CN113801245A

CN113801245A - Preparation method of europium/terbium modified cellulose acetate light conversion film

Info

Publication number: CN113801245A
Application number: CN202010550336.0A
Authority: CN
Inventors: 王砥; 张之慧; 赵正栋; 路雨笳
Original assignee: Northeast Forestry University
Current assignee: Northeast Forestry University
Priority date: 2020-06-16
Filing date: 2020-06-16
Publication date: 2021-12-17

Abstract

The invention belongs to the technical field of biomass/inorganic hybrid materials, and discloses a preparation method of a europium/terbium-modified cellulose acetate light conversion film. The preparation method comprises the following steps: respectively dissolving cellulose acetate and europium/terbium nitrate hexahydrate in an acetone solvent, fully dissolving and mixing, keeping the mass fraction of the cellulose acetate in a constant solution at 10%, and stirring and reacting the mixed solution in a reactor provided with a condensation reflux device at a constant temperature (50-90 ℃) for 35-75 minutes. And cooling the reacted solution to room temperature, placing a proper amount of the solution on a dry and clean glass plate, carrying out blade coating by adopting an SZQ four-side preparation device, and naturally drying to obtain the transparent film. The method has the advantages of short synthesis time, simple preparation process, and good transparency and light conversion performance of the obtained light conversion film, and is suitable for agricultural application.

Description

Preparation method of europium/terbium modified cellulose acetate light conversion film

Technical Field

The invention belongs to the technical field of biomass/inorganic hybrid materials, and particularly relates to a preparation process of an ion europium/terbium modified cellulose acetate light conversion film.

Background

Cellulose is the most abundant renewable resource on earth, and the functionalization of cellulose has been the hot spot of research. The cellulose has the advantages of regeneration, large reserve, easy biodegradation and the like, so that the cellulose has great advantages in the aspect of constructing various functional materials. Cellulose acetate is one of the most widely used cellulose derivative materials, and has wide application in membrane materials. In view of this, we propose a method for preparing a cellulose acetate light conversion film which absorbs ultraviolet light and converts the ultraviolet light into visible light and is beneficial to plant growth by a coordination reaction of cellulose acetate and rare earth ion europium/terbium. The method has short synthesis time and simple preparation process, and can obtain a very transparent cellulose acetate light conversion film.

Disclosure of Invention

In order to overcome the defects and shortcomings in the prior art, the invention aims to provide a preparation method of an europium/terbium modified cellulose acetate light conversion film.

The invention provides a preparation method of a europium/terbium modified cellulose acetate light conversion film, which comprises the following steps:

(1) in an acetone solvent, the ratio of (0.2-5): 1, adding cellulose acetate (39.8 wt% of acetyl, 3.5 wt% of hydroxyl) and 99.99 wt% of rare earth nitrate hexahydrate, wherein the rare earth nitrate hexahydrate is europium nitrate hexahydrate, terbium nitrate hexahydrate or a mixture of the europium nitrate hexahydrate and the terbium nitrate hexahydrate, and the molar ratio of the europium nitrate hexahydrate to the terbium nitrate hexahydrate in the mixture is (0.2-5): 1 in the range of; keeping the mass fraction of the cellulose acetate in the solution to be 10%, and after the cellulose acetate is completely dissolved, carrying out condensation reflux at the temperature of 50-90 ℃ for 35-75 minutes to carry out reaction.

(2) And cooling the reacted solution to room temperature, placing a proper amount of the solution on a dry and clean glass plate, carrying out blade coating by adopting an SZQ type four-side preparation device, and naturally drying to obtain a transparent film, wherein the thickness of the film is 20-1000 mu m.

Compared with the prior art, the invention has the following advantages: the europium/terbium modified cellulose acetate light conversion film is successfully synthesized by coordination reaction of cellulose acetate and rare earth ions, and the obtained light conversion film is very transparent, has good light conversion performance and is suitable for agricultural application.

Drawings

The invention is further illustrated with reference to the following figures and examples.

FIG. 1 is an infrared spectrum of a pure cellulose acetate film and a europium/terbium-modified cellulose acetate light-converting film prepared in example 1.

FIG. 2 is a UV-VIS transmission spectrum of the pure cellulose acetate film and the europium/terbium-modified cellulose acetate light-converting film prepared in example 1.

FIG. 3 shows fluorescence emission spectra of europium-modified cellulose acetate light conversion films (molar ratio 1: 1-1: 5) prepared in example 2.

FIG. 4 shows the fluorescence emission spectrum of the terbium-modified cellulose acetate light conversion film (reaction temperature 50-90 ℃) prepared in example 3.

Detailed Description

The present invention is described in further detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1

The preparation method of the cellulose acetate film and the europium/terbium modified cellulose acetate light conversion film comprises the following specific steps:

(1) 2.6667g of cellulose acetate was added to 30mL of acetone, the mass fraction of cellulose acetate in the solution was kept at 10%, and the solution was heated and stirred to dissolve it sufficiently, thereby obtaining a pure cellulose acetate solution.

(2) Adding cellulose acetate and europium/terbium nitrate hexahydrate into 30mL of acetone solvent according to the molar ratio of 2:1, wherein the mass fraction of the cellulose acetate in the constant solution is 10%, and after complete dissolution, carrying out condensation reflux at 80 ℃ for 35 minutes for reaction to obtain a rare earth ion modified cellulose acetate solution.

(3) And cooling the cellulose acetate solution and the reacted solution to room temperature, placing a proper amount of the solution on a dry and clean glass plate, carrying out blade coating by adopting an SZQ type four-side preparation device, and naturally drying to obtain a transparent film, wherein the thickness of the film is set to be 1000 mu m. The obtained pure cellulose acetate film and the rare earth ion europium/terbium modified cellulose acetate light conversion film have infrared spectrograms shown in figure 1. The ultraviolet-visible transmission spectrograms of the obtained pure cellulose acetate film and the rare earth ion europium/terbium modified cellulose acetate light conversion film are shown in figure 2.

Example 2

The preparation method of the europium-modified cellulose acetate light conversion film comprises the following specific steps:

(1) in acetone solvent at a ratio of 1: (1-5) adding cellulose acetate and europium nitrate hexahydrate in a molar ratio, keeping the mass fraction of the cellulose acetate in the solution constant at 10%, and after complete dissolution, carrying out condensation reflux at 80 ℃ for 35 minutes to carry out reaction.

(2) The solution after the reaction was cooled to room temperature, and a suitable amount was placed on a dry clean glass plate, and knife-coated with an SZQ type four-sided preparation machine, and naturally dried to obtain a transparent film, the thickness of which was set to 1000 μm. The fluorescence emission spectrum of the rare earth ion europium-modified cellulose acetate light conversion film (the molar ratio variable of cellulose acetate to europium ion is 1: 1-1: 5) is shown in fig. 3.

Example 3

The preparation method of the rare earth ion terbium-modified cellulose acetate light conversion film comprises the following specific steps:

(1) adding cellulose acetate and terbium nitrate hexahydrate into an acetone solvent in a molar ratio of 2:1, wherein the mass fraction of the cellulose acetate in a constant solution is 10%, and after complete dissolution, carrying out condensation reflux at 80 ℃ for 35 minutes to carry out reaction.

(2) The solution after the reaction was cooled to room temperature, and a suitable amount was placed on a dry clean glass plate, and knife-coated with an SZQ type four-sided preparation machine, and naturally dried to obtain a transparent film, the thickness of which was set to 1000 μm. The fluorescence emission spectrogram of the rare earth ion terbium-modified cellulose acetate light conversion film (the reaction temperature variable is 50-90 ℃) is shown in FIG. 4.

Claims

1. The preparation method of the europium/terbium modified cellulose acetate light conversion film is characterized by comprising the following operation steps of:

(1) respectively dissolving cellulose acetate and rare earth nitrate ion hexahydrate meeting the requirement of a molar ratio in a solvent, fully dissolving the cellulose acetate and the cellulose nitrate ion hexahydrate in a constant solution at a certain mass fraction, mixing the solution after fully dissolving the cellulose acetate and the cellulose nitrate ion hexahydrate, and stirring the mixed solution at a constant temperature for reacting for a certain time to obtain a rare earth ion modified cellulose acetate solution;

(2) and (3) placing the cellulose acetate solution obtained in the step on a clean glass plate, carrying out blade coating by adopting an SZQ type four-side preparation device, and drying to obtain transparent films with different thicknesses.

2. The method of claim 1, wherein: the rare earth nitrate ion hexahydrate in the step (1) is europium nitrate hexahydrate, terbium nitrate hexahydrate or a mixture of the europium nitrate hexahydrate and the terbium nitrate hexahydrate, and the molar ratio of the europium nitrate hexahydrate to the terbium nitrate hexahydrate in the mixture is (0.2-5): 1, in the above range.

3. The method of claim 1, wherein: the molar ratio of the cellulose acetate to the nitric acid rare earth ion hexahydrate in the step (1) is that the molar ratio of the structural unit in the cellulose acetate to the rare earth ion is (0.2-5): 1, in the range of.

4. The method of claim 1, wherein: the mass fraction of cellulose acetate in the constant solution in step (1) was 10%.

5. The method of claim 1, wherein: the stirring temperature of the mixed solution in the step (1) is within 50-90 ℃, and the reaction time is within 35-75 minutes.

6. The method of claim 1, wherein: and (3) drying the cellulose acetate solution which is coated on a clean glass plate by blade coating to be natural drying, wherein the drying time is not less than half an hour.

7. The method of claim 1, wherein: the thickness of the film in the step (2) is within the range of 20-1000 mu m.

8. A transparent film obtained by the preparation method of claims 1-7, which is a rare earth ion europium/terbium modified cellulose acetate light conversion film.