Artigos de revistas: "SWCNH"

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Szymański, Grzegorz Stanisław, Anna Kaczmarek-Kędziera, Monika Zięba, Piotr Kowalczyk e Artur Piotr Terzyk. "Insight into the Mechanisms of Low Coverage Adsorption of N-Alcohols on Single Walled Carbon Nanohorn". Materials 14, n.º 14 (17 de julho de 2021): 4001. http://dx.doi.org/10.3390/ma14144001.

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We report for the first time the chromatographic study of n-alcohols (from methanol to butanol) adsorption on single walled carbon nanohorn (SWCNH). Using measured temperature dependence of adsorption isotherms (373–433 K) the isosteric adsorption enthalpy is calculated and compared with the data reported for a graphite surface. It is concluded that a graphite surface is more homogeneous, and the enthalpy of adsorption on SWCNHs at zero coverage correlates well with molecular diameter and polarizability, suggesting leading role of dispersive interactions, i.e., no heteroatoms presence in the walls of SWCNH structures. Next using modern DFT approach we calculate the energy of n-alcohols interactions with a graphene sheet and with a single nanocone finally proposing a more realistic—double nanocone model. Obtained results suggest alcohols entrapping between SWCNH with OH groups located toward nanocones ends, leading to the conclusions about very promising future applications of SWCNHs in catalytic reactions with participation of n-alcohols.

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Zieba, Wojciech, Piotr Olejnik, Stanislaw Koter, Piotr Kowalczyk, Marta E. Plonska-Brzezinska e Artur P. Terzyk. "Opening the internal structure for transport of ions: improvement of the structural and chemical properties of single-walled carbon nanohorns for supercapacitor electrodes". RSC Advances 10, n.º 63 (2020): 38357–68. http://dx.doi.org/10.1039/d0ra07748h.

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Sani, Elisa, Nicolò Papi, Luca Mercatelli e Aldo Dell’Oro. "Efficient Optical Limiting in Carbon-Nanohorn Suspensions". Energies 14, n.º 8 (8 de abril de 2021): 2074. http://dx.doi.org/10.3390/en14082074.

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Nonlinear optical properties of aqueous dispersions of single-wall carbon nanohorns (SWCNH) are investigated by a simple and original technique, relating nonlinear transmittance measurements with semi-empirical model fitting and allowing to identify the dominant nonlinear mechanism. The nanofluids shown a particularly strong optical limiting under irradiation by nanosecond laser pulses at 355, 532 and 1064 nm, much stronger than that previously reported in SWCNHs with smaller aggregate size. The effect is more relevant at 355 nm, where a nearly ideal optical limiting behavior with output energy practically independent on the input one is obtained, and it is attributed to the massive production of bubbles under the effect of light irradiation. This result opens interesting perspectives for the use of SWNCH-based suspensions for smart materials applications and green energy.

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Dong, Jinling, Ying Zhang, Zhihong Xie, Jie He e Tiantian Wu. "SWCNH (Single walled carbon nanohorn) supervises ER (Endoplasmic reticulum) stress through triggering autophagy process of hepatocytes, especially in hepatoma cell line HepG2". Materials Research Express 8, n.º 12 (1 de dezembro de 2021): 125602. http://dx.doi.org/10.1088/2053-1591/ac452b.

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Abstract Backgrounds. The cellular homeostasis is major maintained by the catabolic pathway of autophagy. Our previous work indicated that SWCNH were associated with endoplasmic reticulum (ER) stress mediated by calcium flow and autophagic response. But, its mechanism was unclear. Methods. The regulation of SWCNH on the calcium flow then autophagy of liver cells were investigated through inducing ER stress with tunicamycin and SWCNH. The calcuim flow was determined using Fluo-3, then autophagy was examined with immunofluorescence or western blot for LC3, Beclin-1, ATG-5, and p62. Moreover, the apopototic protein of Bax and Bcl-2 was detected, too. Results. Tunicamycin-induced ER stress in hepatocytes was related to calcium flow, especially for hepatoma cell line HepG2. Moreover, SWCNH participated in the regulation of endoplasmic reticulum stress-related calcium flow. Besides, SWCNH induced hepatocyte autophagy and inhibited cell apoptosis, then mediated the process of hepatocyte autophagy. Conclusions. Tunicamycin-induced ER stress in hepatocytes was related to calcium flow. Moreover, SWCNH induced hepatocyte autophagy, inhibited cell apoptosis, and participated in the autophagy regulation of hepatocyte, especially for hepatoma cell line.

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Bera, Ranadip, Sumanta Kumar Karan, Amit Kumar Das, Sarbaranjan Paria e Bhanu Bhusan Khatua. "Single wall carbon nanohorn (SWCNH)/graphene nanoplate/poly(methyl methacrylate) nanocomposites: a promising material for electromagnetic interference shielding applications". RSC Advances 5, n.º 86 (2015): 70482–93. http://dx.doi.org/10.1039/c5ra07718d.

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Single wall carbon nanohorn (SWCNH)/graphene nanoplates (GNP)/poly(methyl methacrylate) (PMMA) nanocomposites were prepared through addition of GNP/PMMA bead into the SWCNH dispersed PMMA matrix during its polymerization.

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Cobianu, Cornel, Bogdan-Catalin Serban, Niculae Dumbravescu, Octavian Buiu, Viorel Avramescu, Cristina Pachiu, Bogdan Bita, Marius Bumbac, Cristina-Mihaela Nicolescu e Cosmin Cobianu. "Organic–Inorganic Ternary Nanohybrids of Single-Walled Carbon Nanohorns for Room Temperature Chemiresistive Ethanol Detection". Nanomaterials 10, n.º 12 (18 de dezembro de 2020): 2552. http://dx.doi.org/10.3390/nano10122552.

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Organic–inorganic ternary nanohybrids consisting of oxidized-single walled carbon nanohorns-SnO2-polyvinylpyrrolidone (ox-SWCNH/SnO2/PVP) with stoichiometry 1/1/1 and 2/1/1 and ox-SWCNH/ZnO/PVP = 5/2/1 and 5/3/2 (all mass ratios) were synthesized and characterized as sensing films of chemiresistive test structures for ethanol vapor detection in dry air, in the range from 0 up to 50 mg/L. All the sensing films had an ox-SWCNH concentration in the range of 33.3–62.5 wt%. A comparison between the transfer functions and the response and recovery times of these sensing devices has shown that the structures with ox-SWCNH/SnO2/PVP = 1/1/1 have the highest relative sensitivities of 0.0022 (mg/L)−1, while the devices with ox-SWCNH/SnO2/PVP = 2/1/1 have the lowest response time (15 s) and recovery time (50 s) for a room temperature operation, proving the key role of carbonic material in shaping the static and dynamic performance of the sensor. These response and recovery times are lower than those of “heated” commercial sensors. The sensing mechanism is explained in terms of the overall response of a p-type semiconductor, where ox-SWCNH percolated between electrodes of the sensor, shunting the heterojunctions made between n-type SnO2 or ZnO and p-type ox-SWCNH. The hard–soft acid–base (HSAB) principle supports this mechanism. The low power consumption of these devices, below 2 mW, and the sensing performances at room temperature may open new avenues towards ethanol sensors for passive samplers of environment monitoring, alcohol test portable instruments and wireless network sensors for Internet of Things applications.

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Liu, Zhongyuan, Wei Zhang, Wenjing Qi, Wenyue Gao, Saima Hanif, Muhammad Saqib e Guobao Xu. "Label-free signal-on ATP aptasensor based on the remarkable quenching of tris(2,2′-bipyridine)ruthenium(ii) electrochemiluminescence by single-walled carbon nanohorn". Chemical Communications 51, n.º 20 (2015): 4256–58. http://dx.doi.org/10.1039/c5cc00037h.

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The quenching of electrochemiluminescence by SWCNH has been reported for the first time. It enables the development of a sensitive, label-free, and signal-on ATP aptasensor using SWCNH as both quencher and scaffold.

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Kim, Ji Hoon, Seunggun Yu, Sang Won Lee, Seung-Yong Lee, Keun Soo Kim, Yoong Ahm Kim e Cheol-Min Yang. "Enhanced Thermoelectric Properties of WS2/Single-Walled Carbon Nanohorn Nanocomposites". Crystals 10, n.º 2 (24 de fevereiro de 2020): 140. http://dx.doi.org/10.3390/cryst10020140.

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Recently, two-dimensional tungsten disulfide (WS2) has attracted attention as a next generation thermoelectric material due to a favorable Seebeck coefficient. However, its thermoelectric efficiency still needs to be improved due to the intrinsically low electrical conductivity of WS2. In the present study, thermoelectric properties of WS2 hybridized with highly conductive single-walled carbon nanohorns (SWCNHs) were investigated. The WS2/SWCNH nanocomposites were fabricated by annealing the mixture of WS2 and SWCNHs using a high-frequency induction heated sintering (HFIHS) system. By adding SWCNHs to WS2, the nanocomposites exhibited increased electrical conductivity and a slightly decreased Seebeck coefficient with the content of SWCNHs. Hence, the maximum power factor of 128.41 μW/mK2 was achieved for WS2/SWCNHs with 0.1 wt.% SWCNHs at 780 K, resulting in a significantly improved thermoelectric figure of merit (zT) value of 0.027 compared to that of pristine WS2 with zT 0.017.

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Roverso, Marco, Roberta Seraglia, Raghav Dogra, Denis Badocco, Silvia Pettenuzzo, Luca Cappellin, Paolo Pastore e Sara Bogialli. "Single-Walled Carbon Nanohorns as Boosting Surface for the Analysis of Low-Molecular-Weight Compounds by SALDI-MS". International Journal of Molecular Sciences 23, n.º 9 (30 de abril de 2022): 5027. http://dx.doi.org/10.3390/ijms23095027.

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Limits of Matrix-Assisted Laser Desorption Ionization (MALDI) mass spectrometry (MS) in the study of small molecules are due to matrix-related interfering species in the low m/z range. Single-walled carbon nanohorns (SWCNH) were here evaluated as a specific surface for the rapid analysis of amino acids and lipids by Surface-Assisted Laser Desorption Ionization (SALDI). The method was optimized for detecting twenty amino acids, mainly present as cationized species, with the [M+K]+ response generally 2-time larger than the [M+Na]+ one. The [M+Na]+/[M+K]+ signals ratio was tentatively correlated with the molecular weight, dipole moment and binding affinity, to describe the amino acids’ coordination ability. The SWCNH-based surface was also tested for analyzing triglycerides in olive oil samples, showing promising results in determining the percentage composition of fatty acids without any sample treatment. Results indicated that SWCNH is a promising substrate for the SALDI-MS analysis of low molecular weight compounds with different polarities, enlarging the analytical platforms for MALDI applications.

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Moreno-Lanceta, Alazne, Mireia Medrano-Bosch e Pedro Melgar-Lesmes. "Single-Walled Carbon Nanohorns as Promising Nanotube-Derived Delivery Systems to Treat Cancer". Pharmaceutics 12, n.º 9 (7 de setembro de 2020): 850. http://dx.doi.org/10.3390/pharmaceutics12090850.

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Cancer has become one of the most prevalent diseases worldwide, with increasing incidence in recent years. Current pharmacological strategies are not tissue-specific therapies, which hampers their efficacy and results in toxicity in healthy organs. Carbon-based nanomaterials have emerged as promising nanoplatforms for the development of targeted delivery systems to treat diseased cells. Single-walled carbon nanohorns (SWCNH) are graphene-based horn-shaped nanostructure aggregates with a multitude of versatile features to be considered as suitable nanosystems for targeted drug delivery. They can be easily synthetized and functionalized to acquire the desired physicochemical characteristics, and no toxicological effects have been reported in vivo followed by their administration. This review focuses on the use of SWCNH as drug delivery systems for cancer therapy. Their main applications include their capacity to act as anticancer agents, their use as drug delivery systems for chemotherapeutics, photothermal and photodynamic therapy, gene therapy, and immunosensing. The structure, synthesis, and covalent and non-covalent functionalization of these nanoparticles is also discussed. Although SWCNH are in early preclinical research yet, these nanotube-derived nanostructures demonstrate an interesting versatility pointing them out as promising forthcoming drug delivery systems to target and treat cancer cells.

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Ramzan, Muhammad, Nazia Shahmir, Hammad Alotaibi, Hassan Ali S. Ghazwani e Taseer Muhammad. "Thermal performance comparative analysis of nanofluid flows at an oblique stagnation point considering Xue model: a solar application". Journal of Computational Design and Engineering 9, n.º 1 (fevereiro de 2022): 201–15. http://dx.doi.org/10.1093/jcde/qwab076.

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Abstract This exploration aims to study the comparison of heat transfer capabilities of two nanofluid oblique, steady stagnation-point flow combinations comprising single-walled carbon/water (SWCNHs/water) and multiwalled carbon nanotube/water (MWCNTs/water) toward a stretching surface influenced by nonlinear thermal radiation employing the Xue model. This envisaged comparison model is inimitable and still scarce in the literature. Relying on the Tiwari–Das nanofluid model, a mathematical framework is constructed. The system of partial differential equations is converted using suitable transformations into an ordinary differential system of three equations, which is evaluated numerically using the bvp4c method. The physical behavior of significant parameters and their graphical representation are thoroughly examined. The results show that the SWCNHs/water nanofluid outperforms the MWCNTs/water nanofluid. It is further witnessed that SWCNH nanoparticle contained nanofluid has considerably greater thermal radiation than MWCNT nanoparticles. The envisaged model is also validated by comparing it with a published study.

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Bobbo, Sergio, Laura Fedele, Anna Benetti, Laura Colla, Monica Fabrizio, Cesare Pagura e Simona Barison. "Viscosity of water based SWCNH and TiO2 nanofluids". Experimental Thermal and Fluid Science 36 (janeiro de 2012): 65–71. http://dx.doi.org/10.1016/j.expthermflusci.2011.08.004.

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Zieba, Wojciech, Joanna Czarnecka, Tomasz Rusak, Monika Zieba e Artur P. Terzyk. "Nitric-Acid Oxidized Single-Walled Carbon Nanohorns as a Potential Material for Bio-Applications—Toxicity and Hemocompatibility Studies". Materials 14, n.º 6 (15 de março de 2021): 1419. http://dx.doi.org/10.3390/ma14061419.

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The results of in vitro studies of single-walled carbon nanohorn (SWCNH) oxidized materials’ cytotoxicity obtained by the cell membrane integrity (Neutral Red Uptake (NRU)) and metabolic activity (by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)) on A549 and human dermal fibroblasts (HDF) cell lines are presented. We also present hemocompatibility studies on human and porcine blood, and an erythrocyte concentrate to prove that the obtained samples will not interfere with blood components. Characterization of the materials is supplemented by ζ-potential measurements, Transmission Electron Microscope (TEM) imaging, and thermogravimetric studies (TG). The presented results show the correlation between the specific surface area of materials and the platelet aggregation, when the ID/IG ratio determined from Raman spectra correlates with hemoglobin release from the erythrocytes (in whole blood testing). A plausible mechanism explaining the observed correlations is given. The cytotoxicity and hemocompatibility studies prove that the studied materials are acceptable for use in biomedical applications, especially a sample SWCNH-ox-1.5 with the best application potential.

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Piotrovskiy, Levon B., Tatiana A. Kudryavtseva e Elena V. Litasova. "Properties and biological potential of single wall carbon nanohorns (SWCNH)". Reviews on Clinical Pharmacology and Drug Therapy 18, n.º 3 (14 de outubro de 2020): 185–95. http://dx.doi.org/10.17816/rcf183185-195.

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Nanohorns (or nanocons) are formed when pentagons are accumulated at the top of the formed nanocarbon structure. hey are a cone formed by one layer of graphene with a diameter of 24 nm and a length of 4050 nm. The review considers the structure of these structures and their properties. The possibilities of using these structures in biology are described in detail.

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Cataldo, Franco, Mihai V. Putz, Ornella Ursini, Yasser Hafez e Susana Iglesias-Groth. "On The Action of Ozone on Single-Wall Carbon Nanohorns (SWCNH)". Fullerenes, Nanotubes and Carbon Nanostructures 23, n.º 12 (9 de novembro de 2015): 1095–102. http://dx.doi.org/10.1080/1536383x.2015.1075513.

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Shirole, Ashutosh, Mahesh Wagh e Vivek Kulkarni. "Thermal Performance Comparison of Parabolic Trough Collector (PTC) Using Various Nanofluids". International Journal of Renewable Energy Development 10, n.º 4 (27 de junho de 2021): 875–89. http://dx.doi.org/10.14710/ijred.2021.33801.

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The objective of this paper is to investigate the theoretical performance of Parabolic Trough Collector (PTC) using various nanofluids. The theoretical performances are calculated for Al2O3, graphite, magnetite, SWCNH, CuO, SiO2, MWCNT, TiO2, Fe2O3, and ZnO in water nanofluids. The heat transfer equations, thermodynamic properties of nanofluid and pumping power are utilised for the development of novel thermal model. The theoretical thermal efficiency of the PTC is calculated, and the economic viability of the technology is predicted for a range of nanofluid concentration. The results showed that the thermal conductivity increases with the concentration of nanoparticles in the base fluid. Magnetite nanofluid showed the highest thermal efficiency, followed by CuO, MWCNT, ZnO, SWCNH, TiO2, Fe2O3, Al2O3, graphite, and SiO2, respectively. The study reveals that MWCNT at 0.4% concentration is the best-suited nanofluid considering thermal gain and pumping power. Most of the nanofluids achieved optimum efficiency at 0.4% concentration. The influence of mass flow rate on thermal efficiency is evaluated. When the mass flow rate increased from 70 Kg/hr to 90Kg/hr, a 10%-20% efficiency increase is observed. Dispersing nanofluids reduces the levelized cost of energy of large-scale power plants. These findings add to the knowledge of the scientific community aimed explicitly at solar thermal energy technology. The report can also be used as a base to pursue solar thermal projects on an economic basis.

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Siavashi, Majid, Kasra Ghasemi, Reza Yousofvand e Shahram Derakhshan. "Computational analysis of SWCNH nanofluid-based direct absorption solar collector with a metal sheet". Solar Energy 170 (agosto de 2018): 252–62. http://dx.doi.org/10.1016/j.solener.2018.05.020.

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Maddala, Gurulakshmi, Meenakshamma Ambapuram, VijayaLaxmi Tankasala e Raghavender Mitty. "Optimal Dye Sensitized Solar Cell and Photocapacitor Performance with Efficient Electrocatalytic SWCNH Assisted Carbon Electrode". ACS Applied Energy Materials 4, n.º 10 (30 de setembro de 2021): 11225–33. http://dx.doi.org/10.1021/acsaem.1c02087.

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Reddy, A. C. Kasi, M. Gurulakshmi, K. Susmitha, M. Raghavender, Narayana Thota e Y. P. Venkata Subbaiah. "A novel PEDOT:PSS/SWCNH bilayer thin film counter electrode for efficient dye-sensitized solar cells". Journal of Materials Science: Materials in Electronics 31, n.º 6 (15 de fevereiro de 2020): 4752–60. http://dx.doi.org/10.1007/s10854-020-03032-3.

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Cataldo, Franco, Susana Iglesias-Groth, Yaser Hafez e Giancarlo Angelini. "Neutron bombardment of single wall carbon nanohorn (SWCNH): DSC determination of the stored Wigner-Szilard energy". Journal of Radioanalytical and Nuclear Chemistry 299, n.º 3 (4 de janeiro de 2014): 1955–63. http://dx.doi.org/10.1007/s10967-013-2893-0.

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Bera, Ranadip, Anirban Maitra, Sarbaranjan Paria, Sumanta Kumar Karan, Amit Kumar Das, Aswini Bera, Suman Kumar Si, Lopamudra Halder, Anurima De e Bhanu Bhusan Khatua. "An approach to widen the electromagnetic shielding efficiency in PDMS/ferrous ferric oxide decorated RGO–SWCNH composite through pressure induced tunability". Chemical Engineering Journal 335 (março de 2018): 501–9. http://dx.doi.org/10.1016/j.cej.2017.10.178.

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Domínguez-Aragón, Angélica, Erasto Armando Zaragoza-Contreras, Gabriela Figueroa-Miranda, Andreas Offenhäusser e Dirk Mayer. "Electrochemical Immunosensor Using Electroactive Carbon Nanohorns for Signal Amplification for the Rapid Detection of Carcinoembryonic Antigen". Biosensors 13, n.º 1 (30 de dezembro de 2022): 63. http://dx.doi.org/10.3390/bios13010063.

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In this work, a novel sandwich-type electrochemical immunosensor was developed for the quantitative detection of the carcinoembryonic antigen, an important tumor marker in clinical tests. The capture antibodies were immobilized on the surface of a gold disk electrode, while detection antibodies were attached to redox-tagged single-walled carbon nanohorns/thionine/AuNPs. Both types of antibody immobilization were carried out through Au-S bonds using the novel photochemical immobilization technique that ensures control over the orientation of the antibodies. The electroactive SWCNH/Thi/AuNPs nanocomposite worked as a signal tag to carry out both the detection of carcinoembryonic antigen and the amplification of the detection signal. The current response was monitored by differential pulse voltammetry. A clear dependence of the thionine redox peak was observed as a function of the carcinoembryonic antigen concentration. A linear detection range from 0.001–200 ng/mL and a low detection limit of 0.1385 pg/mL were obtained for this immunoassay. The results showed that carbon nanohorns represent a promising matrix for signal amplification in sandwich-type electrochemical immune assays working as a conductive and binding matrix with easy and versatile modification routes to antibody and redox tag immobilization, which possesses great potential for clinical diagnostics of CEA and other biomarkers.

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Bera, Ranadip, Amit Kumar Das, Anirban Maitra, Sarbaranjan Paria, Sumanta Kumar Karan e Bhanu Bhusan Khatua. "Salt leached viable porous Fe3O4 decorated polyaniline – SWCNH/PVDF composite spectacles as an admirable electromagnetic shielding efficiency in extended Ku-band region". Composites Part B: Engineering 129 (novembro de 2017): 210–20. http://dx.doi.org/10.1016/j.compositesb.2017.07.073.

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Thameem Basha, H., R. Sivaraj, A. Subramanyam Reddy e A. J. Chamkha. "SWCNH/diamond-ethylene glycol nanofluid flow over a wedge, plate and stagnation point with induced magnetic field and nonlinear radiation – solar energy application". European Physical Journal Special Topics 228, n.º 12 (dezembro de 2019): 2531–51. http://dx.doi.org/10.1140/epjst/e2019-900048-x.

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ZHAO, LI-NA, e HONG-KANG ZHAO. "MESOSCOPIC TRANSPORT THROUGH A QUANTUM DOT–CARBON NANOTUBE SYSTEM IN AN APPLIED MICROWAVE FIELD". International Journal of Modern Physics B 18, n.º 14 (10 de junho de 2004): 2071–84. http://dx.doi.org/10.1142/s0217979204024951.

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The coherent transport through a quantum-dot (QD) coupled with single-wall carbon nanotubes (SWCNs) is investigated by employing the nonequilibrium Green's function (NGF) technique. An external microwave field is applied to the central QD to induce side-bands in addition to the energy levels of the QD. The SWCNs act as quantum wires which open quantum channels for electron to transport through. The novel behaviors are obtained in differential conductance and tunneling current, which are strongly associated with the density of states (DOS) of leads. The hybrid system with a QD coupled to normal metal and SWCN is also investigated as a comparison. The armchair SWCN lead provides rich tunneling channels compared with that of a metal lead. The I–V characteristics is calculated to exhibit stair-like structures which correspond to the resonant peaks of differential conductance versus source–drain bias. The current resonance with the gate voltage is shown to exhibit the photon-assisted tunneling.

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Zhang, Jin, Yang Wei, Fengrui Yao, Dongqi Li, He Ma, Peng Lei, Hehai Fang et al. "SWCNT-MoS2-SWCNT Vertical Point Heterostructures". Advanced Materials 29, n.º 7 (6 de dezembro de 2016): 1604469. http://dx.doi.org/10.1002/adma.201604469.

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Bellayer, S., J. W. Gilman, S. S. Rahatekar, S. Bourbigot, X. Flambard, L. M. Hanssen, H. Guo e S. Kumar. "Characterization of SWCNT and PAN/SWCNT films". Carbon 45, n.º 12 (outubro de 2007): 2417–23. http://dx.doi.org/10.1016/j.carbon.2007.06.057.

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Oskoueian, Arshin, Khamirul Amin Matori, Saadi Bayat, Ehsan Oskoueian, Farhad Ostovan e Meysam Toozandehjani. "Fabrication, Characterization, and Functionalization of Single-Walled Carbon Nanotube Conjugated with Tamoxifen and Its Anticancer Potential against Human Breast Cancer Cells". Journal of Nanomaterials 2018 (2018): 1–13. http://dx.doi.org/10.1155/2018/8417016.

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In this experiment, we aimed to fabricate SWCNT conjugated with tamoxifen and evaluated its anticancer potential against human breast cancer cells (MCF-7). The results showed that SWCNT was synthetized successfully using chemical vapor deposition (CVD) method. The results of Raman spectroscopy, SEM, and TEM analyses confirmed the synthesis of highly pure SWCNT. The functionalization of SWCNT was performed by oxidizing of SWCNT, attachment of polyethylene glycol (PEG) to oxidized SWCNT, and attachment of azelaic acid to the polyethylene glycol group. As a result, the SWCNT with free functional carboxylic acid and hydroxyl groups (SWCNT-PEG) was developed. The SWCNT-PEG was then conjugated with tamoxifen (SWCNT-PEG-TAM). The FT-IR together with NMR results confirmed the conjugation of tamoxifen to functionalized SWCNT (SWCNT-PEG-TAM). The cytotoxic concentrations (CC50) of SWCNT-PEG, tamoxifen, and SWCNT-PEG-TAM were >100, 12.67±2.69, and 5.49±1.34μg/ml, respectively. Linking tamoxifen to functionalized SWCNT enhanced the cytotoxic action of tamoxifen against breast cancer cells up to 2.3 times. The results of the morphological examination and caspase-3 activity confirmed the higher cytotoxic action of SWCNT-PEG-TAM as compared to free tamoxifen. The results obtained in this study indicated that this delivery system enhanced the therapeutic effects and anticancer potential of tamoxifen against human breast cancer cells.

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Zhu, Fulong, Hengyou Liao, Kai Tang, Youkai Chen e Sheng Liu. "Molecular Dynamics Study on the Effect of Temperature on the Tensile Properties of Single-Walled Carbon Nanotubes with a Ni-Coating". Journal of Nanomaterials 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/767182.

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The effect of temperature on the tensile behavior of the armchair (6, 6) single-walled carbon nanotubes with a Ni-coating (SWCNT-Ni) was investigated using molecular dynamics (MD) methods. The mechanical properties of SWCNT-Ni and SWCNT were calculated and analyzed at different temperatures in the range from 220 K to 1200 K. From the MD results, temperature was determined to be the crucial factor affecting the mechanical properties of SWCNT-Ni and SWCNT. After coating nickel atoms onto the surface of a SWCNT, the Young’s modulus, tensile strength, and tensile failure strain of SWCNT were greatly reduced with temperature rising, indicating that the nickel atoms on the surface of SWCNT degrade its mechanical properties. However, at high temperature, the Young’s modulus of both the SWCNT and the SWCNT-Ni exhibited significantly greater temperature sensitivity than at low temperatures, as the mechanical properties of SWCNT-Ni were primarily dominated by temperature and C-Ni interactions. During these stretching processes at different temperatures, the nickel atoms on the surface of SWCNT-Ni could obtain the amount of energy sufficient to break the C-C bonds as the temperature increases.

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Anakha, D. R., e R. Yamuna. "COVALENT LINKING OF Ni (II) COMPLEX OF MESO TETRA(4-AMINOPHENYL) PORPHYRIN WITH SINGLEWALLED CARBON NANOTUBE AND ITS PHOTO-PHYSICAL PROPERTIES". Rasayan Journal of Chemistry, Special (2021): 118–25. http://dx.doi.org/10.31788/rjc.2021.1456425.

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5, 10, 15, 20 meso tetra(4-aminophenyl) porphyrinato nickel (II) complex (Ni-TAP) was connected covalently with a single-walled carbon nanotube (SWCNT). The Infrared (IR) spectrum of SWCNT-NiTAP nanohybrid conveys the shifting of C=O stretching frequency from 1714 cm-1 to 1695 cm-1 which substantiates the covalent bond connection of porphyrin with SWCNT. In Raman spectroscopy, there is a decrease in the ID/IG ratio after the covalent linkage of SWCNT with Ni-TAP compared to SWCNT-COOH, which specifies enriched electronic properties of SWCNTNiTAP. This is perhaps due to the method of acylation. The morphology study of SWCNT-NiTAP retains the tubelike structure even after the covalent functionalization. The presence of significant peaks in the C 1s and N 1s XP spectra of SWCNT-NiTAP indicate the covalent bond connection of porphyrin chromophores on SWCNTs. Fluorescence spectra of SWCNT-NiTAP show that effective fluorescent quenching is due to energy or electron transfer from Ni-TAP to SWCNTs. Moreover, SWCNT-NiTAP reveals hypsochromic shift compared to Ni-TAP, which specifies the covalent linkage of SWCNT with Ni-TAP.

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Zhao, Yanli, e Wenzhi Li. "Electrical Transport Properties of Multilayered Single-Walled Carbon Nanotube Films". Journal of Nanotechnology 2012 (2012): 1–5. http://dx.doi.org/10.1155/2012/601582.

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An improved layer-by-layer vacuum filtration method was adopted for the fabrication of single-walled carbon nanotube (SWCNT) films aiming at a series of SWCNT films with controllable thickness and density. The electrical transport properties of the multilayered SWCNT films have been investigated. With the constant film density, the decrease of the layer number of the SWCNT film results in an increase of the temperature coefficient of resistance (TCR). SWCNT film with 95% metallic nanotubes has shown a lower TCR than that of the SWCNT films with a low percentage of metallic nanotubes. The effect of thermal annealing and subsequent acid (HNO3) treatment on the electrical properties of the SWCNT films has also been investigated.

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Li, Huaping. "Electronically Pure Single Chirality Semiconducting Single-Walled Carbon Nanotube for Large Scale Electronic Devices". MRS Advances 2, n.º 02 (2017): 83–88. http://dx.doi.org/10.1557/adv.2017.15.

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Abstract Carbon nanotube thin film transistors (TFTs) with characteristics resembling those of TFTs constructed on amorphous silicon, low-temperature polycrystalline silicon and metal oxides were fabricated on (6,5) single chirality single-walled carbon nanotube (SWCNT) thin film deposited from electronically pure semiconducting (6,5) single chirality single-walled carbon nanotube (SWCNT) ink. This ink was extracted in industrial scale from raw SWCNTs produced using high pressure carbon monoxide conversion, and deposited on pretreated substrates to form uniform and consistent (6,5) HiPCO SWCNT thin film using solution process. The (6,5) HiPCO SWCNT thin films were characterized as pure semiconductor without metallic impurities showing classic nonlinear current-bias curves in Schottky-type diodes. Both N-type and P-type (6,5) HiPCO SWCNT TFTs were fabricated with femto Ampere off-current and ION/IOFF ratio of 108 by depositing SiNx and HfO2 dielectrics on the top of (6,5) HiPCO SWCNT thin films, respectively. The (6,5) HiPCO SWCNT inverter with voltage gain of 52 was also demonstrated by wire-bonding one P-type HiPCO SWCNT TFT to one N-type HiPCO SWCNT TFT.

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Makinde, Zainab O., Philani Mashazi e Samson Khene. "Electrocatalytic behavior of single walled carbon nanotubes with alkylthio-substituted cobalt binuclear phthalocyanines towards oxidation of 4-chlorophenols". Journal of Porphyrins and Phthalocyanines 23, n.º 01n02 (janeiro de 2019): 142–53. http://dx.doi.org/10.1142/s1088424619500172.

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This work describes the adsorption of synthesized cobalt mono (CoPc) and binuclear phthalocyanines (CoBiPc) with single walled carbon nanotubes (SWCNT) to form SWCNT-CoPc or SWCNT-CoBiPc as non-covalent conjugates onto glassy carbon electrodes (GCE). The cobalt complexes and their SWCNT-conjugate-modified electrodes were studied for their electrocatalytic oxidation towards 4-chlorophenol. All modified electrodes showed improved catalytic current and stability towards the detection of 4-chlorophenol. The best activity was observed for the SWCNT-CoBiPc2 system in terms of current response and the SWCNT-CoBiPc1 system in terms of resistance to electrode fouling.

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KHENE, SAMSON, e TEBELLO NYOKONG. "CHARACTERIZATION OF QUANTUM DOTS, SINGLE WALLED CARBON NANOTUBES AND NICKEL OCTADECYLPHTHALOCYANINE CONJUGATES". International Journal of Nanoscience 11, n.º 02 (abril de 2012): 1250022. http://dx.doi.org/10.1142/s0219581x12500226.

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In this work nickel octadecylphthalocyanine (NiPc(C10H21)8) and cadmium telluride quantum dots (QDs) capped with thioglycolic acid (TGA) are adsorbed on single walled carbon nanotubes (SWCNT) to form NiPc(C10H21)8 -SWCNT-QDs conjugate. X-ray photoelectron, ultra violet/visible and Raman spectroscopies are used to characterize the conjugate. SWCNT, poly- Ni(O)Pc(C10H21)8 , NiPc(C10H21)8 -SWCNT and NiPc(C10H21)8 -SWCNT-QDs complexes are used to modify glassy carbon electrode (GCE) and used for the electro-oxidation of pentachlorophenol as a test molecule. NiPc(C10H21)8 -SWCNT-QDs electrode gave the best detection current for pentachlorophenol.

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Alimin, Alimin, Narsito Narsito, Indriana Kartini e Sri Juari Santosa. "Retracted-Enhanced X-Ray Absorption Property of Gold-Doped Single Wall Carbon Nanotube". Indonesian Journal of Chemistry 15, n.º 3 (12 de novembro de 2015): 211–17. http://dx.doi.org/10.22146/ijc.21187.

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Enhanced X-ray absorption property of single wall carbon nanotube (SWCNT) through gold (Au) doping (Au@SWCNT) has been studied. Mass attenuation coefficient of SWCNT increased 5.2-fold after Au doping treatment. The use of ethanol in the liquid phase adsorption could produce Au nanoparticles as confirmed by the X-ray Diffraction (XRD) patterns. The possibility of gold nanoparticles encapsulated in the internal tube space of SWCNT was observed by transmission electron microscope technique. A significant decrease of nitrogen uptakes and upshifts of Radial Breathing Mode (RBM) of Au@SWCNT specimen suggest that the nanoparticles might be encapsulated in the internal tube spaces of the nanotube. In addition, a decrease intensity of XRD pattern of Au@SWCNT at around 2θ ≈ 2.6° supports the suggestion that Au nanoparticles are really encapsulated into SWCNT.

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Revel, Messika, Michel Fournier, Christian Gagnon e Pierre Yves Robidoux. "Toxic Effect of Single Walled Carbon Nanotubes Combined with Cadmium to the Crustacean Daphnia magna". International Letters of Natural Sciences 42 (julho de 2015): 50–61. http://dx.doi.org/10.18052/www.scipress.com/ilns.42.50.

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The aim of this study was to assess the impact of single-walled carbon nanotubes (SWCNT) on the toxicity of cadmium (Cd) using the crustacean Daphnia magna. LC50 of Cd and SWCNT alone and combined were calculated and compared. Sorption of Cd on SWCNT was also quantified in separate batch experiments. Results showed that the maximum adsorption of Cd onto SWCNT calculated by the Langmuir equation was 24.4 mg kg-1. LC50s for Cd and SWCNT alone were 252.3 µg L-1 and 1400 µg L-1, respectively. In the presence of 500 and 1000 µg L-1 of SWCNT, Cd LC50s were 127.2 and 120.1 µg L-1 respectively. Therefore, Cd toxicity increased when organisms were exposed to both contaminants which indicated that SWCNT induces a synergistic toxic effect on the survival of D. magna. It appears that even if SWCNT had a low adsorption capacity for Cd, toxicity of the metal can be increased. Our study shows the complexity of SWCNT toxicity and how the understanding of their interactions with other contaminants is crucial to determine the consequences of their release into the environment.

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Revel, Messika, Michel Fournier, Christian Gagnon e Pierre Yves Robidoux. "Toxic Effect of Single Walled Carbon Nanotubes Combined with Cadmium to the Crustacean <i>Daphnia magna</i>". International Letters of Natural Sciences 42 (7 de julho de 2015): 50–61. http://dx.doi.org/10.56431/p-5lr918.

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The aim of this study was to assess the impact of single-walled carbon nanotubes (SWCNT) on the toxicity of cadmium (Cd) using the crustacean Daphnia magna. LC50 of Cd and SWCNT alone and combined were calculated and compared. Sorption of Cd on SWCNT was also quantified in separate batch experiments. Results showed that the maximum adsorption of Cd onto SWCNT calculated by the Langmuir equation was 24.4 mg kg-1. LC50s for Cd and SWCNT alone were 252.3 µg L-1 and 1400 µg L-1, respectively. In the presence of 500 and 1000 µg L-1 of SWCNT, Cd LC50s were 127.2 and 120.1 µg L-1 respectively. Therefore, Cd toxicity increased when organisms were exposed to both contaminants which indicated that SWCNT induces a synergistic toxic effect on the survival of D. magna. It appears that even if SWCNT had a low adsorption capacity for Cd, toxicity of the metal can be increased. Our study shows the complexity of SWCNT toxicity and how the understanding of their interactions with other contaminants is crucial to determine the consequences of their release into the environment.

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Nurulhuda, I., R. Poh, M. Z. Mazatulikhma e M. Rusop. "Toxicity Study of SWCNT Synthesis from Fermented Tapioca". International Journal of Bioscience, Biochemistry and Bioinformatics 4, n.º 4 (2014): 240–43. http://dx.doi.org/10.7763/ijbbb.2014.v4.347.

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Shvedova, Anna A., Naveena Yanamala, Elena R. Kisin, Alexey V. Tkach, Ashley R. Murray, Ann Hubbs, Madalina M. Chirila et al. "Long-term effects of carbon containing engineered nanomaterials and asbestos in the lung: one year postexposure comparisons". American Journal of Physiology-Lung Cellular and Molecular Physiology 306, n.º 2 (15 de janeiro de 2014): L170—L182. http://dx.doi.org/10.1152/ajplung.00167.2013.

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The hallmark geometric feature of single-walled carbon nanotubes (SWCNT) and carbon nanofibers (CNF), high length to width ratio, makes them similar to a hazardous agent, asbestos. Very limited data are available concerning long-term effects of pulmonary exposure to SWCNT or CNF. Here, we compared inflammatory, fibrogenic, and genotoxic effects of CNF, SWCNT, or asbestos in mice 1 yr after pharyngeal aspiration. In addition, we compared pulmonary responses to SWCNT by bolus dosing through pharyngeal aspiration and inhalation 5 h/day for 4 days, to evaluate the effect of dose rate. The aspiration studies showed that these particles can be visualized in the lung at 1 yr postexposure, whereas some translocate to lymphatics. All these particles induced chronic bronchopneumonia and lymphadenitis, accompanied by pulmonary fibrosis. CNF and asbestos were found to promote the greatest degree of inflammation, followed by SWCNT, whereas SWCNT were the most fibrogenic of these three particles. Furthermore, SWCNT induced cytogenetic alterations seen as micronuclei formation and nuclear protrusions in vivo. Importantly, inhalation exposure to SWCNT showed significantly greater inflammatory, fibrotic, and genotoxic effects than bolus pharyngeal aspiration. Finally, SWCNT and CNF, but not asbestos exposures, increased the incidence of K-ras oncogene mutations in the lung. No increased lung tumor incidence occurred after 1 yr postexposure to SWCNT, CNF, and asbestos. Overall, our data suggest that long-term pulmonary toxicity of SWCNT, CNF, and asbestos is defined, not only by their chemical composition, but also by the specific surface area and type of exposure.

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Gubarev, V., M. Krivokorytov, V. Krivtsun, N. Novikova, S. Yakunin, A. Pal, Javier A. Ramirez B, D. Krasnikov, V. Medvedev e A. G. Nasibulin. "Ar permeability through densified single-walled carbon nanotube-based membranes". Journal of Applied Physics 133, n.º 9 (7 de março de 2023): 095106. http://dx.doi.org/10.1063/5.0135082.

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Single-walled carbon nanotube (SWCNT)-based membranes (pellicles) and gas counterflows are used as a debris mitigation system in extreme ultraviolet (EUV) lithography. Densification with volatile liquids is a well-known approach to tune the performance of SWCNT membranes. However, densification can change the gas permeability through SWCNT membranes, violating the circulation of buffer gas counterflows. In the present work, we investigate the Ar permeability through SWCNT membranes before and after densification with isopropyl alcohol in the pressure drop test. The effective diffusivity of Ar through pristine and densified SWCNT membranes is, respectively, calculated to be Deffpristine = 330 × 109 m2 s−1 and Deffdensified = 4 × 109 m2 s−1. We developed a probabilistic model of gas penetration through SWCNT membranes. On the basis of the experimental data, the probabilities of Ar atoms penetrating through pristine and densified SWCNT membranes are estimated to be 8% and 0.1%, respectively. Structural changes in SWCNT membranes after densification with scanning electron microscopy and the Brunauer–Emmett–Teller technique are demonstrated. The bulk density of SWCNT membranes, measured using x-ray reflectometry, is found to be 0.38 and 0.89 g/cm3 before and after densification, respectively. The temporal dynamic of isopropyl alcohol evaporation from the volume of SWCNT membranes is analyzed using Fourier-transform infrared spectroscopy (FTIR). Results obtained using EUV and FTIR spectroscopy show that isopropyl alcohol is present in the volume of the SWCNT membrane even after the membrane has been left in vacuum (P < 0.01 Pa) for 22 h.

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Chang, T. P. "Nonlinear Vibration of Single-Walled Carbon Nanotubes Under Magnetic Field by Stochastic Finite Element Method". International Journal of Structural Stability and Dynamics 16, n.º 08 (25 de agosto de 2016): 1550046. http://dx.doi.org/10.1142/s0219455415500467.

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In the present study, we investigate the statistical nonlinear dynamic behaviors of a single-walled carbon nanotube (SWCNT) subjected to a longitudinal magnetic field by considering the effect of geometric nonlinearity. We consider both the Young’s modulus of elasticity and mass density of the SWCNT as stochastic with respect to the position to actually characterize the random material properties of the SWCNT. In addition, we use the theory of nonlocal elasticity to investigate the small scale effect on the nonlinear vibration of the SWCNT. By using the Hamilton’s principle, the nonlinear governing equations of the SWCNT subjected to a longitudinal magnetic field are derived. We utilize the stochastic finite element method along with the perturbation technique to compute the statistical response of the SWCNT. Some statistical dynamic response of the SWCNT, such as the mean values and standard deviations of the midpoint deflections, are computed and checked by the Monte Carlo simulation, besides, the effects of the small scale coefficients, magnetic field and the elastic stiffness of matrix on the statistical dynamic response of the SWCNT are studied and discussed.

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Escobar-Teran, Freddy, Hubert Perrot e Ozlem Sel. "Single Wall Carbon Nanotubes/Polypyrrole Composite Thin Film Electrodes: Investigation of Interfacial Ion Exchange Behavior". Journal of Composites Science 5, n.º 1 (14 de janeiro de 2021): 25. http://dx.doi.org/10.3390/jcs5010025.

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Single-wall carbon nanotubes/polypyrrole (SWCNT/PPy) composite thin-film electrodes were prepared by electrodeposition of the pyrrole monomer on a porous network made of SWCNT bundles. Electrode/electrolyte interface, which is intimately related to the pseudocapacitive charge storage behavior, is investigated by using coupled electrogravimetric methods (electrochemical quartz crystal microbalance (EQCM) and its coupling with electrochemical impedance spectroscopy, Ac-electrogravimetry), in a 0.5 M NaCl electrolyte (pH = 7). Our results show that the range of usable potential is greater for composite SWCNT/PPy films than for SWCNT films, which should allow a higher storage capacity to be obtained. This effect is also confirmed by mass variation measurements via EQCM. The mass change (corresponding to the amount of (co)electroadsorbed species) obtained with composite SWCNT/PPy films is four times greater than that observed for pristine SWCNT films if the same potential range is examined. The permselectivity is also greatly improved in the case of composite SWCNT/PPy films compared to SWCNT films; the former shows mainly cation exchange preference. The quantities of anions estimated by Ac-electrogravimetric measurements are much lower in the case of composites. This corroborates the better permselectivity of these composite SWCNT/PPy films even with a moderate amount of PPy.

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Kim, Kyung-Tae, Keon Woo Lee, Sanghee Moon, Joon Bee Park, Chan-Yong Park, Seung-Ji Nam, Jaehyun Kim, Myoung-Jae Lee, Jae Sang Heo e Sung Kyu Park. "Conformally Gated Surface Conducting Behaviors of Single-Walled Carbon Nanotube Thin-Film-Transistors". Materials 14, n.º 12 (17 de junho de 2021): 3361. http://dx.doi.org/10.3390/ma14123361.

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Semiconducting single-walled carbon nanotubes (s-SWCNTs) have gathered significant interest in various emerging electronics due to their outstanding electrical and mechanical properties. Although large-area and low-cost fabrication of s-SWCNT field effect transistors (FETs) can be easily achieved via solution processing, the electrical performance of the solution-based s-SWCNT FETs is often limited by the charge transport in the s-SWCNT networks and interface between the s-SWCNT and the dielectrics depending on both s-SWCNT solution synthesis and device architecture. Here, we investigate the surface and interfacial electro-chemical behaviors of s-SWCNTs. In addition, we propose a cost-effective and straightforward process capable of minimizing polymers bound to s-SWCNT surfaces acting as an interfering element for the charge carrier transport via a heat-assisted purification (HAP). With the HAP treated s-SWCNTs, we introduced conformal dielectric configuration for s-SWCNT FETs, which are explored by a carefully designed wide array of electrical and chemical characterizations with finite-element analysis (FEA) computer simulation. For more favorable gate-field-induced surface and interfacial behaviors of s-SWCNT, we implemented conformally gated highly capacitive s-SWCNT FETs with ion-gel dielectrics, demonstrating field-effect mobility of ~8.19 cm2/V⋅s and on/off current ratio of ~105 along with negligible hysteresis.

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Tsuzuki, Takahiro, Shuji Ogata e Masayuki Uranagase. "Large-Scale DFT Simulation of Li-atom Insertion and Extraction in Quinons@SWCNT Rechargeable Battery Cathodes". MRS Advances 3, n.º 22 (2018): 1229–34. http://dx.doi.org/10.1557/adv.2018.174.

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ABSTRACTThe system of quinone molecules encapsulated in the single-wall carbon nanotube (SWCNT) has been proposed as a next-generation cathode electrode material for rechargeable battery. We investigate the complex interaction among the SWCNT, phenanthrene-quinone (PhQ), and Li atoms in the encapsulated system by using our original DFT code. We thereby find that the shape of the SWCNT changes significantly in the relaxed state depending on the extent of Li atoms inserted. The SWCNT shows a circular cylinder shape when no Li exists. With sufficient Li atoms inserted, the SWCNT is flattened. Substantial electron transfer from the PhQs to SWCNT is found. As for the dynamics of Li atoms in insertion or extraction process, we find that the Li atoms can take either of the two paths: one is along the inner wall of the SWCNT and the other is hopping on the PhQs.

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Su, Yu-Chi, e Tse-Yu Cho. "Free vibration of a single-walled carbon nanotube based on the nonlocal Timoshenko beam model". Journal of Mechanics 37 (2021): 616–35. http://dx.doi.org/10.1093/jom/ufab028.

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Abstract Free vibration of a single-walled carbon nanotube (SWCNT) embedded in an elastic medium is studied on the basis of the nonlocal Timoshenko beam model. Influences of the slenderness ratios, the boundary conditions, the atomic structures and the stiffness of the embedded medium on the natural frequencies and mode shapes of SWCNT are examined. The nonlocal effect is significant for the higher modes of SWCNT with a small slenderness ratio embedded in a soft elastic medium, and it softens the SWCNT except for the fundamental frequency of the clamped–free SWCNT.

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TACCHINI, IGNACIO, EVA TERRADO, ALEJANDRO ANSÓN-CASAOS e M. TERESA MARTÍNEZ. "SWCNTs AS ELECTRON WITHDRAWERS IN NANOCRYSTALLINE ANATASE PHOTOCATALYSTS". Nano 07, n.º 03 (junho de 2012): 1250020. http://dx.doi.org/10.1142/s1793292012500208.

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Single-walled carbon nanotube (SWCNT)/anatase TiO2 composite materials were prepared by successive sol–gel and hydrothermal processes. The composites contained thin SWCNT bundles embedded in aggregates of ~ 12 nm anatase crystallites. A series of SWCNT/ TiO2 photocatalysts was prepared with various SWCNT contents; a SWCNT content of ~ 8 wt.% was found to be optimal for methylene blue (MB) degradation under combined UV/visible radiation. The optimized SWCNT/ TiO2 composite demonstrated substantially higher photocatalytic activity than pure nanocrystalline anatase (5.2 times) and Degussa P-25 TiO2 powder (2.7 times). The MB degradation and mineralization processes were separately evaluated and complete decomposition of MB was shown to take place. The presence of SWCNTs caused an increase in the visible light absorbance of TiO2 ; however, SWCNT/ TiO2 composites did not show any photocatalytic activity when the UV part of the UV/visible light source was filtered. Therefore SWCNTs worked as acceptors for the TiO2 photoexcited electrons, but did not act as sensitizers for TiO2 .

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Silva, Ribeiro, Cunha, Proença, Young e Paiva. "A Simple Method for Anchoring Silver and Copper Nanoparticles on Single Wall Carbon Nanotubes". Nanomaterials 9, n.º 10 (4 de outubro de 2019): 1416. http://dx.doi.org/10.3390/nano9101416.

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Single walled carbon nanotubes (SWCNT) were functionalized using the 1,3-dipolar cycloaddition reaction of an azomethine ylide under solvent-free conditions, a one-pot procedure that yields pyrrolidine type of groups at the nanotubes surface. The functionalized SWCNT were further decorated with Ag and Cu nanoparticles by reduction of the corresponding metal salts in dimethylformamide. The extensive reduction of silver from its nitrate was observed, as well as the partial reduction of copper from its acetate. X-ray photoelectron spectroscopy (XPS) confirmed the functionalization of SWCNT with pyrrolidine that provided anchoring sites for the metal nanoparticles. Metal nanoparticles (NP) were formed at the surface of the organically functionalized SWCNT in higher yields as compared to the same procedure carried out with pristine SWCNT. This was observed using scanning electron microscopy (SEM) and quantified by XPS. Raman spectroscopy demonstrated that functionalization and metal decoration of the SWCNT did not induce structural damage to the SWCNT.

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Shvedova, Anna A., Elena R. Kisin, Robert Mercer, Ashley R. Murray, Victor J. Johnson, Alla I. Potapovich, Yulia Y. Tyurina et al. "Unusual inflammatory and fibrogenic pulmonary responses to single-walled carbon nanotubes in mice". American Journal of Physiology-Lung Cellular and Molecular Physiology 289, n.º 5 (novembro de 2005): L698—L708. http://dx.doi.org/10.1152/ajplung.00084.2005.

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Single-walled carbon nanotubes (SWCNT) are new materials of emerging technological importance. As SWCNT are introduced into the life cycle of commercial products, their effects on human health and environment should be addressed. We demonstrated that pharyngeal aspiration of SWCNT elicited unusual pulmonary effects in C57BL/6 mice that combined a robust but acute inflammation with early onset yet progressive fibrosis and granulomas. A dose-dependent increase in the protein, LDH, and γ-glutamyl transferase activities in bronchoalveolar lavage were found along with accumulation of 4-hydroxynonenal (oxidative biomarker) and depletion of glutathione in lungs. An early neutrophils accumulation ( day 1), followed by lymphocyte ( day 3) and macrophage ( day 7) influx, was accompanied by early elevation of proinflammatory cytokines (TNF-α, IL-1β; day 1) followed by fibrogenic transforming growth factor (TGF)-β1 (peaked on day 7). A rapid progressive fibrosis found in mice exhibited two distinct morphologies: 1) SWCNT-induced granulomas mainly associated with hypertrophied epithelial cells surrounding SWCNT aggregates and 2) diffuse interstitial fibrosis and alveolar wall thickening likely associated with dispersed SWCNT. In vitro exposure of murine RAW 264.7 macrophages to SWCNT triggered TGF-β1 production similarly to zymosan but generated less TNF-α and IL-1β. SWCNT did not cause superoxide or NO·production, active SWCNT engulfment, or apoptosis in RAW 264.7 macrophages. Functional respiratory deficiencies and decreased bacterial clearance ( Listeria monocytogenes) were found in mice treated with SWCNT. Equal doses of ultrafine carbon black particles or fine crystalline silica (SiO2) did not induce granulomas or alveolar wall thickening and caused a significantly weaker pulmonary inflammation and damage.

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Wei, Shasha, Yichuan Zhang, Haicai Lv, Liang Deng e Guangming Chen. "SWCNT network evolution of PEDOT:PSS/SWCNT composites for thermoelectric application". Chemical Engineering Journal 428 (janeiro de 2022): 131137. http://dx.doi.org/10.1016/j.cej.2021.131137.

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Cohen, Zachary, Sadiyah Parveen e Ryan M. Williams. "Optimization of ssDNA-SWCNT Ultracentrifugation via Efficacy Measurements". ECS Journal of Solid State Science and Technology 11, n.º 10 (1 de outubro de 2022): 101009. http://dx.doi.org/10.1149/2162-8777/ac9929.

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Photoluminescent single-walled carbon nanotubes (SWCNT) hold substantial potential for a variety of applications in biology and medicine. Improved preparation of such materials requires optimization of various parameters, including those pertaining to ultracentrifugation techniques for removing non-photoluminescent carbonaceous materials. In this work, we investigated single-stranded DNA (ssDNA)-SWCNT preparations, which are widely used and exhibit strong photoluminescence (PL). We found, however, that total PL is not well-described by SWCNT concentration, and that it is much more sufficiently described by a comparison of SWCNT E22 transition peaks with surrounding baseline absorbance from non-fluorescent carbonaceous material. We used this metric, defined as efficacy, in optimizing techniques for centrifugation and subsequent fractionation. We found that increased centrifugal forces removed substantial non-photoluminescent material, but also more SWCNT mass, yielding less-concentrated but more-pure fluorescent SWCNT samples. Thus, a tradeoff exists between decreased sensor material and increased sensor quality, one which might be considered for each novel SWCNT-based nanosensor construct. We anticipate these studies serving as a basis for improved applied nanosensor development.

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