bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reversible Redox Behavior of Quinone-Based Molecule with Activated Carbon Slurry Electrode
Authors: Suzuki Keisuke , Takimoto Daisuke , Hideshima Sho , Sugimoto Wataru 
Published: December 2020

The energy density of carbon-based electrochemical capacitors can been improved by grafting electroactive quinone-based molecules.1 The improvement in energy density of the quinone-grafted carbon electrode is attributed to both the redox capacitance of the electroactive molecules and the electrical double layer capacitance of activated carbon. The redox reaction of the quinone-grafted carbon electrodes at high scan rate typically shows quasi-reversible behavior, suggesting rather sluggish charge transfer. In this study, to understand the redox behavior of electroactive molecules in various environments, we investigated the electrochemical properties of activated carbon slurry electrode with electroactive molecules dissolved in the electrolyte (Scheme 1). The behavior of the electroactive molecules was investigated in terms of the pore size, the surface functional group, and specific surface area of activated carbon.
The electrochemical measurements were conducted using a three-electrode cell. A glassy carbon electrode (6 mm in diameter) was used as the working electrode. 4,5-dihydroxy-1,3-benzenedisulfonic acid (BQDS) was used as the electroactive molecule. Activated carbon (AC, average pore diameter = 0.8 nm) was dispersed in n mM BQDS + 0.5 M H2SO4 electrolyte (n = 1, 3, 10, 100 mM).
Cyclic voltammograms show that the ΔE of BQDS dissolved in H2SO4 (1 mM BQDS + H2SO4 | GC) was 345.5 mV at a scan rate of 20 mV s-
1 (Fig. 1a). By adding activated carbon into the electrolyte (1 mM BQDS + AC-dispersed H2SO4 | GC), the peak to peak potential difference ΔE of AC dispersed 1 mM BQDS + 0.5 M H2SO4 | GC was only 3.4 mV at a scan rate of 20 mV s-
1, which is a signature of a fast surface redox reaction (Fig. 1b). The reversibility of the redox reaction was clearly observed when the BQDS concentration was 1-10 mM, while a quasi-reversible reaction was observed when the BQDS concentration was 100 mM (Fig. 1c). The results suggest that the fast surface redox behavior of BQDS is observed only when the BQDS concentration in the electrolyte is low, i.e. below 100 mM BQDS.
AC with various pore sizes was also studied. Fast surface redox behavior was obtained when AC rich with the micropores (pore size < 1 nm) were used even without grafting treatment. The result suggests that the BQDS is trapped in micropores via interaction in confined pores and is responsible for the fast redox reaction.2
,
3

G. Pognon, T. Brousse and D. Bélanger, Carbon , 49, 1340 (2011).

Y. Hanzawa, T. Suzuki and K. Kaneko, Langmuir, 10, 2857 (1994).

K. Kaneko, R. F. Cracknell and D. Nicholson, Langmuir,
10, 4606 (1994).

Figure 1
Growth and Film Properties of Plasma-Enhanced and Thermal Atomic-Layer-Deposited Magnesium Oxide Films Using Bis(ethylcyclopentadienyl)Magnesium Precursor
Authors: Kang Wangu , Choi Byung Joon , Han Jeong Hwan 
Published: December 2020

As the device scaling of dynamic random access memory continues, the demand for the development of new dielectric film with high permittivity and low leakage current that may replace the currently used ZrO2/Al2O3-based dielectric film has increased drastically. In this aspect, MgO thin film has been spotlighted due to its high band gap (7-8 eV) and moderate dielectric constant (9-10).
In this study, we investigated the growth behavior and film properties of the MgO ALD film using Mg(EtCp)2 precursor and the different reactants of H2O and O2 plasma. MgO thin films were deposited at the temperature range of 200-400°C, and the self-limited surface reaction was observed to secure optimal growth conditions. Glancing angle X-ray diffraction and X-ray photoelectron spectroscopy were used to examine crystalline structure and chemical properties, respectively. To evaluate the electrical characteristics of the MgO films, the Pt/MgO/TiN capacitor was fabricated with different MgO thicknesses at various deposition temperatures. The electrical characteristics such as dielectric constant and leakage current density of the MgO film were examined depending on the reactants, and the leakage current conduction mechanism of the MgO thin films was elucidated.

Figure 1
Prevention of Central Venous Catheter Associated Infections Using Boron Carbon Nitride (BCN) Thin Films
Authors: Nehate Shraddha Dhanraj , Saikumar Ashwin Kumar , Naga Varsha , Sundaram Kalpathy B. 
Published: December 2020

Central line-associated blood stream infections (CLABSIs) are the infections caused due to use of central venous catheters in patients. Implanted catheters are susceptible to bacterial colonization, biofilm formation and consequently resulting in infection. CLABSIs continue being important and preventable health-care related infection. Of all the healthcare associated infections, CLABSIs make up to 250,000 cases per year in the US with mortality of up to 35% [1]. Additionally, these infections are associated with high hospital stay durations leading to extremely high cost burden accounting to ~$46,000 per case [2]. However, central venous catheters are imperative in delivery of fluids and medications and to monitor the patient health. Current approach to mitigate this problem heavily focusses on deposition of coatings, inhibiting bacterial adhesion and reducing biofilm formation.
In this study, boron carbon nitride (BCN) coatings will be incorporated on central venous catheters for the first time. Boron carbon nitride (BCN) films have achieved attention owing to their crystal structure and unique properties. BCN compounds are expected to combine excellent properties of diamond, boron carbide and boron nitride with their properties adjustable depending on their composition and structure[3]. B-C-N ternary compounds have been reported previously for biological applications [4-7]. Influence of BCN coating on bacterial colonization of gram-positive and gram-negative bacteria will be investigated. BCN films will be deposited using RF sputtering technique.
References
[1] S. S. Magill et al., "Changes in prevalence of health care–associated infections in US hospitals," New England Journal of Medicine, vol. 379, no. 18, pp. 1732-1744, 2018.
[2] Y. Haddadin and H. Regunath, "Central line associated blood stream infections (CLABSI)," in StatPearls [Internet]: StatPearls Publishing, 2019.
[3] A. Prakash, S. D. Nehate, and K. B. Sundaram, "Boron carbon nitride based metal-insulator-metal UV detectors for harsh environment applications," Optics letters, vol. 41, no. 18, pp. 4249-4252, 2016.
[4] W. Yang, P. Thordarson, J. J. Gooding, S. P. Ringer, and F. Braet, "Carbon nanotubes for biological and biomedical applications," Nanotechnology, vol. 18, no. 41, p. 412001, 2007.
[5] A. Bianco, K. Kostarelos, C. D. Partidos, and M. Prato, "Biomedical applications of functionalised carbon nanotubes," Chemical Communications, no. 5, pp. 571-577, 2005.
[6] S. H. Mir, V. K. Yadav, and J. K. Singh, "Boron–Carbon–Nitride Sheet as a Novel Surface for Biological Applications: Insights from Density Functional Theory," ACS Omega, vol. 4, no. 2, pp. 3732-3738, 2019.
[7] G. Ciofani, S. Danti, G. G. Genchi, B. Mazzolai, and V. Mattoli, "Boron nitride nanotubes: biocompatibility and potential spill‐over in nanomedicine," Small, vol. 9, no. 9‐10, pp. 1672-1685, 2013.
Development of Low Power Consumption Electrochromic Device Using Spontaneous Discoloration Reaction
Authors: Tsukada Kenichi , Abe Hiroya , Nishizawa Matsuhiko , Kato Takehito 
Published: December 2020

Recently, dimming functional materials have been attracted attention as one of the solutions to energy problems. Dimmable materials are capable of continuously adjusting the transmittance of light according to the intensity of external light, which is expected to reduce cooling and heating loads of buildings such as houses and office buildings and realize energy saving. Prussian blue (PB, KFe3+[Fe2+(CN)6]) is known as one of the dimming functional materials that shows reversible color changes upon Fe2+/Fe3+ redox reaction [1], and has been used for electrochromic devices (ECD) as an inexpensive and highly durable dimming function material. The conventional ECD is controlled by bipolar voltage applications for coloration and discoloration [2]. In contrast, , we developed here the ECD equipping a function of a spontaneous discoloration without applying voltage with the aim to reduce power consumption.
ECD is consisted of indium-doped tin oxide (ITO) glass / PB / electrolyte / PB / ITO glass. The PB-coated ITO glasses were prepared by casting PB ink onto ITO glasses (15 x 15 mm) and spin-coated at 2000 rpm for 10 sec. The electrolyte used was a propylene carbonate containing potassium bis(trifluoromethanesulfonyl)imide and polymethyl methacrylate.
By applying the voltage at 1.5 V to the ECD, the wavelength peak of a reflected light shifted from 460 nm (blue color) to 535 nm (yellow color) due to the reduction and oxidation of PB on the anode and the cathode, respectively. That is, KFe3+[Fe2+(CN)6] (blue) was reduced to K2Fe2+[Fe2+(CN)6] (colorless) on a cathode and KFe3+[Fe2+(CN)6] (blue) was oxidized to KFe3+[Fe3+(CN)6] (yellow) on an anode. After removing the voltage application, wavelength shifted back from 535 nm to 500 nm, indicating that PBs spontaneously changed to their original states. It is estimated that the color returns to the original color in about 3 hours. The spontaneous discoloration might be caused by the potential difference between the electrodes. The detailed discussion regarding the relationship between spontaneous discoloration and the elapsed time will be present.
[1] K. Yoshino, “Prussian Blue; New applications and its nanoparticles,” THE CHEMICAL TIMES, 229(3):23-27, (2013)
[2] H. Tanaka, (2010), “Development of electrochromic devices by printing processes,” NEW GLASS, 25(3): 60-63, (2010)

Figure 1
Carbochlorination of Cobalt Oxide and Electrochemical Recovery of Co in an Amide-Type Ionic Liquid
Authors: Yeh Hsing-wen , Serizawa Nobuyuki , Katayama Yasushi 
Published: December 2020

Recycle of rare metals from electric devices is demanded from the viewpoints of production costs and environmental protection. Carbochlorination is a traditional pyrometallurgical process to convert metal oxides in metal waste into metal chlorides. However, high temperature is often required for the carbochlorination process, leading to an increase in the recycling cost. We have already reported that the dissolution of palladium oxide was possible in an amide-type ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (BMPTFSA) containing BMPCl by carbochlorination at a relatively lower temperature. In the present study, the carbochlorination of cobalt oxide (CoO) was investigated in BMPTFSA containing BMPCl. Recovery of Co was also attempted by electrochemical reduction of the cobalt species in the ionic liquid.
CoO was reacted with some carbochlorination reagents in 0.5 M BMPCl/BMPTFSA in a perfluoroethylene propylene copolymer (FEP) tube at 150 °C for 24 h. The residual carbochlorination reagents and byproducts were removed by heating under vacuum at 100 - 150 °C for 24 h. The electrochemical measurements were conducted using a single-compartment cell using glassy carbon as a working electrode, cobalt as a counter electrode, and silver wire immersed in 0.1 M AgCF3SO3/BMPTFSA isolated from the sample electrolyte with porous glass as the reference electrode.
CoO was insoluble in 0.5 M BMPCl/BMPTFSA without the carbochlorination reagents. CoO was found to be dissolved as [CoCl4]2– in 0.5 BMPCl/BMPTFSA in the presence of the carbochlorination reagents at 150 °C by the ultraviolet-visible spectroscopy. A cathodic current peak assignable to the reduction of [CoCl4]2– was observed at -3.1 V in the cyclic voltammogram of a GC electrode in the ionic liquid after carbochlorination of CoO. The deposits containing Co were obtained by the potentiostatic cathodic reduction in the ionic liquid, suggesting the recovery of Co from CoO is possible electrochemically with carbochlorination at low temperature.
Study on the Prevention of Optics Contamination in Photo-Lithography
Authors: Jung Juyoung , Choi Byoung Deog 
Published: December 2020

In semiconductor manufacturing technology, photolitho exposure tools have advanced scaling of integrated circuit (IC) chips for decades. The tools enable illumination optics to expose the patterns of photo-mask onto wafers coated with photo-resist (PR). As the line width of the chip has been scaled down below 20 nm, the contamination of optics degrades the uniformity of light so that it reduces the accuracy of optical patterns. Thus, contamination in the optic system is crucial to enhance wafer pattern scaling.
The level of contamination in optics can be identified with light scattering (i.e., Straylight index). By tracing the Straylight index for years, we determined REMA (Reticle Masking) lens, which is one of the lens element, was contaminated by the chemical ions of FAB air. We implemented destructive inspection with the contaminated lenses to identify degradation mechanisms and detected plenty of positive ions (i.e., Si+) (Table.1) and negative ions (i.e., Silicon Oxide) (Table.2) on REMA Lens. (Fig.1). The humidity in FAB air which is attach to the polar surface of optics, light exposure transforms it to hydroxide ions or highly reactive radical (OH*, H*, O*) by the DUV light. And then the highly reactive radical is easy to combine with non-cleanable contamination (e.g., silicon, sulfur, and nitrogen). Although Photolithographic tools have a purging system using inert N2, XCDA (Extreme clean dry air), CA (Clean Air) to prevent contamination. Each optic has a different purge system and environment, so contamination has been strongly concentrated on the last lens element of REMA.
In this paper, we performed three main tests to slow the rate of lens contamination. First of all, literally hundreds of tools in the factory have measured with the efficiency of the chemical filters for pollutions. Then, we exchanged types of chemical filters based on the different contamination speed. This test helps us to identify contamination sources. Secondly, we changed the air mixing ratio (i.e., Dilution factor). Despite the similar structure of the tool, the air mixing ratio is different respectively as the time of each tools is released. After investigating the three different values, we found an optimized value to slow down the contamination speed. Lastly, we reform the structure of tools to avoid mixing the pollution air. Overall, these test results tell a remedy of how to manage the lens contamination in optics.

Figure 1
Electrical Properties of SiGe/W Plate Node in DRAM Capacitor
Authors: Lee Yongyeol , Choi Byoung Deog , Jung Ilwoo 
Published: December 2020

Recently DRAM(Dynamic Random Access Memory) industry is continuously scaling down to improve productivity and create low power memory products. This trend reduces the capacitance for storing data and increases the unwanted parasitic capacitance, which causes problems in data storage of DRAM. In addition, the plate structure of the node on the current DRAM capacitor further reduces the data storage capacity by causing voltage noise during product operation.
In this paper, electrical properties were evaluated using SiGe/W(tungsten) structure instead of the existing SiGe(silicon germanium) plate, based on the fact that when the resistance of the plate node on the capacitor decreases, the plate noise can be improved during product operation by RC model. W was deposited on the high-doped SiGe by PVD(Physical Vapor Deposition), and it was confirmed that an Ohmic contact between SiGe and W was formed. Sheet resistance and contact resistance were decreased by 86.6% and 51.1%, respectively, compared to the existing SiGe plate structure under the voltage condition of 3 volts. As a result, it was confirmed that the value of capacitance for storing data increased by 20%. In order to confirm the improvement of failure, we conducted a test that caused plate noise by continuously inversion of adjacent data, and confirmed that the failure was improved by 36% in the SiGe/W plate structure.

Figure 1
Optimization of Boron-Doped Diamond Thin-Layer Cell for Chemical Oxygen Demand Sensor Based on Anodic Oxidation of Organics
Authors: Latifah Dian , Ilhwan Oh 
Published: December 2020

The advanced electrochemical oxidation process (AEOPs) has been considered as an appealing approach to overcome problems associated with the conventional water treatment methods. The use of expensive and toxic chemical oxidizing reagents in chemical oxygen demand, for example, can lead to environmental concerns of the production of secondary pollution. Anodic oxidation, one of the most popular AEOPs, offers a rapid and straightforward COD determination by removing the need for chemical oxidants. The process mainly relies on the anode material to degrade the organic molecules; thus, choosing the appropriate material is one of the keys to a successful electrochemical oxidation.
Numerous electrochemical applications utilize boron-doped diamond as the anode material due to its unique properties such as wide potential window, low background current, and resistance to fouling. The employment of BDD for anodic oxidation of organics enables complete oxidation of organics via physically adsorbed hydroxyl radicals (●OH). The species offers a high standard redox potential of E° (●OH/H2O) = 2.80 V/SHE, high reactivity, and short lifetime, makes it possible to be used for the on-site electrochemical oxidation process.
The objective of this study is to develop and optimize an electrochemical system for chemical oxygen demand determination based on a photoelectrochemical degradation principle. The degradation of phenols takes place in a specially designed BDD thin-layer electrode, and the amount of electrons transferred at the electrode can be measured to define the equivalent COD value. A 60μm thick films are used as a spacer, resulting in a contact area of 3 cm2. At 2.54 V vs. SHE, a sample containing 50 mg/L analytes required less than 3 mins to degrade, and the assay time for organics decay increases for a higher concentration of phenols. Incorporating the BDD electrode with cathode materials, such as Pt-coated indium tin oxide (ITO), will be employed as an attempt to improve the degradation efficiency by minimizing the voltage drop between the electrodes. Sandwiching the BDD-cathode using Nafion® membrane will be studied to remove the need for additional supporting electrolytes. The major experimental conditions of the anodic oxidation of organic molecules by BDD, such as applied potential bias, supporting electrolyte concentration, pH, and dissolved oxygen concentration, will be varied to obtain the optimum conditions.
(Invited) Development of Ionic Porous Polymer for Sensing Applications
Authors: Ahmed Kumkum , Furukawa Hidemitsu , Naga Naofumi 
Published: December 2020

Porous polymers with macr/micro- sized pores have potential applications in separation, batteries, fuel cells and sensors [1, 2]. Thiol-ene "click" is a widespread method for monolith preparation owing to its exceptional versatility, simplicity and facile tunability. In our previous work, we reported on the fabrication of extremely soft type thiol-ionic gels (T-IGs) incorporating ionic liquid (IL) (70–85 wt%) in the thiol–ene network of thiol-based end-crosslinker and acrylate monomers [3, 4]. The T-IGs exhibited tunable mechanical and conductive properties and conductivity as high as 5.40 mS cm−1 is attained for longer acrylate group containing gels at room temperature. In this work we developed a series of porous polymers through polymerization induced phase separation by utilizing thiol-ene reaction between multi-functional thiol monomers and diacrylate crosslinkers in ionic Liquid solvent medium. The matrix of the polymers constructed of interconnected micro-globules forming a three-dimensional network. These microporous polymers exhibited tunable mechanical prosperities and morphology. In contrary to the ionic gels, the porous structure with entrapped ILs exhibited high ionic conductivity possibly due to relatively unperturbed transport of ions within the interconnected polymer particles compared to the bulk polymeric network. Physical properties of these porous ionic polymers have been investigated to optimize suitable condition for best performance in piezoresistive sensors (enabling sensing of both pressure and strain). This work is expected to add potential functionality in the applied field of the polymer materials.
References

Sakakibara, K., Kagata, H., Ishizuka, N., Sato, T., Tsujii, Y. Fabrication of surface skinless membranes of epoxy resin-based mesoporous monoliths toward advanced separators for lithium ion batteries. J. Mater. Chem. A, 5, 6866–6873 (2017).

Liu, Z., Ou, J., Zou, H., Click polymerization for preparation of monolithic columns for liquid chromatography. Trends Anal. Chem., 82, 89–99 (2016).

Ahmed, K., Naga, N., Kawakami, M. & Furukawa, H. Development of ionic gels using thiol-based monomers in ionic liquid. 9800,980005 (2016).

Ahmed K, Naga N., Kawakami M. and Furukawa H., Extremely Soft, Conductive and Transparent Ionic Gels by 3D Optical Printing, Macromol. Chem. Phys., 1800216 (2018).
(Invited) Friction Processing and Application to High Strength Hydrogel Surface
Authors: Wada Masato , Yoshida Kazunari , Furukawa Hidemitsu 
Published: December 2020

In the medical field and food manufacturing process, labor costs and manufacturing costs are reduced, delivery times are shortened, and production is streamlined in all aspects. In particular, the slider part uses many consumables that have a negative effect on the human body and the environment. In this research, we aim at the low friction surface of the functional gel that realizes human safety and cost reduction by replacing a part of the functional gel with the functional gel. This technique involves laser cutting the gel, and the method of creating the sliding and gel surfaces comes from the method of creating a low friction surface by texturing. The textured surface swells uniformly and the coefficient of kinetic friction was measured by the ball-on-disk friction test.
The friction force was measured and the coefficient of friction of the untreated and laser treated DN gel surface was calculated. The results show that laser machining (finishing) can reduce the coefficient of friction. Observation of the gel surface suggests that the cause of friction reduction is a change in the roughness of the gel surface due to laser processing. This finding is expected to guide us to a better understanding of the physicochemical properties of hydrogels. We will introduce an example of using this technology as a machine element.
The dynamic friction coefficient of the low friction gel surface prepared by this method was about 1/3 of that of the untreated gel surface. It was also confirmed that wear marks disappeared depending on the degree of texturing.
Using this technique, it can be easily applied to gel surfaces with low friction. We also designed and developed a unique friction tester for machines. Furthermore, by replacing the metal sliding part with a gel mechanical material, we succeeded in miniaturizing the ultrasonic diagnostic equipment.

Figure 1