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

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.

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

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2019.16617 ◽

2019 ◽

Vol 19 (11) ◽

pp. 7410-7415 ◽

Cited By ~ 3

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.

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Safety Evaluation of Engineered Nanomaterials for Health Risk Assessment: An Experimental Tiered Testing Approach Using Pristine and Functionalized Carbon Nanotubes

ISRN Toxicology ◽

10.1155/2013/825427 ◽

2013 ◽

Vol 2013 ◽

pp. 1-13 ◽

Cited By ~ 18

Author(s):

Teresa Coccini ◽

Luigi Manzo ◽

Elisa Roda

Keyword(s):

Carbon Nanotubes ◽

Mtt Assay ◽

Safety Evaluation ◽

Adverse Outcomes ◽

Engineered Nanomaterials ◽

Multiwalled Carbon ◽

Pristine Mwcnts ◽

Lung Histopathology

Increasing application of engineered nanomaterials within occupational, environmental, and consumer settings has raised the levels of public concern regarding possible adverse effects on human health. We applied a tiered testing strategy including (i) a first in vitro stage to investigate general toxicity endpoints, followed by (ii) a focused in vivo experiment. Cytotoxicity of laboratory-made functionalized multiwalled carbon nanotubes (CNTs) (i.e., MW-COOH and MW-NH2), compared to pristine MWCNTs, carbon black, and silica, has been assessed in human A549 pneumocytes by MTT assay and calcein/propidium iodide (PI) staining. Purity and physicochemical properties of the test nanomaterials were also determined. Subsequently, pulmonary toxic effects were assessed in rats, 16 days after MWCNTs i.t. administration (1 mg/kg b.w.), investigating lung histopathology and monitoring several markers of lung toxicity, inflammation, and fibrosis. In vitro data: calcein/PI test indicated no cell viability loss after all CNTs treatment; MTT assay showed false positive cytotoxic response, occurring not dose dependently at exceedingly low CNT concentrations (1 μg/mL). In vivo results demonstrated a general pulmonary toxicity coupled with inflammatory response, without overt signs of fibrosis and granuloma formation, irrespective of nanotube functionalization. This multitiered approach contributed to clarifying the CNT toxicity mechanisms improving the overall understanding of the possible adverse outcomes resulting from CNT exposure.

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EFFECT OF MULTI-WALLED CARBON NANOTUBES ON THE BIODEGRADABLE BEHAVIOR OF POLY (L-LACTIDE) IN VITRO

International Journal of Modern Physics B ◽

10.1142/s0217979209061172 ◽

2009 ◽

Vol 23 (06n07) ◽

pp. 1503-1509 ◽

Cited By ~ 2

Author(s):

JIANGTAO FENG ◽

JIEHE SUI ◽

ALI NABIPOUR CHAKOLI ◽

WEI CAI

Keyword(s):

Carbon Nanotubes ◽

Casting Method ◽

In Vitro Degradation ◽

Pristine Mwcnts ◽

Neat Plla ◽

Multi Walled Carbon Nanotubes ◽

Ft Ir ◽

Walled Carbon Nanotubes

Composites based on multi-walled carbon nanotubes (MWCNTs)s and poly(L-lactide) (PLLA) were prepared by using solvent casting method. Both carboxylated MWCNTs and pristine MWCNTs were considered in order to investigate the interactions between PLLA and MWCNTs and to understand the role of the filler in the biodegradability. In vitro degradation studies were performed by measurement of weight loss, FT-IR, DSC and SEM over a 30 weeks period. Pristine MWCNTs and carboxylated MWCNTs had a different effect on the degradation of PLLA. Thermal properties of MWCNTs based PLLA composites changed compared to neat PLLA. A possible mechanism of MWCNTs effect on the degradation of PLLA was discussed.

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Effect of Size of Multiwalled Carbon Nanotubes Dispersed in Gear Oils for Improvement of Tribological Properties

Advances in Tribology ◽

10.1155/2018/2328108 ◽

2018 ◽

Vol 2018 ◽

pp. 1-13 ◽

Cited By ~ 1

Author(s):

Kodanda Rama Rao Chebattina ◽

V. Srinivas ◽

N. Mohan Rao

Keyword(s):

Carbon Nanotubes ◽

Raman Spectroscopy ◽

Ball Milling ◽

Multiwalled Carbon Nanotubes ◽

Tribological Properties ◽

Extreme Pressure ◽

Multiwalled Carbon ◽

Pristine Mwcnts ◽

Gear Oil ◽

The Stability

The aim of the paper is to investigate the effect of size of multiwalled carbon nanotubes (MWCNTs) as additives for dispersion in gear oil to improve the tribological properties. Since long pristine MWCNTs tend to form clusters compromising dispersion stability, they are mildly processed in a ball mill to shorten the length and stabilized with a surfactant before dispersing in lubricant. Investigations are made to assess the effect of ball milling on the size and structure of MWCNTs using electron microscopy and Raman spectroscopy. The long and shortened MWCNTs are dispersed in EP 140 gear oil in 0.5% weight. The stability of the dispersed multiwalled carbon nanotubes is evaluated using light scattering techniques. The antiwear, antifriction, and extreme pressure properties of test oils are evaluated on a four-ball wear tester. It is found that ball milling of MWCNTs has a strong effect on the stability and tribological properties of the lubricant. From Raman spectroscopy, it is found that ball milling time of up to 10 hours did not produce any defects on the surface of MWCNTs. The stability of the lubricant and the antiwear, antifriction, and extreme pressure properties have improved significantly with dispersion shortened MWCNTs. Ball milling for longer periods produces defects on the surface of MWCNTs reducing their advantage as oil additives.

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Synthesis of Poly(methacrylic acid-co-butyl acrylate) Grafted onto Functionalized Carbon Nanotube Nanocomposites for Drug Delivery

Polymers ◽

10.3390/polym13040533 ◽

2021 ◽

Vol 13 (4) ◽

pp. 533 ◽

Cited By ~ 1

Author(s):

Josué A. Torres-Ávalos ◽

Leonardo R. Cajero-Zul ◽

Milton Vázquez-Lepe ◽

Fernando A. López-Dellamary ◽

Antonio Martínez-Richa ◽

...

Keyword(s):

Carbon Nanotubes ◽

Drug Delivery ◽

Methacrylic Acid ◽

Butyl Acrylate ◽

Chemical Vapor ◽

Vis Spectroscopy ◽

Ir And Raman Spectroscopies ◽

Ft Ir

Design of a smart drug delivery system is a topic of current interest. Under this perspective, polymer nanocomposites (PNs) of butyl acrylate (BA), methacrylic acid (MAA), and functionalized carbon nanotubes (CNTsf) were synthesized by in situ emulsion polymerization (IEP). Carbon nanotubes were synthesized by chemical vapor deposition (CVD) and purified with steam. Purified CNTs were analyzed by FE-SEM and HR-TEM. CNTsf contain acyl chloride groups attached to their surface. Purified and functionalized CNTs were studied by FT-IR and Raman spectroscopies. The synthesized nanocomposites were studied by XPS, 13C-NMR, and DSC. Anhydride groups link CNTsf to MAA–BA polymeric chains. The potentiality of the prepared nanocomposites, and of their pure polymer matrices to deliver hydrocortisone, was evaluated in vitro by UV–VIS spectroscopy. The relationship between the chemical structure of the synthesized nanocomposites, or their pure polymeric matrices, and their ability to release hydrocortisone was studied by FT-IR spectroscopy. The hydrocortisone release profile of some of the studied nanocomposites is driven by a change in the inter-associated to self-associated hydrogen bonds balance. The CNTsf used to prepare the studied nanocomposites act as hydrocortisone reservoirs.

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Synthesis and Performance of Dopa-Modified Multiwalled Carbon Nanotubes

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.184-185.1289 ◽

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.

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Miniemulsion copolymerization of (meth)acrylates in the presence of functionalized multiwalled carbon nanotubes for reinforced coating applications

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.8.134 ◽

2017 ◽

Vol 8 ◽

pp. 1328-1337 ◽

Cited By ~ 4

Author(s):

Bertha T Pérez-Martínez ◽

Lorena Farías-Cepeda ◽

Víctor M Ovando-Medina ◽

José M Asua ◽

Lucero Rosales-Marines ◽

...

Keyword(s):

Carbon Nanotubes ◽

Multiwalled Carbon Nanotubes ◽

Miniemulsion Polymerization ◽

Polymer Chains ◽

Multiwalled Carbon ◽

Neat Polymer ◽

In Situ Composites ◽

3D Network ◽

Insoluble Polymer

Film forming, stable hybrid latexes made of methyl metacrylate (MMA), butyl acrylate (BA) and 2-hydroxyethyl methacrylate (HEMA) copolymer reinforced with modified multiwalled carbon nanotubes (MWCNTs) were synthesized by in situ miniemulsion polymerization. The MWCNTs were pretreated by an air sonication process and stabilized by polyvinylpyrrolidone. The presence of the MWCNTs had no significant effect on the polymerization kinetics, but strongly affected the polymer characteristics (T g and insoluble polymer fraction). The performance of the in situ composites was compared with that of the neat polymer dispersion as well as with those of the polymer/MWCNT physical blends. The in situ composites showed the presence of an additional phase likely due to the strong interaction between the polymer and MWNCTs (including grafting) that reduced the mobility of the polymer chains. As a result, a substantial increase of both the storage and the loss moduli was achieved. At 60 °C, which is above the main transition region of the polymer, the in situ composites maintained the reinforcement, whereas the blends behaved as a liquid-like material. This suggests the formation of a 3D network, in good agreement with the high content of insoluble polymer in the in situ composites.

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Sulfonitric Treatment of Multiwalled Carbon Nanotubes and Their Dispersibility in Water

Materials ◽

10.3390/ma11122442 ◽

2018 ◽

Vol 11 (12) ◽

pp. 2442 ◽

Cited By ~ 5

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.

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