Method for preparing composite metal oxide hollow fibre

Patent metadata

Field	Value
Publication number	US-2020062657-A1
Application number	US-201716466066-A
Country	US
Kind code	A1
Filing date	May 10, 2017
Priority date	Dec 13, 2016
Publication date	Feb 27, 2020
Grant date	—

Abstract

The invention relates to a method for preparing a composite metal oxide hollow fibre. A certain stoichiometry of composite metal oxide raw material and a polymer binding agent are added to an organic solvent, and mixed mechanically to obtain an evenly dispersed spinning solution having a suitable viscosity. After defoaming treatment, the spinning solution is extruded through a spinneret and, after undergoing a certain dry spinning process, enters an external coagulation bath; during this period, a phase inversion process occurs and composite metal oxide hollow fibre blanks are formed. The blanks are immersed in the external coagulation bath and the organic solvent is displaced; after natural drying, the blanks undergo a heat treatment process; during this period, polymer burn off, in situ reaction, and in situ sintering processes occur to obtain the composite metal oxide hollow fibre.

First claim

What is claimed is:

1 . A method for preparing composite metal oxide hollow fibers, specifically a method for obtaining composite metal oxide hollow fibers from the raw chemicals for composite metal oxides by means of directly performing phase inversion and a thermal processing step, wherein the method comprises the following steps: raw chemicals for composite metal oxides and a polymer binding agent are added to an organic solvent, and mixed mechanically to obtain an evenly dispersed spinning solution; after defoaming treatment, the spinning solution is extruded through a spinneret and filling liquid from the spinneret passes through a dry air gap into an external coagulation bath and then is solidified to form composite metal oxide hollow fiber precursors; the precursors are immersed in the external coagulation bath to displace the organic solvent; after natural drying, the precursors are placed in a high temperature furnace for sintering; and polymer burn-off, in situ reaction (i.e., solid phase reaction) and in situ sintering processes occur to obtain the composite metal oxide hollow fibers.

2 . The preparation method according to claim 1 , wherein the composite metal oxide is one or a mixture of perovskite oxide, fluorite oxide, K 2 NiF 4 oxide, pyrochlore oxide or Brownmillerite oxide.

3 . The preparation method according to claim 1 , wherein the raw chemicals for composite metal oxides are a mixture of two or more of carbonates or metal oxides, does not chemically react with the filling liquid or the coagulation bath, and has a particle size of 0.1 to 20 μm.

4 . The preparation method according to claim 1 , wherein the polymer binding agent is any one of polysulfone, polyethersulfone, polyetherimide, polyvinylidene fluoride or polyacetate cellulose.

5 . The preparation process according to claim 1 , wherein the organic solvent is any one of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide or dimethyl sulfoxide.

6 . The preparation method according to claim 1 , wherein the polymer binding agent has a mass fraction of 10% to 25% in the polymer solution; and the raw chemicals for composite metal oxides have a mass fraction of 40% to 80% in the spinning solution.

7 . The preparation method according to claim 1 , wherein the spinneret has a dry air gap (air gap) ranging from 0 to 25 cm; the filling liquid of the spinneret is one or a mixture of two or more of water, methanol, ethanol, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide or dimethyl sulfoxide, at a temperature of 5° C. to 60° C.; and the external coagulation bath is one or a mixture of two or more of water, methanol, ethanol, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide or dimethyl sulfoxide, at a temperature of 5° C. to 60° C.

8 . The preparation method according to claim 1 , wherein the sintering temperature is 1000 to 1500° C. , and the sintering holding time is 2 to 20 hours.

Assignees

• Nanjing University Of Technology

Inventors

• Jin Wanqin
• Zhu Jiawei
• Liu Zhengkun

Classifications

• C01G25/006

  Compounds containing zirconium, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• C01G51/68

  containing rare earths, e.g. (La0.3Sr0.7)CoO3 · CPC title

• C01P2002/36

  pyrochlore-type (A2B2O7) · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title

• C01G49/0054

  containing one rare earth metal, yttrium or scandium · CPC title