High flux high efficiency nanofiber membranes and methods of production thereof

Patent metadata

Field	Value
Publication number	US-2015298065-A1
Application number	US-201514676107-A
Country	US
Kind code	A1
Filing date	Apr 1, 2015
Priority date	Oct 7, 2008
Publication date	Oct 22, 2015
Grant date	—

Abstract

A membrane is provided including a coating layer having cellulose nanofibers produced from oxidized cellulose microfibers and an electrospun substrate upon which the coating layer is applied. The nanofibers of the electrospun substrate have a diameter greater than that of the cellulose nanofibers. The membrane also has non-woven support upon which the electrospun substrate is disposed. Microfibers of the non-woven support have a diameter greater than that of the nanofibers of the electrospun substrate. Application of electrospun membrane is in microfiltration area, while the cellulose nanofiber membrane serves in ultrafiltration, nanofiltration, and reverse osmosis after chemical modification.

First claim

What is claimed is:

1 . A membrane comprising:
a coating layer comprising a mixture of nanofibers comprising PolyVinyl Alcohol (PVA) and cellulose, wherein the nanofibers are cross-linked; an electrospun substrate upon which the coating layer is applied, wherein nanofibers of the electrospun substrate have diameters greater than that of the nanofibers of the coating layer; and a non-woven support upon which the electrospun substrate is disposed, wherein microfibers of the non-woven support have diameters greater than that of the nanofibers of the electrospun substrate.

2 . The membrane of claim 1 , wherein a defined amount of the electrospun substrate is embedded into the coating layer to reinforce a mechanical strength of the coating layer.

3 . The membrane of claim 1 , wherein a maximum pore size of the electrospun substrate is approximately three times a mean pore size of the electrospun substrate when a porosity of the electrospun substrate is approximately 80%.

4 . The membrane of claim 1 , wherein a mean pore size of the electrospun substrate is approximately three times the fiber diameter of the nanofibers of the electrospun substrate, when a porosity of the electrospun substrate is approximately 80%.

5 . A membrane comprising:
a coating layer having a non-woven structure format of at least one of cellulose nanocrystals and microcrystals; an electrospun substrate having a non-woven structure format upon which the coating layer is applied, wherein nanofibers of the electrospun substrate have diameters greater than that of the cellulose nanocrystals and microcrystals; and a non-woven support upon which the electrospun substrate is disposed, wherein microfibers of the non-woven support have diameters greater than that of the nanofibers of the electrospun substrate.

6 . A method for producing a membrane, the method comprising steps of:
producing a coating layer having a non-woven structure format from polysaccharide nanofibers, wherein the polysaccharide nanofibers have diameters between 2 to 50 nanometers; immersing an electrospun substrate having a non-woven structure format into a water-based solution; and applying the coating layer to the electrospun substrate, wherein a gel barrier is formed at an interface between the electrospun substrate and the coating layer to slow diffusion of the coating layer into the electrospun substrate, and wherein nanofibers of the electrospun substrate have diameters greater than that of the polysaccharide nanofibers; wherein the electrospun substrate is disposed on a non-woven support having microfibers with diameters greater than that of the nanofibers of the electrospun substrate.

7 . The method of claim 6 , further comprising heating the coating layer after application to the electrospun substrate to cross-link the polysaccharide nanofibers.

Assignees

• Univ New York State Res Found

Inventors

• Chu Benjamin
• Hsiao Benjamin S
• Ma Hongyang

Classifications

• B01D2239/1233

  Fibre diameter · CPC title

• B01D39/18

  the material being cellulose or derivatives thereof ({cork or peat B01D39/1646} ; making filter paper D21F11/14) · CPC title

• D06M13/123

  Polyaldehydes; Polyketones · CPC title

• Y10T428/2495

  Thickness [relative or absolute] · CPC title

• Y10T428/249921

  Web or sheet containing structurally defined element or component · CPC title