Polymer Binding to Carbon Nanotubes in Aqueous Dispersions: Residence Time on the Nanotube Surface As Obtained by NMR Diffusometry

Frise, Anton; Pagès, Guilhem; Shtein, Michael; Bar, Ilana; Regev, Oren; Furó, István

doi:10.1021/jp209800u

Cited by 38 publications

(74 citation statements)

References 54 publications

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“…PFG-NMR techniques have already been used to study the interaction between CNTs and Pluronic F127 and bovine serum albumin surfactant molecules. [46][47][48] The aim of the present study was to use the PFG-NMR technique to directly observe the exchange of surfactants and the formation of the corona structures around the SWCNTs. We prepared three aqueous SWCNT dispersions each containing a common surfactant used for in vivo and in vitro toxicity assessments: Tween 80, Triton X-100, or Pluronic F127.…”

Section: Introductionmentioning

confidence: 99%

Behavior of surfactants in aqueous dispersions of single-walled carbon nanotubes

2014

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Three aqueous dispersions of single-walled carbon nanotubes (SWCNTs) were prepared with different industrial surfactants: Tween 80, Triton X-100, and Pluronic F127. The pulsed field gradient (PFG)-NMR method showed that the mole fraction ratios of secondary particles composed of SWCNTs and surfactant were approximately 10 : 1 for SWCNT/Tween 80 and SWCNT/Triton X-100, and 5 : 1 for SWCNT/Pluronic F127. When the SWCNTs were dispersed in the aqueous surfactant solutions, the transverse relaxation times of the surfactants were dramatically reduced, indicating that all the surfactant molecules were bound to or interacted with the SWCNTs. After the SWCNT dispersions were mixed with aqueous solutions of artificial lung surfactant (ALS), the industrial surfactants remained strongly adsorbed to the surface of SWCNTs and were not exchanged with ALS. The zeta potentials for the mixtures of the SWCNT dispersions with the ALS solution were similar to the initial values for the SWCNT dispersions, which was consistent with the PFG-NMR results. Our results are significant for determining the inherent toxicity of SWCNTs in vivo.

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Section: Introductionmentioning

confidence: 99%

Behavior of surfactants in aqueous dispersions of single-walled carbon nanotubes

2014

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“…Bundling of nanotubes was possible because the Pluronic F127 dispersing agent was physically adsorbed to the nanotubes, and it could have dissociated from the nanotubes or exchanged with other molecules within the embryo (Cherukuri et al 2006; Frise et al 2012), allowing for bundling of nanotubes via van der Waals interactions that have been estimated to have a strength of 40 k B T /nm (Girifalco et al 2000). We note that uncoated nanotubes are highly hydrophobic and readily bundle in aqueous conditions.…”

Section: Discussionmentioning

confidence: 99%

Developing Xenopus embryos recover by compacting and expelling single wall carbon nanotubes

Holt

Shawky

Dahl

et al. 2015

J of Applied Toxicology

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Single-wall carbon nanotubes are high aspect ratio nanomaterials that are being developed for use in materials, technological and biological applications due to their high mechanical stiffness, optical properties, and chemical inertness. Because of their prevalence, it is inevitable that biological systems will be exposed to nanotubes, yet studies of the effects of nanotubes on developing embryos have been inconclusive and are lacking for single-wall carbon nanotubes exposed to the widely studied model organism Xenopus laevis (African clawed frog). Microinjection of experimental substances into the Xenopus embryo is a standard technique for toxicology studies and cellular lineage tracing. Here we report the surprising finding that superficial (12.5 ± 7.5 μm below the membrane) microinjection of nanotubes dispersed with Pluronic F127 into one-to-two cell Xenopus embryos resulted in the formation and expulsion of compacted, nanotube-filled, punctate masses, at the blastula to mid-gastrula developmental stages, which we call “boluses”. Such expulsion of microinjected materials by Xenopus embryos has not been reported before and is dramatically different from the typical distribution of the materials throughout the progeny of the microinjected cells. Previous studies of microinjections of nanomaterials such as nanodiamonds, quantum dots or spherical nanoparticles report that nanomaterials often induce toxicity and remain localized within the embryos. In contrast, our results demonstrate an active recovery pathway for embryos after exposure to Pluronic F127-coated nanotubes, which we speculate is due to a combined effect of the membrane activity of the dispersing agent, Pluronic F127, and the large aspect ratio of nanotubes.

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“…In particular, the Kärger equations 42,43 form the framework for extracting kinetic exchange parameters from PGSE NMR measurements where exchanges, including dipolar cross-relaxation (via spin diffusion), occur on an intermediate timescale. [44][45][46][47][48] Given the presence of two hydroxyl groups and potential contributions from direct and relayed dipolar cross-relaxation in LCPs, the apparent zero-crossing, pseudo diffraction-like phenomenon of water signal attenuation in LCPs (Fig. 3A) should be considered as the collective outcome of multiple sites involved in magnetization exchange with water.…”

Section: Figmentioning

confidence: 99%

Water diffusion in complex systems measured by PGSE NMR using chemical shift selective stimulated echo: Elimination of magnetization exchange effects

Meikle

Keizer

Separovic

et al. 2021

The Journal of Chemical Physics

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The interpretation of molecular translational diffusion as measured by pulsed gradient spinecho NMR (PGSE NMR) can be complicated by the presence of chemical exchange and/or dipolar cross-relaxation (including relayed cross-relaxation via spin diffusion). The magnitude of influence depends on the kinetics of exchange and/or dipolar cross-relaxation present within the system as well as the PGSE NMR sequences chosen for the measurements. Firstly, we present an exchange induced zero-crossing phenomenon for signal attenuation of water in lipidic cubic phases (LCPs, formed by a mixture of monoolein and water) in the presence of pulsed gradients observed using a standard STimulated Echo (STE) sequence. This magnetization exchange induced zero-crossing phenomenon, a pseudo negative diffractionlike feature, resembles that reported previously for restricted diffusion when locally anisotropic pores are polydisperse or randomly oriented. We then demonstrate the elimination of these exchange and/or dipolar cross-relaxation induced effects with the use of a chemical shift selective STE (CHESS-STE) sequence, adapted from the previously reported band-selective short transient STE (BEST-STE) sequence, along with results obtained from the bipolar pulse pair STE (BPP-STE) sequence for comparison. The CHESS-STE sequence introduced here represents a generic form of PGSE NMR sequences for obtaining water diffusion coefficients free from influence of exchange and/or dipolar cross-relaxation in complex systems. It has potential applications in measuring translational diffusion of water in biopolymer mixtures as well as probing microscopic structure in materials via water restricted diffusion measured by PGSE NMR, particularly when the potential presence of exchange/cross-relaxation is of concern.

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Polymer Binding to Carbon Nanotubes in Aqueous Dispersions: Residence Time on the Nanotube Surface As Obtained by NMR Diffusometry

Cited by 38 publications

References 54 publications

Behavior of surfactants in aqueous dispersions of single-walled carbon nanotubes

Behavior of surfactants in aqueous dispersions of single-walled carbon nanotubes

Developing Xenopus embryos recover by compacting and expelling single wall carbon nanotubes

Water diffusion in complex systems measured by PGSE NMR using chemical shift selective stimulated echo: Elimination of magnetization exchange effects

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