Microporous articles with a three-dimensional porous network of acid-sintered interconnected silica nanoparticles and methods of making the same

Patent metadata

Field	Value
Publication number	US-2017173535-A1
Application number	US-201515300022-A
Country	US
Kind code	A1
Filing date	Apr 3, 2015
Priority date	Apr 11, 2014
Publication date	Jun 22, 2017
Grant date	—

Abstract

Articles are described including a first microfiltration membrane layer having a first major surface and a second major surface disposed opposite the first major surface, and a first silica layer directly attached to the first major surface of the first microfiltration membrane layer. The first silica layer includes a polymeric binder and acid-sintered interconnected silica nanoparticles arranged to form a continuous three-dimensional porous network. A method of making an article is also described, including providing a first microfiltration membrane layer having a first major surface and a second major surface disposed opposite the first major surface, and forming a first silica layer on the first major surface.

First claim

1 . A multilayer article comprising:
a) a first microfiltration membrane layer, the first microfiltration membrane layer having a first major surface and a second major surface disposed opposite the first major surface; and b) a first silica layer directly attached to the first major surface of the first microfiltration membrane layer, the first silica layer comprising a polymeric binder and a plurality of acid-sintered interconnected silica nanoparticles arranged to form a continuous three-dimensional porous network.

2 . The multilayer article of claim 1 , wherein the polymeric binder comprises poly(vinyl alcohol) (PVA), dextran, a urethane resin, or an acrylate resin.

3 . The multilayer article of claim 1 , wherein the first silica layer further comprises a surfactant.

4 . The multilayer article of claim 1 , wherein the silica nanoparticles comprise average particle size diameters less than or equal to 200 nanometers (nm).

5 . (canceled)

6 . The multilayer article of claim 1 , wherein a weight ratio of the silica nanoparticles to the polymer binder is in a range from 90:10 to 70:30.

7 . (canceled)

8 . The multilayer article of claim 1 , wherein the first microfiltration membrane comprises an asymmetric membrane.

9 . The multilayer article of claim 1 , wherein the first major surface of the first microfiltration membrane comprises an average pore size of 50 nm to 500 nm.

10 . The multilayer article of claim 1 , wherein the first silica layer comprises an average pore size of 1 nm to 100 nm.

11 . The multilayer article of claim 1 , wherein the first silica layer comprises an average thickness of 0.1 to 10.0 μm.

12 . The multilayer article of claim 1 , wherein the article is a battery separator or an ultrafiltration membrane.

13 . A method of making a multilayer article comprising:
a) providing a first microfiltration membrane layer, the first microfiltration membrane layer having a first major surface and a second major surface disposed opposite the first major surface; and b) forming a first silica layer on the first major surface, comprising a polymeric binder and a plurality of acid-sintered interconnected silica nanoparticles arranged to form a continuous three-dimensional porous network.

14 . The method of claim 13 , wherein forming the first silica layer comprises preparing a dispersion containing the polymer and the silica nanoparticles acidified with an acid having a pKa less than 3.5 to a pH in a range of 2 to 5, coating the dispersion on the substrate to form a coating, and drying the coating to form the plurality of acid-sintered silica nanoparticles.

15 . The method of claim 14 , wherein the dispersion further comprises an alcohol.

16 . The method of claim 13 , wherein the drying comprises subjecting the coating to a temperature of 40 degrees Celsius to 250 degrees Celsius.

17 . The method of claim 13 , wherein the silica nanoparticles comprise average particle size diameters less than or equal to 200 nanometers (nm).

18 . A multizone article comprising:
a) a first porous zone comprising first average pore size; and b) a second porous zone integral with the first porous zone and having a second average pore size, the second porous zone comprising a polymeric binder and a plurality of acid-sintered interconnected silica nanoparticles arranged to form a continuous three-dimensional porous network.

19 . The multizone article of claim 18 , wherein the polymeric binder comprises poly(vinyl alcohol) (PVA), dextran, a urethane resin, or an acrylate resin.

20 . The multizone article of claim 18 , wherein the silica nanoparticles comprise average particle size diameters less than or equal to 200 nanometers (nm).

21 . The multizone article of claim 18 , wherein the first porous zone comprises an asymmetric membrane and the second porous zone is integral to the asymmetric membrane at a portion comprising a smaller average pore size than the pores of a major surface of the asymmetric membrane opposite the second porous zone.

22 . The multizone article of claim 18 , wherein the second porous zone comprises an average pore size of 1 nm to 100 nm.

Assignees

• 3M Innovative Properties Co

Inventors

• Jiang Xuan
• Lin Kuan-Yin
• Mok Michelle M
• Jing Naiyong
• Dehn Derek J
• Pokorny Richard J
• Yu Ta-Hua

Classifications

• B01D67/0069

  by deposition from the liquid phase, e.g. electrochemical deposition (B01D67/0046 takes precedence) · CPC title

• B01D71/027

  Silicium oxide · CPC title

• B01D61/147 Primary

  Microfiltration · CPC title

• B01D69/148

  Organic/inorganic mixed matrix membranes · CPC title

• B01D69/105

  Support pretreatment · CPC title