Article
Chemistry, Multidisciplinary
Mohammad Aramfard, Ozge Kaynan, Ehsan Hosseini, Mohammad Zakertabrizi, Lisa M. Perez, Amir Asadi
Summary: Dispersing carbon nanomaterials in solvents allows their properties to be transferred to polymers and nanocomposites. This study investigates the dispersion mechanism between cellulose nanocrystals (CNC) and pristine carbon nanotubes (pCNTs) and graphene nanoplatelets (pGnPs), and proposes the formation of carbon-oxygen covalent bonds to prevent re-agglomeration in polar solvents.
Article
Chemistry, Multidisciplinary
Quanfeng He, Lanping Zeng, Lianhuan Han, Matthew M. Sartin, Juan Peng, Jian-Feng Li, Alexander Oleinick, Irina Svir, Christian Amatore, Zhong-Qun Tian, Dongping Zhan
Summary: Studies have shown that the adsorption of atomic hydrogen on single layer graphene can effectively store hydrogen and is suitable for solutions involving hydrogen fuel cells for vehicles. Utilizing a Pt-electrocatalyzed spillover-surface diffusion-chemisorption mechanism, hydrogenation of graphene can be carried out under mild conditions, demonstrating high storage capacity and stability.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Emmanuel Picheau, Anthony Impellizzeri, Dmitry Rybkovskiy, Maxime Bayle, Jean-Yves Mevellec, Ferdinand Hof, Hassan Saadaoui, Laure Noe, Abraao Cefas Torres Dias, Jean-Luc Duvail, Marc Monthioux, Bernard Humbert, Pascal Puech, Christopher P. Ewels, Alain Penicaue
Summary: Above a critical diameter, carbon nanotubes collapse into flattened forms, leading to unique Raman spectra changes. The presence of edge cavities and curvature changes near the edges activate a D band despite overall continuity in the structure. The differing perspectives of chemists and physicists on defects in carbon structures may lead to confusion for researchers in nanotechnologies.
Article
Chemistry, Physical
Shaojie Li, Jun Yan, Yunfeng Zhang, Yuhong Qin, Yuling Zhang, Shiguo Du
Summary: In this study, the dispersion ability of six representative surfactants for carbon nanotubes (CNTs) was compared using molecular dynamics simulations and experimental investigations. Triton X-100 and sodium dodecyl benzenesulfonate (SDBS) showed the strongest interaction with CNTs, while sodium dodecyl sulfate (SDS) showed the weakest interaction. Structural factors such as the presence of benzene rings and long alkyl chains were found to enhance the adsorption efficiency of surfactants on the CNTs surface. This study provides guidance for selecting optimal surfactants for CNTs dispersion.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Chemistry, Multidisciplinary
Aikaterini Gkaravela, Ioanna Vareli, Dimitrios G. Bekas, Nektaria-Marianthi Barkoula, Alkiviadis S. Paipetis
Summary: This study proposes that Electrochemical Impedance Spectroscopy (EIS) can be used to monitor and characterize the dispersion state of carbon nanotubes (CNTs) during sonication. By monitoring the Impedance |Z|, the study confirms that the change in |Z| can indicate the formation or destruction of conductive paths during sonication, providing valuable information for creating an optimum dispersion protocol for conductive CNT suspensions.
Article
Materials Science, Multidisciplinary
Zhichen Yan, Shuangyue Wang, Xianjue Chen, Geedhika K. Poduval, John A. Stride
Summary: Chemical vapor deposition (CVD) shows great potential in large-scale production of graphene films. A new method has been developed to directly grow graphene films on crystalline silicon wafers with a 300 nm oxide layer using a seeded-CVD growth approach. The use of methane as feedstock and optimized graphene seeds has improved the film formation, which consists of graphene layers formed by the coalescence of expanding graphene seeds according to SEM, X-ray photoelectron and Raman spectroscopies. The films also exhibit regions of single graphene crystallites resulting from lateral growth of the seeds. Moreover, the unilateral conductivity of the graphene films suggests potential application in device fabrication due to the presence of graphene nanoribbons.
JOURNAL OF MATERIALS SCIENCE
(2023)
Article
Chemistry, Physical
Thiago A. Moura, Wellington Q. Neves, Rafael S. Alencar, Y. A. Kim, M. Endo, Thiago L. Vasconcelos, Deyse G. Costa, Graziani Candiotto, Rodrigo B. Capaz, Paulo T. Araujo, Antonio G. Souza Filho, Alexandre R. Paschoal
Summary: The unique electronic and vibrational properties of linear carbon chains (LCCs) have attracted attention recently. Raman spectroscopy has been widely used to identify LCC and study its properties. This study investigates the optical resonance window of LCCs encapsulated by multi-walled carbon nanotubes (MWCNTs) and a Raman signature assigned to the LCC's longitudinal acoustic phonon mode. First-principles calculations support the conclusions.
Article
Polymer Science
Guillaume Pillet, Pascal Puech, Sebastien Moyano, Frederic Neumayer, Wolfgang Bacsa
Summary: The conductivity of thermoplastic polymers can be effectively enhanced by incorporating carbon nanotubes on the surface. Multiwall carbon nanotubes thin films were transferred onto the polymer surface to form composite layers with electrical conductivity up to 8 S/cm, showing variations at 2.8 vol% of nanotubes. The distribution and quantity of nanotubes were studied using transmission electron microscopy and optical transmission measurements.
Article
Engineering, Manufacturing
Ayaka Aoki, Toshio Ogasawara, Takuya Aoki, Yuichi Ishida, Yoshinobu Shimamura, Yoku Inoue
Summary: This study utilized polarized Raman spectroscopy to assess the strain in aligned multi-walled carbon nanotube/epoxy composites, aiming to clarify the effective elastic modulus of the carbon nanotubes. The Raman shift rate of the G' band of the carbon nanotubes was found to be 18.84 cm(-1)/% corresponding to the tensile strain of the composite specimen. Through Mori-Tanaka theory and consideration of the three-dimensional orientation distribution of the carbon nanotubes, the effective elastic modulus of the carbon nanotubes was estimated to be 400 GPa. The results demonstrated the utility of Raman spectroscopy in experimentally evaluating the effective elastic modulus of multi-walled carbon nanotubes in composites.
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
(2023)
Article
Chemistry, Multidisciplinary
Samuel Faucher, Matthias Kuehne, Hananeh Oliaei, Rahul Prasanna Misra, Sylvia Xin Li, Narayana R. Aluru, Michael S. Strano
Summary: Recent measurements have shown that fluids under extreme confinement, such as water in narrow carbon nanotubes, deviate significantly from theoretical descriptions. In this study, precise replicas of carbon nanotubes filled with water were generated and analyzed using Raman spectroscopy. The results revealed the presence of submicron vapor-like and liquid-like domains in partially filled nanodroplet states, and a Clausius-Clapeyron-type model was used to calculate the heats of condensation of water inside different diameter carbon nanotubes. The findings suggest the potential of molecular engineering of nanoconfined liquid/vapor interfaces for water treatment or membrane distillation.
Review
Chemistry, Multidisciplinary
Yibo Gao, Jianlin Luo, Zhiqing Li, Fei Teng, Jigang Zhang, Song Gao, Minglei Ma, Xiaoyang Zhou, Xuejun Tao
Summary: This review presents a detailed introduction and summary of the dispersion processes of carbon nanotubes (CNTs) in aqueous cementitious materials. The main processes for CNTs dispersion in aqueous systems, including high shear emulsification, ultrasonic treatment, covalent modification, and non-covalent modification, are discussed. The influences of various factors on the dispersity of CNTs are evaluated, and the pros and cons of dispersion processes are analyzed. Novel techniques such as arc thermal excitation and electromagnetic field-induced method are also introduced.
NANOTECHNOLOGY REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Weili Cui, Lei Shi, Kecheng Cao, Ute Kaiser, Takeshi Saito, Paola Ayala, Thomas Pichler
Summary: Carbyne is a one-dimensional allotrope of carbon, which is stable when grown encapsulated in carbon nanotubes. By using isotopic labeling as a tuning mechanism, researchers were able to control its properties and achieve pioneering results with around 11.9% of C-13 labeling.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Materials Science, Multidisciplinary
Zheling Li, Libo Deng, Ian A. Kinloch, Robert J. Young
Summary: Raman spectroscopy is a crucial technique for analyzing carbon-based materials, providing unique insights into their microstructure. It allows for characterization of aspects such as orientation, layers, defects, and doping, enabling standardization and quality control. The application of Raman spectroscopy in studying graphene has aided in the analysis of carbon nanotubes and fibers. The technique can also be used to track deformation in carbon-based materials and study interfacial micromechanics in composites.
PROGRESS IN MATERIALS SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Youn Kim, Ji Soo Hong, Su Young Moon, Jin-Yong Hong, Jea Uk Lee
Summary: This study evaluated the dispersibility and dispersion stability of carbon nanotubes (CNTs) in aqueous solution using three different dispersing agents. The results showed that CNT dispersion with polyvinyl pyrrolidone (PVP) had superior dispersibility and dispersion stability, as evidenced by viscosity and particle size analyses. Lumisizer analyses further confirmed the excellent dispersion stability of CNT dispersion with PVP compared to dispersion with sodium deoxycholate (DOC) and sodium dodecylbenzene sulfonate (NaDDBS) dispersing agents.
Article
Environmental Sciences
Sawaira Adil, Jong -Oh Kim
Summary: This study successfully utilized iron-carbon nanotubes (Fe-CNT) for phosphate (P) recovery from water. Fe-CNTs showed much higher adsorption capacity compared to pristine carbon nanotubes (CNTs). Fe-CNT-2 exhibited approximately 7 times higher P removal efficiency than pristine CNTs. Characterization analysis confirmed successful deposition of iron oxide nanoparticles on the surface of CNT. The adsorption kinetics and isotherm studies revealed that chemisorption was the nature of adsorption. Fe-CNT-2 demonstrated an estimated Langmuir adsorption capacity of 36.5 mgP/g or 112 mg PO4/g. The presence of SO42-, NO3-, and Cl- had no significant influence on phosphate adsorption. P adsorbed on Fe-CNT-2 can be efficiently recovered using desorbing reagents such as NaOH and NaCO32-. X-ray photoelectron spectroscopy (XPS) analysis indicated that OH group played a major role in P removal by Fe-CNT-2. Overall, Fe-CNT-2 showed great potential as an effective and stable adsorbent for P recovery from water environments.