Vertically Aligned Carbon Nanotubes as a Unique Material for Biomedical Applications

Kohls, August; Ditty, Mackenzie Maurer; Dehghandehnavi, Fahimeh; Zheng, Siyang

doi:10.1021/acsami.1c20423

Cited by 30 publications

(22 citation statements)

References 165 publications

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“…Jiang et al used a distillation–precipitation–polymerization approach to grow polymer chains covalently attached on the MWCNT surface and used then as nanofiller with Nafion matrix to create low energy barrier proton transport pathway . A number of interesting articles were published in recent years exploring the effect of surface functionalization of CNTs. − But no report is found to grow block copolymer chains on the CNT surface. In a series of studies, we found that the surface initiated grafting from RAFT polymerization approach allows the in situ formation of the polymer chains on the modified solid surface effectively − and hence we have chosen this technique in the current work, so that we can control the gradual growth of the block copolymer chain at the molecular level, on the surface of the CNT with better precision and check their properties.…”

Section: Introductionmentioning

confidence: 99%

Poly(N-vinyl triazole-b-N-vinyl imidazole) Grafted on MWCNTs as Nanofillers to Improve Proton Conducting Membranes

Mukherjee

Das

Jana

2022

ACS Appl. Nano Mater.

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Carbon nanotubes (CNTs) are of particular interest because of their ability to enhance the mechanical strength in the material; however, processing difficulties of CNTs often restrict utilization up to its full potential. To resolve this, in the current study, we have developed a simple and efficient method to functionalize the surface of a multiwalled carbon nanotube (MWCNT) with precise functional polymer chains, which were covalently graf ted on the surface of the MWCNT, and delved into an application to demonstrate this material as an efficient nanofiller in developing a proton conducting membrane (PEM) from polybenzimidazole (PBI). At first, the MWCNT surface was converted to a polymerizable surface by attaching a trithiocarbonate based chain transfer agent (CTA). Then, a N-heterocyclic block copolymer, namely poly-N-vinyl-1,2,4-triazole-b-poly-N-vinyl imidazole (pNVT-b-pNVI), was grown from the CTA anchored surface with a one-pot surface initiated reversible addition−fragmentation chain transfer (SI-RAFT) technique. Graf ting of block copolymer chain was confirmed by GPC, NMR, TGA, TEM, FESEM, and EDX studies. To the best of our knowledge, this will be the first report of a growing block copolymer structure graf ted covalently on the surface of the MWCNT. The novelty of the work was further enhanced by incorporating pNVT-b-pNVI-g-MWCNT as a nanofiller into the oxypolybenzimidazole (OPBI) membrane to obtain homogeneous nanocomposite membranes with excellent thermomechanical and tensile properties, thermal stability, superior proton conduction when doped with phosphoric acid (PA), and PA holding capacity. The nanocomposite membrane with 2.5 wt % nanofiller loading displayed a tensile stress of 1.8 MPa and a strain of 176% at break. The basic N-heterocyclic rings dangling from the block copolymer chains graf ted on the MWCNT surface allowed formation of strong H-bonding, acid−base interaction with PA, which is responsible for high acid uptake and superior PA retention, and also exhibited proton conductivity as high as 0.164 S cm −1 at 180 °C, which is a 2.6-fold increment when compared with a pristine OPBI membrane. This significant increase in conductivity is attributed to the proton conducting nanochannel pathway generated along the polymer-g-MWCNT surface.

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Section: Introductionmentioning

confidence: 99%

Poly(N-vinyl triazole-b-N-vinyl imidazole) Grafted on MWCNTs as Nanofillers to Improve Proton Conducting Membranes

Mukherjee

Das

Jana

2022

ACS Appl. Nano Mater.

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“…They have been tested as cold cathodes for flat displays [ 3 , 4 , 5 ] and X-ray tubes [ 6 , 7 , 8 , 9 ], tip probes in scanning probe microscopy [ 10 , 11 ], electrode materials in supercapacitors and lithium-ion batteries [ 12 , 13 , 14 ], elements of biochemical sensors [ 15 , 16 ], and THz absorbers [ 17 ]. Recent reviews summarize the progress in the synthesis of vertically aligned CNTs [ 18 ] and their use in various fields [ 19 ], including biomedical applications [ 20 ].…”

Section: Introductionmentioning

confidence: 99%

Distribution of Iron Nanoparticles in Arrays of Vertically Aligned Carbon Nanotubes Grown by Chemical Vapor Deposition

et al. 2022

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Arrays of aligned carbon nanotubes (CNTs) are anisotropic nanomaterials possessing a high length-to-diameter aspect ratio, channels passing through the array, and mechanical strength along with flexibility. The arrays are produced in one step using aerosol-assisted catalytic chemical vapor deposition (CCVD), where a mixture of carbon and metal sources is fed into the hot zone of the reactor. Metal nanoparticles catalyze the growth of CNTs and, during synthesis, are partially captured into the internal cavity of CNTs. In this work, we considered various stages of multi-walled CNT (MWCNT) growth on silicon substrates from a ferrocene–toluene mixture and estimated the amount of iron in the array. The study showed that although the mixture of precursors supplies evenly to the reactor, the iron content in the upper part of the array is lower and increases toward the substrate. The size of carbon-encapsulated iron-based nanoparticles is 20–30 nm, and, according to X-ray diffraction data, most of them are iron carbide Fe3C. The reasons for the gradient distribution of iron nanoparticles in MWCNT arrays were considered, and the possibilities of controlling their distribution were evaluated.

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“…Graphene and its derivatives are currently being explore for a multitude of applications in electronics, photocatalysis, sensors, medicine, plastics, or construction [2][3][4]. In addition, new applications of graphene and its derivates such as biomedicals applications, or its use in a wearable respiration sensor among others, have been recently published [5,6]. Considering the large commercial interest in graphene products and their fast expansion, safe and sustainable development of graphene-related materials (GRMs) in technologies and products requires close attention due to the potential impact of these materials on human health and the environment [3].…”

Section: Introductionmentioning

confidence: 99%

Nanosafety Analysis of Graphene-Based Polyester Resin Composites on a Life Cycle Perspective

et al. 2022

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The use, production, and disposal of engineering nanomaterials (ENMs), including graphene-related materials (GRMs), raise concerns and questions about possible adverse effects on human health and the environment, considering the lack of harmonized toxicological data on ENMs and the ability of these materials to be released into the air, soil, or water during common industrial processes and/or accidental events. Within this context, the potential release of graphene particles, their agglomerates, and aggregates (NOAA) as a result of sanding of a battery of graphene-based polyester resin composite samples intended to be used in a building was examined. The analyzed samples were exposed to different weathering conditions to evaluate the influence of the weathering process on the morphology and size distribution of the particles released. Sanding studies were conducted in a tailored designed sanding bench connected to time and size resolving measurement devices. Particle size distributions and particle number concentration were assessed using an optical particle counter (OPC) and a condensation particle counter (CPC), respectively, during the sanding operation. A scanning electron microscope/energy dispersive X-ray (SEM/EDX) analysis was performed to adequately characterize the morphology, size, and chemical composition of the released particles. A toxicity screening study of pristine and graphene-based nanocomposites released using the aquatic macroinvertebrate Daphnia magna and relevant human cell lines was conducted to support risk assessment and decision making. The results show a significant release of nanoscale materials during machining operations, including differences attributed to the % of graphene and weathering conditions. The cell line tests demonstrated a higher effect in the human colon carcinoma cell line Caco2 than in the human fibroblasts (A549 cell line), which means that composites released to the environment could have an impact on human health and biota.

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Vertically Aligned Carbon Nanotubes as a Unique Material for Biomedical Applications

Cited by 30 publications

References 165 publications

Poly(N-vinyl triazole-b-N-vinyl imidazole) Grafted on MWCNTs as Nanofillers to Improve Proton Conducting Membranes

Poly(N-vinyl triazole-b-N-vinyl imidazole) Grafted on MWCNTs as Nanofillers to Improve Proton Conducting Membranes

Distribution of Iron Nanoparticles in Arrays of Vertically Aligned Carbon Nanotubes Grown by Chemical Vapor Deposition

Nanosafety Analysis of Graphene-Based Polyester Resin Composites on a Life Cycle Perspective

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