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Dispersions of Goethite Nanorods in Aprotic Polar Solvents

Colloidal suspensions of anisotropic nanoparticles can spontaneously self-organize in liquid-crystalline phases beyond some concentration threshold. These phases often respond to electric and magnetic fields. At lower concentrations, usual isotropic liquids are observed but they can display very str...

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Autores principales: Coursault, Delphine, Dozov, Ivan, Blanc, Christophe, Nobili, Maurizio, Dupont, Laurent, Chanéac, Corinne, Davidson, Patrick
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5666997/
https://www.ncbi.nlm.nih.gov/pubmed/29039797
http://dx.doi.org/10.3390/ma10101191
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author Coursault, Delphine
Dozov, Ivan
Blanc, Christophe
Nobili, Maurizio
Dupont, Laurent
Chanéac, Corinne
Davidson, Patrick
author_facet Coursault, Delphine
Dozov, Ivan
Blanc, Christophe
Nobili, Maurizio
Dupont, Laurent
Chanéac, Corinne
Davidson, Patrick
author_sort Coursault, Delphine
collection PubMed
description Colloidal suspensions of anisotropic nanoparticles can spontaneously self-organize in liquid-crystalline phases beyond some concentration threshold. These phases often respond to electric and magnetic fields. At lower concentrations, usual isotropic liquids are observed but they can display very strong Kerr and Cotton-Mouton effects (i.e., field-induced particle orientation). For many examples of these colloidal suspensions, the solvent is water, which hinders most electro-optic applications. Here, for goethite (α-FeOOH) nanorod dispersions, we show that water can be replaced by polar aprotic solvents, such as N-methyl-2-pyrrolidone (NMP) and dimethylsulfoxide (DMSO), without loss of colloidal stability. By polarized-light microscopy, small-angle X-ray scattering and electro-optic measurements, we found that the nematic phase, with its field-response properties, is retained. Moreover, a strong Kerr effect was also observed with isotropic goethite suspensions in these polar aprotic solvents. Furthermore, we found no significant difference in the behavior of both the nematic and isotropic phases between the aqueous and non-aqueous dispersions. Our work shows that goethite nanorod suspensions in polar aprotic solvents, suitable for electro-optic applications, can easily be produced and that they keep all their outstanding properties. It also suggests that this solvent replacement method could be extended to the aqueous colloidal suspensions of other kinds of charged anisotropic nanoparticles.
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spelling pubmed-56669972017-11-09 Dispersions of Goethite Nanorods in Aprotic Polar Solvents Coursault, Delphine Dozov, Ivan Blanc, Christophe Nobili, Maurizio Dupont, Laurent Chanéac, Corinne Davidson, Patrick Materials (Basel) Article Colloidal suspensions of anisotropic nanoparticles can spontaneously self-organize in liquid-crystalline phases beyond some concentration threshold. These phases often respond to electric and magnetic fields. At lower concentrations, usual isotropic liquids are observed but they can display very strong Kerr and Cotton-Mouton effects (i.e., field-induced particle orientation). For many examples of these colloidal suspensions, the solvent is water, which hinders most electro-optic applications. Here, for goethite (α-FeOOH) nanorod dispersions, we show that water can be replaced by polar aprotic solvents, such as N-methyl-2-pyrrolidone (NMP) and dimethylsulfoxide (DMSO), without loss of colloidal stability. By polarized-light microscopy, small-angle X-ray scattering and electro-optic measurements, we found that the nematic phase, with its field-response properties, is retained. Moreover, a strong Kerr effect was also observed with isotropic goethite suspensions in these polar aprotic solvents. Furthermore, we found no significant difference in the behavior of both the nematic and isotropic phases between the aqueous and non-aqueous dispersions. Our work shows that goethite nanorod suspensions in polar aprotic solvents, suitable for electro-optic applications, can easily be produced and that they keep all their outstanding properties. It also suggests that this solvent replacement method could be extended to the aqueous colloidal suspensions of other kinds of charged anisotropic nanoparticles. MDPI 2017-10-17 /pmc/articles/PMC5666997/ /pubmed/29039797 http://dx.doi.org/10.3390/ma10101191 Text en © 2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Coursault, Delphine
Dozov, Ivan
Blanc, Christophe
Nobili, Maurizio
Dupont, Laurent
Chanéac, Corinne
Davidson, Patrick
Dispersions of Goethite Nanorods in Aprotic Polar Solvents
title Dispersions of Goethite Nanorods in Aprotic Polar Solvents
title_full Dispersions of Goethite Nanorods in Aprotic Polar Solvents
title_fullStr Dispersions of Goethite Nanorods in Aprotic Polar Solvents
title_full_unstemmed Dispersions of Goethite Nanorods in Aprotic Polar Solvents
title_short Dispersions of Goethite Nanorods in Aprotic Polar Solvents
title_sort dispersions of goethite nanorods in aprotic polar solvents
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5666997/
https://www.ncbi.nlm.nih.gov/pubmed/29039797
http://dx.doi.org/10.3390/ma10101191
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