Hydrophobic organic-inorganic composite hollow fiber membrane and method of forming the same

Patent metadata

Field	Value
Publication number	US-12370504-B2
Application number	US-201414467910-A
Country	US
Kind code	B2
Filing date	Aug 25, 2014
Priority date	Aug 23, 2013
Publication date	Jul 29, 2025
Grant date	Jul 29, 2025

Abstract

The invention relates to hydrophobic hollow fiber membranes, and in particular, to hydrophobic organic-inorganic composite hollow fiber membranes. Methods for forming the hydrophobic organic-inorganic composite hollow fiber membranes are also disclosed. The hydrophobic organic-inorganic composite hollow fiber membranes may be used in membrane contactor applications such as gas-liquid (G-L) contactor and liquid-liquid (L-L) contactor processes. Applications for G-L membrane contactors include gas streams purification (gas absorption), water ozonation, and water deoxygenation. Applications for L-L membrane contactors include direct contact membrane distillation and liquid-liquid extraction.

First claim

The invention claimed is:

1. A method for forming an organic-inorganic composite hollow fiber membrane comprising an organic hollow fiber membrane having inorganic nanoparticles incorporated therein, the method comprising:
(I) contacting an organic hollow fiber membrane with an aminosilane solution to obtain a silanol-functionalized organic hollow fiber membrane; and
(II) contacting, for less than five hours, the silanol-functionalized organic hollow fiber membrane formed in (I) with an alkaline solution comprising a mixture of (i) a nanoparticle precursor and (ii) a hydrophobic fluoro-compound, before the nanoparticle precursor and the hydrophobic fluoro-compound start to hydrolyse, so as to have hydrolysis, polycondensation, and fluorination of the nanoparticle precursor occur simultaneously in the presence of the hydrophobic fluoro-compound, whereby the nanoparticle precursor hydrolyzes to form fluorinated inorganic nanoparticles chemically bonded to the silanol-functionalized organic hollow fiber membrane,
and wherein the inorganic nanoparticles comprise the fluorinated inorganic nanoparticles present as an inorganic layer on the membrane surface and embedded in the organic-inorganic composite hollow fiber membrane to provide the organic-inorganic composite hollow fiber membrane with a hierarchical structure of the inorganic nanoparticles with multilevel roughness across a cross-section of the organic-inorganic composite hollow fiber membrane.

2. The method of claim 1 , wherein the organic hollow fiber membrane comprises an imide-containing polymer or copolymer.

3. The method of claim 2 , wherein the imide-containing polymer or copolymer is selected from the group consisting of polyetherimide (PEI), poly (amide-imide) (PAI), polyimide (PI), and co-polyimide of 3,3′-4,4′-benzophenone tetracarboxylic dianhydride (BTDA)-toluene diisocyanate (TDI)/methylene diisocyanate (MDI) BTDA-TDI/MDI).

4. The method of claim 1 , wherein the aminosilane solution comprises (3-aminopropyl) trimethoxysilane (APTMS), (3-aminopropyl) triethoxysilane (APTES), or (4-aminobutyl) triethoxysilane (ABTES).

5. The method of claim 1 , wherein the fluorinated inorganic nanoparticles comprise silica (SiO 2 ), aluminum oxide (Al 2 O 3 ), or titanium dioxide (TiO 2 ).

6. The method of claim 1 , wherein the hydrophobic fluoro-compound is 1H,1H,2H,2H-perfluorooctylethoxysilane (FAS), 1H,1H,2H,2H-perfluorodecyl triethoxysilane (PFTS), or perfluoropolyether.

7. The method of claim 1 , wherein the composite hollow fiber membrane comprises a PEI hollow fiber membrane having fluorinated SiO 2 nanoparticles incorporated therein.

8. The method of claim 1 , wherein the organic hollow fiber membrane is formed from a dry-jet wet spinning technique.

9. The method of claim 8 , wherein the spinning technique comprises a triple-orifice spinneret system.

10. An organic-inorganic composite hollow fiber membrane comprising an organic hollow fiber membrane having inorganic nanoparticles incorporated therein, wherein the organic-inorganic composite hollow fiber membrane is obtained from a method comprising:
(I) contacting an organic hollow fiber membrane with an aminosilane solution to obtain a silanol-functionalized organic hollow fiber membrane; and
(II) contacting, for less than five hours, the silanol-functionalized organic hollow fiber membrane formed in (I) with an alkaline solution comprising a mixture of (i) a nanoparticle precursor and (ii) a hydrophobic fluoro-compound, before the nanoparticle precursor and the hydrophobic fluoro-compound start to hydrolyse, so as to have hydrolysis, polycondensation, and fluorination of the nanoparticle precursor occur simultaneously in the presence of the hydrophobic fluoro-compound, whereby the nanoparticle precursor hydrolyzes to form fluorinated inorganic nanoparticles chemically bonded to the silanol-functionalized organic hollow fiber membrane,
and wherein the inorganic nanoparticles comprise the fluorinated inorganic nanoparticles present as an inorganic layer on the membrane surface and embedded in the organic-inorganic composite hollow fiber membrane to provide the organic-inorganic composite hollow fiber membrane with a hierarchical structure of the inorganic nanoparticles with multilevel roughness across a cross-section of the organic-inorganic composite hollow fiber membrane.

11. The method of claim 1 , wherein the fluorinated inorganic nanoparticles have an average particle size of less than 200 nm.

12. The organic-inorganic composite hollow fiber membrane of claim 10 , wherein the fluorinated inorganic nanoparticles have an average particle size of less than 200 nm.

13. The method of claim 1 , wherein the alkaline solution comprises ammonium.

14. The method of claim 1 , wherein the contacting of the silanol-functionalized organic hollow fiber membrane with the alkaline solution comprises immersing the silanol-functionalized organic hollow fiber membrane into the alkaline solution.

15. The method of claim 1 , wherein the nanoparticle precursor and the hydrophobic fluoro-compound comprise tetraethylorthosilicate (TEOS) and 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFTS), respectively.

16. The organic-inorganic composite hollow fiber membrane of claim 10 , wherein the organic-inorganic composite hollow fiber membrane is operable to have the fluorinated inorganic particles retained thereon even when the organic-inorganic composite hollow fiber membrane is subjected to ultrasonic treatment.

17. A method, comprising:
(I) forming a silanol-functionalized organic hollow fiber membrane by contacting an organic hollow fiber membrane with an aminosilane solution; and
(II) forming an organic-inorganic composite hollow fiber membrane by at least partially immersing, for less than five hours, the silanol-functionalized organic hollow fiber membrane formed in (I) in an alkaline solution comprising a mixture of (i) a nanoparticle precursor and (ii) a hydrophobic fluoro-compound, before the nanoparticle precursor and the hydrophobic fluoro-compound start to hydrolyse, so as to have hydrolysis, polycondensation, and fluorination of the nanoparticle precursor occur simultaneously in the presence of the hydrophobic fluoro-compound, whereby the nanoparticle precursor hydrolyzes to form fluorinated inorganic nanoparticles during the immersion,
and wherein the organic-inorganic composite hollow fiber membrane comprises an organic hollow fiber membrane having the fluorinated inorganic nanoparticles present as an inorganic layer on the membrane surface and embedded in the organic-inorganic composite hollow fiber membrane to provide the organic-inorganic composite hollow fiber membrane with a hierarchical structure of the inorganic nanoparticles with multilevel roughness across a cross-section of the organic-inorganic composite hollow fiber membrane.

18. The method of claim 17 , wherein the nanoparticle precursor is tetraethylorthosilicate (TEOS) and the hydrophobic fluoro-compound is 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFTS).

19. The method of claim 1 , wherein the silanol-functionalized organic hollow fiber membrane formed in (I) is immersed in the alkaline solution before the nanoparticle precursor hydrolyzes.

Assignees

• Univ Nanyang Tech

Inventors

• Wang Rong
• Zhang Yuan

Classifications

• B01D71/643

  Polyether-imides · CPC title

• B01D67/00793

  Dispersing a component, e.g. as particles or powder, in another component · CPC title

• B01D67/00931

  by introduction of specific groups after membrane formation, e.g. by grafting · CPC title

• B01D71/025

  Aluminium oxide · CPC title

• B01D69/02

  characterised by their properties · CPC title