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Most traditional optical biosensors operate through molecular recognition, where ligand binding causes conformational changes that lead to optical perturbations in the emitting motif. Optical sensors developed from single-stranded DNA-functionalized single-walled carbon nanotubes (ssDNA-SWCNTs) have started to make useful contributions to biological research. However, the mechanisms underlying their function have remained poorly understood. In this study, we combine experimental and computational approaches to show that ligand binding alone is not sufficient for optical modulation in this class of synthetic biosensors. Instead, the optical response that occurs after ligand binding is highly dependent on the chemical properties of the ligands, resembling mechanisms seen in activity-based biosensors. Specifically, we show that in ssDNA-SWCNT catecholamine sensors, the optical response correlates positively with the electron density on the aryl motif, even among ligands with similar ligand binding affinities. Importantly, despite the strong correlations with electrochemical properties, we find that catechol oxidation itself is not necessary to drive the sensor optical response. We discuss how these findings could serve as a framework for tuning the performance of existing sensors and guiding the development of new biosensors of this class.

Proteins can be rapidly prototyped with cell-free expression (CFE) but in most cases there is a lack of probes or assays to measure their function directly in the cell lysate, thereby limiting the throughput of these screens. Increased throughput is needed to build standardized, sequence to function data sets to feed machine learning guided protein optimization. Herein, we describe the use of fluorescent single-walled carbon nanotubes (SWCNT) as effective probes for measuring protease activity directly in cell-free lysate. Substrate proteins were conjugated to carboxymethyl cellulose-wrapped SWCNT, yielding stable and sensitive probes for protease detection with a detection limit of 6.4 ng/mL for bacterial protease from Streptomyces griseus . These probes successfully measured subtilisin activity in unpurified CFE reactions, surpassing commercial assays. Furthermore, they enabled continuous monitoring of activity during synthesis of subtilisin in both purified and lysate-based CFE systems without compromising protein expression. Surface passivation techniques, such as pre-incubation with cell lysate and supplement components, reduced the initial signal loss and improved probe signal stability in the complex cell lysate environment. These modular probes can be used, as described, for high-throughput screening and optimization of proteases and, with the change of conjugated substrate, a wider range of other hydrolases., Competing Interests: Conflict of Interest Statement - The authors declare the following competing financial interest(s): N.F.R. is a founder of Zymosense Inc. and has an equity interest in the company. In addition, N.F.R. receives income from Zymosense Inc. for serving in a leadership role. This conflict is managed by a plan in place at Iowa State University.

Understanding the inherent charge carrier transport mechanism within carbon nanotube-organic hybrid thermoelectric (TE) materials is crucial for enhancing their TE performance. Although various carbon nanotube-organic hybrid TE materials have been developed, the influence of the barrier energy on the TE transport mechanism within these hybrids remains elusive. Our study focuses on the engineering of barrier energy between single-walled carbon nanotubes (SWCNTs) and small organic molecules (SOMs) by modulating the mesomeric effects of terminal functional groups on T-shaped SOMs. The minimization of barrier energy in an SWCNTs- BTBIN hybrid to 0.04 eV resulted in a semiconducting-dominant transport character, facilitating the energy filtering of SWCNTs- BTBIN . Consequently, SWCNTs- BTBIN achieved a higher Seebeck coefficient (65 μV K -1 ) than other hybrids (39-54 μV K -1 ) having steeper barrier energies (0.30 and 0.19 eV), enabling the highest power factor (798 μW m -1 K -2 ) and ZT value up to 0.035 at room temperature among SWCNTs- BTBI hybrid series. A TE module consisting of SWCNTs- BTBIN incorporating five-leg TE elements produced an output power exceeding 0.82 μW, suggesting that integrating barrier energy engineering with analyses of TE transport mechanisms can significantly advance the design of high-performance nanocarbon-based organic hybrid TEs.

Modulating the optical response of fluorescent nanoparticles through rational modification of their surface chemistry can yield distinct optical signatures upon the interaction with structurally related molecules. Herein, we present a method for tuning the fluorescence response of single-walled carbon nanotubes (SWCNTs) toward dopamine (DA) and serotonin, two structurally related monoamine-hydroxylated aromatic neurotransmitters, by introducing oxygen defects into (6,5) chirality-enriched SWCNTs suspended by sodium cholate (SC). This modification facilitated opposite optical responses toward these neurotransmitters, where DA distinctly increased the fluorescence of the defect-induced emission of SWCNTs (D-SWCNTs) 6-fold, while serotonin notably decreased it. In contrast, pristine, defect-free SWCNTs exhibited similar optical responses to both neurotransmitters. The underlying mechanisms for the divergent fluorescence response were found to be polydopamine (PDA) surface adsorption in the case of the fluorescence enhancement in response to DA, while the fluorescence decrease in response to serotonin was attributed to enhanced solvent relaxation effects in the presence of defects. Importantly, the divergent optical response of D-SWCNTs to DA and serotonin, via the introduction of defects, was validated in complex biological environments such as serum. Further, the generality of our approach was confirmed by the demonstrations of a divergent fluorescence response of D-SWCNTs suspended by an additional dispersant, namely lipid-polyethylene glycol (PEG). This study offers promising avenues for the broad applicability of surface functionalization of SWCNTs to achieve divergent responses toward structurally related molecules and advance applications in sensing, imaging, and diagnostic technologies.

A new composite material has been synthesized by incorporating an amine-functionalized MIL-53 (Al) metal-organic framework (MOF) and single-walled carbon nanotubes (SWCNT) under hydrothermal conditions. This hybrid material combines the porosity of the MOF with the electrical conductivity of SWCNT. The preservation of MIL-53(Al)-NH 2 MOF structure and morphology in the composite with SWCNT was verified by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and Brunauer-Emmett-Teller surface area analysis. A characteristic current-voltage ( I - V ) curve showed the electrical conductivity of this composite and gave a linear response in the chemiresistive sensor with increasing concentrations of acetone. The MIL-53(Al)-NH 2 /SWCNT composite also displayed fluorescence quenching tendencies across various acetone concentrations, likely attributable to the impact of guest molecules influencing the framework. An alternative approach utilizing layer-by-layer sensor device fabrication was employed for growing this MOF on carbon nanotubes directly onto a silicon chip, demonstrating its potential for versatile on-chip-sensing applications.

Single-walled carbon nanotube (SWNT) films, with exciting electronic properties are increasingly important for next-generation technologies. Here, an Iron-assisted floating solid catalyst chemical vapor deposition (IA-FSCCVD) method is developed for the controlled growth of high-quality and high-purity SWNT films. Titanium carbide nanoparticles with a high melting point are used as the solid catalysts, which provide a stable template for SWNT growth through the perpendicular growth mode. Trace amounts of iron are introduced to increase the efficiency of SWNT growth. Gas chromatography measurements and density functional theory show that the gas-phase iron acts as a pre-cracking assistance for the carbon source, promoting the growth of SWNTs. Carbon nanotube films with a high quality (average I G /I D = 166) are successfully prepared, a small diameter deviation (mean diameter of 1.6 nm), and a high content of SWNTs (97%) using the IA-FSCCVD platform. This work provides a powerful way to prepare the carbon nanotube aggregates with a controlled structure., (© 2024 Wiley‐VCH GmbH.)

Globally, over 60% of useful energy is not harnessed for any productive use, but is instead dissipated to the environment as waste heat, which if harvested could contribute significantly towards meeting the increasing energy demand. Thus, thermoelectric generators (TEGs) have emerged recently as an essential part of the solution to alleviate the current energy crisis due to their potential to effectively utilize waste heat by converting it directly to electricity via the Seebeck effect. However, TEGs are not yet suitable for large-scale practical applications due to the scarcity, high-cost, toxicity, complex fabrication procedures and low thermoelectric (TE) performance of commonly used inorganic TE materials. Consequently, organic TE materials, such as carbon-based materials, in particular, single-walled carbon nanotubes (SWCNTs), have been developed recently owing to their low-cost, facile fabrication procedures, easy scalability, lightweight, excellent flexibility, nontoxicity, high electrical conductivity, tunable band gap, and the natural abundance of carbon. Most importantly, it is possible to tune, and hence optimize the TE properties of SWCNTs to compete with those of traditional inorganic TE materials, especially by preparing nanocomposites to optimize charge carrier transport primarily via the material orientation effect and energy filtering effect, which increases electrical conductivity and the Seebeck coefficient, respectively. In addition, SWCNT-based nanocomposites help to improve TE performance by lowering the lattice thermal conductivity via the phonon scattering effect, and they also help to increase sustainability by enhancing the mechanical and chemical stability of TE materials and devices. Thus, this review highlights the recent breakthroughs in improving TE performance, covering the period from 2018 to 2022, by preparing SWCNT-based nanocomposites, as well as discussing the benefits, challenges and future directions for fabricating highly efficient, sustainable, low-cost and environmentally friendly TEGs for commercial applications.

Self-powered broad-band electrochemical photodetectors (ECPDs) based on broadband photoresponse nanostructured composites are low-cost and promising photoelectrochemical (PEC) devices. In this work a TiO2 nanorod array (TNRA) structure modified by the ZrO2 nanoparticles and metallic single-walled carbon nanotubes (m-SWCNTs) was used to prepare the ECPDs for enabling a high performance ultraviolet-visible (UV-VIS) photoresponse. The ECPDs exhibit a high optical sensitivity with an on/off ratio of 1.59 × 105 and an optical responsivity of 158.67 mA/W under ultraviolet radiation (365 nm) without external bias. The lowest detectable intensity of ultraviolet and visible-light irradiance (465 nm) can reach around 0.1 mW/cm2and 0.18 mW/cm2. The enhanced PEC performance can be attributed to the effective separation and transport of carriers in the PEC system by the type-I band alignment of ZrO2@TiO2 structure and the high conductive network of SWCNTs.

Design of new smart prosthetics or robotic grippers gives a major impetus to low-cost manufacturing and rapid prototyping of force sensing devices. In this paper, we examine piezoresistive force sensors based on carbon nanotube fibers fabricated by a novel wet pulling technique. The developed sensor is characterized by an adjustable force range coupled with high sensitivity to enable the detection of a wide range of forces and displacements limited by the experimental setup only. We have demonstrated the applicability of the developed unit in tactile sensing, displacement sensing, and nanophone vibration monitoring system and evaluated its force sensing characteristics, i.e. displacement/force input and resistance/mechanical response. In the experiments it measures 0â€"115 N force range within 2.5 mm displacement. Moreover, the sensor demonstrates good linearity, low hysteresis, and stability when tested over 10 000 cycles. The developed sensor suits multiple applications in the field of soft and transparent sensors, nanophones, actuators, and other robotics devices for both regular and extreme environments, e.g. deep underwater and radioactive environment. [ABSTRACT FROM AUTHOR]

To design a new electrochemical horseradish peroxidase (HRP) biosensor with excellent analytical performance, black phosphorene (BP) nanosheets and single-walled carbon nanotubes (SWCNTs) nanocomposites were used as the modifier, with a carbon ionic liquid electrode (CILE) as the substrate electrode. The SWCNTs-BP nanocomposite was synthesized by a simple in situ mixing procedure and modified on the CILE surface by the direct casting method. Then HRP was immobilized on the modified electrode with Nafion film. The electrocatalysis of this electrochemical HRP biosensor to various targets was further explored. Experimental results indicated that the direct electrochemistry of HRP was realized with a pair of symmetric and quasi-reversible redox peaks appeared, which was due to the presence of SWCNTs-BP on the surface of CILE, exhibiting synergistic effects with high electrical conductivity and good biocompatibility. Excellent electrocatalytic activity to trichloroacetic acid (TCA), sodium nitrite (NaNO2), and hydrogen peroxide (H2O2) were realized, with a wide linear range and a low detection limit. Different real samples, such as a medical facial peel solution, the soak water of pickled vegetables, and a 3% H2O2 disinfectant, were further analyzed, with satisfactory results, further proving the potential practical applications for the electrochemical biosensor. [ABSTRACT FROM AUTHOR]

Pharmaceutical products such as antibiotics, analgesics, steroids, and non-steroidal anti-inflammatory drugs (NSAIDs) are new emerging pollutants, often present in wastewater, potentially able to contaminate drinking water resources. Adsorption is considered the cheapest and most effective technique for the removal of pollutants from water, and, recently, membranes obtained by wet filtration method of SWCNT aqueous solutions (SWCNT buckypapers, SWCNT BPs) have been proposed as self-standing porous adsorbents. In this paper, the ability of graphene oxide/single-walled carbon nanotube composite membranes (GO-SWCNT BPs) to remove some important NSAIDs, namely Diclofenac, Ketoprofen, and Naproxen, was investigated at different pH conditions (pH 4, 6, and 8), graphene oxide amount (0, 20, 40, 60, and 75 wt.%), and initial NSAIDs concentration (1, 10, and 50 ppm). For the same experimental conditions, the adsorption capacities were found to strongly depend on the graphene oxide content. The best results were obtained for 75 wt.% graphene oxide with an adsorption capacity of 118 ± 2 mg g−1 for Diclofenac, 116 ± 2 mg g−1 for Ketoprofen, and 126 ± 3 mg g−1 for Naproxen at pH 4. Overall, the reported data suggest that GO-SWCNT BPs can represent a promising tool for a cheap and fast removal of NSAIDs from drinking water resources, with easy recovery and reusability features. [ABSTRACT FROM AUTHOR]

Over the last few years, the addition of small amounts of carbon nanotubes (CNTs) to construction materials has become of great interest, since it enhances some of the mechanical, electrical and thermal properties of the cement. In this sense, single-walled and multi-walled carbon nanotubes (SWCNTs and MWCNTs, respectively) can be incorporated into cement to achieve the above-mentioned improved features. Thus, the current study presents the results of the addition of SWCNTs and MWCNTs on the microstructure and the physical properties of the cement paste. Density was measured through He pycnometry and the mass change was studied by thermogravimetric analysis (TGA). The microstructure and the phases were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Finally, the electrical conductivity for different CNT concentrations was measured, and an exponential increase of the conductivity with concentration was observed. This last result opens the possibility for these materials to be used in a high variety of fields, such as space intelligent systems with novel electrical and electronic applications. [ABSTRACT FROM AUTHOR]

Solution-processed single-walled carbon nanotube (SWCNT) thin-film transistors (TFTs) in the research stage often have large active areas. This results in unusual gate leakage currents with high magnitudes that vary with applied voltages. In this paper, we report an improved structure for solution-processed SWCNT-based TFTs. The unusual gate leakage current in the improved structure is resolved by patterning the SWCNT active layer to confine it to the channel region. For comparative purposes, this improved structure is compared to a traditional structure whose unpatterned SWCNT active layer expands well beyond the channel region. As TFT performance also varies with oxide layer thickness, 90 nm and 300 nm thick oxides were considered. The improved TFTs have gate leakage currents far lower than the traditional TFT with the same dimensions (aside from the unpatterned active area). Moreover, the unusual variation in gate leakage current with applied voltages is resolved. Patterning the SWCNT layer, increasing the oxide thickness, and reducing the top electrode length all help prevent a rapid dielectric breakdown. To take advantage of solution-based fabrication processes, the active layer and electrodes of our TFTs were fabricated with solution-based depositions. The performance of the TFT can be further improved in the future by increasing SWCNT solution incubation time and reducing channel size. [ABSTRACT FROM AUTHOR]

Changes in the dynamic viscoelastic properties of silicone rubber with addition of a small fraction (0.05 and 0.10%) of single-walled carbon nanotubes are under study. Elastic modulus and loss factor in the linear deformation region are measured. It is revealed that, with the addition of nanotubes and the aging of materials, the elastic modulus increases and the loss factor may either increase or decrease. [ABSTRACT FROM AUTHOR]

• A continuum-discrete multiscale coupling (CDMC) method for the pristine and defected SWCNTs is proposed. • A variationally consistent meshless computational scheme is built based on the proposed nonlinear multiscale model. • CDMC method is accurate and efficient for nonlinear mechanics of pristine and defected of SWCNTs. • CDMC method is suitable for large scale problems of SWCNTs, especially containing defects. A continuum-discrete multiscale coupling (CDMC) method is developed for predicting the large deformation and buckling behaviors of pristine and defected single-walled carbon nanotubes (SWCNTs). With the use of the moving least squares (MLS) approximation as the linkage for the deformations of the discrete atomic structure and the corresponding continuum model, the delicate microstructures of pristine or defected SWCNTs which possess abnormal properties can be involved accurately in the mechanic model built by this CDMC method. Based on the proposed CDMC method, a variationally consistent meshless computational scheme is developed. As the degree of freedom of SWCNTs can be chosen freely in the context of CDMC method, the numerical computational efficiency is higher than that of the fully atomistic simulations. Various numerical tests are carried out for simulating the nonlinear large and buckling deformations of SWCNTs. The results compared with those of the fully atomistic simulations show that CDMC method is accurate and efficient for predicting the nonlinear mechanical properties of pristine and defective SWCNTs and has great potential for dealing with large scale boundary problems. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) are very promising for use in various areas of human activity, including medicine, but they can have a negative effect on the body, in particular on the nervous system. CNTs in large doses in animal experiments often cause anxiety and depressive disorders. The effect of low doses of CNTs on the behavior of animals has been little studied. In the present work, we studied behavioral parameters in tests for anxiety in rats, which were intranasally injected daily for 4 days with a suspension of single-walled carbon nanotubes (SWCNTs) in small doses, 5.2 µg/kg or 52 µg/kg. It turned out that both doses of SWCNTs unidirectionally changed the following indicators of behavior in rats: in the open field test exploratory activity (rears) decreased; in the light–dark box test the latency of entering to the dark box and peeping out of the dark box and are increased; in the elevated plus maze test (EPM) behavior in the open arm was activated. However, if a dose of 5.2 µg/kg induced the rat behavior with signs of agitation (increased exploratory motor activity in the light–dark box and EPM tests, and motor activity with frequent visits to different boxes or arms and exploratory activity in the light–dark box and EPM tests), then a dose of 52 µg/kg, on the contrary, inhibited a number of behavioral responses, which was expressed in increased anxiety (increased the freezing in the open field and EPM) and in increased the latency of entry into the closed arm of the EPM. It is assumed that SWCNTs in small doses, when injected intranasally into the brain of rats, can dose-dependently disrupt the structural and functional state of nervous tissue cells and/or cause neuroinflammation in the structures involved in the mechanisms of anxiety and related conditions, as a result, the behavior of rats in tests for anxiety also changes in a dose-dependent manner. [ABSTRACT FROM AUTHOR]

Palladium is a well-known hydrogen-absorbing material. When palladium is functionalized with copper-(II) benzene-1,3,5-tricarboxylate (HKUST-1), a hydrogen-adsorbing metal–organic framework, its hydrogen-absorption capacity can be increased. In this work, we show that, by growing the HKUST-1 on palladium nanoparticle-functionalized single-walled carbon nanotubes (Pd NP/SWCNT), we can dynamically monitor the adsorption and desorption of hydrogen from the HKUST-1 and Pd NP composite by using the carbon nanotubes as transducers in chemiresistors. Addition of HKUST-1 to the Pd NP/SWCNT was shown to increase the sensitivity of the nanocomposite material to hydrogen by 300% and limit of detection to hydrogen by 33%. The increase in sensitivity was attributed to the increased hydrogen sorption capacity of the combined HKUST-1/Pd NP. A factor of 8 improvement in sensitivity was further achieved by using semiconductor-enriched SWCNT instead of mixed metallic/semiconducting nanotubes and a corresponding improvement in the theoretical limit of detection down to 70 ppb. [ABSTRACT FROM AUTHOR]

We propose a facile, cost-efficient, environmentally friendly, and scalable process to renew single-walled carbon nanotube membranes serving as extreme ultraviolet (EUV) protective pellicles. The method comprises of high-temperature treatment of the membrane by Joule (resistive) heating at temperatures higher than 1000 °C and pressure below 0.3 Pa. Using model Sn aerosol nanoparticles, the primary contaminant from extreme ultraviolet light sources, we demonstrate the proposed method to clean the membrane with the power consumption as low as 20 W/cm2. We show the proposed method to cause no harm to carbon nanotube structure, opening a route towards multiple membrane renovation. We confirm the applicability of the approach using in situ deposition from the semi-industrial EUV light source and subsequent Sn-based contaminant removal, which restores the EUV-UV-vis-NIR transmittance of the film and, therefore, the light source performance. The proposed method supports pulse-cycling opening an avenue for enhanced protection of the lithography mask and stable performance of the EUV light source. Additionally, the approach suits other composite contaminants based on such species as Pb, In, Sb, etc. [Display omitted] • We propose a technology for cleaning nanotube membranes from aerosol contaminations. • The technology is proven for semi-industrial EUV pellicles and aerosol filters. • The technology is energy efficient (20W/cm2), fast (3 min), sustainable, and scalable. • The cleaning causes no harm for nanotube structure as well as membrane morphology. • The technology is suitable for Sn and In while can be extended for other composites. [ABSTRACT FROM AUTHOR]

Artificial neural networks are employed to predict stress–strain curves for all single-walled carbon nanotube configurations with diameters up to 4 nm. Three model architectures are investigated for the molecular dynamics-derived dataset: a multilayer perceptron, a one-dimensional convolutional neural network, and a residual neural network. The performance of the three models is compared, and they are found to closely match an atomistic-physics-based paradigm while being orders of magnitude faster. The effect of the dataset size on the prediction quality is analyzed. It is shown that 30% of the entire carbon nanotube configuration dataset is representative of the problem. Remarkably, all models demonstrate high accuracy, capturing even the smallest variations due to thermal fluctuations, and can provide averaged stress–strain curves without thermal fluctuations. Additionally, a sensitivity analysis was performed to investigate how the various input feature combinations affect the quality of elimination or prediction of thermal fluctuations. The results are determined by different combinations of input features, with current diameter in combination with temperature identified as the most important parameters affecting the inclusion or exclusion of thermal fluctuations. [ABSTRACT FROM AUTHOR]

Summary: In the past few decades, single‐walled carbon nanotube (SWCNT) fibers have been considered for various applications, from aerospace to electronics including flexible devices. Here, we report an effective way of controlling the viscosity of the liquid crystal SWCNT phases for fiber spinning. By applying Tris(hydroxymethyl)aminomethane (THA)‐functionalization to single‐walled carbon nanotubes (SWCNT_CONH), we enhanced the free volume of individual SWCNTs, which synergistically affected the formation of nematic liquid crystal phases. As a result, we were able to precisely control the viscosity and phase transformation of the nematic liquid crystal phases for fiber spinning. The SWCNT fiber spun from those nematic phases with plasticizer (BP30CONH5; 30 mg/mL of SWCNT_BP with 5 wt% of SWCNT_CONH) exhibited noticeably higher mechanical properties (tensile strength, 1.44 GPa and tensile modulus, 169 GPa) with higher electrical conductivity (1899 S m2/kg). These fibers were also exceptionally flexible and showed endurable performance as wearable and flexible electronic electrode devices from well‐distributed zincophilic sites (CONH). As an Zn‐ion supercapacitor, the SWCNT fiber exhibited linear and volumetric capacitances of 14.33 mF cm−1 and 22.55 F cm−3 at 0.1 mA cm−1 with capacitance retention of 98% after over 30 000 bending tests. [ABSTRACT FROM AUTHOR]

This work is devoted to the formation and study of polymer composites with a segregated structure filled with single-walled carbon nanotubes (SWCNTs), reduced graphene oxide (rGO), and their mixtures. For the first time, polymer composites with a segregated structure filled with rGO/SWCNTs mixtures were obtained. A copolymer of vinylidene fluoride and tetrafluoroethylene (P(VDF-TFE)) was used as a polymer matrix. At a fixed value of the total mass fraction of carbon nanofillers (0.5, 1, and 1.5 wt%), the rGO/SWCNTs ratio was varied. The composites were examined using scanning electron microscopy, wide-range dielectric spectroscopy, and tested for the compression. The effect of the rGO/SWCNTs ratio on the electrical conductivity and mechanical properties of the composites was evaluated. It was shown that, with a decrease in the rGO/SWCNTs ratio, the electrical conductivity increased and reached the maximum at the 1 wt% filling, regardless of the samples' composition. The maximum value of electrical conductivity from the entire data set was 12.2 S/m. The maximum of elastic modulus was 378.7 ± 3.5 MPa for the sample with 1 wt% SWCNTs, which is 14% higher than the P(VDF-TFE) elastic modulus. The composite filled with a mixture of 0.5 wt% rGO and 0.5 wt% SWCNTs reflected 70% of the electromagnetic wave energy from the front boundary, which is 14% and 50% more than for composites with 1 wt% SWCNTs and with 1 wt% rGO, respectively. The lowest transmission coefficient of ultra-high frequencies waves was obtained for a composite sample with a mixture of 0.5 wt% rGO and 0.5 wt% SWCNTs and amounted to less than 1% for a 2 mm thickness sample. [ABSTRACT FROM AUTHOR]

As one of carbon-based nanomaterials, single-walled carbon nanotubes (SWCNTs) are widely regarded as potentially potent drug delivery carriers on account of their prominent properties. Nevertheless, their biomedical application, particularly in the drug delivery field has been seriously restricted by some inherent defects. In this study, SWCNTs materials were functionalized by covalent and non-covalent approaches, respectively. In short, the pristine SWCNTs were first purified with strong oxidizing acids (H2SO4/HNO3), and the resulting carboxylated ones (CNTs) were attached sequentially by different modification agents, including polyethylene glycol (PEG), polyethyleneimine (PEI), folic acid (FA) and chitosan (CS). Various nanocarriers were then systematically characterized and comparatively evaluated. The results illustrated that all CNTs samples could act as drug delivery carriers since they had high drug loading efficiency, good biocompatibility and responsive drug release. In comparison with other CNTs, multi-functionalized ones (CNTs-PPFC) exhibited more excellent performance, such as rapid drug release at low pH condition, higher cell internalization efficiency, and enhanced antitumor activity toward MCF-7 cells. These advantages should be attributed to their better dispersion state and comparably higher affinity with tumor cells, which favor the more efficient selective cellular uptake and subsequent drug accumulation. Moreover, further pharmacological mechanism analysis also revealed that CNTs-PPFC/DOX could induce the apoptosis of MCF-7 cells most effectively, by triggering ROS overproduction and affecting cell cycle distribution. In conclusion, the multi-functionalized CNTs-PPFC can be utilized as promising nanocarriers, and the findings will contribute to the rational design of novel delivery vehicles for anticancer drugs. [ABSTRACT FROM AUTHOR]

Single-walled carbon nanotubes (SWCNTs) are used as a universal additive to increase the mechanical and electrical properties of materials. In this work, we introduced SWCNTs in nitrile butadiene rubbers filled with 60 phr carbon black using concentrates of predispersed SWCNTs in a solution of nitrile butadiene rubber with dibutyl phthalate. It is shown that the addition of 0.15 wt % of SWCNTs allowed decreasing the specific volume electrical resistivity by four orders from 2.3 × 106 to 7.9 × 102 Ω cm and increasing the tensile moduli at 50% and 100% elongation by 50% and 30%, respectively. The tensile moduli at 50% and 100% elongation and the tear resistance linearly depend on the concentration of SWCNTs in the nanocomposite for the studied concentration range up to 0.5 wt %, while the elongation at break and the tensile strength of the rubber do not change within the tolerance of measurements. The specific volume electrical resistivity depends on the concentration of SWCNTs in the rubber according to Kirkpatrick power law with a percolation threshold of 0.05 wt % and achieves 10 Ω cm at 0.5 wt % of SWCNTs. [ABSTRACT FROM AUTHOR]

Conductive textiles with good flexibility and durability are highly demanded for wearable electronics. However, the common approaches of making conductive textiles require multi-step solvent processes, which is tedious and environment unfriendly. Herein, the high-quality single-walled carbon nanotubes (SWCNTs), synthesized by the floating catalyst chemical vapor deposition method, were directed and dry coated on the melt-blown fabrics (MBFs) recycled from the waste masks with binder-free chemical. The obtained MBF/SWCNT composites displayed excellent conductivity and flexibility and thus can be further used as wearable and heatable textiles. The sheet resistance of MBF/SWCNT composites can be further reduced by gold chloride (AuCl3) doping from 57 to 26 Ω/sq. The electrical–thermal measurement showed that the pristine MBF/SWCNT composites can reach the surface temperature of ∼48 °C at a low voltage (5 V), whereas it increased to ∼110 °C after AuCl3 doping at the same voltage. In addition, the AuCl3-doped MBF/SWCNT film with a thickness of ∼150 μm displays a high electromagnetic interference shielding efficiency of 27.1 dB at the X-band. Also, the MBF/SWCNT composites displayed good stability after long-term heating, bending, and washing. Our multi-functional MBF/SWCNT textiles not only demonstrated the reusability of waste masks but also showed great potential applications in electromagnetic interference and heat management, such as thermotherapy pads and fast water evaporators. [ABSTRACT FROM AUTHOR]

Pt nanoparticles deposited on single-walled carbon nanotubes (PtSWCNTs), synthesized via the deposition precipitation (DP) method, were introduced as a substrate for immobilizing antibodies on an electrode surface and then enhancing the electrochemical sensitivity. A PtSWCNT-modified paper-based screen-printed graphene electrode was successfully developed to diagnose hepatitis C virus (HCV) infection. The hepatitis C virus core antigen (HCV-cAg) level was determined by differential pulse voltammetry (DPV) using [Fe(CN)6]3−/4− as a redox solution. In the presence of HCV-cAg, the DPV current response decreased with increasing HCV-cAg concentration. Under the optimal conditions, the change in current response provides a good linear correlation with the logarithm of HCV-cAg concentration in the range 0.05 to 1000 pg mL−1 (RSD < 5%), and the limit of detection was 0.015 pg mL−1 (or 0.71 fmol L−1). Furthermore, the proposed immunosensor has been utilized to quantify HCV-cAg in human serum samples with reliable results compared with standard immunoassays (% relative error < 10%). This sensor offers a simple, sensitive, selective, disposable, and inexpensive means for determination of HCV-cAg in human serum samples. The paper-based label-free immunosensor is versatile and feasible for clinical diagnosis. [ABSTRACT FROM AUTHOR]

Herein, single‐walled carbon nanotubes (SWCNTs) were synthesized by the thermal chemical vapor deposition (CVD) method, and characterized by scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDX), transmission electron microscopy (TEM), Raman spectroscopy, dynamic light scattering (DLS), and thermo‐gravimetric analysis (TGA). The results indicated that obtained nanotubes were SWCNTs with high crystallinity and their average diameter was 10.15 ± 3 nm. Allium cepa ana–telophase and comet assays on the root meristem were employed to evaluate the cytotoxic and genotoxic effects of SWCNTs by examining mitotic phases, mitotic index (MI), chromosomal aberrations (CAs), and DNA damage. A. cepa root tip cells were exposed to SWCNTs at concentrations of 12.5, 25, 50, and 100 μg/ml for 4 h. Distilled water and methyl methanesulfonate (MMS, 10 μg/ml) were used as the negative and positive control groups, respectively. It was observed that MIs decreased statistically significantly for all applied doses. Besides, CAs such as chromosome laggards, disturbed anaphase–telophase, stickiness and bridges and also DNA damage increased in the presence of SWCNTs in a concentration‐dependent manner. In the molecular docking study, the SWCNT were found to be a strong DNA major groove binder showing an energetically very favorable binding free energy of −21.27 kcal/mol. Furthermore, the SWCNT interacted effectively with the nucleotides on both strands of DNA primarily via hydrophobic π and electrostatic interactions. As a result, cytotoxic and genotoxic effects of SWCNTs in A. cepa root meristematic cells which is a reliable system for assessment of nanoparticle toxicology were demonstrated in this study. Research Highlights: SWCNT synthesis with high crystallinity was achieved by the CVD method.Cytotoxic and genotoxic influences of SWCNTs were investigated.Allium and Comet tests were utilized.For all of the applied concentrations of SWCNTs, the MIs significantly decreased.SWCNTs were found genotoxic. [ABSTRACT FROM AUTHOR]

The production demand of high-performance polymer composites utilizing natural and renewable resources, especially agricultural waste fibres, is rapidly growing. However, these polymers’ mechanical properties are strain rate-dependent due to their viscoelastic nature. Particularly, for natural fibre-reinforced polymer composites (NFPCs), the involvement of fillers has caused rather complex failure mechanisms under different strain rates. Moreover, unevenly and micro-sized bagasse-reinforced polymer composites often cause the formation of micro-cracks and voids in composites. Consequently, the rates of crack initiation and propagation of these composites become extremely sensitive. This, in turn, causes low and unpredictable tensile performance at higher tensile crosshead speeds, even within the low strain rate range. In this study, single-walled carbon nanotubes (SWCNTs) were applied to enhance the bagasse-epoxy composites’ strength. The effects of the weightage in the SWCNT loadings on the composites’ tensile properties were subsequently investigated under low strain rates of 0.0005 s−1, 0.005 s−1 and 0.05 s−1. The composites’ failure shifted to a higher distribution (65.7% improvement, from 37.23 to 61.68 MPa, across strain rates) due to the addition of 0.05% SWCNTs, as indicated in a Weibull distribution plot. The high aspect ratio and strong interface adhesion of SWCNTs in and toward the epoxy matrix contributed significantly to the composites’ strengths. However, a further increase in SWCNT content in the tested composites caused early embrittlement due to agglomeration. The toughness and characteristic strength improved significantly as the strain rate increased. A scanning electron microscopic (SEM) analysis revealed that the SWCNTs’ high aspect ratios and large surface areas improved the interface bonding between the filler and matrix. However, higher SWCNT loadings (0.15% and 0.25%) caused a reverse effect in the same properties of these composites under the same strain rate variations, due to agglomeration. Finally, an empirical relationship was developed to describe the strain rate effect of tensile properties containing 0.05% SWCNT-reinforced bagasse-epoxy composites.

Despite continual progress in creating semiconductor-enriched single-walled carbon nanotube (SWCNT) networks, significant challenges still remain in achieving electronically homogeneous channels for field-effect transistors (FETs) due to persisting metallic percolation and uncontrollable nanotube bundling. To address this critical issue, we systematically explored the bundling effect of the SWCNTs on the electrical characteristics of SWCNT network-based FETs. Devices with higher bundle density and larger bundles showed enhanced FET metrics in drive current, on/off ratio, subthreshold swing, transconductance, and thermal dependence, thereby enabling highly uniform and integrated SWCNT FETs at wafer scale. These performance enhancements are attributed to the increased conduction channels, the metallic CNT shielding effect in dense, thick, and locally aligned SWCNT bundles, and enhanced contact properties. Additionally, SWCNT network-based FETs were demonstrated as biosensors to detect the influenza A H5N1 virus. Larger bundles and higher densities of SWCNT improved sensing performance due to enhanced semiconducting properties and the metallic screening effect within the bundles. [ABSTRACT FROM AUTHOR]

A key limitation for achieving deep imaging in biological structures lies in photon absorption and scattering leading to attenuation of fluorescence. In particular, neurotransmitter imaging is challenging in the biologically relevant context of the intact brain for which photons must traverse the cranium, skin, and bone. Thus, fluorescence imaging is limited to the surface cortical layers of the brain, only achievable with craniotomy. Herein, this study describes optimal excitation and emission wavelengths for through-cranium imaging, and demonstrates that near-infrared emissive nanosensors can be photoexcited using a two-photon 1560 nm excitation source. Dopamine-sensitive nanosensors can undergo two-photon excitation, and provide chirality-dependent responses selective for dopamine with fluorescent turn-on responses varying between 20% and 350%. The two-photon absorption cross-section and quantum yield of dopamine nanosensors are further calculated, and a two-photon power law relationship for the nanosensor excitation process is confirmed. Finally, the improved image quality of the nanosensors embedded 2-mm-deep into a brain-mimetic tissue phantom is shown, whereby one-photon excitation yields 42% scattering, in contrast to 4% scattering when the same object is imaged under two-photon excitation. The approach overcomes traditional limitations in deep-tissue fluorescence microscopy, and can enable neurotransmitter imaging in the biologically relevant milieu of the intact and living brain.

A key limitation for achieving deep imaging in biological structures lies in photon absorption and scattering leading to attenuation of fluorescence. In particular, neurotransmitter imaging is challenging in the biologically relevant context of the intact brain for which photons must traverse the cranium, skin, and bone. Thus, fluorescence imaging is limited to the surface cortical layers of the brain, only achievable with craniotomy. Herein, this study describes optimal excitation and emission wavelengths for through-cranium imaging, and demonstrates that near-infrared emissive nanosensors can be photoexcited using a two-photon 1560 nm excitation source. Dopamine-sensitive nanosensors can undergo two-photon excitation, and provide chirality-dependent responses selective for dopamine with fluorescent turn-on responses varying between 20% and 350%. The two-photon absorption cross-section and quantum yield of dopamine nanosensors are further calculated, and a two-photon power law relationship for the nanosensor excitation process is confirmed. Finally, the improved image quality of the nanosensors embedded 2-mm-deep into a brain-mimetic tissue phantom is shown, whereby one-photon excitation yields 42% scattering, in contrast to 4% scattering when the same object is imaged under two-photon excitation. The approach overcomes traditional limitations in deep-tissue fluorescence microscopy, and can enable neurotransmitter imaging in the biologically relevant milieu of the intact and living brain.

Single‐walled carbon nanotubes (SWCNTs) have unique optical and physical properties, with numerous biomedical imaging and sensing applications, owing to their near‐infrared (nIR) fluorescence which overlaps with the biological transparency window. However, their longer emission wavelengths compared to emitters in the visible range result in a lower resolution due to the diffraction limit. Moreover, the elongated high‐aspect‐ratio structure of SWCNTs poses an additional challenge on super‐resolution techniques that assume point emitters. Utilizing the advantages of deep learning and convolutional neural networks, along with the super‐resolution radial fluctuation (SRRF) algorithm for network training, a fast, parameter‐free, computational method is offered for enhancing the spatial resolution of nIR fluorescence images of SWCNTs. An average improvement of 22% in the resolution and 47% in signal‐to‐noise ratio (SNR) compared to the original images is shown, whereas SRRF leads to only 24% SNR improvement. The approach is demonstrated for a variety of SWCNT densities and length distributions, and a wide range of imaging conditions with challenging SNRs, including real‐time videos, without compromising the temporal resolution. The results open the path for accelerated and accessible super‐resolution of nIR fluorescent SWCNTs images, further advancing their applicability as nanoscale optical probes.

Self-driven ultraviolet photodetectors based on wide-bandgap semiconductors have been well investigated but are still being explored for further performance enhancement. Here we report a self-driven electrochemical ultraviolet photodetector (EUVPD) using a three-dimensional nanostructured photoanode based on defect-engineered TiO2 nanotube arrays (TNAs) modified with single-walled carbon nanotubes (SWCNTs) to enhance photoelectric performance. The EUVPDs based on Ar-annealed TNAs modified with 0.1 mg/mL of SWCNTs were found to have higher responsivity (∼60 mA/W), higher on/off current ratio (∼4.3 × 103), the faster response time (4 ms of rise-time and 27 ms of decay-time) when compared with unmodified and air-annealed ones. This performance enhancement is attributed to the highly efficient separation and transport of photoexcited carriers through the electrochemical redox reaction in the SWCNTs network anchored on the defect-engineered TNAs/electrolyte heterojunction nanostructure.

• TET model for nonlinear ρ e ∼ T relation of semiconductive micro/nanoscale materials. • Robust thermal diffusivity (α) measurement by TET using the nonlinear ρ e ∼ T model. • First time thermal diffusivity determination at the zero temperature rise limit. • α ∼ T trend for graphene film is well interpreted by the thermal reffusivity theory. • α ∼ T trend for SWCNT mat reveals strong structure deterioration with T decreasing. The transient electrothermal (TET) technique was developed and has been widely used for measuring the thermal diffusivity of fiber- and film-like materials at the micro/nanoscale. Upon step-current heating, the measured voltage-time (V - t) of the sample usually follows a sole increasing or decreasing trend, depending on the temperature coefficient of its electrical resistivity (θ T = dρ e / dT, ρ e : electrical resistivity, T : temperature). Past physical mode for the V - t profile is based on an assumption that θ T is constant during TET measurement, which applies to a large variety of materials. However, for semiconductive materials, θ T depends on the charge carrier density and scattering time, and both vary with temperature. Therefore, θ T has very strong nonlinear change with temperature, sometimes changes sign during TET measurement. This leads to abnormal V - t profiles that have never been addressed well, thereby making TET measurement not applicable for such scenarios. In this work, a new physical model is developed to consider the strong nonlinear relation between ρ e and T to the third order. Our numerical modeling firmly proves the validity of this new model. Thin films of graphene (GreF) and single-walled carbon nanotube (SWCNTs) mat are measured using the TET technique over a wide temperature range: 84.5–690.9 K for the GreF, and 12–290 K for the SWCNT film. At a specific temperature for each sample, a semiconductive-to-metallic transition comes about and manifests in the resistance-temperature response, hence leading to abnormal TET signals. These TET signals are perfectly fitted using our nonlinear θ T ∼ T model to determine α. Intriguingly, the determined α of the GreF for the transition phase follows the overall α ∼ T trend, confirming the robustness of the model. The obtained α ∼ T trend is interpreted well using the thermal reffusivity theory and structure deterioration under temperature change. This work significantly extends the capability of TET to semiconductors for α measurement. Also, the new methodology developed for obtaining α at zero temperature rise significantly improves the measurement control and accuracy. [Display omitted] [ABSTRACT FROM AUTHOR]

We present a comprehensive optical spectroscopic study on air-suspended single-walled carbon nanotubes (SWNTs) with diameters ranging from 1.7 nm to 3.4 nm and at higher-order optical transitions, a previously inaccessible regime. We establish an atlas of resonant radial breathing modes (RBMs) for more than 100 new SWNTs in this unknown regime, thus significantly extending the RBM dataset in Kataura plot and enhancing our knowledge of SWNTs. Additionally, we develop an innovative transfer technique for manipulating individual SWNTs of known chiralities (determined by optical spectroscopies) by integrating a polarization imaging technique with the conventional van der Waals (vdW) dry transfer. The unprecedented spatial and structural control of this technique enables a deterministic fabrication and integration of a variety of novel mixed-dimensional vdW heterostructures that were considered unachievable before. Our work significantly extends RBM dataset of SWNT Kataura plot and represents a huge advancement towards controlled fabrication and integration of mixed-dimensional vdW heterostructures encompassing one-dimensional vdW materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Programmed cell death-ligand 1 positive (PD-L1+) exosomes play a crucial role in the realm of cancer diagnosis and treatment. Nevertheless, due to the intricate nature of biological specimens, coupled with the heterogeneity, low refractive index (RI), and scant surface coverage density of exosomes, traditional surface plasmon resonance (SPR) sensors still do not meet clinical detection requirements. This study utilizes the exceptional electrical and optical attributes of single-walled carbon nanotubes (SWCNTs) as the substrate for SPR sensing, thereby markedly enhancing sensitivity. Furthermore, sp2 hybridized SWCNTs have the ability to load specific recognition elements. Additionally, through the coordination interaction of Ti with phosphate groups and the ferromagnetism of Fe 3 O 4 , efficient exosomes isolation and enrichment in complex samples are achievable with the aid of an external magnetic field. Owing to the high-quality and high-RI of Fe 3 O 4 @TiO 2 , the response signal experiences amplification, thus further improving the performance of the SPR biosensor. The linear range of the SPR biosensor constructed by this method is 1.0 × 103 to 1.0 × 107 particles/mL, with a limit of detection (LOD) of 31.9 particles/mL. In the analysis of clinical serum samples, cancer patients can be differentiated from healthy individuals with an Area Under Curve (AUC) of 0.9835. This study not only establishes a novel platform for exosomes direct detection but also offers new perspectives for the sensitive detection of other biomarkers. [ABSTRACT FROM AUTHOR]

Graphical abstract represents the tandem approach employed here: single-walled carbon nanotubes are produced in an aerosol CVD reactor, which is directly connected to a thermophoretic chamber, where randomly oriented aerosol nanotubes are being aligned and deposited on a cold substrate. [Display omitted] • A new robust, dry, and scalable technology for orientation of carbon nanotubes; • The method allows producing anisotropic thin films of nanotubes; • The deposition method was shown not to affect particle size distribution; • Tandem reactor approach ensures applicability of other aerosol nanoparticles. Here, we present a robust and dry technology to obtain aligned films of high-quality single-walled carbon nanotube (SWCNT) films. We employ a tandem reactor approach connecting an aerosol CVD setup, producing an aerosol of individual nanotubes, with a thermophoretic deposition chamber. To reach the nanotube alignment on the deposition substrate, we integrate temperature gradient-induced thermophoretic force, which deposits the SWCNT aerosol, with shear force, which orients the nanotubes along the flow. High Reynolds numbers required for the alignment lured us to the regions of high flow rates and, correspondingly, extreme temperature gradients (20,000 K/cm), which has not been assessed previously. Using a comprehensive set of methods (aerosol scanning mobility particle size spectrometry, UV–vis-NIR spectroscopy, scanning electron microscopy, etc.), we prove the nanotubes to deposit with the same rate regardless of the size and observe an orientation of aerosol SWCNT at Reynolds numbers > 1000. With the orientation of carbon nanotubes, we obtain anisotropic thin films with the state-of-the-art equivalent sheet resistance values among pristine SWCNTs, opening bright opportunities for transparent electronics. [ABSTRACT FROM AUTHOR]

The widespread adoption of e-nose devices based on chemiresistive materials has been hindered by issues related to sensor device complexity and reliability, specifically sensor drift, necessitating frequent recalibration and retraining of pattern recognition models. This study introduces a method for thermocycling a single sensor based on a free-standing network of single-walled carbon nanotubes (SWCNTs) to acquire signal patterns for selective analyte detection. Additionally, it employs a data filtering technique to compensate for the sensor drift. A free-standing SWCNT film, only a few nanometers thick, is thermally cycled via Joule heating between room temperature and 120 °C. Under these conditions, the sensitivity was tested towards NO 2 , H 2 S, and acetone vapors (10–25 ppm) in the mixture with dry air. Signal patterns produced through thermocycling were processed using CatBoost and LSTM algorithms. The accuracy of detection reached 90 % in the classification task, and the average root mean squared error of analyte concentration detection in the multioutput regression task was below 4 ppm. By combining original sensor design, thermocycling, signal filtering for drift compensation, and advanced pattern recognition models, this work contributes to overcoming the challenges in multivariate sensing systems, paving the way for practical applications of the more reliable chemiresistive sensors. • A novel free-standing SWCNT film sensor design is reported. • Free-standing architecture facilitates efficient thermocycling through Joule heating. • NO 2 , H 2 S, and acetone at 10 – 25 ppm concentrations in dry air were detected. • Analyte detection accuracy using CatBoost for pattern recognition was 91 %. [ABSTRACT FROM AUTHOR]

The choice of organic dispersant in the fabrication of 3D carbon nanotube architectures affects their macroscopic properties. Binder-free papers (referred to as buckypapers, BPs) consisting of single-walled nanotubes (SWCNTs) fabricated by vacuum filtration of nanotube suspensions in isopropanol, ethanol, benzoic acid dissolved in ethanol and lemon oil show a work of adhesion of water that varies from 25.7 to 112.2 mJ·m−2. Bulk electrical resistivity also changes significantly from 145 to 1010 mΩ cm. Raman and FTIR spectra of pristine SWCNTs and BPs show evidence of permanent adsorption of organic molecules on SWCNTs. Heterogeneous electron transfer (HET) standard rate constants, k 0 , for ferro/ferricyanide and hexaammineruthenium(II)/(III) redox probes estimated from cyclic voltammetry measurements on BP electrodes vary from 12.6 × 10 − 4 cm s − 1 to 32.7 × 10 − 4 cm s − 1 and 12.8 × 10 − 4 cm s − 1 to 26.0 × 10 − 4 cm s − 1 , respectively, depending on the dispersant used. Calculations using the Gerischer-Marcus model show that molecules adsorbed act as electron donors that boost HET kinetics and cause a shift in the reaction half-wave potential. The level of doping of nanotubes depends on the dipole moment of the dispersant molecules and proton affinity. Thus, the electrocatalytic activity of three-dimensional architectures composed of nanotubes can be adjusted by selecting an appropriate dispersant. [Display omitted] • Molecules of organic dispersants permanently adsorb on carbon nanotubes. • The dipole moment of the adsorbed molecules affects the half potential of the redox reaction. • Kinetics of the heterogeneous electron transfer depends on the proton affinity of adsorbed molecules. • The electrocatalytic activity of the carbon nanotube 3D architectures can be tuned by selecting an organic dispersant. [ABSTRACT FROM AUTHOR]

Organic materials have attracted extensive attention in flexible thermoelectric generators due to their solution processability, low thermal conductivity and high flexibility. However, their thermoelectric performances are still far behind those of the inorganic counterparts (e.g. Bi 2 Te 3 , PbTe and other related alloys). Here, by virtue of the dual advantages of both inorganic and organic materials, three Pt (II)-containing diketopyrrolopyrrole (DPP) based donor−acceptor (D−A)-type π-conjugated metallo-copolymers (P1Pt , P2Pt and P3Pt) are designed and synthesized, and they are compared with their control copolymers without Pt (II)-coordination (P1 , P2 and P3). It is shown that Pt (II) centers and copolymerized molecular structures play important roles in tuning the bandgap and coplanarity. A large Fermi level shift is observed after doping with single-walled carbon nanotubes (SWCNTs) in the copolymers. As expected, the introduction of Pt (II)-side chains and doping of SWCNTs into copolymers could significantly improve the power factor (PF), which reaches the highest value of 276.5 ± 26.6 μW m−1 K−2 for P3Pt /60 wt% SWCNTs. The corresponding p-type thermoelectric generator exhibits a large output power of up to 0.55 μW under a 109 K temperature gradient. Our results can provide a pathway for designing and preparing efficient thermoelectric materials and flexible thermoelectric generators. [Display omitted] [ABSTRACT FROM AUTHOR]

Ultrafast synthesis of hard carbon (HC) anodes for sodium-ion batteries (SIBs) was demonstrated by microwave induction heating (MIH) of polymer/carbon nanotube films. The MIH technique allows the direct heating of the samples to the target temperatures in less than 30 s, significantly reducing carbonization time and complexity compared to carbonization by conventional high-temperature furnaces. The MIH approach can be used for the scalable production of HC anodes. [Display omitted] • Free-standing HC/SWCNT anodes were prepared by applying ultrafast MIH. • Microwave-induced Joule heating enabled the heating of films up to 1400 °C in 30 s. • MIH is an alternative to conventional high-temperature furnace-based carbonization processes. • HC anodes prepared by ultrafast MIH were successfully applied to the SIB full cells. • Scalable MIH process was verified through local heating tests using a circular sheet. Hard carbons (HCs) are excellent anode materials for sodium-ion batteries (SIBs). However, the carbonization and granulation of HC powders involve complex processes and require considerable energy. Here, we developed a facile method for manufacturing HC anodes for SIBs via a novel microwave induction heating (MIH) process for polymer/single-walled carbon nanotube (SWCNT) films. Numerical simulations solving electromagnetic field and heat transfer problems revealed the MIH mechanism; the electric current induced by the applied microwave enables direct Joule heating of the SWCNT networks in the composite film. Consequently, the composite films could be heated to the target temperatures (800–1400 °C) and free-standing HC/SWCNT anodes could be prepared by applying MIH for only 30 s. Comparative analyses confirmed that ultrafast MIH is a reliable technique for producing HC anodes and can replace conventional carbonization processes which require a high-temperature furnace. Moreover, the HC/SWCNT anodes prepared by the ultrafast MIH were successfully applied to the SIB full cells. Finally, the feasibility of MIH for scalable roll-to-roll production of HC anodes was verified through local heating tests using a circular sheet larger than a resonator. [ABSTRACT FROM AUTHOR]

• New surfactants based on ionic liquids equipped with carbohydrate moieties were synthesized. • They were used to elucidate the mechanism of purification of single-walled carbon nanotubes. • The experiments revealed insight about the underlying interactions at the heart of the separation. Single-walled carbon nanotubes (SWCNTs) have substantial application potential in many branches of technology. Considering that the spatial order of carbon atoms in SWCNTs determines their properties, the characteristics of a material can be adjusted for a specific application by using only selected types of SWCNTs. Unfortunately, SWCNT purification is challenging as the mechanisms of the currently available sorting techniques are not fully understood. The aqueous two-phase extraction (ATPE) method is a promising approach in this context as it offers SWCNT separation in an aqueous environment, so elucidation of its workings is essential. To come closer to achieving this goal, we synthesized a new range of surfactants based on ionic liquids equipped with amphiphilic carbohydrate moieties. We then examined how the modification of their structure influences SWCNT partitioning in two-phase systems composed of poly(ethylene glycol) and dextran. We concluded that the capacity of the ATPE method for purification of SWCNTs depended upon establishing a sufficient degree of order or disorder in the aqueous medium caused by the introduction of chemical compounds of a kosmotropic and chaotropic nature, respectively. [ABSTRACT FROM AUTHOR]

In this work, polyaniline (PANI) is coated on single-walled carbon nanotubes (SWCNT) via electrochemical polymerization method to fabricate PANI/SWCNT bilayer films with enhanced thermoelectric properties. Effects of deposition time and voltage, and acid types and concentrations on the thermoelectric properties of the films are studied. The results showed that PANI layer was effectively coated on the surface of SWCNT layer by electrochemical polymerization method. In addition, carrier transport and the electrical conductivity (σ) of the PANI/SWCNT bilayer film was improved due to interfacial π-π interaction between PANI and SWCNT, and the Seebeck coefficient (S) was increased due to the energy filtering effect at the interface of PANI/SWCNT. The maximum PF of PANI/SWCNT at room temperature was 155.3 ± 7.2 μW m−1 K−2 with the σ of 654.9 ± 41.8 S cm−1 and the S of 48.7 ± 0.5 μV K−1 when the deposition voltage and time were 1.0 V and 240.0 s using 0.5 M HCl, respectively. Finally, a self-powered thermoelectric device composed of five pairs of p-n junctions was prepared with PANI/SWCNT (1 V, 240 s) as the p-type legs and copper adhesives as the n-type legs, and the maximum output power was 0.27 μW at a temperature difference of 50 K. Therefore, this demonstrates that electrochemical polymerization is a feasible and effective way of fabricating conductive polymers/carbon nanotubes bilayer films with enhanced thermoelectric properties, which have potential application in powering wearable electronics. • Flexible PANI/SWCNT thermoelectric bilayer films were fabricated by electrochemical polymerization method. • The electrochemical polymerization condition for PANI/SWCNT were optimized. • The maximum PF of PANI/SWCNT bilayer film was 155.3 ± 7.2 μW m−1 K−2. [ABSTRACT FROM AUTHOR]

[Display omitted] • PMo 12 clusters are anchored uniformly on the SWCNT surface via electrostatic assembly. • The PMo 12 significantly improves the conductivity of SWCNT electrodes. • Introducing PMo 12 increases the energy density of micro-supercapacitors by ∼ 40 times. • Realizing the fast integration of micro-supercapacitors. The rapid advancement of wearable electronics has pushed the urgent demand for flexible power sources with high energy density and fast integrations. Herein, we created high-energy–density micro-supercapacitors (MSCs) based on phosphomolybdic acid (PMo 12) clusters anchored single-walled carbon nanotubes (SWCNTs) via the electrostatic assembly. The SWCNT microelectrodes for MSCs were directly fabricated by an aerosol process without any solvent-based treatment. The PMo 12 clusters were found to not only increase the electrical conductivity of SWCNT thin-film electrodes, but also offer significant pseudo-capacitance of MSCs. The MSCs based on PMo 12 -modified SWCNTs demonstrated an areal capacitance of 10.2 mF cm−2 when scanned at 5 mV s−1, coupled with a notable energy density of 0.71 μWh cm−2 at a power density of 7 μW cm−2, being much higher than the one without PMo 12 modification. The density functional theory simulation further reveals the enhancement of electrical conductivity and areal capacitance induced by PMo 12 modifications. Moreover, our strategy is highly scalable for integrations via series or parallel connections, which could deliver higher voltage output or areal capacitance. This work demonstrates great potential for high-performance MSCs toward wearable electronics applications. [ABSTRACT FROM AUTHOR]

A thin-film microfluidic vortex fluidic device (VFD) housing a rapidly rotating tube inclined at +45° imparts mechanical energy to the liquid, which can be harnessed to gain access to non-equilibrium states of self-assembled nanomaterials. Coiled single-walled carbon nanotubes (SWCNTs) are formed from entangled counterparts in such a dynamic thin film of toluene, and with a recent detailed understanding of the high-shear topological fluid flow of submicron dimensions in the VFD, a systematic study on forming such toroidal structures in immiscible biphasic systems has been undertaken. This involved using mixtures of water and toluene, m-xylene, or p-xylene containing a suspension of SWCNTs and using VFD quartz tubes of different diameters, such as 10, 15, and 20 mm outside diameter (O.D.), along with changing the common hemispherical base of the tube to a flat-base tube as a strategy for decoupling the effect of different topological fluid flows generated in the VFD. Selective control over the diameter of the resulting toroids of SWCNTs down to ca. 35 nm in diameter has been established with the expected SWCNT ring strain in the toroids, as established by Raman spectroscopy, and its application in sensors. [ABSTRACT FROM AUTHOR]

Biocompatible electrically conducting chitosan-based films filled with single-wall carbon nanotubes were obtained. Atomic force microscopic studies of the free surface topography revealed a change in the morphology of chitosan films filled with single-wall carbon nanotubes. Introducing 0.5 wt.% of single-wall carbon nanotubes into chitosan results in an increase in tensile strength of the films (up to ~180 MPa); the tensile strain values also rise up to ~60%. It was demonstrated that chitosan films containing 0.1–3.0 wt.% of single-wall carbon nanotubes have higher conductivity (10 S/m) than pure chitosan films (10−11 S/m). The investigation of electrical stimulation of human dermal fibroblasts on chitosan/single-wall carbon nanotubes film scaffolds showed that the biological effect of cell electrical stimulation depends on the content of single-walled carbon nanotubes in the chitosan matrix. [ABSTRACT FROM AUTHOR]

Nanomaterials, such as single‐walled carbon nanotubes (SWCNTs) and graphenes, can be readily gelled using bi‐ or multi‐functional reagents as crosslinkers. This study reports a new reaction of monofunctional acetylenes with negatively charged SWCNTs (nanotubides), prepared by reduction. Mono‐acetylenes (e. g. phenylacetylene (PAc) and diphenyl acetylene (DiPAc)) are introduced as crosslinkers to form all‐carbon SWCNT organogels at room temperature. The resulting isolated SWCNT aerogels have a density of ∼4.5–5.5 mg cm−3. Raman spectroscopy and thermogravimetric analysis suggest a covalent surface modification (∼1 functional group per 110 (PAc) and 712 (DiPAc) SWCNT carbon atoms). Significantly, the acetylene reaction does not consume all available negative charges. The SWCNT organogel is still reactive after crosslinking and can reduce a stable gold complex, chloro(triphenylphosphine)gold (I), to form AuNPs (∼12–14 nm), suggesting the formation of a living nanotubide organogel intermediate, suitable for a range of secondary reactions. Mono‐acetylenes can crosslink other negatively charged molecular systems, and surface decoration of the aerogels with other metal NPs is anticipated. [ABSTRACT FROM AUTHOR]

Polymer and carbon nanotube composites have aroused extensive attention for thermoelectric materials owing to the combination of low thermal conductivity of polymer and high electrical conductivity of carbon nanotubes. Surface properties of the substrate are of great importance for the charge transport behaviors of semiconducting thin films, which are less explored in thermoelectric applications. Herein, self‐assembled monolayers (SAMs) are used to modify the substrate for thermoelectric polymer composites. The trifluoromethyl (CF3)‐terminated SAM is beneficial for an improved electrical conductivity; while the SAM with amino group is found to improve their Seebeck coefficient and decrease the electrical conductivity. As a result, polymer composites on CF3‐SAM‐modified substrate show a high room‐temperature power factor of 285 µW m−1 K−2 and a large output power of 2.36 µW for thermoelectric generator at a temperature gradient of 50 K. This work demonstrates that surface modification by SAMs is a promising strategy for improving performance of thermoelectric materials and devices. [ABSTRACT FROM AUTHOR]