bluuebunny/crossref_metadata_2025_split huggingface dataset:
Confirmation of Peg Surface Αcyclodextrin Surface Mechanism
Authors: Roberge Emma , Panahi Zahra , Halpern Jeffrey M 
Published: May 2020

αCyclodextrin (CD) is a unique molecule because of its hydrophobic interior cavity and hydrophilic exterior. This interior cavity can create inclusion complexes with a variety of hydrophobic guest molecules, including resveratrol, a hydrophobic molecule naturally found in red wine and grapes. Our specific surface sensing paradigm, CD attaches temporarily to surface bound polyethyl glycol (PEG), and releases when exposed to our model analyte, resveratrol. αCD-PEG system is a reusable hydrophobic molecule sensor, so understanding the modification mechanism behind its behavior is crucial to the optimization of the sensor. EIS analysis of this system implies removal of physioadsorbed PEG from the surface when first exposed to CD, leaving only thiol-bonded PEG to gold surface and αCD attached to PEG. This theory implies variable surface coverage, and further analysis is needed for optimal reusability.
Within a flow cell, eQCM, setup, αCyclodextrin-PEG system was modified onto a gold electrode using thiol-PEG. A decrease in frequency (proportional to an increase in mass) was observed upon PEG attachment. After this modification, αCD was introduced to the system and attached to the PEG, which resulted in a decrease in mass indicated by the removal of physiosorbed PEG. After this initial decrease in mass, reversibility is achieved between resveratrol measurements and CD reloading. The supported data supports the development of a PEG:CD reusable sensor paradigm.
Acknowledgements: The authors would like to acknowledge the financial support from NIH (P20 GM113131) and the Hamel Center of Undergraduate Research at the University of New Hampshire. The authors also would like to acknowledge the assistance of Dr. Halpern’s laboratory.
Material Modification of Copper Hexacyanoferrates As Cathode Material for Aqueous Sodium Ion Batteries
Authors: Pan Tsung Yu , Haider Ali , Chen Han-Yi 
Published: May 2020

Aqueous sodium ion battery (ASIB) is gaining more attention with the growing concern in safety and environmental issues. However, the potential window of ASIB is limited to the decomposition voltage of water. Recently, the potential window of aqueous electrolyte has been reported that it can be extended in high-concentration electrolytes. Since then, researchers are dedicating to finding cathode materials with higher discharging potential which can increase the energy density of aqueous batteries. In this study, we demonstrate a new concept in cathode material design to reach an ultra-high rate capability by modifying the side group of a Prussian blue analogue, copper hexacyanoferrates (CuHCF). The modified cathode material was carefully analyzed by ex-situ XRD measurements, X-ray photoelectron spectroscopy, cyclic voltammetry (CV), and charge-discharge measurement to reveal their electrochemical performances. The diffusivity was also calculated by potentiostatic intermittent titration technique test and Randles-Sevcik equation.
The results showed a great rate capacity for more than 80% from 1 C to 20 C accompanied with an outstanding cycle stability (~ 100% after 1000 cycle at 20 C). The high discharge plateau at about 0.7 V (vs Ag/AgCl) indicates that this material is promising in high-energy ASIB applications. This Prussian blue analogue cathode material is further tested in a full cell system with NaTi2(PO4)3 as anode material. This new concept may shed light on the field of increasing cycle stability and rate capability of Prussian blue analogues.
Charge Carrier Transport in a Polymeric Semiconductor: Poly(3-hexylthiophene-2,5-diyl) (P3HT)
Authors: Gao Zhaojing , Yelon Arthur , Santato Clara 
Published: May 2020

Organic semiconductors are now widely employed in electronic and optoelectronic devices due to their solution processability and compatibility with flexible substrates. 1 The Meyer Neldel (MN) Rule or isokinetic (IK) law means that a set of comparable samples exhibit kinetic behavior independent of activation energy at an IK or MN temperature.2 It is obeyed by the electron or hole mobility, µ, in many organic semiconductors, including pentacene3, fullerene4, N-Alkyl Perylene Diimides,5 etc. The existence of MNR is still not widely known. Further, despite considerable evidence in its favor, the multi-excitation entropy (MEE) model of its origin is still frequently contested. We fabricated organic field effect transistors (FETs) based on regioregular poly(3-hexylthiophene-2,5-diyl) (RR P3HT) of three different values of molecular weight, MW, and studied the dependence of the mobility, µ, upon the gate bias, Vg
, and temperature, T. For all values of MW, we found that in the range 200 to 290 K (low T), the µ of the FET carriers exhibits an exponential dependence upon 1/T for different Vg
, with an MN temperature about 290K. Between this temperature and 350K (high T), µ increases more rapidly than it did below, and is independent of Vg
. We believe that, in the low T regime, the polaronic carriers hop along the polymer backbone chain. We attribute the high temperature behavior to the alpha relaxation of the polymers, that is to the movement of the backbone chains. We believe that in this regime, the polaronic carriers move with the mobile chains. We have also observed the effect of source-drain voltage upon µ.
Reference
1. F. Cicoira and C. Santato, Organic Electronics: Emerging Concepts and Technology, Wiley-VCH Verlag GmbH & Co. KGaA, 2013, Germany.
2. A. Yelon, et al., Multi-excitation entropy: its role in thermodynamics and kinetics, Rep. Prog. Phys., 69, 1145-1194, 2006.
3. E. J. Meijer, et al., The Meyer–Neldel rule in organic thin-film transistors, Appl. Phys. Lett., 76, 3433, 2000.
4. J. C. Wang and Y. F. Chen, The Meyer–Neldel rule in fullerenes, Appl. Phys. Lett., 73, 948 1998.
5. R. J. Chesterfield, et al., Organic Thin Film Transistors Based on N-Alkyl Perylene Diimides: Charge Transport Kinetics as a Function of Gate Voltage and Temperature, J. Phys. Chem. B, 108, 19281-19292, 2004.
Electrodeposition of Inorganic Cesium Lead Mixed-Halide Perovskites
Authors: Liu Tao , Byers Joshua 
Published: May 2020

Cesium-based halide perovskites have attracted tremendous interest for stable and efficient photovoltaics due to their tunable optical and electronic properties1, 2. Herein, electrodeposition and chemical conversion were combined to access inorganic cesium lead mixed-halide perovskites (CsPbX3, X = I, Br, Cl or their mixture). Their bandgap (E
g) was tuned by controlling the halide stoichiometry in the thin films, which was achieved by varying the solution composition used during chemical conversion. Measurements of the structural and (photo)electrochemical activity of the CsPbX3 thin films will be presented for studying the relationship between composition/structure and optoelectronic properties of perovskites.
1. J. Mater. Chem. C, 2019, 7, 757;
2. Adv. Sci., 2018, 5, 1800509;
(Invited) Are Nanotube Networks the Key to High-Rate, High Capacity Lithium Ion Batteries?
Authors: Coleman Jonathan N 
Published: May 2020

Increasing the energy storage capability of lithium-ion batteries necessitates maximization of their areal capacity. This requires thick electrodes performing at near-theoretical specific capacity. However, achievable electrode thicknesses are restricted by mechanical instabilities, with high-thickness performance limited by the attainable electrode conductivity. Here we show that forming a segregated network composite of carbon nanotubes with a range of lithium storage materials (for example, silicon, graphite and metal oxide particles) suppresses mechanical instabilities by toughening the composite, allowing the fabrication of high-performance electrodes with thicknesses of up to 800 μm. Such composite electrodes display conductivities up to 1 × 104 S m−1 and low charge-transfer resistances, allowing fast charge-delivery and enabling near-theoretical specific capacities, even for thick electrodes. The combination of high thickness and specific capacity leads to areal capacities of up to 45 and 30 mAh cm−2 for anodes and cathodes, respectively. Combining optimized composite anodes and cathodes yields full cells with state-of-the-art areal capacities (29 mAh cm−2) and specific/volumetric energies (480 Wh kg−1 and 1,600 Wh l−1).
However, such thick electrode might be expected to show poor rate performance. Optimisation of the combination of areal capacity and rate performance would be simplified if a simple mechanistic model linked both parameters to electrode properties. Here we demonstrate an equation which can fit capacity versus rate data, outputting three parameters which fully describe rate performance. Most important is the characteristic time associated with charge/discharge which can be linked by a second equation to physical electrode/electrolyte parameters via various rate-limiting processes. We fit these equations to ~200 data sets, deriving parameters such as diffusion coefficients or electrolyte conductivities. It is possible to show which rate-limiting processes are dominant in a given situation, facilitating rational design and cell optimisation. In addition, this model predicts the upper speed limit for lithium/sodium ion batteries, yielding a value that is consistent with the fastest electrodes in the literature. We show that this equation completely describes much experimental rate data.
(Invited) Heat and Solar Harvesting from Thermoelectric Carbon Nanotube Composites
Authors: Campoy-Quiles Mariano 
Published: May 2020

The conversion of waste heat into electricity using solid state devices, namely thermoelectrics, based on carbon materials has experienced renewed interest in the last decade as these materials are particularly suited for large area and low-temperature operation applications since they are abundant, low-toxicity and easy to process [1].
In this presentation we will focus on our recent attempts to further extend the sustainability and range of applications of CNT based thermoelectrics. First, we will describe the use bacteria in environmentally friendly aqueous media to grow large area bacterial nanocellulose (BC) films with an embedded highly dispersed CNT network [2]. The thick films are fully bendable, can conformally wrap around heat sources and are stable above 500 K. The resulting composite films exhibit comparable thermoelectric properties to buckypapers while saving more than 90% of the carbon nanotubes. Interestingly, BC can be enzymatically decomposed, thus completely reclaiming the embedded CNTs once the generator has reached the end of its lifetime. Second, we will show our recent studies on the stability of CNT based thermoelectrics, aimed at precisely extending their operational lifetime.
Finally, we employ the low thermal conductivities of these composites, granted by the phonon stack-electron tunnel behavior [1], to demonstrate their use as solar thermoelectrics, i.e. materials that convert the energy of the absorbed sun light into heat, and then into electricity [3].
[1] Will organic thermoelectrics get hot? M. Campoy-Quiles, Philosophical Transactions of the Royal Society A, 377, 20180352 (2019).
[2] Farming thermoelectric paper, D. Abol-Fotouh, B. Dörling, O. Zapata-Arteaga, X. Rodríguez-Martínez, A. Gómez, J. S. Reparaz, A. Laromaine, A. Roig and M. Campoy-Quiles, Energy and Enviromental Science, 12, 716-726 (2019).
[3] Solar harvesting: a unique opportunity for organic thermoelectrics? José P. Jurado, B. Dörling, O. Zapata‐Arteaga, A. Roig, A. Mihi and M. Campoy‐Quiles, Advanced Energy Materials, 1902385 (2019). DOI: 10.1002/aenm.20190238
(Invited) Macroscopically Aligned Carbon Nanotubes for Efficient Thermophotovoltaic Energy Conversion
Authors: Doiron Chloe F , Gao Weilu , Li Xinwei , Hassan Sakib , Kono Junichiro , Naik Gururaj V 
Published: May 2020

Single-walled carbon nanotubes (SWCNTs) exhibit many unique properties arising from their quantum confinement. However, the lack of a controllable large-scale alignment procedure had limited the exploration of their unique properties. Our recent work has overcome this problem by demonstrating a vacuum-filtration based technique to align SWCNTs on wafer-scale. These aligned SWCNT films exhibit many interesting optical properties such as extreme optical anisotropy or hyperbolic dispersion. Besides, aligned SWCNTs are flexible, refractory (stable up to 1900 K), inexpensive, and based on earth-abundant carbon making them an excellent refractory infrared nanophotonic material platform. Such a refractory infrared material platform is exactly what is necessary to enable efficient thermophotovoltaic energy conversion.
Thermophotovoltaics is a solid-state heat-to-electricity conversion technique. It relies upon photovoltaic conversion of thermal light emanating from a hot surface to electricity. The broadband nature of thermal light makes the thermophotovoltaic conversion inefficient. Optical resonators, filters, spectrally selective thermal emitters are a few methods proposed to increase the efficiency of thermophotovoltaics. Selective thermal emitters are very promising due to their ease of design and integration. Selective thermal emitters are hot surfaces that emit thermal radiation in a narrow spectral band above the bandgap of the photovoltaic cell. The suppression of thermal emission below the bandgap and enhancement above the bandgap are the key requirements for efficient thermophotovoltaic conversion. Generally, optical properties of materials at high temperatures limit the performance of such selective emitters and the current efficiency record is about 8%. But, the hyperbolic optical property of aligned SWCNTs together with their thermal stability make aligned SWCNTs ideal for efficient thermophotovoltaics.
Here in this work, we study the infrared optical properties of aligned SWCNTs at high temperatures (1000 K) and demonstrate spectrally selective thermal emission from plain and nano-patterned thin films. Using deep sub-wavelength sized optical cavities, we show that aligned SWCNTs exhibit hyperbolic dispersion in almost of all of infrared and enhance thermal photon density by at least 100 times. Such a large enhancement in thermal photon density leads to a large suppression of unwanted sub-bandgap thermal photons and a large enhancement of above-bandgap photons. Our analysis shows that aligned SWCNTs enable 30% or higher thermophotovoltaic efficiency when operating at 1300 K with no concentration. With near-field concentration, aligned SWCNTs can allow conversion efficiencies over 50%.
(Invited) Carbon Nanotube Electronic Ratchets
Authors: Ferguson Andrew John , Blackburn Jeffrey L. 
Published: May 2020

Electronic ratchets are recently demonstrated thin-film semiconductor devices with the ability to harvest energy from high-frequency signals or electrical noise. The state-of-the-art electronic ratchets have been fabricated from doped conjugated polymers, but the device performance is limited by the low charge-carrier mobility and relatively poor electrical conductivity. Enriched semiconducting single-walled carbon nanotube (s-SWCNT) networks represent an attractive alternative to conjugated polymers, since they are easy to dope and exhibit good charge-carrier transport.
While the electronic ratchet device is based on a simple field-effect transistor architecture, it requires the generation of asymmetry within the transistor channel. In this presentation, we will outline the approaches employed to control the charge-carrier doping profile to create this asymmetry. We will subsequently discuss the performance of these carbon nanotube electronic ratchets and make a comparison with their conjugated polymer counterparts.
(Invited) Nanocarbon Catalysts for Reversible Energy Storage and Conversion Via Oxygen Electrocatalysis
Authors: Wu Gang 
Published: May 2020

Energy conversion and storage via direct electrochemical oxidation and reduction processes, such as the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER), can provide a clean, efficient, and economically viable means of meeting this sustainability challenge, by allowing stored renewable energy to be reliably delivered where and when it is needed. During the development of the highly demanded nonprecious metal catalysts to replace precious metals for these applications, carbon catalysts have many advantages over metal oxides, including excellent electrical conductivity, high surface area, and easy functionalization. However, most carbon-based catalysts suffer from poor activity and stability for the more challenging OER under a highly oxidative conditions. This represents one of grand challenges in energy conversion research societies.
For the first time, this work demonstrated that a new class of large-diameter tubular nanocarbon (>500 nm in diameter) catalyst is capable of catalyzing both the ORR and the OER with activity comparable to Pt and exceeding Ir, respectively, for these two reactions. Most importantly, the tube catalyst exhibited good stability upon cycling across a wide potential window (0 to 1.9 V vs RHE) in 0.1 M NaOH electrolyte. The high OER activity was verified using well-designed electrochemical tests, demonstrating that the current generated during the OER arose solely from oxygen evolution, rather than carbon oxidation. This is the first example of such excellent OER activity and durability of a nanostructured carbon-based electrocatalyst across the complete ORR-OER potential window. The newly developed carbon tubes were synthesized via a one-step template-free graphitization process using inexpensive dicyandiamide (DCDA) precursor as carbon/nitrogen source and a ternary FeCoNi alloy as a catalyst. Generation of a mixed metal catalyst, i.e., FeCoNi during the graphitization process is the key factor to yield the largest tube size for maximum electrochemically accessible surface areas, dominant graphitic nitrogen doping, and thicker tube walls, which are associated with the significantly improved activity and durability. The cost effective, easily scalable, single step and environmentally benign synthesis procedure further favors this nanocarbon’s application as a practical bifunctional electrocatalyst for the ORR and OER, with potential to advance the development and commercialization of regenerative fuel cell systems and rechargeable metal-air batteries. The use of nanostructured carbon as bifunctional ORR/OER catalysts will open up new research direction in this field and further advance the role of carbon nanomaterials in oxygen electrocatalysis for energy conversion and storage.
(Invited) Electrocatalysts for Oxygen Reduction Reaction Based on Nitrogen-Doped Carbon and Atomically-Dispersed/Nanoclustered Metal
Authors: Roh JeongHan , Liu Jing , Cho EunAe 
Published: May 2020

High cost of the platinum-based catalysts for the sluggish oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cell (PEMFC) is delaying wide-spread commercialization of fuel cell electric vehicles (FCEVs). It is crucial to develop highly-active and cost-effective materials to reduce amount of platinum usage and eventually to replace the platinum-based catalysts. In this respect, nitrogen-doped carbon incorporated with atomically-dispersed metal and/or metal nanoclusters (M-N-C) has attracted tremendous attention owing to their high catalytic activity towards ORR. By atomically dispersing Pt or forming Pt nanoclusters in the nitrogen-doped carbon, utilization of Pt can be maximized, resulting in ultralow usage of Pt catalyst. Fe incorporated in the nitrogen-doped carbon (Fe-N-C) has been reported as the best candidate to attain high ORR activity among the non-precious catalysts. In applying these catalysts for PEMFC, it is still required to improve activity and durability of those M-N-C catalysts in the harsh acidic environment of PEMFC.
Herein, we present Pt-N-C and Fe-N-C as highly-active ORR catalysts prepared through a facile method. To enhance ORR activity of those M-N-C catalysts, a hetero-atom is doped into the M-N-C catalyst. In addition, effects of formation of metal nanoclusters on the ORR activity are investigated with respect to the size of the nanoclusters. DFT calculation study explores active sites for the ORR in M-N-C catalysts by examining the oxygen adsorption energy of reaction intermediates towards benefiting ORR.
(Invited) Creating Optical Nano-Biosensors from Engineered Antibodies for Protein Detection
Authors: Corrie Simon , Islam Jiaul 
Published: May 2020

Biosensors based on fluoro-labelled antibody fragments combine the recognition and transduction element into the same molecule leading to real-time result detection and reducing the need for laborious, multi-step assays. The key challenge is the efficient site-specific modification of antibodies with environmentally-sensitive fluorescent dyes, without affecting binding functionality. Fluorescence labelling via unnatural amino acids (UAAs) is a relatively new and highly efficient method for 100% efficient site-specific fluorescence labelling, and can be genetically incorporated into any permissible site during protein synthesis. Although over 100 UAAs have been incorporated into various proteins for diverse applications including antibody drug conjugates and bispecific antibody development using Fab, to date none of the UAAs has been incorporated into scFv for biosensing applications nor has this been used for detection of large biomolecules (e.g. protein).
We demonstrate that incorporation of environmentally sensitive fluorescent UAA (Anap) into a permissible site of antibody fragments (e.g. anti-EGFR scFv) can be used for detection of target binding by monitoring the wavelength and/or intensity changes in emission spectra. A mutation screen was initially performed in order to identify the Anap mutation site that yielded the largest spectral change. We found that, across two different protein/antibody case studies, that only relatively hydrophobic amino acids within the binding interface could be mutated to generate optically-reactive species, and that the affinity of the mutants was not significantly affected. When immobilising these antibody fragments onto various surfaces (e.g. silica, carbon nanotubes, polymeric nanoparticles) for solid-phase biosensor development, we also observed unique behaviour indicative of the local hydrophilicity of the surface environment, which may be advantageous in identifying optimal surfaces for high specificity and sensitivity in complex biological environments. Here we will present our latest results on generalising this approach for protein detection in complex biological environments, and also to outline the challenges and opportunities for future developments

Figure 1