Preparation of hydroxamic acid functionalized uiO-66-(cooh)2 fibrous membrane adsorbents and their application in adsorbing gallium

Abstract

The application discloses preparation of hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent and belongs to the technical field of hydroxamic acid adsorbent preparation, and comprises the following steps: S1, preparing UiO-66-(COOH)2; S2, preparing UiO-66-COOCH3; S3, preparing UiO-66-HA; and S4, preparing PAN / UiO-66-HA membrane; the prepared PAN / UiO-66-HA membrane has the characteristics of easy preparation, green and environment-friendly preparation process, adsorption of gallium ions from trace gallium solution under acidic conditions, high selective adsorption rate, fast adsorption rate and easy recycling.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hydroxamic acid adsorbent preparation, and particularly relates to preparation of a hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent and application thereof in adsorption of gallium. BACKGROUND

[0002] Gallium is listed as a strategic metal by China, the United States and the European Union, is a "high-tech element" of high-tech industry, and is widely used in electronic communication, new energy, chips, low-melting-point alloys and military fields.

[0003] The abundance of gallium in the earth's crust is only 17 mg / L, which is a typical dispersed metal, and most of it exists in the form of associated ore, making it difficult to extract gallium ions.

[0004] At present, the methods for extracting gallium generally include ion exchange method, solvent extraction method, chlorination separation method, electrodeposition separation method and adsorption method. Among them, the ion exchange method, solvent extraction method, chlorination separation method and electrodeposition separation method have problems of generation of harmful gas, high cost and unstable separation process in the extraction process, so the adsorption method is more widely used.

[0005] Metal organic framework materials have high specific surface area, adjustable pore structure and rich active sites, and are widely used in adsorption methods.

[0006] Although UiO-66-(COOH)2 is a kind of metal organic framework material, its active site is single, which leads to general adsorption effect on gallium ions, and the powder adsorbent is not easy to recycle.

[0007] In view of this, the preparation of a hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent and its application in adsorption of gallium are designed to solve the above problems. SUMMARY

[0008] To solve the problems in the background art, the application provides the preparation of a hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent and its application in adsorption of gallium, which has the characteristics of easy preparation, green and environmentally friendly preparation process, adsorption of gallium ions from trace gallium solution under acidic conditions, high selective adsorption rate, fast adsorption rate and easy recycling of powder materials.

[0009] To achieve the above purpose, the application provides the following technical scheme: the preparation of a hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent, which comprises the following steps:

[0010] S1: preparing UiO-66-(COOH)2

[0011] Zirconium tetrachloride and pyromellitic acid were dispersed in deionized water, stirred at room temperature, and then heated under reflux to obtain a white gel. The gel was centrifuged and washed with deionized water to obtain a solid. The solid was dispersed in deionized water and then heated under reflux to obtain the product. The product was centrifuged and washed with deionized water to obtain a solid. The product was dried under vacuum to obtain UiO-66-(COOH)2.

[0012] S2: Preparation of UiO-66-COOCH3

[0013] The prepared UiO-66-(COOH)2 was added to a 100 mL round-bottom flask, and methanol and trimethylsilane were added. The mixture was heated to react to obtain a solid powder. The solid powder was washed with ethanol and deionized water and dried under vacuum to obtain UiO-66-COOCH3.

[0014] S3: Preparation of UiO-66-HA

[0015] The prepared UiO-66-COOCH3 was added to the hydroxylamine free liquid, heated to react, and a solid was obtained. The solid was washed with ethanol and deionized water, and vacuum dried to obtain UiO-66-HA.

[0016] S4: Preparation of PAN / UiO-66-HA membrane

[0017] PAN was dissolved in DMF, and then the prepared UiO-66-HA was added and stirred at room temperature until it was completely dissolved to prepare a spinning solution, which was then electrospun to prepare a PAN / UiO-66-HA membrane.

[0018] Furthermore, in step S1, the amount of zirconium tetrachloride added is 2.3 g, the amount of pyromellitic acid added is 4.3 g, and the amount of deionized water added is 50 mL.

[0019] Furthermore, in step S1, the reflux heating temperature is 100° C. and the heating time is 24 h.

[0020] Furthermore, in step S2, the amount of prepared UiO-66-(COOH)2 added is 2 g, the amount of methanol added is 40 mL, and the amount of trimethylsilane added is 3 mL.

[0021] Furthermore, in step S3, the added amount of the prepared UiO-66-COOCH3 is 1.5 g.

[0022] Furthermore, in steps S2 and S3, the heating temperature of the heating reaction is 70° C. and the reaction time is 10 h.

[0023] Furthermore, in steps S1, S2 and S3, the vacuum drying temperature is 60°C and the drying time is 24 hours.

[0024] Furthermore, in step S4, the amount of PAN added was 1.0 g, the amount of DMF added was 10 mL, and the amount of UiO-66-HA added was 0.8 g.

[0025] Furthermore, in step S4, the voltage of electrospinning is 13KV and the flow rate is 5μL min -1 .

[0026] The prepared hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent is used in the adsorption of gallium.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The PAN / UiO-66-HA membrane prepared by the present invention has the characteristics of being easy to prepare, having a green and environmentally friendly preparation process, being able to adsorb gallium ions from trace gallium solutions under acidic conditions, having a high selective adsorption rate, a fast adsorption rate, and being easy to recycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The infrared, XRD and SEM images of UiO-66-HA of the present invention are shown;

[0030] Figure 2 This is the SEM image of the PAN / UiO-66-HA fiber membrane of the present invention;

[0031] Figure 3 Graph showing the static adsorption test results of the PAN fiber membrane and the PAN / UiO-66-HA fiber membrane of the present invention;

[0032] Figure 4 This is a graph showing the water flux experimental results of the PAN / UiO-66-HA fiber membrane at a ratio of 4:5 according to the present invention;

[0033] Figure 5 This is a diagram showing the selectivity experimental results of the PAN / UiO-66-HA fiber membrane at a ratio of 4:5 according to the present invention. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0035] Example 1

[0036] The present invention provides the following technical solution: Preparation of hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent, comprising the following steps:

[0037] S1: Preparation of UiO-66-(COOH)2

[0038] Take 2.3g of zirconium tetrachloride and 4.3g of pyromellitic acid and disperse them in 50mL of deionized water, stir at room temperature, and then reflux at 100℃ for 24h to obtain a white gel. Centrifuge and wash with deionized water for more than five times to obtain a solid. Disperse the solid in 50mL of deionized water and then reflux at 100℃ for 24h to obtain the product. Centrifuge and wash with deionized water to obtain a solid. Dry in vacuum at 60℃ for 24h to obtain UiO-66-(COOH)2.

[0039] S2: Preparation of UiO-66-COOCH3

[0040] 2 g of the prepared UiO-66-(COOH)2 was added to a 100 mL round-bottom flask, followed by 40 mL of methanol and 3 mL of trimethylsilane. The mixture was heated to 70 °C and reacted for 10 h to obtain a solid powder. The solid powder was washed with ethanol and deionized water and dried under vacuum at 60 °C for 24 h to obtain UiO-66-COOCH3.

[0041] S3: Preparation of UiO-66-HA

[0042] 1.5 g of the prepared UiO-66-COOCH3 was added to the hydroxylamine free liquid, heated to 70 ° C for 10 h to obtain a solid, washed with ethanol and deionized water, and dried in vacuum at 60 ° C for 24 h to obtain UiO-66-HA;

[0043] S4: Preparation of PAN / UiO-66-HA membrane

[0044] 1.0 g PAN was dissolved in 10 mL DMF, and then 0.2 g of the prepared UiO-66-HA was added and stirred at room temperature until it was completely dissolved to prepare the spinning solution. The spinning solution was heated at 13 KV and 5 μL min -1 PAN / UiO-66-HA membrane was prepared by electrospinning at a flow rate of 1.5 wt %.

[0045] Example 2

[0046] The present invention provides the following technical solution: Preparation of hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent, comprising the following steps:

[0047] S1: Preparation of UiO-66-(COOH)2

[0048] Take 2.3g of zirconium tetrachloride and 4.3g of pyromellitic acid and disperse them in 50mL of deionized water, stir at room temperature, and then reflux at 100℃ for 24h to obtain a white gel. Centrifuge and wash with deionized water for more than five times to obtain a solid. Disperse the solid in 50mL of deionized water and then reflux at 100℃ for 24h to obtain the product. Centrifuge and wash with deionized water to obtain a solid. Dry in vacuum at 60℃ for 24h to obtain UiO-66-(COOH)2.

[0049] S2: Preparation of UiO-66-COOCH3

[0050] 2 g of the prepared UiO-66-(COOH)2 was added to a 100 mL round-bottom flask, followed by 40 mL of methanol and 3 mL of trimethylsilane. The mixture was heated to 70 °C and reacted for 10 h to obtain a solid powder. The solid powder was washed with ethanol and deionized water and dried under vacuum at 60 °C for 24 h to obtain UiO-66-COOCH3.

[0051] S3: Preparation of UiO-66-HA

[0052] 1.5 g of the prepared UiO-66-COOCH3 was added to the hydroxylamine free liquid, heated to 70 ° C for 10 h to obtain a solid, washed with ethanol and deionized water, and dried in vacuum at 60 ° C for 24 h to obtain UiO-66-HA;

[0053] S4: Preparation of PAN / UiO-66-HA membrane

[0054] 1.0 g PAN was dissolved in 10 mL DMF, and then 0.4 g of the prepared UiO-66-HA was added and stirred at room temperature until it was completely dissolved to prepare the spinning solution. The spinning solution was heated at 13 KV and 5 μL min -1 PAN / UiO-66-HA membrane was prepared by electrospinning at a flow rate of 1.5 wt %.

[0055] Example 3

[0056] The present invention provides the following technical solution: Preparation of hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent, comprising the following steps:

[0057] S1: Preparation of UiO-66-(COOH)2

[0058] Take 2.3g of zirconium tetrachloride and 4.3g of pyromellitic acid and disperse them in 50mL of deionized water, stir at room temperature, and then reflux at 100℃ for 24h to obtain a white gel. Centrifuge and wash with deionized water for more than five times to obtain a solid. Disperse the solid in 50mL of deionized water and then reflux at 100℃ for 24h to obtain the product. Centrifuge and wash with deionized water to obtain a solid. Dry in vacuum at 60℃ for 24h to obtain UiO-66-(COOH)2.

[0059] S2: Preparation of UiO-66-COOCH3

[0060] 2 g of the prepared UiO-66-(COOH)2 was added to a 100 mL round-bottom flask, followed by 40 mL of methanol and 3 mL of trimethylsilane. The mixture was heated to 70 °C and reacted for 10 h to obtain a solid powder. The solid powder was washed with ethanol and deionized water and dried under vacuum at 60 °C for 24 h to obtain UiO-66-COOCH3.

[0061] S3: Preparation of UiO-66-HA

[0062] 1.5 g of the prepared UiO-66-COOCH3 was added to the hydroxylamine free liquid, heated to 70 ° C for 10 h to obtain a solid, washed with ethanol and deionized water, and dried in vacuum at 60 ° C for 24 h to obtain UiO-66-HA;

[0063] S4: Preparation of PAN / UiO-66-HA membrane

[0064] 1.0 g PAN was dissolved in 10 mL DMF, and then 0.6 g of the prepared UiO-66-HA was added and stirred at room temperature until it was completely dissolved to prepare the spinning solution. The spinning solution was heated at 13 KV and 5 μL min -1 PAN / UiO-66-HA membrane was prepared by electrospinning at a flow rate of 1.5 wt %.

[0065] Example 4

[0066] The present invention provides the following technical solution: Preparation of hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent, comprising the following steps:

[0067] S1: Preparation of UiO-66-(COOH)2

[0068] Take 2.3g of zirconium tetrachloride and 4.3g of pyromellitic acid and disperse them in 50mL of deionized water, stir at room temperature, and then reflux at 100℃ for 24h to obtain a white gel. Centrifuge and wash with deionized water for more than five times to obtain a solid. Disperse the solid in 50mL of deionized water and then reflux at 100℃ for 24h to obtain the product. Centrifuge and wash with deionized water to obtain a solid. Dry in vacuum at 60℃ for 24h to obtain UiO-66-(COOH)2.

[0069] S2: Preparation of UiO-66-COOCH3

[0070] 2 g of the prepared UiO-66-(COOH)2 was added to a 100 mL round-bottom flask, followed by 40 mL of methanol and 3 mL of trimethylsilane. The mixture was heated to 70 °C and reacted for 10 h to obtain a solid powder. The solid powder was washed with ethanol and deionized water and dried under vacuum at 60 °C for 24 h to obtain UiO-66-COOCH3.

[0071] S3: Preparation of UiO-66-HA

[0072] 1.5 g of the prepared UiO-66-COOCH3 was added to the hydroxylamine free liquid, heated to 70 ° C for 10 h to obtain a solid, washed with ethanol and deionized water, and dried in vacuum at 60 ° C for 24 h to obtain UiO-66-HA;

[0073] S4: Preparation of PAN / UiO-66-HA membrane

[0074] 1.0 g PAN was dissolved in 10 mL DMF, and then 0.8 g of the prepared UiO-66-HA was added and stirred at room temperature until it was completely dissolved to prepare the spinning solution. The spinning solution was heated at 13 KV and 5 μL min -1 PAN / UiO-66-HA membrane was prepared by electrospinning at a flow rate of 1.5 wt %.

[0075] Example 5

[0076] The present invention provides the following technical solution: Preparation of hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent, comprising the following steps:

[0077] S1: Preparation of UiO-66-(COOH)2

[0078] Take 2.3g zirconium tetrachloride and 4.3g pyromellitic acid and disperse them in 50mL deionized water, stir at room temperature, and then reflux at 100℃ for 24h to obtain a white gel. Centrifuge and wash with deionized water for more than five times to obtain a solid. Disperse it in 50mL deionized water and then reflux at 100℃ for 24h to obtain the product. Centrifuge and wash with deionized water to obtain a solid. Dry it in vacuum at 60℃ for 24h to obtain UiO-66-(COOH)2.

[0079] S2: Preparation of UiO-66-COOCH3

[0080] 2 g of the prepared UiO-66-(COOH)2 was added to a 100 mL round-bottom flask, followed by 40 mL of methanol and 3 mL of trimethylsilane. The mixture was heated to 70 °C and reacted for 10 h to obtain a solid powder. The solid powder was washed with ethanol and deionized water and dried under vacuum at 60 °C for 24 h to obtain UiO-66-COOCH3.

[0081] S3: Preparation of UiO-66-HA

[0082] 1.5 g of the prepared UiO-66-COOCH3 was added to the hydroxylamine free liquid, heated to 70 ° C for 10 h to obtain a solid, washed with ethanol and deionized water, and dried in vacuum at 60 ° C for 24 h to obtain UiO-66-HA;

[0083] S4: Preparation of PAN / UiO-66-HA membrane

[0084] 1.0 g of PAN was dissolved in 10 mL of DMF, and then 1.0 g of the prepared UiO-66-HA was added and stirred at room temperature until it was completely dissolved to prepare the spinning solution. The spinning solution was heated at 13 KV and 5 μL min -1 PAN / UiO-66-HA membrane was prepared by electrospinning at a flow rate of 1.5 wt %.

[0085] Comparative Example 1

[0086] The preparation of PAN fiber membrane adsorbent includes the following steps:

[0087] 1.0 g PAN was dissolved in 10 mL DMF and stirred at room temperature until completely dissolved to prepare a spinning solution. The PAN fiber membrane was prepared by electrospinning at a voltage of 13 KV and a flow rate of 5 μL min-1.

[0088] The characterization diagram of UiO-66-HA prepared in the embodiment is shown in the attached figure. Figure 1 As shown in the attached Figure 1 It can be seen that the UiO-66-HA powder material is successful and has a large specific surface area;

[0089] The SEM image of the PAN / UiO-66-HA membrane prepared in the embodiment is shown in the attached figure. Figure 2 As shown in the attached Figure 2 It can be seen that the UiO-66-HA powder material is evenly distributed in the fiber membrane;

[0090] Static adsorption experiments were performed on the PAN / UiO-66-HA membranes and PAN fiber membranes prepared in Examples 1 to 5 and Comparative Example 1;

[0091] The static adsorption experiment was performed as follows: 100 mL of a 100 mg / g gallium solution was prepared, and a static adsorption experiment was performed on the PAN / UiO-66-HA membranes and PAN fiber membranes prepared in Examples 1 to 5 and Comparative Example 1;

[0092] The results of static adsorption experiments are shown in the attached Figure 3 As shown in the attached Figure 3 It can be seen that at a ratio of 4:5, i.e., 0.8 g of PAN / UiO-66-HA membrane has the highest adsorption rate and adsorption capacity, which are 99% and 260 mg / g, respectively;

[0093] The water flux test was conducted on 0.8g of PAN / UiO-66-HA membrane at a ratio of 4:5. The results are shown in the attached figure. Figure 4 As shown in the attached Figure 4 It can be seen that at a lower water flux, the adsorption rate can reach more than 95%;

[0094] The selectivity test was conducted on 0.8 g of PAN / UiO-66-HA membrane at a ratio of 4:5. The results are shown in the attached figure. Figure 5 As shown in the attached Figure 5 It can be seen that the adsorption rate of gallium can reach 99% in the coexisting ion solution of Cu, Zn, Al and Ga, which has good selectivity. That is, the prepared hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent has good applicability in the adsorption of gallium.

[0095] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. Preparation of hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent, characterized in that: The following steps are involved: S1: Preparation of UiO-66-(COOH)2 Zirconium tetrachloride and pyromellitic acid were dispersed in deionized water, stirred at room temperature, and then heated under reflux to obtain a white gel, which was centrifuged and washed with deionized water to obtain a solid. The solid was dispersed in deionized water, then heated under reflux to obtain the product, centrifuged, washed with deionized water to obtain a solid, and dried under vacuum to obtain UiO-66-(COOH)2; S2: Preparation of UiO-66-COOCH3 The prepared UiO-66-(COOH)2 was added to a 100 mL round-bottom flask, and methanol and trimethylsilane were added. The mixture was heated to react to obtain a solid powder. The solid powder was washed with ethanol and deionized water and dried under vacuum to obtain UiO-66-COOCH3. S3: Preparation of UiO-66-HA The prepared UiO-66-COOCH3 was added to the hydroxylamine free liquid, heated to react, and a solid was obtained. The solid was washed with ethanol and deionized water, and vacuum dried to obtain UiO-66-HA. S4: Preparation of PAN / UiO-66-HA membrane PAN was dissolved in DMF, and then the prepared UiO-66-HA was added and stirred at room temperature until it was completely dissolved to prepare a spinning solution, which was then electrospun to prepare a PAN / UiO-66-HA membrane.

2. The preparation of the hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent according to claim 1, characterized in that: In step S1, the amount of zirconium tetrachloride added is 2.3 g, the amount of pyromellitic acid added is 4.3 g, and the amount of deionized water added is 50 mL.

3. The preparation of the hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent according to claim 1, characterized in that: In step S1, the reflux heating temperature is 100° C. and the heating time is 24 hours.

4. The preparation of the hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent according to claim 1, characterized in that: In the step S2, the amount of the prepared UiO-66-(COOH)2 added is 2 g, the amount of methanol added is 40 mL, and the amount of trimethylsilane added is 3 mL.

5. The preparation of the hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent according to claim 1, characterized in that: In step S3, the amount of UiO-66-COOCH3 prepared is 1.5 g.

6. The preparation of the hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent according to claim 1, characterized in that: In the steps S2 and S3, the heating temperature of the heating reaction is 70° C. and the reaction time is 10 h.

7. The preparation of the hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent according to claim 1, characterized in that: In the steps S1, S2 and S3, the vacuum drying temperature is 60°C and the drying time is 24 hours.

8. The preparation of the hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent according to claim 1, characterized in that: In step S4, the amount of PAN added was 1.0 g, the amount of DMF added was 10 mL, and the amount of UiO-66-HA added was 0.8 g.

9. The preparation of the hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent according to claim 1, characterized in that: In step S4, the voltage of electrospinning was 13KV and the flow rate was 5 μL min -1 .

10. Use of the hydroxamic acid functionalized UiO-66-(COOH)2 fiber membrane adsorbent prepared according to any one of claims 1 to 9 in adsorbing gallium.

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