System and method for molecular-like hierarchical self_assembly of monolayers of mixtures of particles

Patent metadata

Field	Value
Publication number	US-10347389-B2
Application number	US-201514947536-A
Country	US
Kind code	B2
Filing date	Nov 20, 2015
Priority date	Nov 21, 2014
Publication date	Jul 9, 2019
Grant date	Jul 9, 2019

Abstract

This invention relates to a technique that uses an externally applied electric field to self-assemble monolayers of mixtures of particles into molecular-like hierarchical arrangements on fluid-liquid interfaces. The arrangements consist of composite particles which are arranged in a pattern. The structure of a composite particle depends on factors such as the relative sizes of the particles and their polarizabilities, and the electric field intensity. If the particles sizes differ by a factor of two or more, the composite particle has a larger particle at its core and several smaller particles form a ring around it. The number of particles in the ring and the spacing between the composite particles depend on their polarizabilities and the electric field intensity. Approximately same sized particles form chains in which positively and negatively polarized particles alternate, and when their polarizabilities are comparable they form tightly packed crystals.

First claim

The invention claimed is:

1. A method for producing a film which comprises:
providing a first plurality of first particles, each of the first particle having a first particle size;
providing a second plurality of second particles, each of the second particle having a second particle size;
providing the first and second pluralities of first and second articles in a fluid-fluid interface,
wherein dipole-dipole forces between the first and second particles are attractive or repulsive, and
wherein capillary forces between the first and second particles are attractive,

applying an ac or dc electric field in a direction normal to the fluid-fluid interface to form a monolayer of the first and second particles through (i) lateral movement of the first and second particles in the fluid-fluid interface and, (ii) hierarchical self-assembly of the first and second particles based on the dipole-dipole forces and capillary forces exerted therebetween;
wherein when the first article size differs from the second article size by a factor of two or more and the second particle size is larger than the first particle size, some of the first particles form a ring around one of the second particle after applying the ac or dc electric field in the direction normal to the fluid-fluid interface to form the monolayer.

2. The method of claim 1 , wherein after formation of the ring, increasing the electric field above an upper intensity range decreases the number of the first particles from the ring.

3. The method of claim 1 , wherein the second particles are selected to attach to the first particles so that the first particles can be removed from the interface.

4. The method of claim 1 , wherein the electric field induces dipole-dipole forces between the first and second particles that are attractive.

5. The method of claim 4 , wherein the electric field induces dipole-dipole forces between the first and second particles that are repulsive.

6. The method of claim 4 , wherein the electric field induces capillary forces between the first and second particles that are attractive.

7. The method of claim 1 , wherein the inter-particle distance of the monolayer is varied dynamically by changing the electric field intensity.

8. The method of claim 1 , wherein the hierarchical self-assembly of the monolayer is varied dynamically by changing the electric field intensity.

9. The method of claim 1 , wherein the first and second particles are dielectric or metals.

10. The method of claim 4 , wherein the first and second particles contain different polarizabilities which come together when the electric field is applied.

11. The method of claim 1 , further comprising embedding the monolayer of the first and second particles on a surface of the film.

12. The monolayer of the first and second particles with the hierarchical self-assembly of the first and second particles formed according to the method of claim 1 .

13. A method for producing a film which comprises:
providing a first plurality of first particles, each of the first particle having a first particle size;
providing a second plurality of second particles, each of the second particle having a second particle size;
providing the first and second pluralities of first and second particles in a fluid-fluid interface,
wherein dipole-dipole forces between the first and second particles are attractive or repulsive, and
wherein capillary forces between the first and second particles are attractive,

applying an ac or dc electric field in a direction normal to the fluid-fluid interface to form a monolayer of the first and second particles through (i) lateral movement of the first and second articles in the fluid-fluid interface and, (ii) hierarchical self-assembly of the first and second particles based on the dipole-dipole forces and capillary forces exerted therebetween;
wherein when the first particle size is comparable to the second particle size and when the polarizability of the first plurality of first particles is comparable to the polarizability of the second plurality of wecond particles, some of the first and second particles form tightly packed crystals with one another after applying the ac or dc electric field in the direction normal to the fluid-fluid interface to form the monolayer.

Assignees

• New Jersey Inst Technology

Inventors

• Singh Pushpendra

Classifications

• H01B19/00

  Apparatus or processes specially adapted for manufacturing insulators or insulating bodies {(manufacture of porcelain for electric insulation C04B33/26)} · CPC title

• H01B3/004 Primary

  with conductive additives or conductive layers · CPC title

• H01B3/002

  Inhomogeneous material in general · CPC title