METHOD FOR PREPARING TUBULAR GRAPHENE COMPOSITE MEMBRANE

Abstract

A method for preparing a graphene composite membrane on the surface of a tubular support. In the method, a tubular ceramic membrane is used as the support, a layer of graphene material is uniformly prepared on the surface of the support by vacuum suction, and the defect-free tubular graphene composite membrane is obtained by the drying process.

Claims

1. A method for preparing tubular graphene composite membrane; the specific steps are as follows: (1) Preprocessing of a support: selecting a tubular ceramic membrane as a support; drying it after flushing with water; sealing one end of the support with a sealant and connecting the other end to a vacuum pump with a pipeline; (2) Preparation of a membrane preparing solution: dissolving a graphene material into a solvent; obtaining a uniformly dispersed membrane preparing solution through ultrasonic processing; (3) Preparation of membrane: immersing the tubular support processed in Step (1) in the membrane preparing solution; starting the vacuum pump and holding for 1-12 hours after the pressure is stabilized; (4) Placing the prepared membrane in a vacuum drying oven and dry the membrane under 25° C.-50° C.

2. The method according to claim 1, wherein, the support of the tubular ceramic membrane can be a single tubular support, a multi-channel tubular support, a single tubular hollow fiber support, a multi-channel hollow fiber or a honeycomb ceramic support.

3. The method according to claim 1, wherein, the material of the tubular ceramic membrane support can be one or two of ZnO.sub.2, Al.sub.2O.sub.3, TiO.sub.2 or ZrO.sub.2.

4. The method according to claim 1, wherein, the sealant can be one of polyurethane sealant, phenolic resin sealant, silicone sealant, vulcanized silicone sealant, epoxy resin sealant or polyacrylic resin sealant.

5. The method according to claim 1, wherein, the solvent can be one of water, ethyl alcohol, DMF, methyl alcohol or DMSO.

6. The method according to claim 1, wherein, the graphene material can be one of graphene, sulfhydrylated graphene, oxidized graphene, hydroxylated graphene, aminated graphene, or carboxylated graphene.

7. The method according to claim 1, wherein, the concentration of the membrane preparing solution is 0.001-1 mg/mL.

8. The method according to claim 1, wherein, the pressure of the vacuum pump is 100-2000 Pa.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 is a schematic diagram of the membrane preparing device;

[0019] FIG. 2 is a picture of the real single tubular support in Embodiment 1;

[0020] FIG. 3 is a picture of the real 19-channel tubular support in Embodiment 2;

[0021] FIG. 4 is a picture of the real single tubular hollow fiber in Embodiment 3;

[0022] FIG. 5 is an electronic microscope photograph of the surface of the oxidized graphene membrane prepared in Embodiment 3;

[0023] FIG. 6 is an electronic microscope photograph of the cross section of the oxidized graphene membrane prepared in Embodiment 3;

[0024] FIG. 7 is a result figure of methanol/water separation of the oxidized graphene membrane prepared in Embodiment 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The embodiments in combination with the technical scheme are as follows:

Embodiment 1

Preparing a Graphene Membrane on the Surface of the Single Tubular Support With the Method Therein

[0026] (1) Preprocessing of a support : selecting a single tubular ceramic membrane (ZrO.sub.2/Al.sub.2O.sub.3) as a support (as shown in FIG. 2); drying it after flushing with water; sealing one end of the support with phenolic resin sealant and connecting the other end to a vacuum pump with a pipeline through a surge flask and a pressure regulating valve, as shown in FIG. 1.

[0027] (2) Preparation of a membrane preparing solution: dissolving the graphene into DMF with a concentration of 0.001 mg/mL; obtaining a uniformly dispersed membrane preparing solution through ultrasonic processing.

[0028] (3) Preparation of membrane: immersing the tubular support processed in Step 1 in the membrane preparing solution; starting the vacuum pump and holding for 12 hours after the pressure is stabilized at 1000 Pa.

[0029] (4) Placing the prepared membrane in a vacuum drying oven and drying the membrane under 40° C.

[0030] Through single component characterization for H.sub.2, N.sub.2, CO.sub.2 and CH.sub.4 of the graphene membrane, the result shows that the membrane has favorable hydrogen selectivity and the ideal selectivity of H.sub.2/N.sub.2, H.sub.2/CO.sub.2 and H.sub.2/CH.sub.4 reaches 67, 85 and 139 respectively.

Embodiment 2

Preparing a Animated Graphene Membrane on the Surface of the 19-Channel Tubular Support With the Method Therein

[0031] (1) Preprocessing of a support: selecting a 19-channel tubular ceramic membrane (TiO.sub.2/Al.sub.2O.sub.3) as a support (as shown in FIG. 3); drying it after flushing with water; sealing one end of the support with polyurethane sealant and connecting the other end to a vacuum pump through a pipeline, as shown in FIG. 1.

[0032] (2) Preparation of a membrane preparing solution: dissolving the aminated graphene into ethyl alcohol with a concentration of 0.03 mg/mL; obtaining a uniformly dispersed membrane preparing solution through ultrasonic processing.

[0033] (3) Preparation of membrane: immersing the tubular support processed in Step 1 in the membrane preparing solution; starting the vacuum pump and holding for 5 hours after the pressure is stabilized at 2000 Pa.

[0034] (4) Placing the prepared membrane in a vacuum drying oven and drying the membrane under 25° C.

[0035] Through single component characterization for H.sub.2, N.sub.2, CO.sub.2 and CH.sub.4 of the aminated graphene membrane, the result shows that the membrane has favorable CO.sub.2 selectivity and the ideal selectivity of CO.sub.2/N.sub.2 and CO.sub.2/CH.sub.4 reaches 35 and 72 respectively.

Embodiment 3

Preparing an Oxidized Graphene Membrane on the Surface of the Single Tubular Hollow Fiber (Al.SUB.2.O.SUB.3.) With the Method Therein

[0036] (1) Preprocessing of a support : selecting a single tubular hollow fiber as a support (as shown in FIG. 4); drying it after flushing with water; sealing one end of the support with polyacrylic resin sealant and connecting the other end to a vacuum pump through a pipeline, as shown in FIG. 1.

[0037] (2) Preparation of a membrane preparing solution: dissolving the oxidized graphene into water with a concentration of 0.1 mg/mL; obtaining a uniformly dispersed membrane preparing solution through ultrasonic processing.

[0038] (3) Preparation of membrane: immersing the tubular support processed in Step 1 in the membrane preparing solution; starting the vacuum pump and holding for 3 hours after the pressure is stabilized at 100 Pa.

[0039] (4) Placing the prepared membrane in a vacuum drying oven and drying the membrane under 50° C. The electronic microscope photographs of the surface and cross section of the prepared oxidized graphene membrane are as shown in FIGS. 5 and 6. From the figures, it can be seen that the prepared graphene is of layer structure with a smooth and complete surface.

[0040] Through methanol/water pervaporation characterization for oxidized graphene membrane, the result (in FIG. 7) shows that the membrane has favorable water permeability with a max. separation factor of 42.

Embodiment 4

Preparing a Carboxylated Graphene Membrane on the Surface of the Honeycomb Ceramic Support With the Method Therein

[0041] (1) Preprocessing of a support: selecting a honeycomb ceramic (ZnO.sub.2) as a support; drying it after flushing with water; sealing one end of the support with silicone sealant and connecting the other end to a vacuum pump through a pipeline, as shown in FIG. 1.

[0042] (2) Preparation of a membrane preparing solution: dissolving the hydroxylated graphene into DMSO with a concentration of 1 mg/mL; obtaining a uniformly dispersed membrane preparing solution through ultrasonic processing;

[0043] (3) Preparation of membrane: immersing the tubular support processed in Step 1 in the membrane preparing solution; starting the vacuum pump and holding for 1 hour after the pressure is stabilized at 500 Pa.

[0044] (4) Placing the prepared membrane in a vacuum drying oven and drying the membrane under 30° C.

[0045] Through ethyl alcohol/water pervaporation characterization for carboxylated graphene membrane, the result shows that the membrane has favorable water permeability with a max. separation factor of 63.