Dissymetric particles (janus particles) and their method of synthesis by bipolar electrochemistry

Patent metadata

Field	Value
Publication number	US-2017130356-A1
Application number	US-201615267538-A
Country	US
Kind code	A1
Filing date	Sep 16, 2016
Priority date	Dec 22, 2010
Publication date	May 11, 2017
Grant date	—

Abstract

Dissymmetric particles also called Janus particles of micron or submicron size and methods of synthesis of Janus particles by bipolar electrochemistry, based on substrates of isotropic or anisotropic shape. The particles include an electrically conductive substrate having at least a chemically and/or physically modified part by deposit of a layer of electrochemically depositable material, and a non-modified part. The particles are of isotropic shape, and the layer of electrochemically depositable material has a specific shape delimited by a precise contour.

First claim

1 . An electrochemical method of synthesis of Janus particles based on submicron or micron electrically conductive substrates of isotropic shape, wherein said electrochemical method comprises:
forming a three-dimensional reaction medium by introducing the submicron or micron electrically conductive substrates of isotropic shape and at least one source of electrochemically depositable material in an electrolytic solution contained in an electrodeposition cell defined by two separators, said electrodeposition cell being positioned between two electrodes, the electrolytic solution having a viscosity adapted to prevent the submicron or micron electrically conductive substrates of isotropic shape from rotating; applying a potential difference between the two electrodes such as to create a sufficiently strong electric field and for a sufficiently long period of time for forming, in the entire volume of the three-dimensional reaction medium, Janus particles with a layer of the electrochemically depositable material, said layer having a predetermined specific shape delimited by a precise contour.

2 . The electrochemical method according to claim 1 , wherein the electrolytic solution is gelled.

3 . The electrochemical method according to claim 2 , wherein the electrolytic solution is one of following gels: (a) hydrogel; (b) hydrogel of agar; (c) hydrogel of agar containing, as the source of electrochemically depositable material, gold chloride; (d) hydrogel of ethylcellulose in ethanol containing, as the source of electrochemically depositable material, platinum chloride.

4 . The electrochemical method according to claim 3 , wherein the precise contour is one of following contour: (a) circular line of variable diameter; (b) point; (c) hemisphere; (d) portion of a hemisphere.

5 . The electrochemical method according to claim 4 , wherein the separators are not permeable to the submicron or micron electrically conductive substrates of isotropic shape, and are placed in a reactor of electrodeposition wrapping the three-dimensional reaction medium and containing the electrolytic solution and the electrodes, by being positioned between said electrodes such as to define:
the electrodeposition cell wherein the substrates and the source(s) of electrically conductive material are put in solution, a cathodic compartment, incorporating the electrode serving as cathode and adjacent to one of said separators, and an anodic compartment, incorporating the electrode serving as anode and adjacent to the other separator, and wherein the separators are in a waterproof material.

6 . The electrochemical method according to claim 5 , wherein the source of electrochemically depositable material is selected from the group consisting of metal ions, semi-conductors formed from metal salts, electro-polymerizable monomers, organic electro-crystallizable salts, inorganic electro-crystallizable salts, organic electro-graftable molecules, electrophoretic paints and precursors of silica-based sol-gel materials, monomers derived from pyrrole, aniline and thiophene, precursors of alkoxysilane type which are selected from methyl trimethoxysilane, tetraethoxysi lane, methyltriethoxylsilane dimethyldiethoxysilane, and combinations thereof, metal ions of gold, copper, zinc, silver, platinum and nickel.

7 . The electrochemical method according to claim 2 , wherein the precise contour is one of following contour: (a) circular line of variable diameter; (b) point; (c) hemisphere; (d) portion of a hemisphere.

8 . The electrochemical method according to claim 2 , wherein the separators are not permeable to the submicron or micron electrically conductive substrates of isotropic shape, and are placed in a reactor of electrodeposition wrapping the three-dimensional reaction medium and containing the electrolytic solution and the electrodes, by being positioned between said electrodes such as to define:
the electrodeposition cell wherein the substrates and the source(s) of electrically conductive material are put in solution, a cathodic compartment, incorporating the electrode serving as cathode and adjacent to one of said separators, and an anodic compartment, incorporating the electrode serving as anode and adjacent to the other separator, and wherein the separators are in a waterproof material.

9 . The electrochemical method according to claim 2 , wherein the source of electrochemically depositable material is selected from the group consisting of metal ions, semi-conductors formed from metal salts, electro-polymerizable monomers, organic electro-crystallizable salts, inorganic electro-crystallizable salts, organic electro-graftable molecules, electrophoretic paints and precursors of silica-based sol-gel materials, monomers derived from pyrrole, aniline and thiophene, precursors of alkoxysilane type which are selected from methyl trimethoxysilane, tetraethoxysilane, methyltriethoxylsilane dimethyldiethoxysilane, and combinations thereof, metal ions of gold, copper, zinc, silver, platinum and nickel.

10 . The electrochemical method according to claim 1 , wherein the separators are not permeable to the submicron or micron electrically conductive substrates of isotropic shape, and are placed in a reactor of electrodeposition wrapping the three-dimensional reaction medium and containing the electrolytic solution and the electrodes, by being positioned between said electrodes such as to define:
the electrodeposition cell wherein the substrates and the source(s) of electrically conductive material are put in solution, a cathodic compartment, incorporating the electrode serving as cathode and adjacent to one of said separators, and an anodic compartment, incorporating the electrode serving as anode and adjacent to the other separator, and wherein the separators are in a waterproof material.

11 . The electrochemical method according to claim 1 , wherein the source of electrochemically depositable material is selected from the group consisting of metal ions, semi-conductors formed from metal salts, electro-polymerizable monomers, organic electro-crystallizable salts, inorganic electro-crystallizable salts, organic electro-graftable molecules, electrophoretic paints and precursors of silica-based sol-gel materials, monomers derived from pyrrole, aniline and thiophene, precursors of alkoxysilane type which are selected from methyl trimethoxysilane, tetraethoxysilane, methyltriethoxylsilane dimethyldiethoxysilane, and combinations thereof, metal ions of gold, copper, zinc, silver, platinum and nickel.

12 . A device for implementing the electrochemical method according to claim 10 , wherein the device comprises an electrodeposition cell containing the electrolytic solution, said cell being bounded by separators into a sealing material outside which electrodes are positioned contiguously.

13 . Janus particles of micron or submicron size obtained by the electrochemical method according to claim 1 , said Janus particles comprising an electrically conductive substrate of isotropic shape having at least a chemically and/or physically modified part by deposit of a layer of electrochemically depositable material and an unmodified part.

14 . The Janus particles according to claim 13 , wherein the Janus particles exhibit at least two chemically and/or physically modified parts, wherein one of said at least two modified parts is covered with a layer of a first electrochemically depositable material, and the other part of said at least two modified parts is covered with a layer of a second electrochemically depositable material different from said first material, and wherein said first and second mat

Assignees

• Univ Bordeaux
• Inst Polytechnique Bordeaux
• Centre Nat Rech Scient

Inventors

• Loget Gabriel Michel Pierre
• Kuhn Alexander

Classifications

• C25D5/02

  Electroplating of selected surface areas · CPC title

• Y10T428/2991

  Coated · CPC title

• B01J13/04 Primary

  by physical processes, e.g. drying, spraying · CPC title

• C25D13/12 Primary

  characterised by the article coated · CPC title