bluuebunny/crossref_metadata_2025 huggingface dataset:
Ion Pairs of Charged Porphyrins: Ordered Arrangement and Radical-Pair Formation
Authors: Maeda Hiromitsu
Published: September 2023

π-Electronic ions with appropriate geometries and peripheral substituents provide assemblies through the interactions between charged building subunits, resulting in fascinating electronic properties. Structures and properties of the assemblies can be controlled by the combined positively and negatively charged species in the assemblies.[1,2] In fact, π-electronic ion pairs comprising porphyrin-based π-electronic anions[3] have exhibited characteristic assembling modes via
i
π–
i
π interactions and resulting electronic properties such as solid-state absorption, which was correlated with the arrangement of constituent charged π-systems, and photoinduced electron transfer.[4] On the other hand, ion pairs of porphyrin–AuIII complexes as π-electronic cations, prepared with the combination of various anions including π-electronic anions, formed assemblies as crystals and thermotropic liquid crystals, whose ionic components were highly organized by
i
π–
i
π interactions (mainly electrostatic and dispersion forces).[5] Among various combinations of these porphyrin cations and anions, the “activated” ion pair of meso-EWG (electron-withdrawing group)-substituted cation and meso-EDG (electron-donating group)-substituted anion exhibited the electron transfer in the steady state according to solvent polarity, resulting in the production of the radical pair. The ESR in frozen toluene revealed the formation of a heterodiradical in a close stacking structure by the antiferromagnetic dipolar interaction and temperature-dependent spin transfer behavior.[6,7]

[1] Recent reviews: (a) Haketa, Y. et al. Mol. Syst. Des. Eng.
2020, 5, 757; (b) Yamasumi, K. et al. Bull. Chem. Soc. Jpn.
2021, 94, 2252. [2] Recent reports on pyrrole-based π-electronic molecules: (a) Watanabe, Y. et al. Chem. Eur. J.
2020, 26, 6767; (b) Haketa, Y. et al. J. Am. Chem. Soc.
2020, 142, 16420; (c) Kuno, A. et al. Chem. Eur. J.
2021, 27, 10068; (d) Fujita, M. et al. Chem. Commun.
2022, 58, 9870. [3] (a) Sasano, Y. et al. Dalton Trans.
2017, 46, 8924; (b) Sasano, Y. et al. Chem. Eur. J.
2019, 25, 6712. [4] Sasano, Y.; Tanaka, H. et al. Chem. Sci.
2021, 12, 9645. [5] (a) Haketa, H. et al. iScience
2019, 14, 241; (b) Tanaka, H. et al. Chem. Asian J.
2019, 14, 2129. [6] Tanaka, H. et al. J. Am. Chem. Soc.
2022, 144, 21710. [7] The details of excited-state radical pairs: Tanaka, H. et al. to be submitted.
Synthesis, Structure, and Physicochemical Properties of Electron Donor-Acceptor Conjugates Based on Porphyrinoids and Tetracyanobuta-1,3-Diene
Authors: Lavarda Giulia , Fernández Vera Oscar , Osuka Atsuhiro , Guldi Dirk Michael , Torres Tomas , Bottari Giovanni
Published: September 2023

As result of their synthetic versatility and unique physical features, porphyrinoids have been widely utilized as building blocks for the preparation of molecular and supramolecular electron donor-acceptor (D-A) ensembles in which photoinduced energy/electron transfer events can be triggered/modulated as a function of the electronic character of the macrocycles’ counterpart(s).

In this talk, after a general introduction about porphyrinoids and their use in optoelectronic applications, I will present some examples from our group on the preparation and study of phthalocyanine-,[1] subphthalocyanine-,[2] and subporphyrin-[3] based D-A systems in which the porphyrinoid has been connected to tetracyanobuta-1,3-diene, a molecular fragment with unique structural and electronic features (Figure 1a-c).

References

Sekita, M.; Ballesteros, B.; Diederich, F.; Guldi, D. M.; Bottari, G.; Torres, T. Angew.
Chem. Int. Ed.
2016, 55, 5560.

a) Winterfeld, K. A.; Lavarda, G.; Guilleme, J.; Sekita, M.; Guldi, D. M.; Torres, T.; Bottari, G. J. Am. Chem. Soc.
2017, 139, 5520; b) Winterfeld, K. A.; Lavarda, G.; Guilleme, J.; Guldi, D. M.; Torres, T.; Bottari, G. Chem. Sci., 2019, 10, 10997; c) Lavarda, G.; Bhattacharjee, N.; Brancato, G.; Torres, T.; Bottari, G. Angew. Chem. Int. Ed., 2020, 59, 21224; d) Esteso, V.; Caliò, L.; Espinós, H.; Lavarda, G.; Torres, T.; Feist, J.; García-Vidal, F. J.; Bottari, G.; Míguez, H. Solar RRL, 2021, 5, 2100308.

Winterfeld, K. A.; Lavarda, G.; Yoshida, K.; Bayerlein, M. J.; Kise, K.; Tanaka, T.; Osuka, A.; Guldi, D. M.; Torres, T.; Bottari, G. J. Am.
Chem. Soc.
2020, 142, 7920.

Figure 1
Nanotexaphyrins for Cancer Imaging and Therapy
Authors: Zheng Gang
Published: September 2023

Texaphyrins are expanded porphyrin macrocycles with a 5-coordination pocket that can form stable 1:1 complexes with a large group of metal cations including many lanthanide ions, making them inherently amenable for theranostics (e.g., photodynamic therapy, MRI and radiation therapy). For example, gadolinium-texaphyrin (Gd-Tex, Xcytrin®) developed by the Sessler group was evaluated as a radiosensitizer all the way to Phase III trials. Although Gd-Tex did not gain FDA approval due to its limited radiosensitization efficacy, the fact that Gd-Tex showed good safety profile in phase III clinical trials makes texaphyrins attractive building block to develop new theranostic agents.

We recently synthesized a texaphyrin-phospholipid building block via a key 1,2-dinitrophenyl-phospholipid intermediate, along with stable chelation of a library of 18 different metal ions into texaphyrin-lipid without compromising their self-assembly into nanotexaphyrins. To realize nanotexaphyrin’s theranostic properties, we developed a customizable strategy to build a family of nanotexaphyrins with quantitatively mixed and matched metal ions. We also developed a rapid and robust nanotexaphyrin radiolabeling method using a home-made disposable microfluidic system that achieved a high radiochemical yield. The optimized metalated nanotexaphyrin displayed excellent chemical, photo, and colloidal stabilities, and favorable pharmacokinetics and biodistribution profiles, resulting versatile cancer imaging and therapy applications. For example, the PSMA-targeted 111In/Lu-nanotexaphyrin demonstrated a preferential tumor accumulation in PSMA-positive tumor by both NIR fluorescence and SPECT/CT imaging, and a potent PDT effect that successfully inhibited PSMA+ tumor growth. On the radiation therapy front, we developed Gd-nanotexaphyrin to allow high density packing of Gd-Tex in a single nanovesicle to overcome the limited radiosensitization efficacy of monomeric Gd-Tex. As hypoxia is a common cause of radiation resistance, we loaded oxygen-carrying myoglobin into Gd-nanotexaphyrins, which enabled spatiotemporal codelivery of O2 and Gd-Tex into tumors, resulting in efficient relief of tumor hypoxia and significant enhancement of Gd-Tex radiosensitization. The synergistic mechanism between appropriate O2 delivery and enhanced Gd-Tex radiosensitization has been demonstrated. The high versatility and clinical translatability of nanotexaphyrins is a promising platform to develop cancer theranostics.
Peptide-Targeted Photosensitisers: Synthesis and Applications in Photobiology
Authors: Eggleston Ian M. , Yaghini Elnaz , Dondi Ruggero , Tewari Kunal M. , Edler Karen J. , Loizidou Marilena , MacRobert Alexander J.
Published: September 2023

The conjugation of porphyrin derivatives to peptide ligands is a valuable strategy for enhancing their aqueous solubility and tissue selectivity in the photodynamic therapy (PDT) of cancer. To this end, bioorthogonal ligation (“click”) chemistries provide an efficient way to link porphyrins and other tetrapyrrole systems with complementary multifunctional peptides. We will describe some of our work in this area towards the generation of specific targeted conjugates between porphyrin and chlorin derivatives and tumour-homing or cell-penetrating peptide carriers [1, 2]. Linking otherwise hydrophobic photosensitisers to cationic cell-penetrating peptides (e.g. HIV Tat 48-57) provides amphiphilic derivatives with improved water solubility plus enhanced cellular uptake and predictable sub-cellular localisation. Such molecules are very suitable for use in the light-triggered delivery of macromolecular therapeutics by photochemical internalisation (PCI), which will be illustrated for the targeted delivery of the protein toxin, saporin [3].

Peptide targeting strategies are also valuable for PDT with 5-aminolevulinic acid (ALA) [4]. In ALA-PDT, administered ALA is converted within cells via the heme biosynthetic pathway to protoporphyrin IX which may then be exploited as a photosensitiser. In this context, we will present some recent chemical and biological data on the application of peptide targeting for the enhanced delivery of multiple ALA units to specific cell types [5].

References

[1] R. Dondi, E. Yaghini, K. M. Tewari, L. Wang, F. Giuntini, M. Loizidou, A. J. MacRobert, I. M. Eggleston, Org. Biomol. Chem. 14 (2016) 11488.

[2] E. Yaghini, R. Dondi, K. M. Tewari, M. Loizidou, I. M. Eggleston, A. J. MacRobert, Sci. Rep. 7 (2017) 6059.

[3] E. Yaghini, R. Dondi, K. J. Edler, M. Loizidou, A. J. MacRobert, I. M. Eggleston, Nanoscale 10 (2018) 20366.

[4] K. M. Tewari, I. M. Eggleston, Photochem. Photobiol. Sci. 17 (2018) 1553.

[5] K. M. Tewari, R. Dondi, E. Yaghini, C. Pourzand, A. J. MacRobert, I. M. Eggleston, Bioorg. Chem. 109 (2021) 104667.
Silicon Phthalocyanines as Emerging n-Type Semiconductors in Thin Film Transistors
Authors: Lessard Benoit
Published: September 2023

Silicon phthalocyanines are emerging n-type semiconductors for use in organic photovoltaics (OPVs) and organic thin-film transistors (OTFTs).[1] Their low synthetic complexity paired with their versatile axial group facilitates the finetuning of their chemical properties, solution properties and processing characteristics without significantly affecting their frontier orbital levels or their absorption properties. The crystal engineering and film forming characteristics of silicon phthalocyanine semiconductors can be tuned through appropriate axial group functionalization, therefore facilitating their integration into OTFTs by solution processing or vapor deposition.

We were the first to integrate SiPcs into OTFTs, and unlike the majority of phthalocyanines, SiPcs are inherently better electron transporting materials then hole transport materials. We demonstrated n-type mobilities on the order of 0.5 cm2/Vs which is among the best of all phthalocyanines.[3] Through axial functionalization we reported that changes in the electron withdrawing character of the axial group lead to predictable drops in device threshold voltage from 45 V to 5 V.[4] The axial group can also be used to improve the SiPc solubility leading to solution processable OTFTs where the choice of axial group also dictates the thin film morphology an ultimately the resulting device performance.[5] GIWAXS studies show that processing conditions and choice of axial groups leads to changes in molecular alignment at the interface providing critical insight into device optimization.

This presentation will cover our recent advances in the development of structure property relationships between SiPc structure, thin film processing and resulting charge transport properties.

REFERENCES

1. ACS Applied Materials & Interfaces. 2021, 13, 31321-31330

2. Organic Electronics. 2020, 87, 105976

3. Advanced Electronic Materials. 2019, 5, 1900087

4. ACS Appl. Electron. Mater. 2021, 3, 5, 2212–2223

5. ACS Applied Materials & Interfaces. 2020, 13, 1008-1020

Figure 1
(Invited) Synthesis, Characterization and Quality Control of Heteroatom-Doped Graphene
Authors: Bekyarova Elena
Published: September 2023

Heteroatom doped graphene materials have gained attention as promising candidates for a variety of energy-related applications. Addition of heteroatoms in the graphene lattice is a powerful tool to modify their electronic, electrochemical, and catalytic properties. This presentation focusses on N-doped reduced graphene oxide and summarizes strategies to engineer the structure and properties of the material through control of the synthetic conditions. The produced N-doped graphene materials are characterized to determine their chemical composition, nitrogen content, degree of graphitization, surface area, electronic and electro-chemical properties. The scalability and manufacturability of the N-doped graphene materials are assessed and various examples of their current and future applications in batteries and supercapacitors are discussed.
(Invited) Industrial Face of Nanotechnology
Authors: Shur Michael
Published: September 2023

Ever since the proposal and demonstration of quantum dots in 1980 by Drs. A. Efros, Al. Efros and A. Ekimov, the relentless progress of nanotechnology has been unstoppable. And nowhere this progress is more evident than in the Si Very Large Scale Integrated Circuits (VLSI) and Thin Film Transistor (TFT) technologies. The minimum feature size of the Si VLSI with up to 2.6 trillion transistors on a chip was reduced to 3 nm in 2022 with plans for the 2 nm technology. TFTs fabricated on glass or even on cloth or paper enable integrated circuits with 50 nm tolerances over square meter sizes. These technologies have become disruptive with applications ranging from 5G and Beyond 5G communications to robotics, driverless cars, and electronic warfare. This talk will focus on the new counter-intuitive physics of ballistic transport required to support the design, characterization, and parameter extraction for nanoscale Si VLSI and TFT integrated circuits.

Figure 1
(Digital Presentation) Hydrogen Peroxide Assisted Fluorescent Carbon Nanoparticles from Teak Leaves
Authors: Uddin Jamal , Roy Arup K , Ghann William E
Published: September 2023

H2O2supported carbon nanoparticles were synthesized through hydrothermal treatment. The Fluorescent Carbon Nanoparticles (FCNs) could be easily functionalized with H2O2
and showed blue emission fluorescence with higher stability in aqueous solution. The FCNs were characterized using absorption spectroscopy, Fluorescence spectroscopy, Fourier-transformed Infrared spectroscopy, Field Emission Scanning Microscopy, and Transmission Electron Microscopy. The synthesized FCNs were subsequently applied in dye sensitized solar cells to enhance the efficiency of the solar cells. The essential photovoltaic parameters, such as open circuit voltage (VOC), short circuit current density (ISC), fill factor (FF), and the overall conversion efficiency (η), were evaluated. The solar-to-electric efficiency of the fabricated dye sensitized solar cell was 0.10%. Furthermore, electrochemical impedance spectroscopy (EIS) was performed to elucidate the charge transfer and transport processes that occur in the fabricated DSSC.
Growth of Carbon Nanotubes on Metallic Substrate: Growth Mechanism and Electrochemical Applications
Authors: Osman Abdalghaffar Mohammad , Hendi Abdulmajeed , Osman Nadir
Published: September 2023

This work reports the use of carbon nanotubes-modified silver (CNTs-Ag) electrode prepared by chemical vapor deposition (CVD) as indicating system in differential electrolytic potentiometry (DEP) for both redox and precipitation reactions. Characterization of CNTs-Ag electrode by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) showed the formation of aligned CNTs of a good degree of crystallinity and well-graphitized sheets. CNTs-Ag electrode was applied successfully for the determination of ascorbic acid in both pure form and in pharmaceutical and food samples along with in the determination of cyanide too down to quite low concentrations. CNTs-Ag electrode exhibited a fast and stable response and attained equilibrium in a short time. These good characteristics are attributed to the rapid heterogeneous electron transfer and high electrode surface area offered by CNTs. Additionally, modification of the Ag with CNTs grown via CVD method offers adhesion of the CNTs layers to the Ag surface and direct electrical contact better than the external modification methods commonly used such as casting the CNTs or mixing them with Nafion. Moreover, CVD method offers the chance to produce aligned CNTs that have better electrical properties than the randomly distributed ones. This work also proposed a CNTs growth mechanism by XPS depth profiling analysis.

Figure 1
Investigation of Corrosion Mechanisms of Copper Microstructures Underneath Polymer Coatings: Experiment and Simulation
Authors: Mayr Maximilian , Nabi Hasan Sadat , Jordan Steffen , Altieri-Weimar Paola , Fafilek Guenter
Published: September 2023

BACKGROUND

Reliability and stability of electronic components are crucial for both consumer and producer. External influences (e.g. bias, humidity) can enable corrosion processes and lead to accelerated failure. For example, field-driven electrochemical migration (ECM) of copper (Cu), a material that is widely used for electrical connections, can drive corrosion processes and ultimately lead to component failure.

METHODOLOGY

In this work, a miniaturized test chip, manufactured with techniques used in the semiconductor industry, is employed to investigate ECM and corrosion mechanisms of copper electrodes covered by an organic coating. Combinations of applied bias and aqueous electrolytes atop the organic layers are used to drive ions into and inside the coating. The distribution of ions in the polymer layer and at the interface Cu/coating is investigated by optical, electrochemical and analytical methods (e.g. EIS, LA-ICP-MS). The experimental work is complemented with a dynamic multi-ion finite element simulation model created with COMSOL Multiphysics®. The simulation model of polymer coated copper structures is developed starting from a previous electrochemical model of Cu electrodes in aqueous electrolytes, which was validated experimentally. Refinement and validation is achieved by comparison with literature and experimental data acquired through test chip measurements.

RESULTS

The course of current and solution resistance transients determined by EIS show the slow progression of corrosion processes until a fast breakdown is observed. Experimental results and the comparison with simulation enable insights into electrochemical migration of Cu and corrosion mechanisms. The combination of the two helps elucidate corrosion processes and thereby allows the identification of on-going electrochemical processes in electronic components at different stages.
Enhance of Anticorrosive Properties of Green-PU-Silica Coatings by Incorporation of Lignin
Authors: Braz Alvaro Guimarães , Harb Samarah Vargas , Pulcinelli Sandra Helena , Santilli Celso Valentim
Published: September 2023

The tailored combination of organic polymers and inorganic ceramics can produce organic-inorganic hybrid (OIH) coatings to act as corrosion protection barriers.1
,2 In this work, we proposed the use of glycerol and lignin as polyol sources to prepare green polyurethane to be used in the sol-gel synthesis of PU-silica hybrid coating for steel corrosion protection. The PU pre-polymer was synthesized from MDI (4,4’-methylenebis (phenyl isocyanate)), glycerol and lignin, and then it was functionalized with APTES ((3-aminopropyl) triethoxysilane) to ensure the covalent conjugation with polysilanol network formed from TEOS (Tetraethyl orthsilicate) sol-gel reactions leading to a class II hybrid. Three samples were synthesized varying the proportion between the polyols, one sample containing only glycerol (ZL_PU-S) and the others with a molar ratio of GlyOH:LigOH of 7.5 and 16.1 (FL_PU-S and HL_PU-S, respectively).The effects of lignin content on the structure and properties were evaluated. FTIR and 13C NMR showed the formation of the PU-silica hybrid and the total incorporation of lignin to the PU chain. TGA showed that the presence of lignin into the OIH matrix improved the thermal stability allowing to continuous increase of the initial temperature of mass loss: T5% = 173, 186 and 190 °C for ZL_PU-S, HL_PU-S and FL_PU-S, respectively. The steel substrate coated with the OIH show a water contact angle of 90° for the samples HL_PU-S and FL_PU-S and 80° for ZL_PU-S. The electrochemical impedance spectroscopy analysis performed in a three electrode cell configuration with a NaCl 3.5% solution, showed that the coating with the higher lignin concentration, FL_PU-S, have a |Z| of over 1010 Ω.cm2 for the lowest frequency point and a phase angle of approximately -90° during the 28 days of analysis. The FL_PU-S had better performance than the coating without lignin, ZL_PU-S, that presented |Z|=107 Ω.cm2 on the initial period of immersion with a decrease of two decades in value through out the subsequent period of analysis. In summary, the addition of lignin to the PU polymeric matrix enables the production of a green OIH coating with high efficiency for corrosion protection of steel substrates.

Acknowledgments: This work was supported by the Brazilian funding agencies CNPq, FAPESP, CAPES and by PROPe UNESP.

Keywords: Renewable feedstock, green coating, PU-silica, lignin, corrosion protection, sol-gel process, hydrophobic coating.

1-BRAZ, Á. G.; PULCINELLI, S. H.; SANTILLI, C. V. Glycerol-based polyurethane-silica organic-inorganic hybrid as an anticorrosive coating. Progress in Organic Coatings, v. 169, p. 106939

2-HARB, S. V. et al. Siloxane–PMMA hybrid anti-corrosion coatings reinforced by lignin. Surface and Coatings Technology, v. 275, p. 9-16.
(Dielectric Science &Technology Thomas D. Callinan Award) Semiconductor Nanostructures for Optoelectronics and Energy Applications
Authors: Jagadish Chennupati
Published: September 2023

Semiconductors have played an important role in the development of information and communications technology, solar cells, solid state lighting. Nanowires are considered as building blocks for the next generation electronics and optoelectronics. In this talk, I will present the results on growth of nanowires, nanomembranes and microrings and their optical properties. Then I will discuss theoretical design and experimental results on optoelectronic devices. In particular I will discuss nanowire and micro-ring lasers and integration of nanowires and microrings. I will also present the results on polarization sensitive, broad bandwidth THz detectors operating at room temperature. Nanowire based energy devices such as solar cells and photoelectrochemical (PEC) water splitting will be discussed. I will discuss about Neuro-electrodes to study brain signaling to understand dementia. Future prospects of the semiconductor nanostructures will be discussed.
Low-Cost Clean One-Step Production of Solar Silicon from Natural Quartzite
Authors: Asadikiya Mohammad , Powell Adam Clayton
Published: September 2023

Despite the fact that many groups have tried to achieve solar silicon production using molten salt electrolysis, the motivation for this project is to build on a recent breakthrough in silicon molten salt chemistry. The novel molten salt bath comprised of MgF₂-CaF₂-YF₃-CaO-SiO₂ exhibits low volatility (<0.1 μg/cm2·s), low viscosity (<5 mPa·s), high ionic conductivity (>4 S/cm), SiO₂ solubility (>5 wt%), and yttria-stabilized zirconia (YSZ) solid oxide membrane (SOM) compatibility, which are all at least an order of magnitude better than prior works. Our goal is to produce high-purity silicon from natural 99.7-99.9% pure quartzite (SiO₂) in only one step, utilizing molten salt electrolysis with a state-of-the-art molten salt composition. This process can potentially produce silicon with 4-5N purity at $1.70/kg using <30 kWh/kg, with pure oxygen by-product and zero direct Greenhouse Gas (GHG) emissions. The 4-5N product purity would be sufficient for directional solidification, resulting in $2.20-2.70/kg solar-grade silicon cost, i.e., 90-95% lower than today. Besides considerable silicon price reduction, our novel technology provides a high level of scalability that can control solar silicon price fluctuations, while it is a "green" production.
Zero-Direct-Carbon-Emission Production of Si Epitaxy Enabled by Solid Oxide Membrane (SOM) Electrolysis
Authors: Yan Haoxuan , Flagg Hadassah , Pal Uday , Powell Adam Clayton , Zhong Yu
Published: September 2023

State-of-the-art Solar-grade silicon production is energy intensive and has a negative impact on the environment. Due to the rapid growth of the Si-based photovoltaic (PV) industry, it is necessary to develop a greener technology for silicon production. Solid oxide membrane (SOM) electrolysis is a proven versatile green technology that can be developed to economically produce many important metal or metal compounds from their oxides. This work will discuss the application of SOM electrolysis to produce solar-grade silicon epitaxially from silica in a single-step, which results in net zero-carbon emission. The high-temperature SOM electrolysis cell employs stable molten oxide-fluoride bath with silicon wafer cathode and stabilized zirconia membrane-based novel anodes. The cell design and process parameters are selected to enable high-efficiency silicon deposition on the Si-wafer cathode and mitigate undesired side-reactions. The SOM process is electrochemically characterized with detailed microstructural analysis of the Si deposit on the Si wafer cathode.
Direct Printing Composite Materials by Electro-Codeposition
Authors: Hall Timothy , Wang Dan , Le Huong , Moran Andrew , Minary Majid , Alderman Victor , Jiao Yuxin
Published: September 2023

We are developing an on-demand direct metal printing technology that can utilize the unique advantages of manufacturing in a zero-gravity Low Earth Orbit (LEO) environment, to produce value-added next generation materials that are challenging to manufacture terrestrially. One such class of materials, covetics (nanocarbon-infused metals), are inherently difficult to produce on Earth but have great in-space and terrestrial commercial potential due to their enhanced physicochemical properties, such as higher thermal/electrical conductivity and higher strength at lower mass as compared to conventional wrought metals.

Specifically, this talk will highlight an ongoing activity at Faraday to directly print composite nanowires via a pulse electro-codeposition approach. This activity has indicated that these composite materials can achieve a greater than 50% reduction in sheet resistance and a ~50% increase in mechanical strain compared to Cu foils. We will also discuss the opportunity to produce a wide range of material shapes by enabling a direct print apparatus that combines x,y,z control methods with an electro-codeposition printhead. If successful, we envision that the method to print next generation composite materials like ‘covetics’ has the potential to meet many of the electronics and space community’s needs by enabling in-space structural repairs, fabrication of new electronic components or sensors, or be utilized as heat exchanger composite materials.

Acknowledgements: Faraday Technology acknowledges the NASA SBIR activities under 80NSSC22CA99.
Electrodeposition of Multi-Segment Nanowires and Site-Selective Solder Deposition for Magnetic Assembly and Nanoscale Joining
Authors: Fratto Edward S. , Wang Jirui , Sun Hongwei , Gu Zhiyong
Published: September 2023

Electronic device packaging involves complex wiring assemblies for transport of electrical and thermal energy, enabling increasingly sophisticated circuit designs in an industry favoring aggressive device miniaturization. Nanoscale miniaturization of the wire morphology has become increasingly sophisticated in recent years with regards to synthesis; however, the ability to arrange and manufacture these small-scale materials to fully exploit their novel properties has been quickly outpaced. The purpose of this investigation is the establishment of a synthesis technique for a core/shell nanowire structure with tunable compositional templating via electrodeposition which can pass through this bottleneck via directed matrix assembly. A gold-nickel-gold nanowire structure was utilized as the core, synthesized via electrochemical deposition into an anodic aluminum oxide (AAO) template; the nickel segment was chosen to act as a magnetic vehicle for directed assembly, while the bordering gold tips were coated with a solder shell. Gold-selective deposition of this tin solder shell was achieved by establishing a chemisorbed nickel-protective monolayer via immersion in azelaic acid solution. Next, the protected nanowires were dispersed in an aqueous reaction vessel with excess sodium borohydride reducing agent. Controlled addition of tin sulfate and sodium dodecyl sulfate solution to the vessel resulted in the formation of tin seeds which deposited along the gold tips of the nanowires, growing into a “dumbbell” shape nanowire with tin deposited on both gold tips. Composition and confirmation of the solder deposition was performed with scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopic (EDS) analysis. Crystal structure of the core/shell nanowires was performed with x-ray diffraction (XRD) to identify intermetallic formation between the tin and gold. The core/shell nanowires were arranged magnetically across a conductive interdigitated electrode and melted by an infrared-driven reflow procedure under flux atmosphere, establishing ohmic contact tip-to-tip between nanowires and in wire-to-pad morphologies. This work establishes an effective and scalable method for site-specific nanowire functionalization while simultaneously addressing miniaturization-associated assembly issues in its desired applications.
Electroplated Rhodium as a Functional Adhesion Layer
Authors: Arrington Christian L. , Bullivant John Paul , Murtagh Christopher , Ghanbari Zahra
Published: September 2023

Electroplated Rhodium is deposited in thin films used for aesthetic purposes in the mass manufacturing of jewelry and functional coatings on optical fibers, spark plugs, and thermocouples. Our interest in electroplating rhodium is creating a functional adhesion layer. In this work we vary electroplating conditions to maximize adhesion onto semiconductor material substrates such as silicon. We target pull strength as our desired metric for comparing adhesion of rhodium thin films while varying electroplating deposition conditions. These variables include cleaning of substrates, activation, pulse plating, DC plating, metal thickness, and annealing. These results could be applied to the mass manufacturing of electroplated rhodium targeting optics, microelectronics, and printed circuit boards where adhesion is critical to functionality, as well as other possible industries.

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525 SAND2022-10340A
(Invited) Composite Electroforming from Ionic Liquids for Energy Applications
Authors: Soergel Timo , Scherzl Phillip , Kaupp Michael , El Mofid Wassima , Mejia Chueca María del Carmen , Stich Michael , Ispas Adriana , Bund Andreas
Published: September 2023

This paper will present recent results from the authors’ labs on electroformed aluminum based composite films from room temperature chloroaluminate melts. Although the research field of aluminum electrodeposition has been very active, there are still numerous scientific and technical challenges to be addressed, such as minimization of the incorporation of impurities in the films.

This contribution will discuss the new process of composite electroplating [1,2] for the production of ultra power dense cathodes for lithium-ion batteries. Electrode foils consisting of an aluminum matrix with particles of different active materials have been prepared by composite electroforming. The aim is to reduce the number while improving the properties of electrode components for lithium ion batteries, that will finally promise very high-power densities and cell efficiencies for these batteries, e.g. by reducing internal resistances. Here we will discuss the design of the electroforming process, as well as the characterization of the battery cathodes.

[1] C. Erhardt, Ș. Sörgel, S. Meinhard, T. Sörgel, J. Power Sources 2015, 296, 70-77

[2] T. Sörgel, S. Meinhard, Ş. Sörgel, Film Composite Material, EP 3114721 B1, 2015
Role of the Coordination of Metal Ions by Ammonia for the Anodic Electrosynthesis of MOF Films
Authors: Guo Wei , Zhang Xuan , Fransaer Jan
Published: September 2023

Metal-organic frameworks (MOFs), consisting of inorganic nodes coordinated by organic ligands, have received tremendous attention in the past decades due to their high surface area, high porosity, designable pore-aperture shape/size, and tunable building units (including metal centers and functional ligands). For most of their applications, such as separation, catalysis, sensors, and energy storage/conversion devices, MOFs in the form of films/membranes are desired. Anodic electrodeposition is a promising and cost-effective method to in-situ prepare metal-organic framework (MOF) films on metal substrates. However, the anodic synthesis of continuous zeolitic imidazolate framework (ZIF) films, an important subclass of MOF materials, has been proved challenging. Here, we report a facile anodic deposition method that enables the ultra-fast preparation of uniform and continuous ZIF-8 films with tunable thickness from the aqueous solution at room temperature by using the ammonia hydroxide-assisted deprotonation strategy (AHADS). The growth rate of the MOF films is flexibly controlled by the applied current densities, the concentration of the linkers, and the amount of added ammonia hydroxide. The roll-to-roll deposition of the ZIF-8 films on the zinc foils shows the possibility of this method for large-scale industrial synthesis. The control experiments and theoretical calculations reveal that the formation of Zn(NH3)4
2+ complex by adding excessive ammonia hydroxide is crucial to promote the coordination of 2-Methylimidazole (Hmim) with Zn2+. Afterward, the Zn2+ cation attracts electrons of Hmim and thus weakens the N-H bond, which decreases the free energy for the deprotonation of Hmim. As a result, the ZIF-8 films can be aqueously deposited at low pH under room temperature. Various pure ZIF films (ZIF-4, ZIF-7, and ZIF-67) with different metal nodes or organic linkers were successfully deposited via this strategy. In addition, ZIF-8 films deposited on the zinc foil show ability to decrease the overpotential for the zinc plating and stripping, suggesting its possibility for use in reversible zinc metal batteries. This work broadens the applicability of anodic deposition and indicates the potential applications of metal-supported MOF films in energy storage and conversion fields
Fiber Based Devices for Sensing and Actuating Applications
Authors: Beregoi Mihaela , Evanghelidis Alexandru , Diculescu Victor , Botta Daciana , Matei Elena , Enculescu Ionut
Published: September 2023

The importance of multifunctional smart medical devices increases constantly during the last decades, fuelled by socio - economic challenges such as population aging and high costs of the healthcare system. Consequently, numerous research teams are focused on developing such devices with multiple functionalities in terms of both diagnostic and therapeutical approaches.Wearables become ubiquitous since computing and communication devices got smaller and more powerful, new functions being constantly added to consumer products such as smart watches or fitness monitors. Physical or chemical parameters including pulse, blood pressure or oxygen saturation are easily measured. Employing complex architectures based on nanostructures and materials with tailored properties represents an important path in developing a new generation of wearable medical devices which may both monitor chemical parameters (sweat or blood composition) and deliver various therapies.

The present report focuses on describing such architectures with the potential of incorporating both health monitoring, transdermal drug delivery and other therapeutic functions in a relatively straightforward manner. As functional elements microscopic fibers are employed as both electrodes for electrochemical sensors, as microscopic heaters for the drug delivery function or, as building blocks for other specific functions. The fibers are fabricated using electrospinning or centrifugal/force spinning and functionalization (e.g. electrical conductivity) is achieved through physical and electrochemical deposition. Therefore, the fibers can be covered with thin metal layers and rendered conductive, oxidic or polymeric layers making them responsive to various stimuli. Heating is achieved in a straightforward manner through Joule effect and the use of a temperature responding hydrogel enables a controlled release of specific drugs while simultaneously improving epidermal permeation.

These fiber-based systems can be easily employed on cheap, biocompatible substrates such as paper or textile materials and therefore can be mass produced with reasonable costs leading to a new generation of medical devices with increased functionality.
Fabricating Lithium Metal Foils with Desired Morphology
Authors: Liaw Boryann (Bor Yann)
Published: September 2023

Rechargeable lithium batteries (RLB) are the hope for the next generation energy storage and power source systems due to the promise to achieve the highest specific energy. Reliable performance of RLB, particularly with long lifespan, requires high quality lithium metal anode that can withstand repetitive stripping and deposition during cycle aging. Fabricating lithium metal of desired thickness is thus critical to enable and achieve high specific energy design. Morphology of lithium metal foil with densely packed large grains is desired. To consistently reach the desired morphology in practice is however difficult. Such a difficulty challenges us from the lack of proper understanding of lithium deposition at the fundamental level. Recent understanding on lithium nucleation and growth gave us a new perspective to formulate and achieve proper morphological control, which might lead to a new pathway for desired lithium metal foil fabrication technique.
(Invited) Poly(lactic acid)-Nanodiamond Composites for Electroanalytical Applications
Authors: Cieślik Mateusz , Formela Krzysztof , Banasiak Mariusz , Niedzialkowski Pawel , Bogdanowicz Robert , Ryl Jacek
Published: September 2023

There has been an exponential increase in the popularity of 3D printing technology in the last few years, also in everyday life. Numerous applications are reported for poly(lactic acid) (PLA) based polymer composites with various conductive carbon fillers for electrochemical needs, such as sensors, batteries, water remediation, etc. The bulk of these reports is based on commercially available 3D printing filaments, with carbon black, graphene or carbon nanotubes as fillers. Regardless of good conductivity, these materials possess characteristics that are suboptimal for electrochemical applications, including charge transfer kinetics, stability to oxidation, electrolytic window, etc.

3D printouts offer versatility in terms of ease of cheap and on-demand fabrication of free-standing multielectrode setups e.g. by dual-extruder printing. However, to fully embrace their advantages enhancement of charge transfer kinetics by removing an excess of PLA and uncovering the nanofillers, is needed. Recently we have demonstrated laser ablation for locally sculptured effective modification of the electrochemical response of these materials.

There is a great focus on the development of new conductive filaments that exhibit better mechanical, electric, thermal, and electrochemical properties. We have evaluated for the first time various forms of conductive nanodiamonds (ND), i.e. detonation nanodiamonds and diamond-phase rich boron-doped carbon nanowalls, as fillers for PLA-based composites for 3D printing. The goal of the research was to investigate and thoroughly understand the interactions between composite components and those that affect the mechanical parameters and electrochemical characteristics of printed elements, studying how ND addition to PLA matrix affects material strength, rheology, and melting temperature. In particular, the enhancement of electrode kinetics and electrochemically available surface area by ND was revealed and discussed.

The authors acknowledge the financial support by The National Science Centre (Republic of Poland) SONATA BIS 2020/38/E/ST8/00409.
Mechanistic Changes with Applied Potential in Cu Fouling during Furfural Electrochemical Hydrogenation and Hydrogenolysis
Authors: May Andrew S. , Biddinger Elizabeth J.
Published: September 2023

CO2 emissions are generated in the chemical industry by factors such as the generation of reactants, including hydrogen, as well as in heating of the reactors. Electrochemical methods can avoid the need for externally provided hydrogen by generating required protons in-situ from the electrolyte, and can be more easily coupled with renewable electricity than their thermocatalytic counterparts. Therefore, to assist in the mitigation of CO2 emissions, electrochemical processes can be used. Furfural is a biomass-derived platform molecule that can be electrochemically reacted to form several species of interest including fine chemicals and fuels. Furfuryl alcohol, the hydrogenation product, is one fine chemical of interest used to make furanic molds or resins. The hydrogenolysis product of furfural, 2-methylfuran, has been identified as a fuel additive. The electrochemical hydrogenation and hydrogenolysis over Cu catalysts in acidic media allows for the parallel production of furfuryl alcohol and 2-methylfuran. During the electrochemical hydrogenation and hydrogenolysis of furfural over Cu in acidic electrolyte, the Cu catalyst will become covered in carbonaceous material with use. This fouling changes with applied potential, with a polymeric material being formed at -560 mV RHE while at -700mV a non-polymeric carbonaceous material is formed on the Cu. In both cases, the fouling leads to deactivation of the catalyst. In this work, Cu metal foils were intentionally fouled to study the mechanisms that led to catalyst fouling to provide insights into possible mitigation techniques.

A semi batch reactor was used in which the Cu working electrode was recycled to further foul the catalyst. The catholyte had 200 mM furfural and 0.5 M H2SO4 in a 80:20 vol% water:acetonitrile co-solvent. The Cu electrode was recycled thrice with fresh electrolytes each time. After use at -560 mV RHE a polymer formed on the surface; FTIR of the fouled surface showed consistent spectra as poly(furfuryl alcohol). At -700 mV RHE, no polymer was found, however a carbonaceous layer was found. XPS was used to better distinguish between the carbonaceous fouling that occurred at different applied potentials.
(Invited) Delineating the Intricacies Involved in the Synthesis of Cobalt-Free High-Nickel Layered Oxide Cathodes for Lithium-Ion Batteries
Authors: Lee Steven , Manthiram Arumugam
Published: September 2023

Improving the energy density and cost of lithium-ion batteries (LIBs) requires a rational compositional design of layered oxide LiNi1-x-yMnxCoyO2 (NMC) cathodes. The prevailing trend is to increase the nickel content in the cathode to maximize energy density, but high-nickel NMC generally suffers from surface and bulk instabilities that shorten battery life. Dopants, such as cobalt, can help mitigate these issues, but its supply shortage issue prohibits its usage especially in the massive electric vehicle market. Our recent finding suggests that a combination of manganese and aluminum in LiNi0.9Mn0.05Al0.05O2 (NMA-90) promotes attractive energy density, cycle life, rate capability and thermal stability, proving that cobalt can be eliminated in high-nickel cathodes. Post-mortem analysis further reveals that the Mn-Al combination provides synergistic improvements in structural and surface stabilities compared to LiNi0.9Mn0.05Co0.05O2 (NMC-90) and LiNi0.9Co0.05Al0.05O2 (NCA-90). A thorough understanding of the relationship between the synthesis condition and optimal materials properties of NMA-90 is necessary to enable its large-scale deployment. We will present findings from the calcination and coprecipitation study of several cobalt-free cathodes to elucidate this relationship. It is revealed that the cycle stability of LiNi0.9Mn0.1O2 (NM-90) is not dependent on Li/Ni mixing or primary particle size, but is dependent on the calcination temperature. Incorporating Al into NM-90 during coprecipitation reactions cause high internal porosity in the hydroxide precursor, which impacts the final morphology of the calcined cathodes and thus their electrochemical stability. The ongoing work in our lab provides insight on the synthesis sensitivity of NMA and strategizes methods to control its electrochemical properties.
(Invited) Rational Composition and Structure Designs for Layered Oxide Cathodes
Authors: Liu Tongchao
Published: September 2023

Since its birth nearly three decades ago, lithium-ion battery (LIB) has changed all aspects of our life, from portable electronics, electric vehicles (EVs) to large-scale energy storage systems and the emerging electric flight applications. Currently, the bottleneck of the energy density of LIB is set by the intercalation cathode materials, which has been a significant push to develop high energy density and low-cost cathodes in response to rapidly expanding market. In this talk, I will focus on the identification of key failure modes and development of mitigation strategies for facilitating the future application of battery technologies. I will present some insights into the failure mechanism of battery materials that differ from the existing paradigms. Further, I will discuss how we can utilize rational composition and structure design to improve energy density, battery life without compromising safety, speed up battery charging, and reduce the cost of batteries.
Separating O-Redox and Mn-Redox Voltage Hysteresis in a Cation-Disordered Rock-Salt Cathode
Authors: Huang Tzu-Yang , McCloskey Bryan D.
Published: September 2023

Pronounced voltage hysteresis is commonly associated with oxygen redox in Li-excess cathode materials. However, they often involve coexisting transition-metal and oxygen redox, whose contributions to hysteresis are challenging to distinguish. In this work, a two-step aqueous redox titration was developed with the aid of mass spectrometry (MS) gas analyzer to quantify two coexisting solid-phase analytes, namely oxidized oxygen and Mn3+/4+ in a representative Li-excess cation-disordered rock salt (DRX) material. Two MS-countable gas molecules evolve from two separate titrant-analyte reactions, which allows decoupling Mn and O redox capacities. As incremental redox capacities are quantitatively decoupled, each redox voltage hysteresis can be further evaluated through deconvoluted energy efficiency and overvoltages. Overall, a low DRX operating efficiency arises not only from quasi-static voltage hysteresis of O redox, but also from asymmetric Mn-redox overvoltages. The results reveal that O redox is not always the only culprit for a low energy efficiency and slow kinetics, but instead discharging overvoltage, associated with transition-metal redox, can significantly drag down overall operating efficiency. This work further shows the potential of designing new analytical workflow to experimentally diagnose various DRX materials and inform improvement direction.