Structural characterization of the fullerene nanotubes prepared by the liquid–liquid interfacial precipitation method

2005 ◽  
Vol 20 (3) ◽  
pp. 688-695 ◽  
Author(s):  
Kun'ichi Miyazawa ◽  
Jun-ichi Minato ◽  
Tetsuro Yoshii ◽  
Masahisa Fujino ◽  
Tadatomo Suga
Keyword(s):  
Linear Relationship ◽  
Wall Thickness ◽  
Structural Characterization ◽  
Tube Wall ◽  
Precipitation Method ◽  
Outer Diameter ◽  
Tubular Structures ◽  
Growth Axis ◽  
Inner Diameter

Fine tubular fibers composed of C60 and C70 fullerene molecules were successfully fabricated by the liquid–liquid interfacial precipitation method. The walls of the tubular fibers were crystalline, and the fullerene molecules were densely packed along the growth axis of tube wall. The tubular structures are called “fullerene nanotubes.” The inner diameter and the outer diameter of C70 tubes showed a linear relationship, suggesting a constant wall thickness of the tubes. The tubular structures composed of C70 molecules could be formed when their diameter was larger than about 240 nm. The fullerene tubes were successfully fabricated by using a C60-C70 soot as well. The formation of fullerene nanotubes can be understood by assuming a mechanism of core dissolution of the solvated fullerene nanowhiskers.

scholarly journals Towards Manufacturing of Ultrafine-Laminated Structures in Metallic Tubes by Accumulative Extrusion Bonding

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 389
Author(s):  
Matthew R. Standley ◽  
Marko Knezevic
Keyword(s):  
Solid State ◽  
Wall Thickness ◽  
Complex Geometry ◽  
Tube Wall ◽  
Film Theory ◽  
Radial Strain ◽  
Surface Preparation ◽  
Grain Structure ◽  
Outer Diameter ◽  
Laminated Structures

A severe plastic deformation process, termed accumulative extrusion bonding (AEB), is conceived to steady-state bond metals in the form of multilayered tubes. It is shown that AEB can facilitate bonding of metals in their solid-state, like the process of accumulative roll bonding (ARB). The AEB steps involve iterative extrusion, cutting, expanding, restacking, and annealing. As the process is iterated, the laminated structure layer thicknesses decrease within the tube wall, while the tube wall thickness and outer diameter remain constant. Multilayered bimetallic tubes with approximately 2 mm wall thickness and 25.25 mm outer diameter of copper-aluminum are produced at 52% radial strain per extrusion pass to contain eight layers. Furthermore, tubes of copper-copper are produced at 52% and 68% strain to contain two layers. The amount of bonding at the metal-to-metal interfaces and grain structure are measured using optical microscopy. After detailed examination, only the copper-copper bimetal deformed to 68% strain is found bonded. The yield strength of the copper-copper tube extruded at 68% improves from 83 MPa to 481 MPa; a 480% increase. Surface preparation, as described by the thin film theory, and the amount of deformation imposed per extrusion pass are identified and discussed as key contributors to enact successful metal-to-metal bonding at the interface. Unlike in ARB, bonding in AEB does not occur at ~50% strain revealing the significant role of more complex geometry of tubes relative to sheets in solid-state bonding.

Synthesis and Structural Characterization of Zinc and Magnesium Doped Hydroxyapatite

2012 ◽  
Vol 531-532 ◽  
pp. 250-253 ◽  
Author(s):  
Hong Quan Zhang ◽  
Ming Zhang ◽  
Lu Wei Fu ◽  
Yu Ning Cheng
Keyword(s):  
Hydrothermal Treatment ◽  
Structural Characterization ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Starting Solution ◽  
Wet Chemical ◽  
Zn Ions ◽  
Wet Chemical Precipitation ◽  
Surface Of Crystals

Zn or Mg ions doped hydroxyapatite (HA) particles were successfully developed by introducing various concentration of Zn or Mg in the starting solution using wet chemical precipitation method and followed a hydrothermal treatment. The products were identified as HA by XRD and FTIR, and the precipitated particles had a rod-like morphology. All the products for Mg and Zn ions concentration in the preparation solution less than 40 mol% were identified as HA. Substitution of Mg and Zn in HA crystal would impair the crystallization of HA and significantly reduce the length of a, c values of HA unit cell, which clearly demonstrated that Mg or Zn ions were structurally incorporated into the apatite crystals, they were not just absorbed on the surface of crystals.

Fabrication and Characterization of Titanium Based Nanotubes

2009 ◽  
Vol 79-82 ◽  
pp. 581-584 ◽  
Author(s):  
Li Ang Song ◽  
Li Xin Cao ◽  
Ge Su ◽  
Wei Liu ◽  
Hui Liu ◽  
...  
Keyword(s):  
Diffuse Reflectance Spectroscopy ◽  
Cost Effective ◽  
Outer Diameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Phases ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Inner Diameter

Titanium based nanotubes (8-12nm outer diameter and 4-6nm inner diameter) were successfully fabricated by a simple and cost-effective hydrothermal method. The nanotube-like amorphous phases TNT(Na) and TNT(H) were obtained with different post treatment. The samples were characterized by means of high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), selected area electron diffraction (SAED), energy dispersive X-ray spectrum (EDS) and UV-Vis diffuse reflectance spectroscopy (DRS). The photocatalytic activities of the nanotubes were evaluated using photo-oxidation of methyl orange.

scholarly journals Cross-sectional analysis of tubular polymer semi-finished products using ultrasound in comparison with other measuring methods

2020 ◽  
Vol 6 (3) ◽  
pp. 151-154
Author(s):  
Olga Sahmel ◽  
Stefan Siewert ◽  
Wolfram Schmidt ◽  
Klaus-Peter Schmitz ◽  
Niels Grabow
Keyword(s):  
Wall Thickness ◽  
Biomedical Engineering ◽  
Measuring Method ◽  
Outer Diameter ◽  
Micro Computed Tomography ◽  
Cross Sectional ◽  
Biodegradable Poly ◽  
Ultrasonic Measuring ◽  
Inner Diameter ◽  
Sectional Analysis

AbstractIn the sector of biomedical engineering and implant technology, high-precision geometry is often decisive for successful end product functionalization. Especially in the production of tubular polymer semi-finished products, e.g. for stent fabrication, it is important to assure the desired parameters, such as inner and outer diameter and wall thickness. Within the current study we analyzed semifinished products for manufacturing of polymeric stents using three different methods. Biodegradable poly-L-lactide (PLLA) tubes were examined by means of micro computed tomography, ultrasonic scanning and scanning electron microscopy. The final evaluation presents clear advantages of the ultrasonic measuring method for the measurement of outer and inner diameter and wall thickness.

SAXS characterization of polymer-embedded hollow nanoparticles and of their shell porosity

2013 ◽  
Vol 46 (6) ◽  
pp. 1654-1664 ◽  
Author(s):  
Zhi Hong Chen ◽  
Sun Hye Hwang ◽  
Xiang-bing Zeng ◽  
Jongmin Roh ◽  
Jyongsik Jang ◽  
...  
Keyword(s):  
Gas Adsorption ◽  
Alternative Form ◽  
Outer Diameter ◽  
Hollow Nanoparticles ◽  
Polymer Layers ◽  
X Ray Scattering ◽  
Poly Ethylene Oxide ◽  
Inner Diameter ◽  
Poly Ethylene

Size parameters of SiO2/TiO2hollow nanoparticles (HNPs) of 25–100 nm in diameter were characterized by small-angle X-ray scattering (SAXS). On the basis of the decoupling and the Percus–Yevick approximations, and using a hollow sphere model, size information on HNPs was extracted, including average outer diameter, average inner diameter and polydispersity. Application of an alternative form factor based on hollow ellipsoids, and of a sticky hard sphere structure factor, did not improve the fit significantly. The shell porosity of the HNPs and the size of the pores in the HNP shell were further characterized by combining SAXS with gas adsorption methods. The above HNPs were then supported on a porous poly(ethylene oxide) scaffold by freeze drying from aqueous solution. To characterize the product, a multishell model was applied to fit the experimental SAXS curves and extract the following morphological information: distribution of HNPs between the surface and interior of the polymer, thickness of the polymer layers lining the outer and inner surfaces of HNPs, and densities of the outer and inner polymer layers. The work demonstrates the versatility of SAXS in obtaining key information on dissolved and polymer-supported HNPs in applications such as drug delivery and catalysis.

scholarly journals A New Method for Precision Measurement of Wall-Thickness of Thin-Walled Spherical Shell Parts

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 467
Author(s):  
Jiang Guo ◽  
Yongbo Xu ◽  
Bo Pan ◽  
Juntao Zhang ◽  
Renke Kang ◽  
...  
Keyword(s):  
Spherical Shell ◽  
Wall Thickness ◽  
High Surface ◽  
Measurement Data ◽  
Outer Diameter ◽  
Surface Errors ◽  
Inner Diameter ◽  
Thickness Error ◽  
Thin Walled ◽  
Physics Experiments

Thin-walled parts are widely used in shock wave and detonation physics experiments, which require high surface accuracy and equal thickness. In order to obtain the wall thickness of thin-walled spherical shell parts accurately, a new measurement method is proposed. The trajectories, including meridian and concentric trajectories, are employed to measure the thickness of thin-walled spherical shell parts. The measurement data of the inner and outer surfaces are unified in the same coordinate system, and the thickness is obtained based on a reconstruction model. The meridian and concentric circles’ trajectories are used for measuring a spherical shell with an outer diameter of Φ210.6 mm and an inner diameter of Φ206.4 mm. Without the data in the top area, the surface errors of the outer and inner surfaces are about 5 μm and 6 μm, respectively, and the wall-thickness error is about 8 μm with the meridian trajectory.

scholarly journals Fabrication and Characterization of a Biodegradable Hollow Microneedle from Chitosan

2020 ◽  
Vol 32 (2) ◽  
pp. 401-407 ◽  
Author(s):  
Masato Suzuki ◽  
◽  
Tomokazu Takahashi ◽  
Seiji Aoyagi
Keyword(s):  
Acetic Acid ◽  
Alkaline Solution ◽  
Silicone Rubber ◽  
Dip Coating ◽  
Outer Diameter ◽  
Coating Method ◽  
Inner Diameter ◽  
Fabrication And Characterization ◽  
Dip Coating Method

A biodegradable chitosan-acetate microneedle is developed based on the proboscis of a mosquito, which consists of chitin and protein. The formability of chitosan, which is a deacetylated compound of chitin, is improved by dissolving it in dilute acetic acid. Thereafter, the dissolved chitosan is coated around an Al wire by a dip-coating method, followed by drying. Afterward, the Al wire is removed by etching using an alkaline solution to form the chitosan micropipe. Subsequently, the micropipe is baked at 200°C for 0.20 min. The optimum baking time was found to be 17 min. Finally, the micropipe is cut and its tip sharpened to transform it into a microneedle with a length, an outer diameter, and an inner diameter of 4 mm, 150 μm, and 100 μm, respectively. The Young’s modulus of the fabricated chitosan microneedle is approximately 10 GPa. This microneedle could be inserted into an artificial skin made of silicone rubber without buckling, and it could aspirate blood from a frog at a rate of 2.5 μL/s.

Structural characterization of C60 nanowhiskers formed by the liquid/liquid interfacial precipitation method

2003 ◽  
Vol 35 (1) ◽  
pp. 117-120 ◽  
Author(s):  
K. Miyazawa ◽  
Y. Kuwasaki ◽  
K. Hamamoto ◽  
S. Nagata ◽  
A. Obayashi ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Precipitation Method

Conditions for Wall Thickness Reduction in Hollow Sinking of SUS304 Tubes With Drawing Speed Control in Entrance and Exit Sides of Die

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Takuma Kishimoto ◽  
Shiori Gondo ◽  
Kosuke Takemoto ◽  
Kenichi Tashima ◽  
Shinsuke Suzuki
Keyword(s):  
Wall Thickness ◽  
Threshold Value ◽  
Back Stress ◽  
Thickness Reduction ◽  
Speed Ratio ◽  
Geometric Condition ◽  
Outer Diameter ◽  
Cross Sectional ◽  
Drawing Speed ◽  
Inner Diameter

Abstract In this study, the conditions for wall thickness reduction in hollow sinking were obtained by tube drawing experiments in which the drawing speed ratio was controlled under three conditions (1.09, 1.11, and 1.14). These conditions have not been found in the history of hollow sinking. The results of the experiment and the theoretical formulas indicate that the geometric condition is obtained from the figure of the ratio of inner diameter to outer diameter after drawing against that ratio before drawing. Furthermore, the ratio of the inner diameter to the outer diameter after drawing must be above the constant wall thickness line derived from the cross-sectional change. To satisfy this geometric condition, the drawing speed ratio must be larger than the threshold value, which is obtained from the ratio of the inner diameter to the outer diameter before drawing, and the reduction of the die. However, the value of the back stress approaches that of the strength of the tube when the drawing speed ratio increases. A simple dynamical model shows that parameters other than the drawing speed ratio do not significantly decrease the back stress during drawing. Therefore, the drawing speed ratio should be set such that the tube does not break.

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