 1, depicts the CDI system components with the pressurized and non-pressurized regions highlighted. The natural pressure gradient that occurs across the cell due to flow resistance remains constant because the entire cell lies within the pressurized portion of the system. This operating method takes advantage of Henry’s Law (where more dissolved oxygen is found at higher pressure) removing oxygen from the cell.
Initial data, shown in Figure 2, demonstrates the response of dissolved oxygen to changes in system pressure for a ~5mM aerated sodium chloride solution. A CDI system, treating the same concentration sodium chloride solution, operating at increased pressure demonstrates a similar increase in dissolved oxygen, which decays back once the trapped air is removed.

References

M. E. Suss, S. Porada, X. Sun, P. M. Biesheuvel, J. Yoon and V. Presser, Energy & Environmental Science, 8, 2296 (2015).

I. Cohen, E. Avraham, Y. Bouhadana, A. Soffer and D. Aurbach, Electrochimica Acta, 153, 106 (2015).

C. Zhang, D. He, J. Ma, W. Tang and T. D. Waite, Water research, 128, 314 (2017).

A. Omosebi, X. Gao, N. Holubowitch, Z. Li, J. Landon and K. Liu, Journal of The Electrochemical Society, 164, E242 (2017).

Figure 1
Electrochemical Removal of Copper from Regenerated Pickling Solutions of Steel Plants
Authors: Karakaya Esra , Aras Mustafa Serdal , Erdogan Metehan , Karagul Sedef , Ersoy Merve , Karakaya Ishak 
Published: February 2020

The spent pickle liquor contains the dissolved metal salts of iron, chrome, copper, nickel and zinc [1]. The acid can be cleaned from its impurities, except for its copper ion, by the regeneration process. When the copper concentration of the pickling solution exceeds the level of about 100 ppm, the copper inside the solution replaces the iron in the steel and copper starts plating randomly on the metal surface in the following pickling processes. Because of the plating problem, the acid needs to be discard from the acid line. By adding fresh acid to the line the discarding can be delayed [2]. An electrochemical procedure was conducted to overcome the cementation problem experimentally in an environmental and economical way. Electrowinning of dilute copper from strong acid solution is a challenge in this case so the optimum current density, electrolysis duration and the electrode materials were determined in this study.
It was found that increase in the current density and electrolysis duration increases the copper removal, but changes the morphology of deposits. A slower compact deposition procedure was selected to achieve continuous removal of copper instead of faster discontinuous powder deposition from the regenerated pickling solutions of steel plants.
References
[1] A. Agrawal, S. Kumari, and K. K. Sahu, “Iron and Copper Recovery/Removal from Industrial Wastes,” Metal Extraction and Forming DiVision, National Metallurgical Laboratory, India, 2009.
[2] M. A. Nicholls, Z. Koont, B.D. Nelson, D. Bray and J. Felker (2008), Copper Plating Phenomenon During the Pickling of Steel. Pickling and Cold Rolling Department, ArcelorMittal Dofasco Inc., Hamilton, Ont., Canada.