bluuebunny/crossref_metadata_2025_split huggingface dataset:
Friction Properties and Surface Observation By Surface Processing on High Strength Gels
Authors: Wada Masato , Yoshida Kazunari , Khosla Ajit , Furukawa Hidemitsu 
Published: February 2020

We measured the friction forces and calculated the friction coefficients of non-processed and laser-processed High Strength gel surfaces. The results indicate that laser processing (finishing) has an ability to reduce the friction coefficients. The observation of gel surfaces suggests that the cause of friction reduction is change in roughness of gel surfaces due to laser processing. This finding is expected to lead us to further understanding of physicochemical properties of hydrogels.
We showed the low-friction processing technique. We demonstrated that the laser processing has an ability to reduce the friction of hydrogel surfaces. The results of microscopic observations suggest that the cause of friction reduction is decrease in apparent contact area between hydrogel surface and glass ball. This technique may lead us to next step in the fields of physics, physical chemistry, and medical applications.
Thermo-Responsive Behavior of Polymer Solutions Coated with Phospholipids
Authors: Yoshida Kazunari , Horii Keitaro , Saito Azusa , Takashima Akito , Nishio Izumi 
Published: February 2020

Various kinds of cell model systems have been utilized for fundamental studies on physical properties of cells. Water-in-Oil (W/O) droplet system coated with phospholipids is one of the beneficial simple model systems of living cells. For instance, a biomimetic phase-separated membrane was constructed in the W/O systems with phospholipid mixture (Hamada et al., J. Phys. Chem. Lett., 2010) since phase separation in lipid membrane system corresponds to the separation between lipid raft domains and other soft domains in the living cell membranes.
Phase transition of a polymer has been studied for many years, such as coil-globule transition (Nishio et al., Nature, 1979), and helix-coil transition (Tanaka et al., J. Chem. Phys., 1973). In addition to the phase transition of polymers, phase separation in a binary polymer solution was also reported (Yanagisawa et al., J. Mol. Liq., 2014). However, cell-sized confinement effects on polymer solutions have been poorly confirmed.
To clarify the cell-sized confinement effects on polymer solutions, we previously observed the dynamic behavior of polymer droplets (Yoshida et al., Polymers, 2017). The previous study revealed that droplet size influences the start time of phase separation in the case of temperature change from 10 to 65 degrees Celsius.
In this study, we observed the dynamic behavior of hydroxypropyl cellulose (HPC) solution droplets in response to temperature change from 10 to 65 degrees Celsius using a fluorescence microscope. The droplets were coated with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) or 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE). As a control, we observed non-coated water droplets. DPPC and DPPE are widely used for studies on model cell membranes. Using time-lapse images, we confirmed the water/HPC distribution using a spatial autocorrelation function. The results revealed that water-rich region appeared in the case of lipid coated droplets with increase in temperature while such phenomenon was not observed in the case of non-coated droplets.
(Invited) Economical and Safer Approach to Biodegradable Biocompatible Hydrogel
Authors: Meabe Leire , Takahashi Junko , Zivic Nicolas , Sardon Haritz , Mecerreyes David , Fukushima Kazuki 
Published: February 2020

The use of polycarbonates in the biomedical application has been largely studied, owing to appropriate biodegradation reaction, without producing any by-products [1, 2]. Generally, the synthesis of the polycarbonates is via ring opening polymerization, which requires several steps and high purity of the reagents.
Step growth polymerization can be an easy method to design polycarbonates with molar masses around 20,000 g mol-1 [3]. The protocol of organocatalytic polycondensation consists of a two-step reaction, which involves an initial condensation and the subsequent chain propagation based on transesterification. The reaction will be catalyzed by organic based catalyst, N,N’-dimethyl-4-aminopyridine (DMAP). From Scheme 1, the possibility of tuning the polycarbonate structure can be deduced; the diol is a key reagent of designing the final homopolymer or copolymer structure. This methodology gives us an opportunity to obtain linear or cross-linked polymer. In our work, we have incorporated a mono-ether functionality for biocompatibility as well as a double bond for formation of a cross-linked network.
Scheme 1. The polycondensation approach for new polycarbonate-based biocompatible gels.
[1] K. Fukushima, Poly(trimethylene carbonate)-based polymers engineered for biodegradable functional biomaterials, Biomaterials Science, 4 (2016) 9-24.
[2] K. Fukushima, Y. Inoue, Y. Haga, T. Ota, K. Honda, C. Sato, M. Tanaka, Monoether-Tagged Biodegradable Polycarbonate Preventing Platelet Adhesion and Demonstrating Vascular Cell Adhesion: A Promising Material for Resorbable Vascular Grafts and Stents, Biomacromolecules, 18 (2017) 3834-3843.
[3] L. Meabe, N. Lago, L. Rubatat, C. Li, A.J. Müller, H. Sardon, M. Armand, D. Mecerreyes, Polycondensation as a Versatile Synthetic Route to Aliphatic Polycarbonates for Solid Polymer Electrolytes, Electrochimica Acta, 237 (2017) 259-266.

Figure 1
(Invited) The P2 Sodium Layered Oxides in Na Ion-Batteries
Authors: Delmas Claude , Carlier Dany , Guignard Marie , Yoshida Jun 
Published: February 2020

The development of very large scale renewable energy systems requires optimizing the lifetime, the price and the material availability. From these points of view, sodium based batteries have to be investigated. Our research group studied layered oxides as positive electrode for 30 years. Now a special focus is devoted on P2-type layered phases.
One of the main interests of this structure is the existence of an ion conduction plane made of face sharing trigonal prims which exhibits a high ionic diffusivity thanks to the existence of a large bottleneck (oxygen rectangle) for sodium diffusion. This structure is able to accommodate a lot of transition metal cations, allowing the optimization of the properties by cationic substitution.
Studies was performed on the P2- Nax(Mn,Co)O2, Nax(Mn,Fe)O2, Nax(Mn,Fe,Co)O2 and Nax(Mn,Fe,Ni)O2 systems with various amounts of transition metal ions. All materials crystallize in the hexagonal system (P63/mmc space group). The structure is made of MO2 slabs built of corner sharing MO6 octahedra. The sodium ions are in trigonal prismatic sites. Half of them share edges (Nae) with the MO6 octahedra while the other one share faces (Naf). As the two types of prisms share a common face, they cannot be occupied simultaneously at the atomic scale. The sodium distribution depends of the cationic charge distribution and of the sodium amount is order to minimize the Na+-Na+ and Na+-Mn+ electrostatic repulsions. This lead to a large number of ordered Na+ distribution as it was shown in the case of the NaxCoO2 systems. In materials with several transition metal cations, their statically distribution in the slabs prevent generally from Na+ ordering.
In all systems, the P2 type packing is preserved in the 0.3 < x < 1 range. The fully intercalated phase is difficult to be obtained due to the very low ionic conductivity when the amount of vacancies is very small. For these compositions, only the Naf prisms are occupied. The specific capacity is in the 130-170 mAh.g-1 depending on the voltage range.
For large deintercalation amounts (x < 0.3) a large polarization occurs in discharge. The GITT experiment shows that this “polarization” is not kinetics. The in-situ XRD during battery cycling from the Na0.7(Mn0.5Fe0.3Ni0.2)O2 phase shows the existence at high voltage of two phases with different interslab distances. The change in the shape of the diffraction line profiles is characteristic of the continuous formation of stacking faults.
For manganese based materials, structural distortions (Jahn-Teller effect) occurs at the end of discharge. Even if these distortions are fully reversible, they have a very bad effect on the cycling behavior.
In the intermediate composition range the reversibility is very good. Therefore, these materials can be interesting for practical applications in stationary batteries due to their low price and the availability of the raw materials.
Analysis of Oxide Film on Aluminum Electrode in Ionic Liquid Based Aluminum-Air Battery
Authors: Mohammad Abdul , Gong Jue , Hosmane Narayan S , Xu Tao , Cho Kyu Taek 
Published: February 2020

In this research, aluminum air battery system was revisited to investigate key issues which have challenged its full application as a rechargeable battery. The Al-air battery had received intense attention once due to the excellent benefits such as low cost and high energy density, but due to the challenging issues such as hydrogen evolution, and inactive oxide film formed on the Al surface, it could not be fully applied. Recently, ionic liquid which is a salt in liquid form at room temperature started to be applied in the battery system to overcome the issues in aqueous electrolyte [1,2], but the inactive oxide film on Al surface is still dominant in decreasing cell performance and detailed research to understand how to control the oxide film was not conducted. In this study, 1-Ethyl 3-Methyl Imidazolium Chloride ([EmIm]Cl) and Aluminum Chloride (AlCl3) was applied in the Al-air battery, and its effect on oxide film on the surface aluminum electrode was analyzed through cell-base test, and SEM image analysis.
It was found that the inert oxide film on aluminum, which is one of the most challenging issues, could be controlled and removed by using of proper ratio of [EmIm]Cl and AlCl3, and the growth/breakdown mechanism of the oxide film was theoretically considered. This research results are expected to suggest a new direction to control the surface of aluminum electrode to make it the most promising system.
References
[1] D. Gelman, B. Shvartsev, Y. Ein-Eli, Journal of Materials Chemistry A, 2 (2014) 20237-20242.
[2] R. Revel, T. Audichon, S. Gonzalez, J. Power Sources, 272 (2014) 415-421.
All Coconut Sprout Sodium Ion Hybrid Capacitor
Authors: Surendran Vishnu , Suviresh Arya Raveendran , Vineesh Thazhe Veettil , Babu Binson , Shaijumon Manikoth M 
Published: February 2020

Electrochemical Energy storage systems play a vital role in many applications like electronics, automotive, aerospace, smart electric grids etc. There are mainly two types of energy storage systems known as batteries and supercapacitors. The first one offers high energy density, and the later one is well known for its power density. Hybrid ion capacitor (HIC) is a new class of energy storage device, a combination of battery and supercapacitor1. Commonly anode part in HIC is taken from a battery, and the cathode part will be from a capacitor and in principle, the duo offers intermediate energy and power density in comparison with batteries and supercapacitors2
3. Sodium based hybrid capacitors are extensively explored today due to large abundance and low cost of sodium4. Here in we report for the first-time, fabrication of a hybrid sodium ion capacitor, in which the cathode, anode and separator are derived from a single precursor called coconut sprout (CS). Graphene-like carbon derived from CS, employed as an intercalating anode, provides a specific capacity of 181.09 mAhg-
1. High surface area (BET surface area of 2000 m2g-1) ion adsorption cathode part obtained by KOH activation of CS delivers a capacity of 90.15 mAhg-
1. Combination of CS derived anode, cathode and separator give rise to a capacitor works in a potential window of 1.5 -4.0V. The all sprout capacitor could deliver an energy density of 88.12 Whkg-1 at power density 273.26 Wkg-1 and energy density of 25.07 Whkg-1 at power density 7078 Wkg-1. This green, all sprout hybrid capacitor retained 65% of its initial capacity after 5000 cycles, while cycled at a current density of 1Ag-1. The spongy sprout separator showed excellent chemical and mechanical stability even after 10000 cycles of charge and discharge. Though the performance is not outstanding, low cost single precursor, facile synthesis route, minimal environmental impact of the device makes it a promising candidate among eco-friendly electrochemical systems.

Reference

(1) Amatucci, G. G.; Badway, F.; Du Pasquier, A.; Zheng, T. An Asymmetric Hybrid Nonaqueous Energy Storage Cell. J. Electrochem. Soc.
2001, 148 (8), A930.
(2) Ding, J.; Wang, H.; Li, Z.; Cui, K.; Karpuzov, D.; Tan, X.; Kohandehghan, A.; Mitlin, D. Peanut Shell Hybrid Sodium Ion Capacitor with Extreme Energy-Power Rivals Lithium Ion Capacitors. Energy Environ. Sci.
2015, 8 (3), 941–955.
(3) Sivakkumar, S. R.; Pandolfo, A. G. Evaluation of Lithium-Ion Capacitors Assembled with Pre-Lithiated Graphite Anode and Activated Carbon Cathode. Electrochim. Acta
2012, 65, 280–287.
(4) Ding, J.; Hu, W.; Paek, E.; Mitlin, D. Review of Hybrid Ion Capacitors : From Aqueous to Lithium to Sodium. Chem. Rev.
2018, 118, 6457–6498.
Cell Optimisation of Supercapacitors through the Use of a Quasi-Reference Electrode and Potentiostatic Analysis
Authors: Le Fevre Lewis 
Published: February 2020

In this study, the authors demonstrate a new potentiostatic aging method for the electrochemical stable potential window (ESPW) of supercapacitors and thus the calculation of the optimal mass ratio for electrode-electrolyte pairings. For this purpose a novel quasi-reference electrode (QRE) was incorporated within CR2032 coin cell containment enabling three electrode potentiostatic aging measurements to be performed using organic electrolytes whilst outside of a glovebox. Monitoring of the final current during potentiostatic aging was used to determine the ESPW of each electrode. Calculation of the voltage optimised mass ratio for activated carbon electrodes in 1 M TEABF4 ACN and PC electrolytes was achieved through attained knowledge of the ESPW and associated capacitance values[1]. The validity of the technique and use of the QRE is verified by full cell potentiostatic aging experiments on mass balanced and mass symmetric supercapacitors[2]. For both electrolytes the operating voltage and cycle lifetime of the device was improved significantly.
References
[1] D. Weingarth, H. Noh, A. Foelske-Schmitz, A. Wokaun, R. Kötz, A reliable determination method of stability limits for electrochemical double layer capacitors, Electrochim. Acta. 103 (2013) 119–124.
[2] S. Vaquero, J. Palma, M. Anderson, R. Marcilla, Mass-balancing of electrodes as a strategy to widen the operating voltage window of carbon/carbon supercapacitors in neutral aqueous electrolytes, Int J Electrochem Sci. 8 (2013) 10293–10307.
Performance of Li-Ion Batteries: Contribution of Electronic and Ionic Factors
Authors: Jaegermann Wolfram , Hausbrand René 
Published: February 2020

Different combinations of cathode and anode materials have been investigated for improving the energy content of Li-ion battery materials. One of the dominant factors of performance is related to the achieved battery voltage depending on the charging state of the battery. The voltage difference of the electrochemical cell is given by the change in the Gibbs energy for the exchange of Li which will again will depend on the exchange of electrons and ions between the two phases. A systematic experimental study on the relative influence of both contributions on the measurable battery voltage have not been performed yet. Therefore we will present in this contributions surface science studies of well-defined thin film electrodes which allows to compare changes in electronic structure and related electronic surface potentials with voltage measurements. In addition, we will present first experiments on the direct measurements of the ionic work function.
A number of different thin film cathode materials with different composition of the layered oxides and olivine structural family have been prepared in recent years mostly by sputter deposition inside an integrated UHV system. Subsequently, the electronic structure and surface potentials as e. g. the electronic work function and the changes induced with charging have been determined by applying photoelectron spectroscopy. The experiments allow to relate energetic changes in the Fermi level positions to the measured battery voltage and thus deduce the relative contribution of the different electronic chemical potential to the battery voltage. Based on our data we conclude that the major contribution to the battery voltage is related to electronic work function variations of the different electrode materials.
In addition, we have performed first experiments by experimentally determining the electronic and ionic work function of electrode materials. Such experiments allow to directly determine the chemical potential of the Li atom as given by the electronic and ionic contribution in relation to the vacuum level. With a Born-Haber cycle we can show that the experimentally determined values are in reasonable correspondence to the battery voltage.
Summarizing our results we conclude that the performance of Li-ion batteries depend on the relative changes of bonding contributions for electrons and ions within the used electrodes with electrons providing the larger part to the battery voltage. Measured variations in performance must be related to deviations of the rigid band behavior of the electrode materials and to surface effects occurring in the given battery set-up.
Structure of Confined Ionic Liquids in Graphitic Nanopores from Ab-Initio Molecular Dynamics Simulations
Authors: Pham Tuan Anh , Coulthard Riley , Zobel Mirijam , Buchsbaum Steven , Plata Desirée , Wood Brandon C. , Fornasiero Francesco , Meshot Eric 
Published: February 2020

Room temperature ionic liquids (ILs) have recently emerged as highly promising electrolytes for a wide range of emerging energy technologies, including next-generation supercapacitors and ion-batteries, due to their high thermal stability, ionic conductivity and wide electrochemical windows. In this presentation, we combine first-principles simulations and synchrotron X-ray characterization experiments to unravel the structural properties of several imidazolium-based ILs in the bulk and at the graphitic interface, which play an important role in determining the performance of carbon-based supercapacitors. In particular, we utilize extensive ab initio molecular dynamics simulations to probe the local density distribution and medium-range order of bulk ILs, which can be directly compared and validated by X-ray scattering measurements. Having established this cross-validation, we then compare and contrast via simulation the structural, chemical and electronic properties of the ILs in the bulk and under confinement in sub-2-nm carbon slit nanopores constructed of graphene layers, which serve as model systems for understanding confinement effects in porous graphitic carbon. Our integrated theoretical and experimental approach relates these structural and chemical signatures with the intrinsic cation-anion interactions, by considering ILs with anions having significant differences in the molecular geometry, chemical composition, and charge distribution.
This work was supported by the U.S. Department of Energy at the Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
Muli-Bath Electrodeposition of CTZS Increasing Sulfur Ratio Close to Back Contact
Authors: Saeed Mahfouz Ali 
Published: February 2020

Cu2(ZnSn)(S)4 (CTZS) has several good optical properties compared with other thin solid films. Producing CTZS cell layers by electrodeposition techniques is mostly attractive due to its low cost compared with other common deposition methods. According to literature review, there are serious challenges to deposit CTZS by electrochemical technique. The most challenging issue is sulfur atomic ratio which is about 50% of CTZS alloy.
We introduce in this work multi-steps electrodepostion techniques on order to obtain the desired atomic composition. First step is electroplating sulfur layer on the molybdenum back contact for 5 minutes followed by CTZS low sulfur layer, the third step is electroplating sulfur again for 8 minutes, the final step is electroplating CTZS low sulfur layer for 12 minutes. Electrolyte composition of sulfur electrodeposition: was 0.085 M CuSO4 and 0.074 M Na2S2O3. Electrolyte composition of CTZS electrodeposition is similar to the previous work used in the literature 1-4. The bath composition is: 0.053 M CuSO4, 0.04 M ZnSO4, 0.086 M SnCl2, 0.075 M Na2S2O3, and 0.055 M Na2S2O3. PHydrion is used to buffer the electrolyte to pH=2, and supporting electrolyte is 0.6 M LiCl.
Experiments were conducted at a rotating disk electrode in order to control and characterize the flow (Ambient temperature). The annealing post treatment is conducted on tube furnace under sulfur atmosphere for 55 minutes with no extra material addition on gas phase. Alloy surface analyses of CTZS from single bath and from multi-steps electrodeposition are in Fig. 1 and 2. The effects of both, bath composition and the electroplating time were optimized and discussed on this work. The amount of sulfur on the absorber layer was optimized by different run of multi-step electroplating technique. The alloy composition was examined using Energy-dispersive X-ray spectroscopy technique (EDS). XRD analysis method was used to characterized CTZS thickness and final crystallography.

Acknowledgements

Case Western Reserve University for using their instruments

References

[1] M. Cao, L. Li, B. L. Zhang, J. Huang, L. J. Wang, Y. Shen, Y. Sun, J. C. Jiang, G. J. Hu,
Sol. Energy Mater. Sol.Cells, 93, 583 (2009).
[2] Y. Lin, S. Ikeda, W. Septina, Y. Kawasaki, T. Harada, M. Matsumura, Sol. Energy Mater. Sol. Cells, 120,
218 (2014).
[3] Lee SG, Kim J, Woo HS, Jo Y, Inamdar AI, et al. Current Applied Physics 14: 254-258 (2014.
[4] R. Bhattacharya , J. Kim. The Open Surface Science Journal 4: 19-24 (2012).

Figure 1