scholarly journals Frame Coating of Single-Walled Carbon Nanotubes in Collagen on PET Fibers for Artificial Joint Ligaments

2020 ◽  
Vol 21 (17) ◽  
pp. 6163 ◽  
Author(s):  
Alexander Yu. Gerasimenko ◽  
Natalia N. Zhurbina ◽  
Nadezhda G. Cherepanova ◽  
Anna E. Semak ◽  
Vadim V. Zar ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Connective Tissue ◽  
Single Walled Carbon Nanotubes ◽  
Binding Energies ◽  
Tight Binding Approximation ◽  
Single Walled Carbon ◽  
Collagen Coating ◽  
Equilibrium Configurations ◽  
Pet Fibers ◽  
Walled Carbon Nanotubes

The coating formation technique for artificial knee ligaments was proposed, which provided tight fixation of ligaments of polyethylene terephthalate (PET) fibers as a result of the healing of the bone channel in the short-term period after implantation. The coating is a frame structure of single-walled carbon nanotubes (SWCNT) in a collagen matrix, which is formed by layer-by-layer solidification of an aqueous dispersion of SWCNT with collagen during spin coating and controlled irradiation with IR radiation. Quantum mechanical method SCC DFTB, with a self-consistent charge, was used. It is based on the density functional theory and the tight-binding approximation. The method established the optimal temperature and time for the formation of the equilibrium configurations of the SWCNT/collagen type II complexes to ensure maximum binding energies between the nanotube and the collagen. The highest binding energies were observed in complexes with SWCNT nanometer diameter in comparison with subnanometer SWCNT. The coating had a porous structure—pore size was 0.5—6 μm. The process of reducing the mass and volume of the coating with the initial biodegradation of collagen after contact with blood plasma was demonstrated. This is proved by exceeding the intensity of the SWCNT peaks G and D after contact with the blood serum in the Raman spectrum and by decreasing the intensity of the main collagen bands in the SWCNT/collagen complex frame coating. The number of pores and their size increased to 20 μm. The modification of the PET tape with the SWCNT/collagen coating allowed to increase its hydrophilicity by 1.7 times compared to the original PET fibers and by 1.3 times compared to the collagen coating. A reduced hemolysis level of the PET tape coated with SWCNT/collagen was achieved. The SWCNT/collagen coating provided 2.2 times less hemolysis than an uncoated PET implant. MicroCT showed the effective formation of new bone and dense connective tissue around the implant. A decrease in channel diameter from 2.5 to 1.7 mm was detected at three and, especially, six months after implantation of a PET tape with SWCNT/collagen coating. MicroCT allowed us to identify areas for histological sections, which demonstrated the favorable interaction of the PET tape with the surrounding tissues. In the case of using the PET tape coated with SWCNT/collagen, more active growth of connective tissue with mature collagen fibers in the area of implantation was observed than in the case of only collagen coating. The stimulating effect of SWCNT/collagen on the formation of bone trabeculae around and inside the PET tape was evident in three and six months after implantation. Thus, a PET tape with SWCNT/collagen coating has osteoconductivity as well as a high level of hydrophilicity and hemocompatibility.

Single-walled carbon nanotubes functionalized by a series of dichlorocarbenes: DFT study

2016 ◽  
Vol 30 (08) ◽  
pp. 1650118 ◽  
Author(s):  
Igor K. Petrushenko ◽  
Konstantin B. Petrushenko
Keyword(s):  
Carbon Nanotubes ◽  
Young’S Modulus ◽  
Elastic Properties ◽  
Density Functional ◽  
Young's Modulus ◽  
Strong Dependence ◽  
Single Walled Carbon Nanotubes ◽  
Binding Energies ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

The structural and elastic properties of neutral and ionized dichlorocarbene (CCl2) functionalized single-walled carbon nanotubes (SWCNTs) were studied using density functional theory (DFT). The Young’s modulus of ionized pristine SWCNTs is found to decrease in comparison to that of neutral models. The interesting effect of increase in Young’s modulus values of ionized functionalized SWCNTs is observed. We ascribe this feature to the concurrent processes of the bond elongation on ionization and the local deformation on cycloaddition. The strong dependence of the elasticity modulus on the number of addends is also observed. However, the CCl2-attached SWCNTs in their neutral and ionized forms remain strong enough to be suitable for the reinforcement of composites. In contrast to the elastic properties, the binding energies do not change significantly, irrespective of CCl2 coverage.

scholarly journals Antimony Selenide Crystals Encapsulated within Single Walled Carbon Nanotubes-A DFT Study

2009 ◽  
Vol 6 (s1) ◽  
pp. S147-S152 ◽  
Author(s):  
Navaratnarajah Kuganathan
Keyword(s):  
Carbon Nanotubes ◽  
Binding Energy ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Single Walled Carbon Nanotubes ◽  
Binding Energies ◽  
Single Walled Carbon ◽  
Transmission Electron ◽  
Antimony Selenide ◽  
Walled Carbon Nanotubes

The structure and binding energies of antimony selenide crystals encapsulated within single-walled carbon nanotubes are studied using density functional theory. Calculations were performed on the simulated Sb2Se3structure encapsulated within single walled nanotube to investigate the perturbations on the Sb2Se3crystal and tube structure and electronic structure and to estimate the binding energy. The calculated structures are in good agreement with the experimental high resolution transmission electron microscopy images of the Sb2Se3@SWNT. The calculated binding energy shows that larger diameter tube could accommodate the Sb2Se3crystals exothermically. Minimal charge transfer is observed between nanotube and the Sb2Se3crystals.

scholarly journals Stacking Interactions of Poly Para-Phenylene Vinylene Oligomers with Graphene and Single-Walled Carbon Nanotubes: A Molecular Dynamics Approach

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4812
Author(s):  
Nii Amah Dagadu ◽  
Shahram Ajori ◽  
Yaw Delali Bensah ◽  
Kwabena Kan-Dapaah ◽  
Stephen Kofi Armah ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Monomer Unit ◽  
Single Walled Carbon Nanotubes ◽  
Distribution Functions ◽  
Binding Energies ◽  
Phenylene Vinylene ◽  
Radius Of Gyration ◽  
Stable Conformation ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

This study is meant to address the understanding of the interactions between poly para-phenylene vinylene (PPV) oligomers, graphene and single-walled carbon nanotubes (SWCNT). To this end, the binding energies of the PPV oligomers with graphene and SWCNTs were investigated. Calculations are performed and the parameters related to van der Waal vdW interactions are discussed to achieve and confirm the crystallization of oligomers of PPV into herringbone (HB) structure arrangement, which is known to be the most stable conformation at 300 K. Finally, the interfacial interactions between crystal PPV, graphene and SWCNT are carried out. According to the results, the intramolecular potential energies of PPV chains are found to increase linearly with each extending PPV monomer unit by approximately 50 kcal/mol. Moreover, the interfacial interaction properties analysis using radial distribution functions (RDFs) for PPV-graphene and PPV-SWCNT show significant disordering of the arrangement of molecules, which is more pronounced for PPV-SWCNT than that in PPV-graphene. The radius of gyration (Rg) profiles show a net decrease of ∼−0.8, for PPV-graphene with different surface coverage, and, a net increase of ∼+0.6, for PPV-SWCNT; meaning that, the binding between PPV-graphene is much stronger than with PPV-SWCNT.

Alteration of deposition pattern and pulmonary response as a result of improved dispersion of aspirated single-walled carbon nanotubes in a mouse model

2008 ◽  
Vol 294 (1) ◽  
pp. L87-L97 ◽  
Author(s):  
R. R. Mercer ◽  
J. Scabilloni ◽  
L. Wang ◽  
E. Kisin ◽  
A. R. Murray ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Connective Tissue ◽  
Single Walled Carbon Nanotubes ◽  
Tissue Response ◽  
Mouse Lung ◽  
Single Walled Carbon ◽  
Inflammatory Phase ◽  
Macrophage Phagocytosis ◽  
Granulomatous Lesions ◽  
Walled Carbon Nanotubes

Nanoparticles have a fundamental dimension of <100 nm. However, on suspension in media, agglomerates of nanoparticles are the more common structure. This is particularly evident in prior intratracheal instillation or aspiration studies of single-walled carbon nanotubes (SWCNT), in which granulomatous lesions encased by epithelioid macrophages were produced by large agglomerates. In this study, we tested the hypothesis of whether exposure to more dispersed SWCNT structures would alter pulmonary distribution and response. A dispersed preparation of single-walled carbon nanotubes (DSWCNT) with a mean diameter of 0.69 μm was given by pharyngeal aspiration to C57BL/6 mice. Electron microscopy demonstrated a highly dispersed, interstitial distribution of DSWCNT deposits by 1 day postexposure. Deposits were generally <1 μm. Macrophage phagocytosis of DSWCNT was rarely observed at any time point. Lung responses were studied by lavage and morphometry at 1 h, 1 day, 7 day, and 1 mo after a single DSWCNT exposure of 10 μg/mouse. Lung sections and lavage cells demonstrated an early, transient neutrophilic and inflammatory phase that rapidly resolved and was similar to that observed with large agglomerates. No granulomatous lesions or epithelioid macrophages were detected. Morphometric measurement of Sirius red staining was used to assess the connective tissue response. The average thickness of connective tissue in alveolar regions was 0.10 ± 0.02, 0.09 ± 0.02, 0.10 ± 0.01, 0.48 ± 0.04, and 0.88 ± 0.19 μm for PBS and 1-h, 1-day, 7-day, and 1-mo postexposure groups, respectively. The results demonstrate that dispersed SWCNT are rapidly incorporated into the alveolar interstitium and that they produce an increase in collagen deposition.

scholarly journals DFT Calculations of Hydrogen Adsorption inside Single-Walled Carbon Nanotubes

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Igor K. Petrushenko
Keyword(s):  
Carbon Nanotubes ◽  
Dft Calculations ◽  
Hydrogen Molecule ◽  
Hydrogen Adsorption ◽  
Single Walled Carbon Nanotubes ◽  
Binding Energies ◽  
Hydrogen Binding ◽  
Single Walled Carbon ◽  
Hydrogen Molecules ◽  
Walled Carbon Nanotubes

DFT calculations have been performed to study noncovalent interactions of a hydrogen molecule and single-walled carbon nanotubes (SWCNTs) of various diameters. Understanding these interactions is crucial for the development of systems for hydrogen storage and delivery. The barrier and barrier-free introduction of a hydrogen molecule into SWCNTs is observed. It has been found that hydrogen molecules bind differently onto SWCNTs, depending on their diameters and the orientation of an H2 molecule inside the SWCNT. The binding inside SWCNTs with small diameters ((3,3); (4,4)) is very unfavorable; the opposite situation is in the case of larger ((5,5); (6,6)) SWCNTs. Finally, in the case of ((7,7); (8,8)) SWCNTs, the hydrogen binding energies decrease, and their values approach to those of graphene.

[2+1] Additions of (n,0)(n=6−10) single-walled carbon nanotubes with di-vacancies based on defect curvature: A first-principles study

2019 ◽  
Vol 18 (01) ◽  
pp. 1950004
Author(s):  
Lei Li ◽  
Hongwei Fan ◽  
Hezhuan Wei ◽  
Shengli An ◽  
Guixiao Jia
Keyword(s):  
Carbon Nanotubes ◽  
Single Walled Carbon Nanotubes ◽  
Binding Energies ◽  
Vacancy Defects ◽  
Single Walled Carbon ◽  
Highest Occupied Molecular Orbital ◽  
Defect Area ◽  
Structure Formula ◽  
Atomic Vacancy ◽  
Walled Carbon Nanotubes

Binding energies ([Formula: see text], geometric and electronic structures for [[Formula: see text]](O/[[Formula: see text]]) additions of O atom on ([Formula: see text])([Formula: see text] − 10) single-walled carbon nanotubes with di-vacancies are studied using a GGA-PBE method, and defect curvature ([Formula: see text]) is used to predict reactivities of different C—C bonds at defect area. Calculated results show that the C—C bonds can be divided into two types: broken C—C bonds corresponding to adducts with a C—O—C configuration structure and unbroken C—C bonds corresponding to adducts with a closed-3MR structure. [Formula: see text] of O/[[Formula: see text]] additions for the adduct with the C—O—C configuration structure monotonously increases with the increase of [Formula: see text] in any ([Formula: see text],0)([Formula: see text]) tube and decreases with the increase of [Formula: see text] in ([Formula: see text],0)([Formula: see text], 7, 10) tubes. Besides the fact that [Formula: see text] value is mainly determined by the defect curvature, it is also affected by band gaps, bonding characteristic of C—C bonds in the highest occupied molecular orbital (HOMO) and geometric structures. The study would provide a theoretical basis for surface modifications of carbon nanotubes with atomic vacancy defects.

Two-photon photoluminescence and exciton binding energies in single-walled carbon nanotubes

2006 ◽  
Vol 243 (10) ◽  
pp. 2428-2435 ◽  
Author(s):  
R. Pomraenke ◽  
J. Maultzsch ◽  
S. Reich ◽  
E. Chang ◽  
D. Prezzi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Single Walled Carbon Nanotubes ◽  
Binding Energies ◽  
Single Walled Carbon ◽  
Two Photon ◽  
Walled Carbon Nanotubes

Purity Evaluation of Single-Walled Carbon Nanotubes Using Thermogravimetric Analysis

2013 ◽  
Vol 51 (2) ◽  
pp. 137-144
Author(s):  
Naesung Lee ◽  
Jeung Choon Goak ◽  
Tae Yang Kim ◽  
Jongwan Jung ◽  
Young-Soo Seo ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Thermogravimetric Analysis ◽  
Single Walled Carbon Nanotubes ◽  
Single Walled Carbon ◽  
Purity Evaluation ◽  
Walled Carbon Nanotubes
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