CN109369925B

CN109369925B - Covalent organic framework material capable of changing color when meeting water and preparation method and application thereof

Info

Publication number: CN109369925B
Application number: CN201811188065.8A
Authority: CN
Inventors: 韩正波; 高明亮
Original assignee: Liaoning University
Current assignee: Liaoning University
Priority date: 2018-10-12
Filing date: 2018-10-12
Publication date: 2021-04-13
Anticipated expiration: 2038-10-12
Also published as: CN109369925A

Abstract

The invention relates to a covalent organic framework material capable of changing color when meeting water, a preparation method and application thereof. Firstly, p-phenylenediamine and triacyl phenol are taken as synthesis monomers to synthesize covalent organic framework materials by a room temperature solid phase method. The covalent organic framework material has large specific surface area and rich pore structure, changes the energy level of the covalent organic framework material by forming hydrogen bonds with water molecules, changes the color of the covalent organic framework material, expands the new application of the covalent organic framework material in the field of catalysis, and has the advantages of simple process, easy repeated operation, controllable structure, suitability for large-scale production and the like.

Description

Covalent organic framework material capable of changing color when meeting water and preparation method and application thereof

Technical Field

The invention belongs to the technical field of porous materials, and particularly relates to a preparation method of a covalent organic framework material capable of changing color when meeting water, and expands the potential application of the covalent organic framework material.

Background

The covalent organic framework material is a crystalline porous material formed by combining light elements such as C, N, O, B, Si through covalent bonds, and the COF has high stability, structural regularity, pore adjustability and easy functionality, so that the COF is applied to the fields of gas storage, drug release, catalysis, photoelectricity and the like.

Recently, as a novel porous carbon-based material, a covalent organic framework material attracts attention due to its unique properties such as rigid structure (two-dimensional or three-dimensional), lower density, high stability, larger specific surface area and void, and these characteristics make it hopeful to solve the defects of low activity, poor stability and the like of a non-metal catalyst. Common synthetic methods for covalent organic framework materials include solvothermal methods, ionothermal methods, microwave heating methods, and the like. CN103755588A discloses a novel covalent organic framework photocatalyst and a preparation method thereof, wherein trimesic aldehyde and 2, 5-di (N, N-dimethyl) amino-1, 4-benzenedihydrazide are used as synthetic monomers to prepare a covalent organic framework material by adopting a solvothermal method, and the method has the advantages of long synthetic time, difficult reaction regulation and control and no contribution to large-scale synthesis.

Disclosure of Invention

In order to overcome the defects in the prior art, the covalent organic framework material is synthesized by a standing method at room temperature in an open system. The synthesis method has the advantages of short reaction time, low energy consumption, no volatile organic matter pollution, simple operation and the like, and the obtained covalent organic framework material has the performance of changing color when meeting water.

The technical scheme adopted by the invention is as follows: a covalent organic framework material changing color when meeting water is prepared by the following steps: dispersing an organic solvent and glacial acetic acid in distilled water to form a mixed solution; dispersing p-phenylenediamine and triacylglycol in the formed mixed solution, uniformly stirring for 0.1-0.5h at room temperature, standing, filtering, washing the obtained solid powder with tetrahydrofuran and acetone in sequence, and vacuum drying at 80 ℃ for 12 to obtain the target product, namely the covalent organic framework material changing color when meeting water.

Furthermore, the covalent organic framework material capable of changing color when meeting water is prepared from p-phenylenediamine and triacyl phenol in a molar ratio of 2: 3.

Further, the covalent organic framework material capable of changing color when meeting water is prepared by mixing one or more than two of tetrahydrofuran, 1,3, 5-trimethylbenzene, toluene, dioxane, ethanol, n-butyl alcohol and o-dichlorobenzene.

Furthermore, the above covalent organic skeleton material discolours when it is used in water, the organic solvent is a mixture of dioxane and 1,3, 5-trimethylbenzene or toluene, or a mixture of dioxane and tetrahydrofuran, or a mixture of n-butanol and o-dichlorobenzene.

Furthermore, the above covalent organic framework material changing color when meeting water is prepared by mixing dioxane and 1,3, 5-trimethylbenzene; according to the volume ratio, 1,3, 5-trimethylbenzene, dioxane and glacial acetic acid are 1:1: 0.01-1: 1: 0.5.

The covalent organic framework material changing color when meeting water is applied to the field of environmental humidity detection. The method comprises the following steps: and (3) placing the dried covalent organic framework material changing color when meeting water in a container, placing the container under different humidity conditions for 10min, taking out the covalent organic framework material changing color when meeting water, and testing the covalent organic framework material in an ultraviolet-visible spectrum tester.

The invention has the beneficial effects that: the covalent organic framework material capable of changing color when meeting water prepared by the invention can show color change under water or different humidity, and the color change is caused by the fact that the material per se forms hydrogen bonds with water molecules, so that the energy level is changed.

Drawings

FIG. 1 is a PXRD of a covalent organic framework material that changes color when exposed to water prepared in accordance with the present invention.

FIG. 2 is a scanning electron microscope image of a covalent organic framework material discolored when encountering water prepared by the present invention.

FIG. 3 is a UV-Vis spectrum of a water-color-changing covalent organic backbone material made in accordance with the present invention.

FIG. 4 is a color photograph of a water-color-changing covalent organic backbone material made in accordance with the present invention.

Detailed Description

The following examples further illustrate the invention but are not intended to limit the invention thereto. The experimental methods described in the following examples are all conventional methods unless otherwise specified; the reagents and materials are commercially available, unless otherwise specified.

Example 1A covalent organic framework Material that changes color upon Water

(I) preparation method

1mL of 1,3, 5-trimethylbenzene, 1mL of dioxane, and 0.5mL of glacial acetic acid were dispersed in 0.3mL of distilled water to form a mixed solution. Dispersing 21.6mg (1mmol) of p-phenylenediamine and 10.8mg (1.5mmol) of triacylglycol in the mixed solution, uniformly stirring for 0.5h at room temperature, standing, filtering, washing the obtained solid powder with tetrahydrofuran and acetone in sequence, and drying in vacuum at 80 ℃ for 12h to obtain yellow powder which is a covalent organic framework material capable of changing color when meeting water.

(II) detection

Fig. 1 is an XRD diffraction pattern of the product and an XRD diffraction pattern of the simulated product, which can be seen from fig. 1, the simulated pattern and the product pattern are identical, which indicates that the prepared material has a correct structure and is a pure phase.

Fig. 2 is a scanning electron micrograph of the product, and as can be seen from fig. 2, the material exhibits a columnar cross-linked state, thereby producing a hierarchical pore structure.

Example 2 color Change Properties of a covalent organic framework Material that changes color when exposed to Water

The method comprises the following steps: 100mg of the covalent organic framework material prepared in example 1 was weighed out and placed at different humidity for 10min, and then solid UV-Vis spectroscopy was performed.

FIG. 3 is a UV-Vis spectrum of the covalent organic framework material discolored when it is in contact with water, the UV-Vis spectrum of the material changes to some extent under different humidity, and it can be seen from the graph that under the influence of humidity, the UV-Vis absorption of the material at 500nm-750nm is obviously enhanced, thereby causing color change, but under the humidity condition that the humidity is 6%, the UV-Vis absorption does not change obviously, and under the other humidity, the change is more obvious.

FIG. 4 is a color photograph of the water-color-changeable covalent organic backbone material prepared in example 1. As can be seen from fig. 4, the color of the material changed from reddish brown (dry sample) to black (wet sample) before and after the humidity measurement.

After testing, the recovered covalent organic framework material was activated at 120 ℃ and the material recovered its own color.

Claims

1. An application of a covalent organic framework material changing color when meeting water in detection of environmental humidity is characterized in that the method comprises the following steps: placing the dried covalent organic framework material which changes color when encountering water in a container, placing the container under different humidity conditions for 10min, taking out the covalent organic framework material which changes color when encountering water, and testing the covalent organic framework material in an ultraviolet-visible spectrum tester; the preparation method of the covalent organic framework material changing color when meeting water comprises the following steps: dispersing an organic solvent and glacial acetic acid in distilled water to form a mixed solution; dispersing p-phenylenediamine and triacylglycol in the formed mixed solution, uniformly stirring for 0.1-0.5h at room temperature, standing, filtering, washing the obtained solid powder with tetrahydrofuran and acetone in sequence, and drying in vacuum at 80 ℃ to obtain the target product, namely the covalent organic framework material changing color when meeting water;

p-phenylenediamine to triacylglycol =2:3 in mole ratio.

2. The use of a covalent organic framework material that changes color upon exposure to water according to claim 1, wherein: the organic solvent is one or a mixture of more than two of tetrahydrofuran, 1,3, 5-trimethylbenzene, toluene, dioxane, ethanol, n-butanol and o-dichlorobenzene.

3. The use of a covalent organic framework material that changes color when exposed to water according to claim 2, wherein: the organic solvent is the mixture of dioxane and 1,3, 5-trimethylbenzene or toluene, or the mixture of dioxane and tetrahydrofuran, or the mixture of n-butyl alcohol and o-dichlorobenzene.

4. The use of a covalent organic framework material that changes color when exposed to water according to claim 3, wherein: the organic solvent is the mixture of dioxane and 1,3, 5-trimethylbenzene; according to the volume ratio of 1,3, 5-trimethylbenzene to dioxane to glacial acetic acid =1:1: 0.01-1: 1: 0.5.