Surface Of Nanotubes Research Articles

Formulation and characterization of cisplatin-loaded hydroxyl functionalized single-walled carbon nanotubes for targeting gastric cancer stem cells

Chemotherapy is the most commonly used therapeutic method for treating many malignancies including gastric cancer. Due to their non-specific and non-targeted drug delivery, it causes resistance leading to cancer progression, relapse, and metastasis of cancer. To overcome this problem we carried out a study aimed to develop a new cisplatin (Cisp) loaded hydroxyl functionalized single-walled carbon nanotube (OH-SWCNT) nanocarrier system to selectively eliminate gastric cancer stem cells. To our understanding, this is the first study of the non-covalent interaction of cisplatin loaded on the surface of hydroxyl-functionalized single-walled carbon nanotubes by ultrasonication. The physical and morphological characterization was carried out by UV–Vis, FTIR spectroscopy, and TEM. A sustained and controlled release of cisp from OH-SWCNT at all three pHs 3.5, 5.5, and 7.4 was observed. Gastric cancer stem cells were isolated from primary cells and were identified by using CD133+ and CD44+ specific markers. Cisplatin-loaded OH-SWCNT nanocarrier was capable of limiting the self-renewal capacity of both CD133+ and CD44+ populations and also decreasing the number of tumorspheres in gastric CSCs. The cell viability percent of AGS cells was 20% at 250 μg/ml concentration. The IC50 value was less than 50% mol/L at both 200 μg/ml and 250 μg/ml of cisplatin-loaded OH-SWCNT. Our findings suggest that cisplatin-loaded OH-SWCNT nanocarrier complexes could target gastric CSCs and also could provide a potential strategy for selectively targeting and efficiently eliminating gastric CSCs. This could be a promising approach to prevent gastric cancer recurrence and metastasis and also improve gastric cancer therapy.

Development of a Multiwalled Carbon Nanotube Voltage Sensor Using Copper Oxide Nanofluids

Carbon Nanotubes (CNT) are allotropes of carbon having superior mechanical, electronic, physical, and optical properties. When a fluid is passed through the nanotubes, the fluid exerts a mechanical force on the walls of the CNT due to which a strain is induced on the surface of the carbon nanotubes creating a net charge at the center of the strained hexagon. This induced polarity produces a voltage across the nanotubes. In this project, nanofluids (cuprous oxide in ethylene glycol) in addition to conventional fluids were passed through multi-walled carbon nanotubes, and a voltage was observed (upto 4.1 mV in the case of nanofluids) after the capillary rise of the flowing fluid in the nanotube sensor. This was in agreement with previously conducted studies on the piezoelectric effect due to the flow of conventional fluids on single-walled carbon nanotubes. The voltage generated across the multi-walled carbon nanotubes (MWCNTs) for the different fluid systems was compared and characterization was done with respect to the fluid system. An attempt was made to present voltage generated as a function of the fluid and flow properties. The paper aims to highlight the possible use of MWCNTs in sensor-based technology and energy conversion devices.

3D printing of porous Ti6Al4V bone tissue engineering scaffold and surface anodization preparation of nanotubes to enhance its biological property

Abstract Porous structures and surface morphology of bone tissue scaffolds play an important role in improving the biocompatibility and antibacterial properties for bone repair. In this study, we investigated the effect of different anodic oxidation parameters on the nanotubes morphology in 3D printed porous titanium scaffolds. Micron-scale pores were fabricated by 3D printing first, and then the nano-scale tubes were obtained via anodizing treatments. The results demonstrated that the morphology of the nanotubes depended on the anodic oxidation time and voltage, respectively. Longer anodic oxidation led to the formation of circle-like nanotubes, and the diameter of the nanotubes increased with the voltage. The scaffolds anodized at 30 V showed the best cell proliferation potential. The presence of nanotubes on the surface of scaffold altered the adhesion of bacteria so that it improved the antibacterial properties of scaffold. The formation of nanotubes improved the drug-loading ability of the scaffold, which are used for loading of minocycline antibacterial drugs. The proposed 3D printed porous Ti6Al4V scaffold with nanotubes surface modification showed obvious antibacterial effect, which is expected to have a promising application in antibacterial bone prosthesis.

High Crystallinity 2D π-d Conjugated Conductive Metal-Organic Framework forBoosting PolysulfideConversion in Lithium-Sulfur Batteries.

The catalytic performance of metal-organic frameworks (MOFs) in Li-S batteries is significantly hindered by unsuitable pore size, low conductivity, and large steric contact hindrance between the catalytic site and lithium polysulfide (LPSs). Herein, the smallest π-conjugated hexaaminobenzene (HAB) as linker and Ni(II) ions as skeletal node are in situ assembled into high crystallinity Ni-HAB 2D conductive MOFs with dense Ni-N4 units via dsp2 hybridization on the surface of carbon nanotube (CNT), fabricating Ni-HAB@CNT as separator modified layer in Li-S batteries. As-obtained unique π-d conjugated Ni-HAB nanostructure features ordered micropores with suitable pore size (≈8 Å) induced by HAB ligands, which can cooperate with dense Ni-N4 chemisorption sites to effectively suppress the shuttle effect. Meanwhile, the conversion kinetics of LPSs is significantly accelerated owing to the small steric contact hindrance and increased delocalized electron density endued by the planar tetracoordinate structure. Consequently, the Li-S battery with Ni-HAB@CNT modified separator achieves an areal capacity of 6.29 mAh cm-2 at high sulfur loading of 6.5mg cm-2 under electrolyte/sulfur ratio of 5µL mg-1 . Moreover, Li-S single-electrode pouch cells with modified separators deliver a high reversible capacity of 791 mAh g-1 after 50 cycles at 0.1 C with electrolyte/sulfur ratio of 6µL mg-1 .

Copper-Based Silica Nanotubes as Novel Catalysts for the Total Oxidation of Toluene.

Cu (10 wt%) materials on silica nanotubes were prepared via two different synthetic approaches, co-synthesis and wetness impregnation on preformed SiO2 nanotubes, both as dried or calcined materials, with Cu(NO3)2.5H2O as a material precursor. The obtained silica and the Cu samples, after calcination at 550 °C for 5 h, were characterized by several techniques, such as TEM, N2 physisorption, XRD, Raman, H2-TPR and XPS, and tested for toluene oxidation in the 20-450 °C temperature range. A reference sample, Cu(10 wt%) over commercial silica, was also prepared. The copper-based silica nanotubes exhibited the best performances with respect to toluene oxidation. The Cu-based catalyst using dried silica nanotubes has the lowest T50 (306 °C), the temperature required for 50% toluene conversion, compared with a T50 of 345 °C obtained for the reference catalyst. The excellent catalytic properties of this catalyst were ascribed to the presence of easy copper (II) species finely dispersed (crystallite size of 13 nm) on the surface of silica nanotubes. The present data underlined the impact of the synthetic method on the catalyst properties and oxidation activity.

1D-ordered mesoporous corncob-like Mo2C carbon nanotubes loaded with FeMnO3 hollow porous nanospheres as an efficient electrochemical sensing platform for rutin detection

One-dimensional (1D) ordered mesoporous carbon hybrid nanotubes loaded with bimetallic oxide hollow nanospheres are expected to be very attractive electrocatalysts. In this study, through high-temperature pyrolysis, we generated Mo2C@C PNTs with outstanding electrical conductivity, a significant surface area, and effective catalytic activity by wrapping ordered mesoporous polypyrroles on the surface of 1D MoO3 nanotubes using block polymers that self-assembled. FeMnO3 hollow porous nanospheres have a large specific surface area, many electroactive sites, and excellent molecular/charge diffusion properties, which can be compounded with 1D ordered mesoporous nitride-rich carbon to solve the problem of poor electrical conductivity of metal oxides and to prevent the accumulation of 1D nanotubes. The composite showed excellent electrocatalytic activity towards rutin due to the synergistic interaction between Mo2C@C PNTs and FeMnO3. In the best case, rutin has a limit of detection (LOD) as low as 0.35 × 10−9 M and a wide linear range (3 ×10−9 to 3.1 ×10−6 M). The sensor displays a remarkable level of selective response to rutin in the presence of other co-interfering species. Furthermore, it has superb repeatability and reproducibility. The sensor has shown outstanding recovery (95.7–104.1 %) in the practical viability of detecting rutin in beverages. This work not only provides a new candidate for the accurate detection of rutin but also provides insight into the exploration of advanced sensing materials.

Single-atom transition metals (Rh, Ir, Co) doped silicon carbide nanotubes (SiCNT) as nonenzymatic nitrotyrosine (NTS) sensor: Insight from theoretical calculations

Transition metals Namely Rhodium (Rh), Iridium (Ir), and Cobalt (Co) doped silicon carbide nanotube (SiCNT) surfaces were theoretically investigated using first-principles density functional theory (DFT) at the B3LYP-GD3(BJ)/def2SVP computational level of theory to understand the biological adsorption, selectivity, reactivity and trapping efficacy of Nitrotyrosine (NTS) as a biomarker for Alzheimer disease. The different parameters and studies conducted showed that there was an increase in conductivity after doping of the metal impurities on SiCNT nanotubes on adsorption of the drugs there and was increase in adsorption strength which lead to chemisorption of the drug on metal-dope-doped surfaces with adsorption energies of −90.550 kcal/mol, −84.839 kcal/mol, −81.702 kcal/mol, and −34.952 kcal/mol corresponding to NTS_Ir@SiCNT, NTS_Co@SiCNT, NTS_Rh@S,iCNT and NTS_@SiCNT systems, hereby suggesting them as a promising biomarker system for Alzheimer disease control.

Sono-enhanced heterogeneous Fenton catalysis: magnetic halloysite nanotube synthesis and accelerated free radical generation.

Although heterogeneous Fenton catalysis has captured increasing attention compared to its homogeneous counterpart, it still confronts some inherent drawbacks in use, such as the dilemma in solid-liquid separation and greater mass transfer resistance. Driven by the acoustic cavitation effect, herein, a sono-enhanced heterogeneous Fenton catalysis process was built to overcome the above two shortcomings, by rapidly synthesizing magnetic Fenton-like catalysts and accelerating electron transfer during the catalytic reaction. The results show that, compared to the traditional chemical coprecipitation method, Fe3O4 with smaller particle size and better crystallinity grew on the surface of halloysite nanotubes (HNTs) by using the sonochemical strategy, leading to displaying the higher catalytic activity toward the degradation of methylene blue (MB, improved by ~2.5 times). In parallel, more •OH and •O2- were produced after the ultrasound was further introduced to the routine Fenton-like catalysis system, thus highly accelerating the removal of MB (improved by ~50%). Besides, benefiting from the robust chemical integration of Fe3O4 and HNTs, Fe3O4@HNTs-S had a lower iron ion leaching in use, showing superior catalytic stability. The speed, simplicity, and generality, together with the enhanced mass transfer rate, make the use of ultrasound an enabling methodology to improve the heterogeneous Fenton catalysis.

Boosting the comprehensive behaviors of LiNi0.5Co0.2Mn0.3O2 lithium-ion batteries via CNTs/Super-P composite conductive agent

In this work, a conductive slurry containing CNTs is used as a modification reagent for the Super-P (SP) conductive agent. After CNTs is recombined with SP, spherical SP particles with a diameter of about 60 nm are evenly dispersed on the surface of CNTs nanotubes with a diameter of 20 nm, which effectively improves the specific surface area of the conductive agent. As a result, the battery using 1.5 % CNTs/SP composite conductive agent shows a smaller EIS impedance value, which makes the comprehensive behaviors of the LiNi0.5Co0.2Mn0.3O2 battery significantly improved. The CNTs/SP battery shows larger CV curve area and smaller potential difference between oxidation and reduction peaks. In addition, the initial charge and discharge capacity of CNTs/SP battery are 181.7 and 184.7 mAh/g respectively with initial Coulombic efficiency of 98.4%, which are much higher than the pristine SP battery (173.7 and 182.0 mAh/g respectively with initial Coulombic efficiency of 95.4 %). After 70 cycles, the discharge capacity of CNTs/SP battery can still remain at 175.3 mAh/g with capacity retention ratio of 97.2 %, which are also much higher than the pristine SP battery (142.5 mAh/g with capacity retention ratio of 82.8 %). Moreover, compared with the pristine SP batteries, the CNTs/SP batteries show larger discharge capacities at different rates of 0.2 C, 0.5 C, 1.0 C, 2.0 C, 3.0 C and 5.0 C. After combining SP with CNTs nanowires, the discharge capacity, initial coulombic efficiency, cycle stability and rate capability of LiNi0.5Co0.2Mn0.3O2 electrode are effectively improved, which provides a new idea for the development of novel conductive agent for high-performance cathode materials of lithium ion batteries.

Synthesis and Characterization of Titania Nanotubes with Au Nanoparticles

TiO2 nanotubes were prepared by hydrothermal synthesis and modified with different amounts of gold nanoparticles by deposition-precipitation with urea. The catalysts were characterized to determine the effect of the presence of Au nanoparticles on the physico-chemical characteristics of the materials and their electron storage capability. Raman spectroscopy revealed the transformation of the trititanate structure into the titania anatase domains upon gold deposition. This transformation was enhanced by an increase in Au loading and the thermal treatment of the materials. The size of Au nanoparticles increased upon the reduction treatment. The presence of Au nanoparticles produced a slight narrowing of the energy bandgap of the titania nanotubular material and had an important effect on its photoluminescence properties, important for some practical applications. Photoluminescence spectroscopy showed that the presence of Au nanoparticles on the surface of titania nanotubes significantly delayed electron-hole recombination and increased the ability of materials for charge separation. Superior performance of Au-containing titania nanotubes was illustrated by the evaluation of their photocatalytic activity. Au-containing titania nanotubes showed enhanced photocatalytic activity in the degradation of methylene blue dye in aqueous solutions upon UV irradiation compared to the pristine nanotubes and the titania Degussa P25.

Construction of novel photocatalysts for efficient hydrogen evolution: The key role of natural halloysite nanotubes

Hydrogen (H2) evolution by photocatalytic water splitting is a potential strategy to solve worldwide energy shortage. Sulfide nanocatalysts showed great potential for H2 evolution, but suffered from low charge separation efficiency and easy agglomeration. In this work, ZnIn2S4 (ZIS) nanoflowers were anchored onto the surface of halloysite nanotubes (HNTs) modified by ethylenediaminetetraacetic acid (EDTA). Photocatalyst 3ZnIn2S4-HNTs/EDTA3 (3ZIS-HNTs/E3) displayed the optimum H2 evolution rate of 10.4 mmol·g−1·h−1, being 3.4 times as that of the original ZIS. Moreover, 3ZIS-HNTs/E3 presented satisfied property in the photocatalytic hydrogenation reaction of 4-nitrophenol to produce 4-aminophenol. HNTs as substrates not only hindered the growth and agglomeration of ZIS, but also induced more S vacancies in ZIS. The production of Schottky junctions between ZIS and Pt, the high utilization of light energy in tubular HNTs, and the trapping effect of EDTA for photogenerated h+ were all favorable for enhancing the catalytic property. The density functional theory (DFT) calculations showed that 3ZIS-HNTs/E3 with more S vacancies had the lowest adsorption energy and the most appropriate ΔGH* for H* to enhance the H2 evolution efficiency, which was consistent with the experimental catalytic results. This study contributes a novel thought for synthesizing composites on the basis of natural minerals for taking part in and enhancing the catalytic performance.

Surface characterization, electrochemical properties and in vitro biological properties of Zn-deposited TiO2 nanotube surfaces

In this work, to improve antibacterial, biocompatible and bioactive properties of commercial pure titanium (cp-Ti) for implant applications, the Zn-deposited nanotube surfaces were fabricated on cp-Ti by using combined anodic oxidation (AO) and physical vapor deposition (PVD-TE) methods. Homogenous elemental distributions were observed through all surfaces. Moreover, Zn-deposited surfaces exhibited hydrophobic character while bare Ti surfaces were hydrophilic. Due to the biodegradable behavior of Zn on the nanotube surface, Zn-deposited nanotube surfaces showed higher corrosion current density than bare cp-Ti surface in SBF conditions as expected. In vitro biological properties such as cell viability, ALP activity, protein adsorption, hemolytic activity and antibacterial activity for Gram-positive and Gram-negative bacteria of all surfaces were investigated in detail. Cell viability, ALP activity and antibacterial properties of Zn-deposited nanotube surfaces were significantly improved with respect to bare cp-Ti. Moreover, hemolytic activity and protein adsorption of Zn-deposited nanotube surfaces were decreased. According to these results; a bioactive, biocompatible and antibacterial Zn-deposited nanotube surfaces produced on cp-Ti by using combined AO and PVD techniques can have potential for orthopedic and dental implant applications.

State-of-the-art predictive modeling of heavy metal ions removal from the water environment using nanotubes

In this research, molecular dynamics (MD) simulation is used to investigate the efficiency of carbon nanotubes (CNT) and boron nitride nanotubes (BNNT) in removing lead ions from contaminated waters. Then the effect of functionalizing nanotubes with –COO– and COOH– functional groups and the nanotubes’ absorption performance of two different concentrations of lead ions are studied. To better evaluate adsorption process, the set of descriptors, such as interaction energies, radial distribution function, etc., are calculated. The MD results show that the absorption performance is significantly improved by modifying the surface of CNT and BNNT with functional groups. In addition, the adsorption capacity increases in higher concentrations of Pb ions at BNNTCOO– and CNTCOOH systems. The interaction energy of BNNTCOO– with a concentration of 50 lead ions is − 2879.28 kJ/mol, which is about 106 kJ/mol more negative than BNNTCOO– at a concentration of 20 lead ions. Also, it is observed that the functionalization of both nanotubes with –COO– increases their absorption capacity. The obtained results from this study provide significant information about the mechanisms of lead adsorption on the surface of nanotubes.

Preparation and tribological performance of corncob-shaped nanospherical-Ni-BTC MOFs@HNTs nanocomposite towards friction improvement

The improvement of interface compatibility of nanomaterials as nanoadditives was conductive to raise the friction performances in oil. Herein, we successfully constructed a corncob-shaped Ni-BTC MOFs@HNTs nanocomposite through the controllable growth of nanospherical Ni-BTC MOFs on the external surface of HNTs nanotubes. The composition and structure of Ni-BTC MOFs@HNTs were determined by a catalog of characterization. Due to being the better interface compatibility of MOFs in organic compound, the existence of Ni-BTC MOFs on the external surface of HNTs evidently promoted the dispersibility of HNTs nanotubes in oil. The tribological behaviors of Ni-BTC MOFs@HNTs as nanoadditives in base oils were deeply studied by ball-on-ball contact friction. The experimental results showed that the average friction coefficient and wear scar diameter of Ni-BTC MOFs@HNTs -base oil were decreased by 39.7% and 29.4% at 0.04 wt% adding content relative to base oil, respectively. Meanwhile, the carrying capacity of Ni-BTC MOFs@HNTs-base oil was increased by 16.3%. Finally, the worn surfaces lubricated by Ni-BTC MOFs@HNTs-base oil were deeply characterized by a series of spectra analysis, thus revealing the synergistic lubrication effect of Ni-BTC MOFs and HNTs.

Superhydrophobic TiO2 nanotube arrays with switchable adhesion in both air and oil

Superhydrophobic surfaces with smart adhesion has aroused increased interest. However, all reported surfaces can only display switchable adhesion in air. Herein, we report a fluoroalkylsilane-modified TiO2 nanotube surface that has switchable adhesion in both air and oil as it is alternately Ultraviolet-irradiated and heated. The transition is not synchronous; a longer Ultraviolet-irradiation time is needed to obtain high adhesion in oil than in air, and the transition is more difficult in polar oil than in non-polar oil. The reversible transition attributes to the combined effect between the nanostructure and surface chemical variation, the out-of-step transition is attributed to different roles of the exposed naked TiO2, which offers water-adhesive force in air and oil-adhesive/water-repellent force in oil. This works reveals the effect of environmental media on surface-wetting/adhesion transition, which is helpful for design of novel adhesive surfaces to meet practical requirements.

Fabrication of TiO2 nanotubes with effect of water and in‐situ condition for biomedical application

AbstractSynthesis of TiO2 nanotubes on titanium alloys for environmental and energy applications are highly encouraged by medical industries. Formation of nanotubes on titanium material delivers superior properties in the view of phase transformation, surface morphological, nanomechanical properties, and corrosion resistances. In this research work, synthesis of TiO2 nanotubes under 8 and 12 Vol. % of water content with in‐situ voltage condition. The fabricated nanotubes surface morphology was analyzed with the use of HR‐Sem. The formation of nanotubes surface has been identified with composite faces of smooth and rough (length of 1.6 and 1.8 μm) by the effect of water content and voltage variations. The nanomechanical properties were analyzed with nanoindentation Pmax received as max of 265 and min of 248 μN. Nanotubes strength depends on the nanotubes length. Potentiodynamic polarization analysis indicated that combination of smooth and rough surfaces was highly encouraging the corrosion resistances.

Chiral Nanoparticle Chains on Inorganic Nanotube Templates.

Fabrication of chiral assemblies of plasmonic nanoparticles is a highly attractive and challenging task, with promising applications in light emission, detection, and sensing. So far, primarily organic chiral templates have been used for chirality inscription. Despite recent progress in using chiral ionic liquids in synthesis, the use of organic templates significantly limits the variety of nanoparticle preparation techniques. Here, we demonstrate the utilization of seemingly achiral inorganic nanotubes as templates for the chiral assembly of nanoparticles. We show that both metallic and dielectric nanoparticles can be attached to scroll-like chiral edges propagating on the surfaces of WS2 nanotubes. Such assembly can be performed at temperatures as high as 550 °C. This large temperature range significantly widens the portfolio of nanoparticle fabrication techniques, allowing us to demonstrate a variety of chiral nanoparticle assemblies, ranging from metals (Au, Ga), semiconductors (Ge), and compound semiconductors (GaAs) to oxides (WO3).

Photothermal-photocatalytic thin-layer flow system for synergistic treatment of wastewater

The integration of the photocatalytic effect into solar steam is highly desirable for addressing freshwater shortages and water pollution. Here, a ternary film structure for the adsorption and photothermal and photocatalytic treatment of wastewater was designed by combining the technique of self-assembled carbon nano paper with a nitrogen composite titanium dioxide (N-TiO2) deposited on the surface of carbon nanotubes (CNT) using polyvinylidene fluoride (PVDF) as a substrate. The photogeneration of reactive oxygen species can be promoted by rapid oxygen diffusion at the three-phase interface, whereas the interfacial photothermal effect promotes subsequent free radical reactions for the degradation of rhodamine B (93%). The freshwater evaporation rate is 1.35 kg·m−2·h−1 and the solar-to-water evaporation efficiency is 94%. Importantly, the N-TiO2/CNT/PVDF (N-TCP) film not only effectively resists mechanical damage from the environment and maintains structural integrity, but can also be made into a large film for outdoor experiments in a large solar energy conversion device to collect fresh water from polluted water and degrade organic dyes in source water simultaneously, opening the way for applications in energy conversion and storage.

Enabling hydrate-based methane storage under mild operating conditions by periodic mesoporous organosilica nanotubes

Biomethane is a renewable natural gas substitute produced from biogas. Storage of this sustainable energy vector in confined clathrate hydrates, encapsulated in the pores of a host material, is a highly promising avenue to improve storage capacity and energy efficiency. Herein, a new type of periodic mesoporous organosilica (PMO) nanotubes, referred to as hollow ring PMO (HR-PMO), capable of promoting methane clathrate hydrate formation under mild working conditions (273 K, 3.5 MPa) and at high water loading (5.1 g water/g HR-PMO) is reported. Gravimetric uptake measurements reveal a steep single-stepped isotherm and a noticeably high methane storage capacity (0.55 g methane/g HR-PMO; 0.11 g methane/g water at 3.5 MPa). The large working capacity throughout consecutive pressure-induced clathrate hydrate formation-dissociation cycles demonstrates the material’s excellent recyclability (97% preservation of capacity). Supported by ex situ cryo-electron tomography and x-ray diffraction, HR-PMO nanotubes are hypothesized to promote clathrate hydrate nucleation and growth by distribution and confinement of water in the mesopores of their outer wall, along the central channels of the nanotubes and on the external nanotube surface. These findings showcase the potential for application of organosilica materials with hierarchical and interconnected pore systems for pressure-based storage of biomethane in confined clathrate hydrates.

Velocity and Out-Step Frequencies for a Micro-Swimmer Based on Spiral Carbon Nanotubes.

The existing producing processes of micro spiral swimmers are complex. Here, a microswimmer with a magnetic layer on the surface of the spiral carbon nanotubes is proposed, which has a simple producing process. For the microswimmer, its equations of the velocities and out-step frequency are deduced. Using these equations, the velocities and out-step frequency of the microswimmer and their changes with related parameters are investigated. Results show that its velocities are proportional to the radius and helix angle of the spiral carbon nanotubes, and its out-step frequencies are proportional to magnetic field strength, the helix angle and magnetic layer thicknesses of the spiral carbon nanotubes, and inversely proportional to the fluid viscosity. The out-step frequency of the microswimmer is measured, which is in good agreement with the calculative ones.