bluuebunny/crossref_metadata_2025 huggingface dataset:
(Invited) Tailored Functionalization of Single-Walled Carbon Nanotubes for Real-Time Monitoring of Hydrolytic Enzymes Activity
Authors: Bisker Gili
Published: July 2021

Single-walled carbon nanotubes (SWCNTs) have unique optical and physical properties, and they benefit from the ease of surface functionalization and biocompatibility. Semiconducting SWCNTs fluoresce in the near-infrared (nIR) part of the spectrum, which overlaps with the transparency window of biological samples. The SWCNTs fluorescence is sensitive to the environment, and depending on the surface functionalization, subtle changes in the proximity of the nanotube can result in significant spectral modulations. Hence, SWCNTs can be utilized as optical sensors enabling real-time detection with optical signal transduction1–3. Here, we demonstrate tailored functionalization of SWCNTs, which render the nanotubes substrate for hydrolytic enzymes. We show that the chemical composition and functional groups of the SWCNTs wrapping mediate the interaction between the nanotube and the enzymes. Our results open new avenues for monitoring enzymatic activity with fluorescent nanoparticles and hold great promise for biomedical research and applications.

Reference

(1) Hendler-Neumark, A.; Bisker, G. Fluorescent Single-Walled Carbon Nanotubes for Protein Detection. Sensors
2019, 19 (24), 5403.

(2) Bisker, G.; Bakh, N. A.; Lee, M. A.; Ahn, J.; Park, M.; O’Connell, E. B.; Iverson, N. M.; Strano, M. S. Insulin Detection Using a Corona Phase Molecular Recognition Site on Single-Walled Carbon Nanotubes. ACS Sensors
2018, 8 (2), 367–377.

(3) Bisker, G.; Dong, J.; Park, H. D.; Iverson, N. M.; Ahn, J.; Nelson, J. T.; Landry, M. P.; Kruss, S.; Strano, M. S. Protein-Targeted Corona Phase Molecular Recognition. Nat. Commun.
2016, 7, 1–14.
Remote Near Infrared Identification of Pathogens with Multiplexed Nanosensors
Authors: Nissler Robert , Bader Oliver , Dohmen Maira , Walter Sebastian , Noll Christine , Selvaggio Gabriele , Groß Uwe , Kruss Sebastian
Published: July 2021

Infectious diseases are worldwide a major cause of morbidity and mortality. Fast and specific detection of pathogens such as bacteria is needed to combat these diseases. Optimal methods would be non-invasive and without extensive sample-taking/processing. Here, we developed a set of near infrared (NIR) fluorescent nanosensors and used them for remote fingerprinting of clinically important bacteria. The nanosensors are based on single-walled carbon nanotubes (SWCNTs) that fluoresce in the NIR optical tissue transparency window, which offers ultra-low background and high tissue penetration. They are chemically tailored to detect released metabolites as well as specific virulence factors (lipopolysaccharides, siderophores, DNases, proteases) and integrated into functional hydrogel arrays with 9 different sensors. These hydrogels are exposed to clinical isolates of 6 important bacteria (Staphylococcus aureus, Escherichia coli, ...) and remote (≥25 cm) NIR imaging allows to identify and distinguish bacteria. Sensors are also spectrally encoded (900 nm, 1000 nm, 1250 nm) to differentiate the two major pathogens P. aeruginosa as well as S. aureus and penetrate tissue (>5 mm). This type of multiplexing with NIR fluorescent nanosensors enables remote detection and differentiation of important pathogens and the potential for smart surfaces.
Development of In Vivo Nanosensors Using Organic Color Centers
Authors: Kim Mijin , Chen Chen , Yaari Zvi A , Shah Janki , Langenbacher Rachel , Frederiksen Rune , Wu Xiaojian , Wang YuHuang , Heller Daniel A.
Published: July 2021

Covalent bonding of organic functional groups to the sp2 carbon lattice of single-walled carbon nanotubes produces tunable sp3 quantum defects that fluoresce brightly in the second near-infrared region (NIR-II, 1000-1700 nm). Such synthetic defects, also known as organic color centers (OCCs), provide a molecular focal point that sensitively and selectively responds to the local dielectric environments. To take advantage of these unique electronic and optical properties of OCCs for biomedical applications, we discuss a new method that controls the biological interactions/biocompatibility of OCC-based nanosensors via their supramolecular interactions with polymers and other excipients. The resulting nanosensor sensitively detects local intracellular environments in live cells and in vivo. We assess the utility of the nanosensor for cancer research.
Monitoring Plant Health with Near-Infrared Fluorescent H2O2 Nanosensors
Authors: Giraldo Juan Pablo , Wu Honghong , Nissler Robert , Morris Victoria , Herrmann Niklas , Hu Peiguang , Jeon Su-Ji , Kruss Sebastian
Published: July 2021

Near-infrared (nIR) fluorescent single-walled carbon nanotubes (SWCNTs) were designed and interfaced with leaves of Arabidopsis thaliana plants to report hydrogen peroxide (H2O2), a key signaling molecule associated with the onset of plant stress. The sensor nIR fluorescence response (>900 nm) is quenched by H2O2 with selectivity against other stress-associated signaling molecules and within the plant physiological range (10−100 H2O2 μM). In vivo remote nIR imaging of H2O2 sensors enabled optical monitoring of plant health in response to stresses including UV-B light (−11%), high light (−6%), and a pathogen-related peptide (flg22) (−10%), but not mechanical leaf wounding (<3%). The sensor’s high biocompatibility was reflected on similar leaf cell death (<5%) and photosynthetic rates to controls without SWCNT. These optical nanosensors report early signs of stress and will improve our understanding of plant stress communication, provide novel tools for precision agriculture, and optimize the use of agrochemicals in the environment.
Nitrogen-Doped Graphene Quantum Dots and Reduced Graphene Oxide Quantum Dots As Intracellular Temperature Sensors
Authors: McKinney Ryan L , Lee Bong Han , Hasan Md. Tanvir , Naumov Anton V.
Published: July 2021

Non-invasive temperature sensing is necessary for the analysis of biological processes occurring in the human body including cellular enzyme activity, protein expression, and ion regulation. In order to probe temperature-sensitive processes at the nanoscale we develop novel luminescence nanothermometers based on graphene quantum dots (GQDs) synthesized via top-down (RGQDs) and bottom-up (N-GQDs) approaches from reduced graphene oxide and glucosamine precursors. Because of their small 3-6 nm size, non-invasive optical sensitivity to temperature change, and high biocompatibility, GQDs enable biologically safe sub-cellular resolution sensing. Both GQD types exhibit temperature-sensitive, yet photostable fluorescence in the visible and near-infrared for RGQDs, utilized as a sensing mechanism in this work. Distinctive linear and reversible fluorescence quenching with temperature by up to 19.3 % is observed for the visible and near-infrared GQD emission in aqueous suspension, in a small temperature range from 25 to 49℃. An even more pronounced trend is observed with GQD nanothermometers internalized into the cytoplasm of HeLa cells as they are tested in vitro in the temperature range of 25℃ to 45℃ with over 40% quenching response. Our findings suggest that the temperature-dependent fluorescence quenching of bottom-up and top-down-synthesized GQDs studied in this work can serve as non-invasive reversible photostable deterministic mechanism for temperature sensing in microscopic sub-cellular biological environments.
Multi-Walled Carbon Nanotubes and Carbon Black Incorporated Heterogeneous Layered Polymer Composites with Enhanced Electrical Features
Authors: Hussain Tajamal , Malik Tayyaba , Mujahid Adnan , Intisar Azeem
Published: July 2021

The present work is centered on the study of electrical properties of three different types of composites i.e. single layer carbon black (CB) and multi-walled carbon nanotubes (MWCNTs) based PMMA composites, CB/PMMA and MWCNTs/PMMA, and bilayer polymer composites CB/PMMA-MWCNTs/PMMA, prepared by solution mixing method using chloroform as dispersion medium. It is expected that two layers in bilayer polymer composites would show increased interfacial interactions resulting in improved electrical character especially dielectric properties. Prepared composites have been characterized by UV-Vis and FTIR spectroscopy for successful synthesis. Electrical properties, conductivity, dielectric constant and tangent loss of all composites were measured at frequency range of 40Hz to 1MHz by using LCR meter. Percolation threshold value was obtained by using data of electrical conductivity as a function of volume fraction of fillers. The obtained value of percolation threshold was much lower for bilayer polymer composites i.e. 0.01 vol% as compared to the single layer polymer composites. Observed data of dielectric constant encourages the synthesis of composites with this kind of structure.
(Nanocarbons Division Best Poster Award - 2nd Place) Nitrogen-Doped Graphene Quantum Dot Formulation for Cancer Imaging and Redox-Based Drug Delivery
Authors: Campbell Elizabeth , Hasan Md. Tanvir , Gonzalez Rodriguez Roberto , Truly Tate , Lee Bong Han , Green Kayla , Akkaraju Giridhar , Naumov Anton V.
Published: July 2021

This work develops a new multifunctional biocompatible anticancer nanoformulation to provide targeted image-guided cancer-selective therapeutics. It consists of three active covalently bound components: (1) biocompatible nitrogen-doped graphene quantum dots (GQDs) as a multifunctional delivery and imaging platform, (2) hyaluronic acid (HA) unit targeted to the CD44 receptors on a variety of cancer cells, and (3) oxidative stress-based cancer-selective ferrocene (Fc) therapeutic. The biocompatible GQD platform synthesized from glucosamine exhibits high-yield intrinsic fluorescence. It is utilized for tracking Fc-GQD-HA formulation in vitro indicating internalization enhancement in HeLa cells targeted by the HA over non-cancer HEK-293 cells not overexpressing CD44 receptor. Fc-GQD-HA, non-toxic at 1 mg/mL to HEK-293 cells, induces cytotoxic response in HeLa enhanced over time, while therapeutic ROS generation by Fc-GQD-HA is ~3 times greater than that of Fc alone. This outlines the targeted delivery, imaging, and cancer-specific treatment capabilities of the new Fc-GQD-HA formulation enabling desired cancer-focused nanotherapeutic approach.
(Energy Technology Division Graduate Student Award sponsored by Bio-Logic) Understanding Charge Transport for Current and Future Electrochemical Energy Storage Technologies
Authors: Housel Lisa M. , Takeuchi Esther S. , Marschilok Amy C. , Takeuchi Kenneth J.
Published: July 2021

Advances in electrochemical energy storage are key for the integration of intermittent wind and solar energy sources into the grid, widespread adoption of electric vehicles, and development of new safe and reliable consumer devices. For grid, transportation, and electronic energy storage markets, each application has distinct needs. Therefore, developing battery technology for emerging and wide-spread applications demands greater understanding of the complex chemical and electrochemical processes that occur within rechargeable batteries. Electron transfer and ion transport are the foundation of battery function where the capacity, loaded voltage and current define the practical energy and power delivery of the system. During operation, repetitive addition and removal of electrons and ions can lead to structural change within the electrode and interfacial formation that can dramatically impact electrochemical outcomes. Thus, structural, chemical, and electrochemical characterization during operation is critically important for next generation electrochemical energy storage technologies. The research efforts highlighted in this talk use multiple advanced characterization techniques, including operando methods, to probe charge transport properties, structural changes, and interfacial evolution in multiple rechargeable battery systems. Specifically, spatiotemporal x-ray fluorescence mapping was used to quantify elemental composition near the electrode and in the electrolyte of operando cells. Isothermal microcalorimetry was used to determine heat evolution due to parasitic or decomposition reactions operando. X-ray absorption spectroscopy enabled structure and oxidation state elucidation in the absence of long-range order. X-ray diffraction was employed to track phase changes of distinct electroactive materials. Using advanced characterization, these research efforts provide insight into electron transfer and ion transport properties and their impact on application relevant outcomes (resistance, cycle life, delivered capacity) of electrochemical energy storage technologies.
(Invited) Determining Surfactant Concentrations for Separation of (n,m) Chirality Swcnts in ATPE via Fluorescence Detection
Authors: Sims Christopher , Fagan Jeffrey
Published: July 2021

In this talk I will present a methodology for rapid and quantitative determination of surfactant concentrations that result in top or bottom-phase partitioning of individual (n,m) SWCNTs species in an aqueous two-polymer phase extraction using near-infrared fluorescence measurements. This methodology enables quantitative evaluation of parameters affecting ATPE such as temperature, polymer molecular weight and composition, and surfactant choice without conducting an actual separation. Additional advantages of the technique include a very low sample concentration for measurement, rapid measurement, and no mass transfer derived limitations in interpreting results. Using the technique, we have investigated different combinations of surfactants to explore the effects of surfactant chemistry. In most cases, two transitions in the NIR fluorescence are observed with co-surfactant concentration for each (n,m) species, which we identify as differential separation of left and right-handed SWCNT enantiomers. Specific trends with (n,m) diameter and with variation of surfactant chemistry will be discussed.
(Invited) Nanotube-Based Nanohybrids: Dyes Encapsulated inside Nanotubes
Authors: Martel Richard
Published: July 2021

The inner and outer surfaces of a nanotube made of either carbon or boron nitride material can be functionalized to tailor the chemical and optical properties of the assembly. Our studies on the optical properties of dyes encapsulated in nanotubes (dyes@CNT) have shown, for instance, enhancement effects in both Raman and fluorescence spectroscopies, which are of interest for bio-imaging and photonics. A chemical functionalization of the outer wall has also been developed to promote specific chemical interactions of the nanohybrids with a host, such as a biomarker. Here we will review some of our recent progress on the nanotube-based nanohybrids. More particularly, we will present advances towards the development of the boron-nitride nanotube nanohybrids for fluorescence imaging in the visible and near-infrared. New results on the outer functionalization to work more effectively in biological media and infer an optical response to pH will be presented. Lastly, the mechanism of the encapsulation process and the optical response due to aggregation effects of the encapsulated dyes in different conditions will be discussed.

This work was done in collaboration with E. Gaufrès, C. Allard, S. K. Mal, N. Tang, R. Nascimento, C. David, L. Durate, L. Gaboury and S. Blais-Ouellette
(Invited) Ultrasonication-Induced Inner Shell Extraction from Double‐Wall Carbon Nanotubes: Characterisation By Ultracentrifugation and in Situ Raman and Fluorescence-Excitation Spectroscopy
Authors: Wenseleers Wim , Erkens Maksiem , Cambré Sofie , Flahaut Emmanuel , Fossard Frédéric , Loiseau Annick
Published: July 2021

We show that ultrasonication extracts inner tubes from double-wall carbon nanotubes (DWCNT), and characterize the process by density gradient ultracentrifugation (DGU) combined with in situ spectroscopic characterization in the density gradient. Our observations also cast new light on the question whether or not the inner tubes of DWCNTs fluoresce, which has been the subject of a long-standing debate, even though single‐DWCNT experiments have already shown drastic PL‐quenching for the inner CNT [1]. Indeed, in previous studies to characterise the PL from DWCNTs, they were typically solubilised using sonication, while here we see that upon sonication, the extraction of the inner tubes from the DWCNTs leads to much more, efficiently fluorescing SWCNTs. First, the DWCNTs were purified from SWCNTs and bundles using density gradient ultracentrifugation (DGU). Then, sonication is applied, after which the extracted inner tubes were separated from the DWCNTs by DGU and characterised by in situ resonant Raman and PL‐spectroscopy as a function of height in the centrifuge tube [2]. These subsequent in situ DGU experiments unambiguously prove the extraction of inner SWCNTs from DWCNTs, even by very brief sonication, and sonication-time-dependent measurements show that the process quickly saturates.

[1] D. Levshov, R. Parret, H.-N. Tran, T. Michel, T.T. Cao, V.C. Nguyen, R. Arenal, V.N. Popov, S.B. Rochal, J.-L. Sauvajol, A.-A. Zahab, M. Paillet, Phys. Rev. B
96, 195410 (2017).

[2] S. Cambré, P. Muyshondt, R. Federicci, W. Wenseleers, Nanoscale
7, 20015 (2015).
(Invited) Near-Unity Radiative Quantum Efficiency of Excitons in Carbon Nanotubes
Authors: Machiya Hidenori , Yamashita Daiki , Ishii Akihiro , Kato Yuichiro
Published: July 2021

We experimentally determine the radiative quantum efficiency of bright excitons in carbon nanotubes by modifying the exciton dynamics through cavity quantum electrodynamical effects [1]. Specially designed air-mode silicon nanobeam cavities [2,3] are used to obtain efficient coupling to individual air-suspended carbon nanotubes. Spectral and temporal behavior of the cavity enhancement is characterized by photoluminescence spectroscopy at room temperature, and the fraction of the radiative decay process is evaluated. We find that the radiative quantum efficiency is near unity for the bright excitons in suspended nanotubes.

Work supported in part by MIC (SCOPE 191503001), JSPS (KAKENHI JP20H02558, JP20J00817, JP20K15199), MEXT (Nanotechnology Platform JPMX09F19UT0072), and RIKEN (Incentive Research Project). H.M. acknowledges support from RIKEN (Junior Research Associate Program). Finite-difference time-domain calculations are performed using HOKUSAI BigWaterfall supercomputer at RIKEN. We thank the Advanced Manufacturing Support Team at RIKEN for technical assistance.

[1] H. Machiya, D. Yamashita, A. Ishii, Y. K. Kato, in preparation.

[2] R. Miura, S. Imamura, R. Ohta, A. Ishii, X. Liu, T. Shimada, S. Iwamoto, Y. Arakawa, Y. K. Kato, Nat. Commun. 5, 5580 (2014).

[3] H. Machiya, T. Uda, A. Ishii, Y. K. Kato, Appl. Phys. Lett. 112, 021101 (2018).
(Invited) Quantum Light Emission from Coupled Defect-States in DNA-Functionalized Carbon Nanotubes
Authors: Zheng Yu , Kim Younghee , Jones Andrew , Bachilo Sergei M. , Doorn Stephen , Weisman R. Bruce , Piryatinski Andrei , Htoon Han
Published: July 2021

Solid-state single-photon sources are the essential building block for quantum photonics and quantum information technologies. The report here illustrates an advanced perspective of implanting coupled fluorescent quantum defects in single-wall carbon nanotubes (SWCNTs) through chemical reactions between the nanotube sidewall and the guanine nucleotides in single-stranded DNA (ssDNA) that coats the nanotube. Through low-temperature photoluminescence spectroscopy and photon correlation experiments, we have revealed that multiple guanine defects within a single ssDNA strand couple together to form a cumulative deep trapping potential supporting a localized quantum state that is capable of room-temperature single-photon emission. Helical wrapping of multiple ssDNA strands in single nanotubes allows a series of exciton localization sites to be created along the length of the SWCNTs. Such unique exciton trapping potential landscape gives rise to previously inaccessible intrinsic emission characteristics including coupling of multiple spatially separated quantum emitters. Our joint experimental and computational studies together reveal quantum emission properties from multiple spatially patterned covalent defects in SWCNTs, identify capture of the band-edge exciton as the underlying cause of the cross-correlated photon emission and open a distinctive prospect for tailoring chemically altered nanotubes as quantum light emitters.
(Invited) Organic Color Center Photoluminescence Modulation for Biomedical Applications
Authors: Heller Daniel A. , Kim Mijin , Chen Chen , Wang Peng , Langenbacher Rachel , Frederiksen Rune , Jagota Anand , Zheng Ming , Wang YuHuang
Published: July 2021

The modulation of single-walled carbon nanotube (SWCNT) photoluminescence has been under investigation for the unique potential to develop biosensors to detect many classes of analytes. Covalent sp3 defects on SWCNTs, dubbed organic color centers (OCCs), have been explored for their photoluminescent properties, including increasing quantum yield and introducing new chemical sensitivities. The application of OCCs for biomedical applications requires new methods to control SWCNT surface chemistry and the resulting biological interactions/biocompatibility via supramolecular interactions with polymers and other excipients. We have found specific utilities of OCCs for the detection of chemical phenomena where SWCNT photoluminescence is normally relatively insensitive, such as pH changes in the physiologic range of 4.5 - 8. We developed OCC-based sensors to measure pH in live cells and in vivo, as well as other emerging applications. We believe that OCCs will facilitate the development of biosensors for disease detection and biomedical research.
(Invited) A Cleanly Removable Surfactant for Carbon Nanotubes
Authors: Zhang Chiyu , Wang Peng , Barnes Benjamin , Wang YuHuang
Published: July 2021

Surfactants are widely used to stabilize single-walled carbon nanotubes (SWCNTs) and many other nanomaterials to facilitate their solution processing and device integration. However, it is notoriously difficult to subsequently remove these molecules when they are no longer needed. Methods to remove surfactant, including rinsing with organic solvents, acidic oxidation and annealing at high temperature, are inefficient to recover their intrinsic electrical and optical properties or even damage these nanomaterials. Here, we report the synthesis of a new carbon nanotube surfactant that can be cleanly removed by a two-step post-annealing process at a relatively low temperature. Additionally, this tailored surfactant is as efficient as sodium deoxycholate at individually dispersing SWCNTs in water. The insight may help guide the choice or design of surfactants for nanomaterials applications such as sensors, printed electronics, and high performance devices, where the clean removal of the dispersant is key to enhanced performance.
(Invited) Molecular Structure-Based Photoluminescence Modulation of Locally Functionalized Single-Walled Carbon Nanotubes Using Bis-Aryl Functionalization
Authors: Shiraki Tomohiro , Yu Boda , Niidome Yoshiaki , Aoki Haruka , Hayashi Keita , Fujigaya Tsuyohiko
Published: July 2021

Single-walled carbon nanotubes (SWCNTs) show photoluminescence (PL) in the near infrared (NIR) region, which is applicable to bioimaging and telecommunication devices. Recently, local chemical functionalization of SWCNTs has been developed to enhance their NIR PL properties, in which defects such as sp3 carbon are locally doped to the crystalline sp2 carbon network of the tube walls by the functionalization.[1-3] Actually, E
11* PL of the locally functionalized SWCNTs (lf-SWCNTs) is observed with red-shifted wavelengths and increased quantum yields compared to original E
11 PL of pristine SWCNTs. It is due to formation of new emissive sites with narrower band gaps and exciton trapping features in the tube structures.

In the local chemical functionalization, doped site structures of the lf-SWCNTs can be changed depending on modifier molecules, which results in effective modulation of the NIR PL wavelengths of the lf-SWCNTs beyond 1000 nm-region. Previously, we have developed bis-aryldiazonium salts (bAs) that have two reactive aryldiazonium groups connected with a methylene linker and observed E
11
2* PL over 1200 nm regions from the lf-SWCNTs with (6,5) chirality based on its proximal aryl functionalization.[4]

Here, we synthesize new modifier molecules with the bis-aryldiazonium motif and modify the geometry of the proximal aryl-functionalized sites of the lf-SWCNTs. As a result, for example, methylene linker positions on the aryldiazonium groups of bAs clearly changed the trend of methylene length-dependent wavelength shifts of E
11
2* PL. [5] Moreover, bAs having rigid linker structures changed peak positions of E
11
2* PL, indicating that the control of the proximal defect configuration would be an effective way for the PL property modulation of lf-SWCNTs. As another aspect of the proximal aryl functionalization, we found that E
11
2* PL showed unique wavelength shift behaviors by microenvironment changes using various organic solvents. The observed trend was different from those of E
11 PL and E
11* PL[6], in which proximal defect distances could be an important factor for their microenvironment responsiveness.

Therefore, molecularly designed bis-aryldiazonium modifiers become promising tools to create structurally controlled bis-aryl functionalized sites of lf-SWCNTs and precisely modulate their NIR PL wavelengths (> 1000 nm).

[1] T. Shiraki et al. Acc. Chem. Res., 53, 1846 (2020). [2] S. Tretiak et al., Acc. Chem. Res., 53, 1791(2020) [3] Y. Wang et al. Nat. Rev. Chem., 3, 375 (2019). [4] T. Shiraki et al. Sci. Rep., 6, 28393 (2016). [5] T. Shiraki et al. Chem. Lett., 48, 791 (2019). [6] T. Shiraki et al. Chem. Commun., 55, 3662 (2019).

Figure 1
(Invited) Thermal and Electrical Conductivity of Carbon Nanotube Network Materials: Theoretical Analysis and Mesoscopic Simulations
Authors: Volkov Alexey N. , Zhigilei Leonid V.
Published: July 2021

A general framework for theoretical analysis and numerical calculations of the effective thermal and electrical conductivity of homogeneous and isotropic disordered materials composed of carbon nanotubes (CNTs) is developed. The model utilizes similarity in the mathematical description of thermal and electrical transport in nanotube materials. The analysis accounts for both the inter-tube contact conductance and intrinsic conductivity of CNTs, and is performed in a wide space of governing parameters that includes the fiber aspect ratio, Biot number calculated for a single contact between nanotubes, and density ranging from values corresponding to the percolation threshold up to those characteristic of dense fiber networks. For dense networks, exact theoretical equations for the effective conductivity of materials composed of nanotubes with arbitrary aspect ratio and Biot number are derived. The effect of the intrinsic conductivity of nanotubes on the thermal and electrical transport is found to depend on the density of inter-tube contacts and, thus, is usually significant in the dense materials. The theoretical finding are confirmed in large-scale simulations of quasi-two-dimensional CNT films and three-dimensional CNT aerogels, where nanotubes form continuous networks of intertwined bundles. The simulations are performed based on a mesoscopic model of CNT materials, where every nanotube is represented by a curved chain of stretchable cylindrical segments. The dependences of the conductivity on the CNT length, Biot number, and material density predicted in these simulations agree well with the scaling laws derived theoretically. The comprehensive theoretical description developed in this work can facilitate tailoring thermal and electrical conductivity of CNT materials to the needs of practical applications by varying the material density, CNT length, and aspect ratio. Financial support for this work is provided by the National Aeronautics and Space Administration (NASA) through an Early Stage Innovations grant from NASA's Space Technology Research Grants Program (grant NNX16AD99G). A.N.V. also acknowledges support from the National Science Foundation through the CAREER award CMMI-1554589.
Coupling of Vibrational Modes to the Electron-Hole Continuum in Doped Single-Wall Carbon Nanotubes
Authors: Eckstein Klaus , Müller Daniel , Hirsch Florian , Martel Richard , Fischer Ingo , Hertel Tobias
Published: July 2021

Electron-phonon coupling is at the heart of many physical phenomena like superconductivity, charge transport and the Raman effect (Ferrari2007). Previously, it has been shown that a coupling of vibrational modes to the low-energy electronic continuum absorption in graphene and carbon nanotubes results in transparency windows in the mid-infrared spectral region (Lapointe2012, Lapointe2017). The reduced absorption at the vibrational energies can be attributed to so-called Fano (anti-)resonances (Fano1961).

Here, we present a systematic study of the infrared continuum absorption and such antiresonances in purely semiconducting, monochiral carbon nanotube (CNT) thin-films. We observe strong antiresonances for the Raman active D- and G-phonons, which acquire oscillator strength via coupling to the bright Drude-like intraband continuum in doped CNTs. Both the spectrum of the continuum absorption and the amplitude of the Fano resonances critically depend on the doping level. With increasing carrier concentration, we find a redshift of the Drude peak accompanied with a non-monotonic doping level dependence of the antiresonance intensity. Our observations show that carrier localization and delocalization as well as disorder induced by defects play a critical role for both charge transport and electron-phonon coupling as evidenced by the Fano resonances. We suggest that our findings also have implications for other low-dimensional systems with a low-energy electronic continuum absorption.

C. Ferrari, Solid State Commun.
2007, 143, 47-57.

Lapointe et al., Phys. Rev. Lett.
2012, 109, 097402.

Lapointe et al., J. Phys. Chem. C
2017, 121, 9053-9062.

Fano, Phys. Rev.
1961, 124, 1866-1878.
(Invited) Computational Simulations of Selective Interactions between ssDNA and SWCNTs
Authors: Alizadehmojarad Ali A. , Bachilo Sergei M. , Kolomeisky Anatoly , Weisman R. Bruce
Published: July 2021

Structure-specific interactions between single-stranded DNA oligos and SWCNTs form the basis of important selective sorting methods yet remain poorly understood. Among these interactions is the differential affinity of (ATT)4 for one of the two (7,5) enantiomers. To understand the nature of the affinity difference, we have performed molecular dynamics (MD) simulations followed by free energy (replica exchange) calculations over the temperature range of 290 to 727 K. Comparisons between the conformational free energy landscapes of (ATT)4 structure on right-handed and left-handed (7,5) SWCNTs (respectively known as M and P in stereochemical convention) suggest that (ATT)4 has more contact area with M than with the P enantiomer. However, the corresponding end-to-end distances of (ATT)4 fall nearly in the same region on the landscape. Our standard MD simulations for (ATTT)3 interactions with SWCNTs also suggest that this DNA sequence covers (8,4) SWCNT more effectively than (7,6) and (8,3) SWCNTs, which is consistent with our recent dye-quenching experiments.

Other experiments have revealed that when guanines in ssDNA oligos are covalently functionalized to SWCNT sidewalls, the extent of functionalization can depend on the position of the guanine within the oligo. Central positions within long oligos (e.g. T15GT15) lead to greater functionalization than end guanine positions (e.g. T30G). We have performed both standard MD and free energy calculations to investigate the source of this effect. For efficient guanine functionalization of SWCNTs, guanine needs to remain adsorbed on the SWCNT surface. Our computational observations suggest that the central guanine within T15GT15 oligo remains adsorbed on the (6,5) SWCNT surface even when the DNA interacts with other neighboring DNA strands. Under these conditions, the end guanine in T30G is destabilized and tends to desorb from (6,5) SWCNT surface due to inter-strand interactions. Our free energy calculations also suggest that oligos with a central guanine assume more elongated DNA conformations at the surface of a (6,5) SWCNT than do oligos with end guanines. We suggest that DNA elongation is associated with more stable adsorption on the SWCNT surface, supporting efficient covalent functionalization of central guanines.

Figure 1
Charge Transport in Networks of sp3-Functionalized Single-Walled Carbon Nanotubes
Authors: Zorn Nicolas Frederic , Berger Felix Julian , Zheng Wenhao , Wang Hai , Zaumseil Jana
Published: July 2021

The controlled introduction of luminescent sp3 defects into semiconducting single-walled carbon nanotubes (SWCNTs) leads to narrowband, tunable emission in the near-infrared and increases their photoluminescence (PL) quantum yield for potential optoelectronic applications [ACS Nano
2019, 13, 9259]. While the spectroscopic properties of sp3-functionalized SWCNTs are already well-established, a detailed understanding of the impact of functionalization on their electrical performance especially in a network is still lacking. Here, we investigate charge transport in ambipolar, light-emitting field-effect transistors based on networks of pristine and sp3-functionalized (6,5) SWCNTs. While both hole and electron mobilities decrease with increasing degree of functionalization, the transistors remain fully operational, showing electroluminescence from the defect states. Charge-modulated PL spectroscopy, which exclusively probes the mobile charge carriers in SWCNT networks [ACS Nano
2020, 14, 2412], confirms that the defects are efficiently sampled by mobile carriers and consequently, sp3-functionalized SWCNTs actively participate in the charge transport within the network. Temperature-dependent transport measurements of transistors combined with ultrafast photoconductivity dynamics of individually dispersed SWCNTs measured by optical-pump THz-probe spectroscopy provide further insights into the impact of sp3-functionalization on charge transport within a single nanotube and within a network.
(Invited) Organic/Inorganic Hybrid Interfaces between Perovskite Semiconductors and Semiconducting SWCNTs
Authors: Blackburn Jeff , Hao Ji , Kim Young-Hoon , Lu Haipeng , Habisreutinger Severin , Luther Joey
Published: July 2021

Low-dimensional semiconductors provide a rich tapestry of tunable optical and electrical properties for a wide variety of applications. Semiconducting single-walled carbon nanotubes (s-SWCNTs) have shown tremendous potential in applications ranging from digital logic, biological imaging, quantum information processing, photovoltaics, and thermoelectric energy harvesting. Energy harvesting applications rely critically upon the creation of tailored interfaces that enable the movement of energetic species (excitons, electrons, holes) in specified directions. While organic energy harvesting devices often employ interfaces between distinct organic species such as polymers, fullerenes, and carbon nanotubes, hybrid interfaces between organic and inorganic semiconductors have unique properties that are relatively unexplored.

In this talk, I will discuss our recent efforts at constructing novel hybrid interfaces between s-SWCNTs and low-dimensional perovskite-based semiconductors. I will highlight time-resolved spectroscopy results that illustrate long-lived photoinduced charge separation across such interfaces, demonstrating utility for photovoltaics and photodetectors. Interestingly, some systems demonstrate additional transient processes that are exceptionally slow and may indicate ion movement within the hybrid systems. Complementary device studies demonstrate exceptional efficiencies for conversion of photons into stable photocurrent, and I will highlight several novel applications in which these interfaces can be employed.
Hydrated PET-LiClO4 Electrolyte for Structural Energy Storage Applications
Authors: Joyal Nathaniel , Shen Caiwei
Published: July 2021

In recent years mobile devices have become increasingly dependent on energy storage components such as batteries. Multifunctional structural supercapacitors, which can serve as structural components and store electrical energy at the same time, offer a solution to reducing the total weight of all kinds of mobile devices. Previous work on structural supercapacitors always point to devices with good mechanical strength or good electrical properties but rarely both, as those solid polymer electrolytes with good ionic conductivities use a liquid phase for the transfer of ions which can diminish the mechanical properties of the base polymer.

We present here a strong and conductive all-solid-state electrolyte composed of polyethylene terephthalate (PET) and lithium perchlorate (LiClO4) with a single continuous phase. We find that the electrolyte shows extraordinary ionic conductivity while maintaining its all-solid state when exposed to controlled humidity. The hygroscopic electrolyte will absorb controlled amount of water molecules, all bound to LiClO4 without forming a liquid phase, when the humidity is below 70% at room temperature. Such bound water facilitates ion transport, improves electrode-electrolyte interface, and has minimum impact on the mechanical properties of the electrolyte.

Through both X-Ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis of numerous solid electrolyte compositions that have undergone different treatments it has been shown that the electrolyte has an amorphous phase. The electrochemical tests conducted were electrochemical impedance spectroscopy (EIS) to determine the ionic conductivity, linear sweep voltammetry (LSV) to determine the operating voltage range, and cyclic voltammetry (CV) to determine the interfacial capacitance. These tests were conducted on a range of electrolytes varying in the ratio of PET and LiClO4, as well as varying in the relative humidity that the samples were exposed to. These results demonstrate comparable ionic conductivity to gel electrolytes with operating ranges of at least +2V. The preliminary mechanical testing shows that the solid electrolyte has a high stiffness and good interfacial bonding strength to carbon electrode surface. The use of hydrated lithium salts as opposed to an ionic liquid allows for the electrolyte to perform similarly to the base polymer.

In conclusion, we believe that this solid electrolyte shows great promise for application in composite supercapacitors for structural applications. This solid electrolyte when applied to structural energy storage can be used to deliver a better power to weight ratio than a conventional battery, solving the problem of large and heavy power banks that increase overall weight and take up space.
Assessing Electrochemical Stability Windows of Li1+XAlxM2-X(PO4)3 (M=Ge,Ti) Nasicon Solid Electrolytes for Their Application in All Solid-State Lithium Batteries
Authors: Benabed Yasmine , Rioux Maxime , Rousselot Steeve , Hautier Geoffroy , Dolle Mickael
Published: July 2021

All-Solid-State Lithium Batteries (ASSLBs) are a new generation of lithium batteries that are developed to meet expectations in terms of safety, stability and high energy density. The liquid electrolyte of conventional Li-ion batteries is replaced in ASSLBs by a safer and more stable solid electrolyte (SE). ASSLBs are promising because they may enable the use of high potential materials as positive electrode and lithium metal as negative electrode. This is only possible through SE stated large electrochemical stability windows (ESW). Nevertheless, values for these electrochemical windows are very divergent in the published literature. Recently, several studies have come to specifically decry the frequent overestimation of SE electrochemical stability windows
1-
4
. Establishing a robust procedure to accurately determine SEs ESW has therefore become crucial.

Our work is focused on using an original experimental set up to assess the ESW of two widely investigated NASICON-type SEs Li1.3Al0.3Ti1.7(PO4)3 (LATP) and Li1.5Al0.5Ge1.5(PO4)3 (LAGP). The experimental set-up provides a large contact surface between the SE and the conductive material, which maximizes the redox current signals. A combination of Potentiostatic Intermittent Titration Technique (PITT) and Electrochemical Impedance Spectroscopy (EIS) measurements allowed us to precisely determine the ESW of LATP and LAGP solid electrolytes. Using EIS and physico-chemical characterizations, we attempted to shed light on the degradation mechanisms occurring upon the solid electrolytes’ oxidation.

1 - Y. Tian et al. Energy Environ. Sci.
2017, 10, 1150.

2 - Z. Zhang et al. Energy Environ. Sci.
2018, 11, 1945-1976.

3 - F. Han et al. Adv. Energy Mater. 2016, 6(8), 1501590.

4 - T. Schwietert et al. Nature Mat. 2020, 19, 428–435.
Rational Design of Interlayer Binding Towards Highly Reversible Anion Intercalation Cathode for Dual Ion Batteries
Authors: Zhang Maiwen , Yu Aiping
Published: July 2021

Dual-ion batteries (DIBs) with high working voltages and energy densities have gained more and more attention these years. However, general graphitic intercalation compounds (GICs) still require substantial improvements in both cathode practical capacity and structural stability. In this work, rational edge carboxylic anhydride functionality is introduced between carbon layers. One of the advantages is to expand the interlayer stacking, significantly improving active site accessibility and enhancing anion intercalation kinetics. Moreover, it can also serve as strong binding forces within interlayers, which can effectively prevent interlayer exfoliation during repeated anion intercalation/deintercalation. Benefited from this rational design, the carboxylic anhydride functionalized graphitic cathode is able to improve discharge capacity by over 37% with no obvious voltage deduction. Meanwhile the capacity retention of over 80% after 1000 cycles is achieved. Overall, this work reveals an effective way to improve both energy density and longevity of the graphite cathodes for dual ion batteries.
Rechargeable Lithium Metal Pouch Cell Development
Authors: Crowther Owen
Published: July 2021

Commercially available Li-ion batteries using graphite or graphite-silicon blended anodes are currently approaching a cell level specific energy of 300 Wh kg−1. The use of lithium metal instead as an anode an intriguing possibility to further increase cell level specific energies to 400 Wh kg−1 and beyond. Lithium is an ideal anode because it is the lightest metal and highly electronegative. However, attempts to commercialize cells using lithium metal anodes have been slowed by poor cycle life and safety issues. This is because nonuniform lithium plating leads to the growth of dendrites that cause loss of active lithium and can eventually lead to internal cell shorts. Safe cell cycle life must be improved to 50-100 cycles for special purpose applications like unmanned aerial vehicles, >300 cycles for portable power applications and >1000 cycles for electric vehicle applications.

The performance of prototype cells developed at EaglePicher Technologies using lithium metal anode will be highlighted. The figure below on the left shows the specific discharge energy of a 2.5 Ah prototype pouch cell using a lithium anode, high nickel cathode and nonaqueous electrolyte. The cell demonstrates an extremely high specific energy of >400 Wh kg−1 at low rates. The effect of electrolyte on capacity retention is shown in the figure below on the right. The optimized electrolyte demonstrates good retention to >50 cycles. This presentation will focus on design considerations for pouch cells with lithium anodes, as well as improving the cycle life and safety characteristics of these cells. Prototype performance data including cycle life, rate capability, temperature effects and safety testing will be presented.

EaglePicher Technologies would like to acknowledge the US Army DEVCOM C5ISR Center in Aberdeen Proving Ground, Maryland for funding this research.

Figure 1
Hydrogen Electrochemical Engine (HECE)
Authors: Park Jong-Hee
Published: July 2021

Fuel cell has longer than 200 years of long history but still has been met the several key limits from the fundamental scientific points for further development, especially the electrical energy conversion hydrogen via electrochemical devices. Namely, (i) Enhancing the thermodynamic energy efficiency for utilizing all the chemical reaction energy for resulting reduction costs for the manufacturing and fuel, (ii) avoiding from expensive precious metal, and (iii) raising productivity via AI based mass production strategy, i.e., lowering the production cost with enhancing the quality. This paper will be provided the fundamental design aspect on hydrogen electrochemical energy devices along with the predicted energy efficiency to help the world clean, economical, and highest hydrogen fuel efficiency could be extracted throughout the presentation.
Improvement of Preparation Scheme for Microelectrode and Single Particle Electrochemical Measurements of LiCoO2 Interfaces Under Absence / Presence Chemical Additives
Authors: Takai Kasane , Takahashi Keitaro , Miyauchi Hibiki , Nishikawa Kei , Nakamura Tatsuya , Seki Shiro
Published: July 2021

Introduction

Li-ion batteries (LIBs) are expected to stabilize the electrical power supply and utilize the electrical vehicle. Electrode of LIBs is consisted of mixture of active material, conductive additive, and binder. The conventional electrochemical measurement method is influenced not only by active materials but also by conductive additive and binder. Therefore, electrochemical measurement method with improved microelectrode in contact with single particle of active material was proposed［
1
］. This measurement method is generally known as single particle electrochemical measurement, and expected to evaluate the essential characteristics of active materials［
2
］. In this case, shapes and smooth of microelectrode are important factor in order to obtain the high-reliability results.

In this study, we investigated the effects of microelectrode morphology and suitable contact with the surface of active materials.

Experiments

A Pt wire (φ30 µm) was inserted to glass capillary and was heated and cut to obtain supported fine line coating. Coated tip was polished by grinding machine and obtained well-prepared microelectrode (Fig.2(b)).

An open cell was constructed in the argon-filled glovebox (-90℃ dew point). Li foil (φ10 mm) was put on the center of the stainless steel cup as a negative electrode, and a glass separator 110 µL electrolyte (1M-LiClO4/kg-PC) were added as electrolyte layer. LiCoO2 particles (20-30 µm diameter) were put onto electrolyte. The tip of microelectrode was directly attached to certain LiCoO2 single particle and charge / discharge measurements were carried out.

Results & Discussion

Fig.1 shows the charge / discharge profiles of the cell prepared by conventional process. Charge voltage did not reach the upper limited of 4.4V, and sufficient discharge profile was not observed.

Fig.2 also shows the charge / discharge profiles of the cell prepared by new process. Reversible charge-discharge operation of single LiCoO2 particle was observed with appropriate capacity. Sufficient preparation prosses of the microelectrode was important for concise measurement of single particle electrochemical measurements. In the presentation, we will report detailed preparation method of microelectrode, and in-situ directly adding effect of chemical additives into the measurement cells.

References

[1] K. Dokko, et. al., J. Electrochem. Soc.,
148, A422 (2001).

[2] T. Saito, et. al., J. Phys. Chem. C,
124, 31, 16758 (2020).

Figure 1