Surface Of Single-walled Carbon Nanotubes Research Articles

Curvature dependence of single-walled carbon nanotubes for SO2 adsorption and oxidation

Porous carbon-based catalysts showing high catalytic activity for SO2 oxidation to SO3 is often used in flue gas desulfurization. Their catalytic activity has been ascribed in many publications to the microporous structure and the effect of its spatial confinement. First principles method was used to investigate the adsorption and oxidation of SO2 on the inner and outer surface of single-walled carbon nanotubes (SWCNTs) with different diameters. It is interesting to found that there is a direct correlation: the barrier for the oxidation O_SWCNT+SO2→SO3+SWCNT monotonically decreases with the increase of SWCNTs’ curvature. The oxygen functional located at the inner wall of SWCNTs with small radius is of higher activity for SO2 oxidation, which is extra enhanced by the spatial confinement effects of SWCNTs. These findings can be useful for the development of carbon-based catalysts and provide clues for the optimization and design of porous carbon catalysts.

A novel fluorescent aptasensor for ultrasensitive detection of microcystin-LR based on single-walled carbon nanotubes and dapoxyl

To assure water safety and protect human health, precise and simple analytical approaches are highly desired to determine low concentrations of microcystin-leucine-arginine (MC-LR), a toxin, in both water and serum samples. Herein, a simple, rapid and accurate aptamer-based fluorescent sensor was used for selective recognition of MC-LR, based on single-walled carbon nanotubes (SWNTs) as immobilizers, dapoxyl as a fluorescent dye, DAP-10 as a specific aptamer for dapoxyl and unmodified MC-LR aptamer (Apt) as a sensing ligand. The sensing method was developed to produce a remarkable fluorescence intensity difference in the absence and presence of MC-LR. Moreover, the Apt was used without any modification. In the absence of MC-LR, the dapoxyl could bind to DAP-10, leading to a strong fluorescence intensity. In the presence of MC-LR, DAP-10 bound to the surface of SWNTs, resulting in a very weak fluorescence intensity. Under optimized conditions, the presented fluorescent analytical approach showed high selectivity toward MC-LR with a limit of detection (LOD) of 138 pM. This new method indicated excellent analytical performance for MC-LR detection in tap water and serum samples with LODs of 135 and 168 pM, respectively.

The effect of defects on the catalytic activity of single Au atom supported carbon nanotubes and reaction mechanism for CO oxidation.

The mechanism of CO oxidation by O2 on a single Au atom supported on pristine, mono atom vacancy (m), di atom vacancy (di) and the Stone Wales defect (SW) on single walled carbon nanotube (SWCNT) surface is systematically investigated theoretically using density functional theory. We determine that single Au atoms can be trapped effectively by the defects on SWCNTs. The defects on SWCNTs can enhance both the binding strength and catalytic activity of the supported single Au atom. Fundamental aspects such as adsorption energy and charge transfer are elucidated to analyze the adsorption properties of CO and O2 and co-adsorption of CO and O2 molecules. It is found that CO binds stronger than O2 on Au supported SWCNT. We clearly demonstrate that the defected SWCNT surface promotes electron transfer from the supported single Au atom to O2 molecules. On the other hand, this effect is weaker for pristine SWCNTs. It is observed that the high density of spin-polarized states are localized in the region of the Fermi level due to the strong interactions between Au (5d orbital) and the adjacent carbon (2p orbital) atoms, which influence the catalytic performance. In addition, we elucidate both the Langmuir-Hinshelwood (LH) and Eley-Rideal (ER) mechanisms of CO oxidation by O2. For the LH pathway, the barriers of the rate-limiting step are calculated to be 0.02 eV and 0.05 eV for Au/m-SWCNT and Au/di-SWCNT, respectively. To regenerate the active sites, an ER-like reaction occurs to form a second CO2 molecule. The ER pathway is observed on Au/m-SWCNT, Au/SW-SWCNT and Au/SWCNT in which the Au/m-SWCNT has a smaller barrier. The comparison with a previous study (Lu et al., J. Phys. Chem. C, 2009, 113, 20156-20160.) indicates that the curvature effect of SWCNTs is important for the catalytic property of the supported single Au. Overall, Au/m-SWCNT is identified as the most active catalyst for CO oxidation compared to pristine SWCNT, SW-SWCNT and di-SWCNT. Our findings give a clear description on the relationship between the defects in the support and the catalytic properties of Au and open a new avenue to develop carbon nanomaterial-based single atom catalysts for application in environmental and energy related fields.

Adsorption Properties of Typical Lung Cancer Breath Gases on Ni-SWCNTs through Density Functional Theory

A lot of useful information is contained in the human breath gases, which makes it an effective way to diagnose diseases by detecting the typical breath gases. This work investigated the adsorption of typical lung cancer breath gases: benzene, styrene, isoprene, and 1-hexene onto the surface of intrinsic and Ni-doped single wall carbon nanotubes through density functional theory. Calculation results show that the typical lung cancer breath gases adsorb on intrinsic single wall carbon nanotubes surface by weak physisorption. Besides, the density of states changes little before and after typical lung cancer breath gases adsorption. Compared with single wall carbon nanotubes adsorption, single Ni atom doping significantly improves its adsorption properties to typical lung cancer breath gases by decreasing adsorption distance and increasing adsorption energy and charge transfer. The density of states presents different degrees of variation during the typical lung cancer breath gases adsorption, resulting in the specific change of conductivity of gas sensing material. Based on the different adsorption properties of Ni-SWCNTs to typical lung cancer breath gases, it provides an effective way to build a portable noninvasive portable device used to evaluate and diagnose lung cancer at early stage in time.

Novel properties of 0D metal-organic polyhedra bonded to the surfaces of 2D graphene and 1D single-walled carbon nanotubes.

A strategy for the stabilization of metal-organic polyhedra (MOP) cages on graphene (Gr) and single-walled carbon nanotubes (NT) is reported. The surface area of the composites, MOPGr and MOPNT increases by an order of magnitude with a significant increase in pore volume in comparison to bulk MOP. The composites show an enhancement in the catalytic activity of up to ∼80% relative to bulk MOP in the conversion of propylene oxide into propylene carbonate. Depositing individual MOP cages on graphene or SWNT surfaces is beneficial in terms of gas adsorption and catalytic properties and provides a good example for useful effects of bonding materials of different dimensionalities.

Evaluation of chemical modification effects on DNA plasmid transfection efficiency of single-walled carbon nanotube-succinate- polyethylenimine conjugates as non-viral gene carriers.

Polyethylenimine (PEI) is a widely used non-viral vector for DNA delivery. One major obstacle of higher molecular weight PEIs is the increased cytotoxicity despite the improved transfection efficiency and numerous chemical modifications that have been reported to overcome this problem. Carbon nanotubes (CNT) are carbon nanomaterials capable of penetrating into cell membranes with no cytotoxic effects. Covalent and noncovalent functionalization methods have been used to improve their solubility in aqueous media. The idea of conjugating PEIs and CNT through different chemical bonds and linkers seems promising as it may result in highly effective carriers due to combination of the transfection ability of PEI with cell internalization of CNT. In this study, six different water-soluble PEI conjugates of single-walled carbon nanotubes (SWNTs) were prepared by grafting PEI with one of three molecular weights (1.8, 10 and 25 kDa) through succinate as a linker which refers to "an organic moiety through which a SWNT is conjugated to PEI." The succinate linker was introduced to the surface of SWNTs through two different chemical strategies: a) ester and b) acyl linkages. The resulting SWNT-PEI vectors were characterized by IR spectroscopy, thermogravimetric analysis (TGA) and SEM imaging. All synthesized carriers were evaluated and compared for their cytotoxicity and transfection efficiency in murine neuroblastoma cells as polyplexes with plasmid DNA for luciferase and green fluorescent protein (GFP). The most efficient carriers were prepared by attaching PEI with the lowest molecular weight (1.8 kDa) through acyl linkage, which gave a transfection efficiency 190-fold greater than that of the corresponding free PEI. Transfection efficiency was the highest in polyplexes prepared with acyl-linked conjugates in all the plasmid/vector ratios studied.

Nanoemitters and innate immunity: the role of surfactants and bio-coronas in myeloperoxidase-catalyzed oxidation of pristine single-walled carbon nanotubes.

Single-walled carbon nanotubes (SWCNTs) are experimentally utilized in in vivo imaging and photothermal cancer therapy owing to their unique physicochemical and electronic properties. For these applications, pristine carbon nanotubes are often modified by polymer surfactant coatings to improve their biocompatibility, adding more complexity to their recognition and biodegradation by immuno-competent cells. Here, we investigate the oxidative degradation of SWCNTs catalyzed by neutrophil myeloperoxidase (MPO) using bandgap near-infrared (NIR) photoluminescence and Raman spectroscopy. Our results show diameter-dependence at the initial stages of the oxidative degradation of sodium cholate-, DNA-, and albumin-coated SWCNTs, but not phosphatidylserine-coated SWCNTs. Moreover, sodium deoxycholate- and phospholipid-polyethylene glycol coated SWCNTs were not oxidized under the same reaction conditions, indicating that a surfactant can greatly impact the biodegradability of a nanomaterial. Our data also revealed that possible binding between MPO and surfactant coated-SWCNTs was unfavorable, suggesting that oxidation is likely caused by a hypochlorite generated through halogenation cycles of free MPO, and not MPO bound to the surface of SWCNTs. The identification of SWCNT diameters and coatings that retain NIR fluorescence during the interactions with the components of an innate immune system is important for their applications in in vivo imaging.

Evaluation of Surface Cleaning Procedures in Terms of Gas Sensing Properties of Spray-Deposited CNT Film: Thermal- and O₂ Plasma Treatments.

The effect of cleaning the surface of single-walled carbon nanotube (SWNT) networks by thermal and the O2 plasma treatments is presented in terms of NH3 gas sensing characteristics. The goal of this work is to determine the relationship between the physicochemical properties of the cleaned surface (including the chemical composition, crystal structure, hydrophilicity, and impurity content) and the sensitivity of the SWNT network films to NH3 gas. The SWNT networks are spray-deposited on pre-patterned Pt electrodes, and are further functionalized by heating on a programmable hot plate or by O2 plasma treatment in a laboratory-prepared plasma chamber. Cyclic voltammetry was employed to semi-quantitatively evaluate each surface state of various plasma-treated SWNT-based electrodes. The results show that O2 plasma treatment can more effectively modify the SWNT network surface than thermal cleaning, and can provide a better conductive network surface due to the larger number of carbonyl/carboxyl groups, enabling a faster electron transfer rate, even though both the thermal cleaning and the O2 plasma cleaning methods can eliminate the organic solvent residues from the network surface. The NH3 sensors based on the O2 plasma-treated SWNT network exhibit higher sensitivity, shorter response time, and better recovery of the initial resistance than those prepared employing the thermally-cleaned SWNT networks.

Molecular dynamics simulations of the orientation properties of cytochrome c on the surface of single-walled carbon nanotubes.

Electron transfer between cytochrome c (Cytc) and electrodes can be influenced greatly by the orientation of protein on the surface of the electrodes. In the present study, different initial orientations of Cytc on the surface of five types of single-walled carbon nanotubes (SWNTs), with different diameters and chirality, were constructed. Properties of the orientations of proteins on the surface of these tubes were first investigated through molecular dynamics simulations. It was shown that variations in SWNT diameter do not significantly affect the orientation; however, the chirality of the SWNTs is crucial to the orientation of the heme embedded in Cytc, and the orientation of the protein can consequently be influenced by the heme orientation. A new electron pathway between Cytc and SWNT, which hopefully benefits electron transfer efficiency, has also been proposed. This study promises to provide theoretical guidance for the rational design of bio-sensors or bio-fuel cells by using Cytc-decorated carbon nanotube electrodes.

In situ Raman spectroelectrochemical study of potential-induced molecular encapsulation of β-carotene inside single-walled carbon nanotubes

The effect of the electrochemical potential of single-walled carbon nanotubes (SWCNTs) on the encapsulation behavior of β-carotene inside the SWCNT cavities was investigated by in situ Raman spectroelectrochemistry. Prior to Raman measurement, the electrochemical behavior of β-carotene at SWCNT electrodes was investigated. Weak adsorption of β-carotene was observed, whereas at glassy carbon (GC) and highly oriented pyrolytic graphite (HOPG) electrodes, β-carotene showed diffusion-controlled reactions and was not adsorbed. Furthermore, a negative potential shift of the oxidation reaction of β-carotene was observed at the SWCNT surface compared with that at other carbon materials such as GC and HOPG. To remove the ends of SWCNTs to allow encapsulation of β-carotene and minimize damage of the side wall of SWCNTs, we used finely controlled potential oxidation method. Results of the in situ Raman measurements indicated that encapsulation of β-carotene into the SWCNT cavity occurred most smoothly when a potential of 0.3V (vs. Ag/Ag+) was applied to the SWCNTs. When the applied potential was >0.4V, the encapsulated β-carotene could be oxidized and decomposed through formation of cation radical and dication forms of β-carotene, even though the β-carotene was encapsulated in the SWCNTs. Applied potentials of –0.2~0.2V did not result in smooth encapsulation compared with that at 0.3V. Overall, we found that the encapsulation behavior of β-carotene in SWCNTs depended on the potential of the SWCNTs.

Hydrogen adsorption on Pt-decorated closed-end armchair (3,3), (4,4) and (5,5) single-walled carbon nanotubes

ABSTRACTStructures of small lengths of capped (3,3), (4,4) and (5,5) single-walled carbon nanotubes (SWCNTs) and their structures decorated by Pt atom and Ptn clusters (n = 2–4) were obtained using density functional theory calculations. Binding abilities of Pt atom and Ptn clusters on the outer surface of SWCNTs at various adsorption sites were explored. Adsorptions of H2 onto Pt atom of the Pt-decorated (3,3), (4,4) and (5,5) SWCNTs were studied and their adsorption energies are reported. The thermodynamic properties and equilibrium constants for H2 adsorptions on the Pt4-decorated (3,3), (4,4) and (5,5) SWCNTs were obtained. The adsorption of H2 on the Pt atom of the Pt4/(3,3) SWCNT was found to be the most preferred reaction of which enthalpy and free energy changes at room temperature are −46.61 and −23.99 kcal/mol, respectively.

Growth of single wall carbon nanotubes using PECVD technique: An efficient chemiresistor gas sensor

In this work, the uniform and vertically aligned single wall carbon nanotubes (SWCNTs) have been grown on Iron (Fe) deposited Silicon (Si) substrate by plasma enhanced chemical vapor deposition (PECVD) technique at very low temperature of 550°C. The as-grown samples of SWCNTS were characterized by field emission scanning electron microscope (FESEM), high resolution transmission electron microscope (HRTEM) and Raman spectrometer. SWCNT based chemiresistor gas sensing device was fabricated by making the proper gold contacts on the as-grown SWCNTs. The electrical conductance and sensor response of grown SWCNTs have been investigated. The fabricated SWCNT sensor was exposed to ammonia (NH3) gas at 200ppm in a self assembled apparatus. The sensor response was measured at room temperature which was discussed in terms of adsorption of NH3 gas molecules on the surface of SWCNTs. The achieved results are used to develope a miniaturized gas sensor device for monitoring and control of environment pollutants.

Single-walled carbon nanotubes coated with ZnO by atomic layer deposition

The possibility of ZnO deposition on the surface of single-walled carbon nanotubes (SWCNTs) with the help of an atomic layer deposition (ALD) technique was successfully demonstrated. The utilization of pristine SWCNTs as a support resulted in a non-uniform deposition of ZnO in the form of nanoparticles. To achieve uniform ZnO coating, the SWCNTs first needed to be functionalized by treating the samples in a controlled ozone atmosphere. The uniformly ZnO coated SWCNTs were used to fabricate UV sensing devices. An UV irradiation of the ZnO coated samples turned them from hydrophobic to hydrophilic behaviour. Furthermore, thin films of the ZnO coated SWCNTs allowed us switch p-type field effect transistors made of pristine SWCNTs to have ambipolar characteristics.

Photopatterned Single-Walled Carbon Nanotube Films Utilizing the Adsorption/Desorption Processes of Photofunctional Dispersants

We describe the application of photodetachable and recyclable dispersants for single-walled carbon nanotubes (SWNTs) in the fabrication of photopatterned SWNT thin films. Because adsorption and desorption of the dispersants on the SWNT surfaces affect not only their dispersibility in water but also their solubility, SWNT photopatterns were obtained on glass substrates in only three steps, i.e., casting the SWNT/dispersant solution, UV-light exposure of the casted SWNT/dispersant films through a photomask, and subsequent rinsing with neutral water. This patterning procedure is simple and scalable and will enable us to prepare microfabricated SWNT thin films.

Substrate-Mediated Cooperative Adsorption of Sodium Cholate on (6,5) Single-Wall Carbon Nanotubes.

The interaction of sodium cholate (NaC) with (6,5) single-wall carbon nanotubes (SWNTs) is investigated using photoluminescence spectroscopy. Dilution of SWNT-NaC suspensions is accompanied by changes in the exciton PL quantum yield and peak emission energy. An abrupt change of the exciton emission peak energy at NaC concentrations between 10 and 14 mM indicates strongly cooperative formation of a micellar phase on (6,5) SWNT surfaces with a Hill coefficient of nH = 65 ± 6. This is in contrast to the formation of free NaC micelles with aggregation numbers of only about 4 and suggests that the cooperativity of NaC micelle formation on nanotube surfaces is strongly substrate-enhanced. The temperature dependence of this previously unobserved transition is used for a determination of ΔmicG(⊖)/(1 + β) = -(11.4 ± 0.2) kJ·mol(-1) which, for typical Na(+) counterion binding with β ≈ 0.2, yields a free SWNT-NaC micellization enthalpy ΔmicG(⊖) of -13.7 kJ·mol(-1).

Dynamic stability of modified strain gradient theory sinusoidal viscoelastic piezoelectric polymeric functionally graded single-walled carbon nanotubes reinforced nanocomposite plate considering surface stress and agglomeration effects under hydro-thermo-electro-magneto-mechanical loadings

ABSTRACTIn this article, dynamic stability analysis of the viscoelastic piezoelectric polymeric nanocomposite plate reinforced by functionally graded single-walled carbon nanotubes (FG-SWCNTs) based on modified strain gradient theory (MSGT) is explored. The viscoelastic piezoelectric polymeric nanocomposite plate reinforced is subjected to hydrothermal and electro-magneto-mechanical loadings. The viscoelastic piezoelectric polymeric nanocomposite plate is rested on viscoelastic foundation. Uniform distribution (UD), various functionally graded (FG) distribution types such as FG-V, FG-X, and FG-O are considered for single-walled carbon nanotubes (SWCNTs). The extended mixture approach is applied to estimation of the elastic properties. The equations of motion are derived by Hamilton's principle. The resonance frequency or the parametric resonance is obtained then dynamic stability region is specified. There is a good agreement between the present work and the literature result. Various parametric investigations are performed for the influences of the small scale parameters, direct and alternating applied voltage, magnetic field, viscoelastic foundation coefficients, and aspect ratios on the dynamic stability region of the viscoelastic piezoelectric polymeric nanocomposite plate. The results indicated that SWCNT agglomeration and surface stress have significant effects on the dynamic stability region and the parametric resonance. Dynamic stability region increases with increasing of thickness to width ratio, magnetic field, applied voltage, static load factor, viscoelastic foundation parameters, and surface density constant, and decreasing of length to width ratio and residual surface stress constant. Also, the dynamic stability region shifts to lower parameter resonance with increasing of temperature and moisture changes. The results can be employed for design of micro-electro-mechanical systems and nano-electro-mechanical systems.

π-Conjugated polymers with pendant coumarins: design, synthesis, characterization, and interactions with carbon nanotubes

A series of new fluorene-based π-conjugated polymers having coumarin derivatives as part of dendritic side chains were designed and prepared using the Suzuki–Miyaura cross-coupling reaction. A new coumarin derivative bearing a heptyl side chain for solubility was utilized to ensure solubility of the final polymers. It was found that fluorescence resonance energy transfer (FRET) from the coumrains to the polyfluorene backbone was efficient, especially for the polymers decorated with lower-generation dendrons. Each of the polymers was found to interact strongly with the surface of single-walled carbon nanotubes (SWNTs) in THF, and their ability to selectively disperse specific SWNT chiralities was investigated. Photoluminescence studies revealed that the strong polymer emission is efficiently quenched in the corresponding supramolecular complexes with SWNTs. This high quenching efficiency indicates that the coumarin–polymer FRET system can be supramolecularly bound to the surface of (SWNTs to produce an energy transfer system in which the energy absorbed by the donor coumarin chromophores is channeled to the SWNTs.

Development of Air-Stable n-Type Thermoelectric Single-Walled Carbon Nanotubes Doped By Benzimidazole Drivative

Despite the remarkable growth of microelectronics such as wearable and portable devices, remote sensors, etc. on the market in recent years, most of the microelectronics are still powered by batteries that are required to recharge and replace at stated periods. These electronic devices require energy autonomy for an extended working time without the need for the intervention of users. One possible solution for powering these wireless microelectronics without a battery is to harvest energy from the human body by using thermoelectric (TE) generation which generates electricity especially from temperature difference. To generate electricity via Seebeck effect is promising. Seebeck effect is the phenomenon that a temperature difference between hot and cold ends of the TE generators that produces a voltage. The conversion efficiency of TE generators can be evaluated by the dimensionless figure of merit, ZT = S2σT/κ, where S is the Seebeck coefficient, σ is the electrical conductivity, T is the absolute temperature, and κ is the thermal conductivity. TE generator with a high Seebeck coefficient, high electrical conductivity, and low thermal conductivity are expected to get good TE properties. To fabricate the TE devices, p- and n-type materials are necessary and the study of TE materials using inorganic semiconductors such as Bi2Te3 have been done for a long time as they illustrate high performance more than ZT = 1. However, these materials contain rare elements which show toxicity and poor processability. Therefore among the several candidates including conducting polymers, transition metal dichalcogenide and carbon nanotubes (CNTs) single-walled CNTs (SWNTs) are emerged as the promising candidate due to their non-toxicity, processability, abundant resources together with the remarkable electrical conductivity, potentially large Seebeck coefficient and light weight. However, due to the air oxidation, SWNTs only show p-type semiconducting property in air. In the development of the CNT-based TE devices, instability of the n-type CNT has been a central issue, n-type SWNT are easily oxidized due to an electrophilic chemisorption of oxygen on the charge polarization.1 Previously, we reported n-type SWNT by encapsulating cobaltcence to SWNT, however, n-type stability lasts only 30 days in air.2 Therefore, in this study we explored an air-stable n-type thermoelectric material by covering the anion part of the SWNT surface by using cationic molecules as a dopant (n-type dopant). In this strategy, 2-(2-methoxyphenyl)-1,3-dimethyl-2,3-dihydro-1H-benzo [d] imidazole (DMBI) was chosen, since it is stable in the atmosphere, forms a stable cationic state by hydride transfer3 and is known as n-type dopant for other carbon materials, such as graphene and fullerene.4 We evaluated the air stability of SWNT doped by DMBI and found that the n-type nature of the DMBI-doped SWNT was stable at least for 90 days at room temperature.5 1) Zhu, X.-Q.; Zhang, M.-T.; Yu, A.; Wang, C.-H.; Cheng, J.-P. J. Am. Chem. Soc. 2008, 130, 2501. 2) Fukumaru, T.; Fujigaya, T.; Nakashima, N. Sci. Rep. 2015, 5, 7951. 3) Wei, P.; Oh, J. H.; Dong, G.; Bao, Z. J. Am. Chem. Soc. 2010, 132, 8852. 4) Wei, P.; Liu, N.; Lee, H. R.; Adijanto, E.; Ci, L.; Naab, B. D.; Zhong, J. Q.; Park, J.; Chen, W.; Cui, Y.; Bao, Z. Nano Lett. 2013, 13 (5), 1890. 5) Nakashima, Y.; Fujigaya, T.; Nakashima, N. in preparation.

Arginine Suppresses the Adsorption of Lysozyme onto Single-wall Carbon Nanotubes

Single-wall carbon nanotubes (SWCNTs) are applied in biotechnological applications, such as biosensors. However, their intrinsic physical properties are impaired by the nonspecific adsorption of proteins onto SWCNT surfaces. Thus, it is necessary to prevent such protein adsorption to maintain the unique functions of SWCNTs. In this study, we demonstrated that arginine reduced the adsorption of hen egg white lysozyme onto SWCNTs. The effect of arginine can be ascribed to an inhibition of the interactions between the aromatic amino acid residues of lysozyme and SWCNTs. Arginine thus helps retain the potential of SWCNTs in their biotechnological applications.

Origin of the Surfactant‐Dependent Redox Chemistry of Single‐Wall Carbon Nanotubes

AbstractThe redox chemistry of single‐walled carbon nanotubes (SWCNTs) was examined by using optical absorption spectroscopy measurements in the presence of sodium dodecyl sulfate (SDS) and its analog surfactants, that is, sodium 1‐undecanesulfonate (SUS) and sodium dodecylbenzenesulfonate (SDBS). Redox reactions of the SWCNTs were observed in the SDS and SUS solutions, whereas such reactions were suppressed in the SDBS solution. Molecular dynamics simulations were performed to investigate the assembly of the surfactants around an SWCNT. SDS and SUS were shown to primarily form single layers on the SWCNT and certain solvent‐exposed areas, whereas SDBS predictably densely coated the SWCNTs. The results suggest that the SDBS layer on the SWCNT surfaces prevents charge‐transfer reactions; in contrast, the sparse layers of SDS and SUS allow the redox chemistry through the charge‐transfer reactions. Interestingly, a positively charged SWCNT as a model for the oxidized SWCNT showed an increase in the number of surfactant molecules around the SWCNT in the SDS and SUS solutions owing to electrostatic interaction, which is related to the chirality‐dependence of the SWCNT colloidal stability.