阅读说明：本技术 一种金属有机骨架mil-101的氨基功能化修饰方法 (amino functional modification method of metal organic framework MIL-101 ) 是由 陈恒 李兵 刘云鹏 于 2019-08-09 设计创作，主要内容包括：本发明属于金属有机骨架的修饰技术领域,公开了一种金属有机骨架MIL-101的氨基功能化修饰方法,具体包括如下步骤：S1)制备MIL-101；S2)研磨MIL-101；S3)称取MIL-101研磨粉和超纯水,并其放入于烧杯中进行混合；S4)对混合后的溶液进行超声分散,分散后加入氨基偶联剂,搅拌均匀；S5)将步骤S4)形成的混合溶液放入三口烧瓶中,并进行回流处理；S6)对回流后的反应液进行离心处理,分离出反应液中反应所得的沉淀；S7)烘干沉淀,得到NH<Sub>2</Sub>-MIL-101的合成品；依据上述方法能有效实现氨基与骨架MIL-101之间的嫁接,并在保留原始骨架结构的基础上,完成对金属有机骨架MIL-101的功能化修饰；同时整体修饰方法还具有制备条件易于达到,制备操作简便的优点。(The invention belongs to the technical field of modification of metal organic frameworks, and discloses an amino functional modification method of a metal organic framework MIL-101, which specifically comprises the following steps: s1) preparing MIL-101; s2) grinding MIL-101; s3) weighing MIL-101 grinding powder and ultrapure water, and putting the MIL-101 grinding powder and the ultrapure water into a beaker for mixing; s4) carrying out ultrasonic dispersion on the mixed solution, adding an amino coupling agent after dispersion, and uniformly stirring; s5) putting the mixed solution formed in the step S4) into a three-neck flask, and performing reflux treatment; s6) carrying out centrifugal treatment on the refluxed reaction liquid, and separating out the precipitate obtained by the reaction in the reaction liquid; s7) drying and precipitating to obtain a synthetic product of NH 2-MIL-101; according to the method, grafting between amino and the framework MIL-101 can be effectively realized, and functional modification of the metal organic framework MIL-101 is completed on the basis of keeping the original framework structure; meanwhile, the integral modification method also has the advantages of easy achievement of preparation conditions and simple and convenient preparation operation.)

1. an amino functional modification method of a metal organic framework MIL-101 is characterized in that amino on an amino coupling agent is grafted on the framework MIL-101, and the method specifically comprises the following steps:

S1) dissolving 4-nitroimidazole, terephthalic acid and chromium nitrate nonahydrate in deionized water according to the concentration ratio of 1: 2, stirring until the mixture is completely dissolved, putting the mixture into a reaction kettle, crystallizing the mixture for 5 days in a drying box at 150 ℃, naturally cooling the crystallized mixture to room temperature, and centrifugally collecting and drying the crystallized mixture to obtain MIL-101;

s2) grinding the prepared MIL-101 into powder;

s3) weighing MIL-101 grinding powder and ultrapure water according to the mass ratio of 1: 50-60, and putting the MIL-101 grinding powder and the ultrapure water into a beaker for mixing;

S4) carrying out ultrasonic dispersion on the mixed solution until the mixed solution is dispersed, adding an amino coupling agent, and uniformly stirring;

S5) putting the mixed solution formed in the step S4) into a three-neck flask, and performing reflux treatment at 100 ℃, wherein the covalent bonding between amino groups in the amino coupling agent and hydroxyl groups in MIL-101 is realized in the reflux treatment;

s6) carrying out centrifugal treatment on the refluxed reaction liquid, and separating out the precipitate obtained by the reaction in the reaction liquid;

S7) drying and precipitating to obtain a synthetic product of NH 2-MIL-101.

2. The method for amino-functional modification of metal-organic framework MIL-101 as claimed in claim 1, wherein: the centrifugal collection in the step S1) means that the collection is completed by centrifuging for 10 minutes under the condition that the rotating speed is 10000 r/min.

3. the method for amino-functional modification of metal-organic framework MIL-101 as claimed in claim 1, wherein: the drying temperature in step S1) was 50 ℃.

4. the method for amino-functional modification of metal-organic framework MIL-101 as claimed in claim 1, wherein: in the step S4), the amino coupling agent is amino trimethoxy silane coupling agent.

5. The method for amino-functional modification of metal-organic framework MIL-101 as claimed in claim 1, wherein: the drying temperature in step S7) was 80 ℃.

Technical Field

the invention belongs to the technical field of modification of metal organic frameworks, and particularly relates to an amino functional modification method of a metal organic framework MIL-101.

background

The metal-organic framework is a novel crystalline porous material which is formed by metal ions or metal clusters and organic ligands through coordination bonds and has a periodic infinite topological structure, and has the advantages of high porosity, large specific surface area, various structures and the like;

according to the prior art, functional groups are introduced into a metal organic framework in a certain way, and the functional metal organic framework is constructed, so that the service performance of the metal organic framework can be improved;

however, most of the functional modification methods used in the prior art have problems of complicated steps and difficulty in modification conditions, and thus it is necessary to provide a modification method that is simple in both operation and modification conditions.

disclosure of Invention

The invention aims to provide an amino functional modification method of a metal organic framework MIL-101, so as to meet the requirement of preparing a functional metal organic framework more simply and conveniently in the background technology.

in order to achieve the purpose, the invention provides the following technical scheme: an amino functional modification method of a metal organic framework MIL-101 specifically comprises the following steps:

s1) dissolving 4-nitroimidazole, terephthalic acid and chromium nitrate nonahydrate in deionized water according to the concentration ratio of 1: 2, stirring until the mixture is completely dissolved, putting the mixture into a reaction kettle, crystallizing the mixture for 5 days in a drying box at 150 ℃, naturally cooling the crystallized mixture to room temperature, centrifuging the crystallized mixture for 10 minutes at the rotation speed of 10000 r/min to obtain a precipitate, and drying the precipitate in the drying box at 50 ℃ to obtain MIL-101;

S2) grinding the prepared MIL-101 into powder;

s3) weighing MIL-101 grinding powder and ultrapure water according to the mass ratio of 1: 50-60, and putting the MIL-101 grinding powder and the ultrapure water into a beaker for mixing; for example: when the dosage of MIL-101 is 0.30g, the dosage of ultrapure water is 15 ml; in the following examples: when the dosage of MIL-101 is 0.50g, the dosage of ultrapure water is 30 ml;

s4) carrying out ultrasonic dispersion on the mixed solution until the mixed solution is dispersed, adding an amino trimethoxy silane coupling agent, and uniformly stirring;

s5) putting the mixed solution formed in the step S4) into a three-neck flask, and performing reflux treatment at the temperature of 100 ℃, wherein the covalent bonding between the amino group in the amino trimethoxy silane coupling agent and the hydroxyl group in the MIL-101 is realized in the reflux treatment;

s6) carrying out centrifugal treatment on the refluxed reaction liquid, and separating out the precipitate obtained by the reaction in the reaction liquid;

s7) drying and precipitating at the temperature of 80 ℃ to obtain a synthetic product of NH 2-MIL-101.

Compared with the prior art, the invention has the following beneficial effects:

(1) according to the method provided by the invention, grafting between amino and the framework MIL-101 can be effectively realized, and functional modification on the metal organic framework MIL-101 is completed on the basis of keeping the original framework structure; meanwhile, the integral modification method also has the advantages of easy achievement of preparation conditions and simple and convenient preparation operation.

(2) the invention takes the amino trimethoxy silane coupling agent as the basis of amino grafting, and has the advantage of shortening the reaction time while ensuring the effective grafting.

(3) the skeleton crystal particles prepared based on the method are in an octahedral structure, so that the modified crystal structure is more uniform.

drawings

FIG. 1 is a table comparing synthetic products prepared according to different APS contents of the present invention;

FIG. 2 is an XRD spectrum of a synthetic product prepared according to different APS contents in the present invention;

FIG. 3 is a FT-IR spectrum of a synthetic product of the present invention made according to different levels of APS;

FIG. 4 is a scanning electron micrograph of a composite of the present invention prepared according to different APS contents;

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

1. the reagents used in the present invention: the catalyst comprises 4-nitroimidazole, terephthalic acid and chromium nitrate nonahydrate, wherein the concentration of the 4-nitroimidazole is 0.1mol/L, the concentration of the terephthalic acid is 0.2mol/L, and the concentration of the chromium nitrate nonahydrate is 0.2 mol/L;

2. MIL-101 preparation and skeleton MIL-101 functional modification are carried out based on the reagent: