scholarly journals Thermoplastic Intumescent Coatings Modified with Pentaerythritol-Occluded Carbon Nanotubes

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6284
Author(s):  
Michał Tomczak ◽  
Jakub Łopiński ◽  
Agnieszka Kowalczyk ◽  
Krzysztof Kowalczyk
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Structure ◽  
Fire Test ◽  
Steel Substrate ◽  
Solid Dispersions ◽  
Multiwalled Carbon ◽  
Ft Ir ◽  
Fire Curve ◽  
Occluded Carbon ◽  
Unmodified Sample

A thermoplastic intumescent coating system (IC) based on poly(vinyl acetate) was modified by two forms of multiwalled carbon nanotubes (CNTs), i.e., by a nanofiller powder and its solid dispersions in pentaerythritol (PER-CNTs). It was revealed that only the PER-CNTs modifier allows us to obtain solvent-borne ICs with a relatively high CNTs concentration (1–3 wt. parts of CNTs/100 wt. parts of paint solids) and acceptable application viscosity. Thermal insulation time (TIT) and intumescent factor (IF) of the ICs on a steel substrate (a fire test according to a cellulosic fire curve), as well as morphology, chemical structure (by the FT-IR technique) and mechanical strength of the charred systems, were investigated. It was found that the CNTs powder decreases TIT and IF values while PER-occluded CNTs improve these parameters (e.g., +4.6 min and +102% vs. an unmodified sample, respectively). Compressive strength of the charred ICs was improved by the PER-CNTs modifier as well.

Hemostatic Effect of Aminated Multiwalled Carbon Nanotubes/Oxidized Regenerated Cellulose Nanocomposites

2019 ◽  
Vol 19 (11) ◽  
pp. 7410-7415 ◽  
Author(s):  
Baode Zhang ◽  
Ali Nabipour Chakoli ◽  
Jin Mei He ◽  
Yu Dong Huang ◽  
Andrey N. Aleshin
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Regenerated Cellulose ◽  
Oxidized Regenerated Cellulose ◽  
Multiwalled Carbon ◽  
Hemostatic Effect ◽  
Pristine Mwcnts ◽  
Ft Ir ◽  
Cellulose Nanocomposites

We have investigated the covalent conjugation of aminated multiwalled carbon nanotubes (MWCNTNH2)s with Oxidized Regenerated Cellulose (ORC) in order to enhance the hemostatic effect. The MWCNT-NH2s were prepared by functionalization of pristine MWCNTs (pMWCNTs) using amine groups. Neat ORC gauze and MWCNT-NH2s were reacted using glutamic acid as cross linking bridge. We investigated an amination of pMWCNTs as well as the dispersion of MWCNT-NH2s in the ORC gauze as matrix and their interfacial interactions by SEM and FT-IR. The results revealed that relatively strong interaction exists between aminated MWCNTs and the ORC macromolecules. The hydrophilicity test results in the significant increment of water uptake of MWCNT-NH2s/ORC composites with increasing the concentration of MWCNT-NH2s in composite. The in-vitro procoagulation test shows that the MWCNT-NH2s/ORC gauzes have significant procoagulant activity. The hemostatic evaluation of MWCNT-NH2s/ORC composites on rabbits shows that the aminated MWCNTs increase the rate of blood stopping and hence they decrease the blood loosing from injured sites. Hemostatic evaluation indicates that the MWCNT-NH2s/ORC gauze has a valuable hemostatic performance. The products of platelets release reaction, activated platelets glycoprotein and activated clotting enzymes were increased simultaneously. The mechanism of the hemostasis for MWCNT-NH2s/ORC gauze is discussed.

Synthesis and Performance of Dopa-Modified Multiwalled Carbon Nanotubes

2012 ◽  
Vol 184-185 ◽  
pp. 1289-1293
Author(s):  
Lu Zhi Wang ◽  
Lin Yu ◽  
Xiao Ling Cheng ◽  
Jun He ◽  
Le Jia Lin ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Multiwalled Nanotubes ◽  
Mixed Acid ◽  
Transmission Electron ◽  
Ft Ir ◽  
And Performance

The Dopamine-modified multiwalled carbon nanotubes (MWNT-Dopa) were synthesized by chemical reaction between dopamine (Dopa) and multiwalled carbon nanotubes which oxidazed by mixed-acid (MWNT-COOH). The structure of MWNT-Dopa were analyzed by Fourier transform infrared spectroscopy (FT-IR), Thermogravimetric (TG), Transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) techniques and the dispersity of MWNT-Dopa were studied by Dispersion stability analyzer. The results show that dopamine has been grafted on multiwalled carbon nanotubes successfully, and a dopamine layer which wraps on the surface of multiwalled nanotubes make multiwalled nanotubes have outstanding dispersity in water.

scholarly journals Sulfonitric Treatment of Multiwalled Carbon Nanotubes and Their Dispersibility in Water

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2442 ◽  
Author(s):  
Hui Liu ◽  
Jianfeng Wang ◽  
Jiachen Wang ◽  
Suping Cui
Keyword(s):  
Carbon Nanotubes ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Multiwalled Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Oxidation Degree ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Scattering Measurements ◽  
Ft Ir

In this study, Multiwalled carbon nanotubes (MWCNTs) were oxidized by a mixture of sulfuric acid and nitric acid (V:V = 3:1) at 70 °C for 1, 2, and 4 h, respectively. The oxidized MWCNTs were characterized by N2 adsorption, Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), and Raman spectroscopy to determine the oxidation degree. The dispersion of the MWCNTs was investigated by UV-vis-NIR, SEM, and dynamic light scattering measurements. Results show that sulfonitric treatment increased the surface area and total pore volume and reduced the average pore diameter of MWCNTs. The treatment promoted the formation of oxidized species on the surface MWCNTs, as identified by FT-IR, TGA, and X-ray photoelectron spectroscopy measurements, and more oxygen-containing functional groups were generated when treatment time was extended. Moreover, a general relationship between oxidation degree and dispersibility of MWCNTs in water was established. UV-vis-NIR and dynamic light scattering measurements and SEM images revealed that MWCNTs with higher oxidation degree showed better dispersibility in water.

Ar Plasma Modified Multiwalled Carbon Nanotubes/NiFe2O4/Polyimide Nanocomposites

2011 ◽  
Vol 399-401 ◽  
pp. 394-398 ◽  
Author(s):  
Lei Zhang ◽  
Jia Jun Li ◽  
Chun Sheng Shi ◽  
En Zuo Liu ◽  
Nai Qin Zhao
Keyword(s):  
Carbon Nanotubes ◽  
Plasma Treatment ◽  
Structural Damage ◽  
Mechanical Test ◽  
Dielectric Barrier Discharge Plasma ◽  
Multiwalled Carbon ◽  
Temperature Plasma ◽  
Physico Chemical ◽  
Barrier Discharge Plasma ◽  
Ft Ir

The emphasis of this study was surface modification on MWNTs by dielectric barrier discharge plasma at atmospheric pressure. The effects of the plasma treatment on the MWNTs were characterized by SEM, XRD and FT-IR. The results show that surface of carbon nanotubes (CNTs) emerge carboxyl group, and the plasma modified CNTs by a physico chemical adsorption without structural damage. Modified CNTs/ferrite/polyimide nanocomposites, were prepared and mechanical test demonstrate the low temperature plasma treatment is an effective way to improve interfical bonding bewteen CNTs and polyimide (PI) matrix.

Enhanced Photoluminescence Effect of Poly(L-lactide) Biodegradable Polymer with Functionalized Carbon Nanotubes

2013 ◽  
Vol 829 ◽  
pp. 304-308 ◽  
Author(s):  
Maryam Amirian ◽  
Ali Nabipour Chakoli ◽  
Hossein Zamani Zeinali ◽  
Hossein Afarideh
Keyword(s):  
Carbon Nanotubes ◽  
Oxygen Vacancies ◽  
Blue Shift ◽  
Polymer Chains ◽  
Multiwalled Carbon ◽  
Enhanced Photoluminescence ◽  
Pristine Mwcnts ◽  
Ft Ir ◽  
Amine Groups

Functionalization of Multiwalled Carbon Nanotubes (MWCNTs) for biological applications was considered. For this purpose, the pristine MWCNTs (pMWCNTs) are covalently aminated using p-amino benzoic acid and phosphoric acid without shortening of pMWCNTs. The grafted amine groups on the sidewall of pMWCNTs are useful as initiator for grafting of polymer chains on the sidewall of aminated MWCNTs (MWCNT-NH2). The PLLA homopolymer chains grafted covalently from the sidewall of aminated MWCNTs successfully. The FT-IR spectra revealed that the amine groups and the PLLA chains grafted form the sidewall of pMWCNTs strongly. The fluoroscopy test results shows that the pMWCNTs and aminated MWCNTs have not any significant photoluminescence (PL) effect at 350 nm excitation. The MWCNT-g-PLLAs exhibit an extremely strong visible emission at 404 nm and 429 nm. These results may be ascribed to the contribution of oxygen vacancies and defects at the end chain of grafted PLLA chains on the sidewall of MWCNTs that created by Sn atoms of initiator during polymerization on the sidewall of MWCNTs. The oxygen vacancies usually act as radiative centers in the PL process. In addition, The MWCNT-g-PLLAs enhance the PL of neat PLLA. The PL of composites slightly diminishes with blue shift during in-vitro degradation. As mentioned above, the MWCNT-g-PLLAs are the functionalized MWCNTs that applicable in the field of medicine. Due to biocompatible and biodegradable molecular groups on the sidewall of MWCNTs, it is predictable that the MWCNT-g-PLLAs will pass all exams for its application in medicine.

scholarly journals Epoxy Nanocomposites Reinforced with Functionalized Carbon Nanotubes

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1816
Author(s):  
Anton Mostovoy ◽  
Andrey Yakovlev ◽  
Vitaly Tseluikin ◽  
Marina Lopukhova
Keyword(s):  
Carbon Nanotubes ◽  
Epoxy Composites ◽  
Chemical Compatibility ◽  
Multiwalled Carbon ◽  
Epoxy Composition ◽  
Bending Modulus ◽  
Transmission Electron ◽  
Ft Ir ◽  
Functionalized Multiwalled Carbon Nanotubes ◽  
Tensile Elastic Modulus

In this article, amino functionalized multiwalled carbon nanotubes (MWCNTs) were prepared by chemical modification of the surface of a MWCNTs using γ-aminopropyltriethoxysilane (APTES) and dispersed into the epoxy composition. The modifying agent (APTES) was directly deposited on the MWCNTs surfaces. For the functionalization of MWCNTs, was used not the APTES concentrate, as it had been described in previous works, but its freshly prepared aqueous solution. Properties of APTES-treated MWCNTs were characterized by transmission electron microscope (TEM), Raman spectroscopy and FT-IR. The results showed that the functionalization and chemical compatibility of APTES-treated MWCNTs with epoxy composition provides their best dispersion in the epoxy composition, had important influence on curing behavior, structure and physicochemical properties of the epoxy composites plasticized with trichloroethyl phosphate. The results showed that the functionalization and chemical compatibility of APTES-treated MWCNTs with epoxy composition provides increased of physicomechanical properties of epoxy composites: bending stress increases by 194% and bending modulus increases by 137%, the tensile strength increases by 108% and the tensile elastic modulus increases by 52%, impact strength increases by 300%, in comparison with plasticized epoxy composite that does not contain MWCNTs.

Preparation and Structure of Amino-Modified Multi-Walled Carbon Nanotubes

2015 ◽  
Vol 1096 ◽  
pp. 441-445
Author(s):  
Yun Hua Li ◽  
Jun Fen Sun
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Elemental Analysis ◽  
Chemical Structure ◽  
Ethylene Diamine ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multi Walled Carbon Nanotubes ◽  
Ft Ir ◽  
Walled Carbon Nanotubes

Carboxylic multi-walled carbon nanotubes (MWCNTs-COOH) were modified by using ethylene diamine (EDA) to prepare amino-modified multi-walled carbon nanotubes (MWCNTs-NH2). The chemical structure of MWCNTs-NH2 was characterized by FT-IR, Raman spectroscopy, X-ray diffraction (XRD) test, TG analysis and elemental analysis. The results show that MWCNTs-COOH was effectively modified by EDA. Key words: MWCNTs-COOH; ethylene diamine; chemical modification; elemental analysis

scholarly journals Utilizing Fullerenols as Surfactant for Carbon Nanotubes Dispersions Preparation

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Jianlong Ji ◽  
Chang Qiao ◽  
Yali Liu ◽  
Wendong Zhang ◽  
Shengbo Sang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Raman Spectra ◽  
Surfactant Concentration ◽  
Ph Value ◽  
Multiwalled Carbon ◽  
Sem Images ◽  
Factors Influencing ◽  
Ft Ir ◽  
Ir And Raman

Dispersions of individual carbon nanotubes (CNTs) are crucial for nanodevices and polymer/CNTs nanocomposites. In this paper, stable and homogenous dispersions of individual multiwalled carbon nanotubes (MWCNTs) have been synthesized. The factors influencing the dispersibility mechanism, including the surfactant concentration and the pH value, have been investigated. SEM images display the impurities sticking on MWCNTs which have been removed. The oxygen-containing groups on the surface of MWCNTs sample have been detected through FT-IR and Raman spectra. All experimental results illustrate that using fullerenols as surfactant can greatly improve the dispersibility of MWCNTs. Moreover, the prepared dispersions exhibit good stability that the sediment percentage of fullerenols-MWCNTs is only 5.2% after 5 days.

Microwave Absorption Study of Polyaniline Nanocomposites with Different Dimension of Multiwalled Carbon Nanotubes

2016 ◽  
Vol 846 ◽  
pp. 465-470
Author(s):  
Yen Nee Koh ◽  
Nurrafiqah Mokhtar ◽  
Sook Wai Phang
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Structure ◽  
Multiwall Carbon Nanotubes ◽  
Dielectric Permeability ◽  
Chemical Oxidation ◽  
Network Analyzer ◽  
Vibrating Sample Magnetometer ◽  
Multiwalled Carbon ◽  
Magnetization Behavior ◽  
Multiwall Carbon

Polyaniline (PAni) Nanocomposites Containinganiline (Ani) Monomer and Hexanoic Acid (HA) Dopant were Successfullysynthesized by Using Chemical Oxidation Method. Titanium Dioxide (TiO2)and Different Dimension of Multiwall Carbon Nanotubes (MWNT) Have been Added Inorder to Improve the Dielectric Permeability and Magnetic Permittivityproperties of the Pani Nanocomposites. Fourier Transform Infrared (FTIR) Andultraviolet-Visible (UV-Vis) Spectra Confirmed the Chemical Structure of Paninanocomposites. Conductivity and Magnetization Behavior were Investigated Byresistivity Meter and Vibrating Sample Magnetometer (VSM). Microwave Absorptionstudies were Carried out by Microwave Vector Network Analyzer (MVNA) from 0.5to 18 Ghz. among all the Pani Nanocomposites, Pani Nanocomposites with MWNT (D = 10-2- Nm, l = 5-15 μm) Shows Agood Reflection Loss (RL = -58 Db) at 7 Ghz with a Sharp and Narrow Peak due Tohigher Values of Magnetization (0.074 Emu/g) Andmoderate Electrical Conductivity (1.11 x 10-2 S/cm)

scholarly journals REMOVAL OF O,M,P-XYLENE FROM AIR SAMPLES ON OXIDIZED CARBON NANOTUBES CARTRIDGES

2018 ◽  
Vol 56 (2A) ◽  
pp. 226-233
Author(s):  
Le Huu Quynh Anh
Keyword(s):  
Carbon Nanotubes ◽  
Selective Adsorption ◽  
Multiwalled Carbon ◽  
Air Samples ◽  
Pristine Cnts ◽  
Oxidized Carbon ◽  
Oxidized Carbon Nanotubes ◽  
Cnts Surface ◽  
Ft Ir ◽  
Xylene Isomers

Carbon nanotubes (CNTs) have been considered as an excellent adsorbent in environmental engineering, especially for treatment of volatile organic compounds (VOCs). The paper presents a new approach for the selective adsorption of Xylene isomers from air samples using nanomaterial based on oxidized multiwalled carbon nanotubes. In the first study, the functionalization of two oxidized MWCNTs was achieved with hydrogen peroxide and sodium hypochlorite. The characterization of functionalized CNTs (CNT-NaOCl, CNT-H2O2) was performed by Fourier transform infrared spectroscopy (FT-IR) and X-Ray diffractometer (XRD). Afterthat, the applications of pristine CNTs and oxidized CNTs for removal of three Xylene isomers from air samples were discussed. The results demonstrate that the correlation of CNTs and three isomers was significantly different with an affinity order o-Xylene > m-Xylene > p-Xylene. The oxidized CNTs with carbonyl groups increased significantly its adsorption capacity for these isomers. A comparison in term of adsorption performance shows that the framework distinguishes among these adsorbents due to the dispersive properties and the electrostatic interaction between the Xylene isomers and oxidized CNTs surface.

Sign in / Sign up

Export Citation Format

Share Document