Preparation method of room temperature phosphorescent sodium alginate functional fiber

Abstract

The application discloses a preparation method of a room-temperature phosphorescent sodium alginate functional fiber, which comprises the following steps: 1) immersing the sodium alginate fiber into an acid solution to acidify, then adding EDC and NHS, and continuously stirring to prepare an activated sodium alginate fiber mixture; 2) dissolving 1-amino pyrene in a tetrahydrofuran solution to activate the sodium alginate fiber, performing ultrasonic oscillation treatment, slowly adding the solution into the mixture under intense stirring, and continuously stirring for 24 hours; and 3) washing the sodium alginate fiber in the solution after the stirring in the step 2) with tetrahydrofuran, and then performing vacuum drying after deionization, so as to obtain the room-temperature phosphorescent sodium alginate functional fiber. The room-temperature phosphorescent sodium alginate functional fiber is prepared through the reaction between the sodium alginate fiber and the active dye 1-amino pyrene under certain conditions, the fluorescent emission wavelength of the room-temperature phosphorescent sodium alginate functional fiber is 380-410 nm, the longest phosphorescent lifetime is 1236 milliseconds, the room-temperature phosphorescent sodium alginate functional fiber can be further woven into a phosphorescent functional fabric, and can be applied to the fields of anti-fake encryption and information storage.

Description

TECHNICAL FIELD

[0001] The present application relates to a luminescent material, in particular to a preparation method of a room-temperature phosphorescent sodium alginate functional fiber. BACKGROUND

[0002] Luminescent fiber has always been a research hotspot of functional fiber, which generally refers to a fiber capable of emitting fluorescence or phosphorescence under the excitation of ultraviolet light or visible light, having the functions of photoluminescence, photochromic or long afterglow, and is usually applied in the fields of anti-counterfeiting encryption or information storage.

[0003] There are mainly two methods for preparing the luminescent fiber: one method is to treat the fiber with a direct dye capable of emitting light, which is simple to operate, but has high requirements for the direct dye, and needs to form a cation-anion or salt bond or other interactions with the fiber; the fiber prepared by this method is not ideal in terms of washing resistance and durability, and thus needs to be post-treated with water and oil resistant agents and finishing agents; the other method is to treat the fiber with a reactive dye capable of emitting light, which needs specific pH, temperature and catalysts, and the reactive dye can form a stable covalent bond with the fiber; the fiber prepared by this method is superior to that prepared by the first method in terms of water resistance and durability.

[0004] The structure of the material and the luminescence process are different, and the lifetimes of the fluorescence and phosphorescence are also quite different. Due to the particularity of the luminescence mechanism, phosphorescence is easily quenched by oxygen and is sensitive to temperature. Therefore, it is usually difficult to observe phosphorescence emission in room-temperature air. However, in general, to achieve organic long afterglow luminescence, it is necessary for the material to produce phosphorescence with an ultra-long lifetime. This brings great challenges to obtaining organic long afterglow materials with high efficiency and long lifetime. Although many luminescent fibers have been developed, it is still difficult to prepare functional fibers with room-temperature phosphorescence and long lifetime, and there are few related researches and products. SUMMARY

[0005] In view of the short lifetime of the existing room-temperature phosphorescent luminescent fiber, the present application provides a preparation method of a room-temperature phosphorescent sodium alginate functional fiber, which comprises the following steps:

[0006] 1) acidifying the sodium alginate fiber by immersing it in an acidic solution, and then adding 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) and continuing to stir, to obtain an activated sodium alginate fiber mixture;

[0007] 2) activating the sodium alginate fiber by dissolving 1-aminopyrene in a tetrahydrofuran solution, and then performing ultrasonic oscillation treatment, and slowly adding it to the mixture obtained in step 1) under vigorous stirring, and continuing to stir for 24 hours;

[0008] 3) washing the sodium alginate fiber in the stirring solution of step 2) with tetrahydrofuran, and vacuum drying after washing to obtain the room-temperature phosphorescent sodium alginate functional fiber.

[0009] Sodium alginate is a natural polysaccharide extracted from brown algae or sargassum, has the advantages of good biocompatibility, water-solution processability, and strong intramolecular and intermolecular hydrogen bond interaction, and attracts extensive attention of researchers as an excellent carrier in the field of marine new materials. The 1-aminopyrene can promote its intersystem crossing due to the electronic interaction between the lone pair of electrons and the aromatic ring, which can make more excited singlet electrons jump to the triplet state, thereby generating phosphorescence. The hydrogen bond interaction of sodium alginate can inhibit the non-radiative transition of the amino-molecule grafted to the molecular chain, form a rigid matrix, and thus make it produce super-long lifetime room-temperature phosphorescence.

[0010] In the present application, first, the sodium carboxylate groups in the fiber are activated by using an acidic solution to expose active carboxyl groups, and then the active groups are esterified by using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide, so as to activate the sodium carboxylate groups of sodium alginate into active ester groups. After the acylation reaction of the active ester groups with 1-aminopyrene, the sodium alginate fiber and the phosphorescent material are connected in the form of stable covalent bond.

[0011] Further, the pH value of the acidic solution in the present application is 3-4, which is dilute hydrochloric acid or 2-morpholinoethanesulfonic acid buffer.

[0012] Further, in the method of the present application, the acidic solution is 5-15 parts by weight, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride is 80-120 parts by weight, N-hydroxysuccinimide is 40-60 parts by weight, and 1-aminopyrene is 10-30 parts by weight, based on 100 parts by weight of sodium alginate fiber; the weight ratio of 1-aminopyrene to tetrahydrofuran is (2-4):1.

[0013] The present application has the following advantages:

[0014] 1) The present application prepares the organic room-temperature phosphorescent functional fiber by the reaction of sodium alginate fiber and active dye 1-aminopyrene under certain conditions, the fluorescence emission wavelength of which is 380-410 nm, and the longest phosphorescent lifetime is 1236 milliseconds. The sodium alginate organic room-temperature phosphorescent fiber can be further woven into phosphorescent functional fabric, and can be applied in the fields of anti-counterfeiting encryption and information storage.

[0015] 2) The room temperature phosphorescent sodium alginate functional fiber of the present application has a stimulus response function, and exhibits a color change from green to yellow to red in afterglow under different excitation wavelengths. A certain fiber exhibits a delay time responsiveness in afterglow color after stopping irradiation of 254 nm ultraviolet light, and the color of the afterglow changes from yellowish white to green as the afterglow duration increases.

[0016] 3) The room temperature phosphorescent sodium alginate functional fiber of the present application is dyed by reactive dyes, has good water and oil resistance, and can exist stably in water and organic solvents. When it comes into contact with water, the fluorescence wavelength changes to produce a new fluorescence emission peak at 494 nm. After drying again, the fluorescence and phosphorescence properties return to the original state, and it exhibits certain water-responsive luminescence characteristics. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 Photographs of the luminescence of the fiber obtained in Example 1 under irradiation of an ultraviolet lamp and after stopping irradiation.

[0018] Figure 2 Photographs of the luminescence of the fiber obtained in Example 2 under irradiation of an ultraviolet lamp and after stopping irradiation.

[0019] Figure 3 Photographs of the luminescence of the fiber obtained in Example 3 under irradiation of an ultraviolet lamp and after stopping irradiation.

[0020] Figure 4 Photoluminescence spectra of the fiber obtained in Examples 1-3 (D1-D3).

[0021] Figure 5 CIE coordinates corresponding to the photoluminescence spectra of the fiber obtained in Examples 1-3 (D1-D3).

[0022] Figure 6 Delayed luminescence spectra of the fiber obtained in Examples 1-3 (D1-D3).

[0023] Figure 7 CIE coordinates corresponding to the delayed luminescence spectra of the fiber obtained in Examples 1-3 (D1-D3).

[0024] Figure 8 Phosphorescence lifetime of the fiber obtained in Examples 1-3 (D1-D3).

[0025] Figure 9 Photoluminescence spectra of the fiber obtained in Example 1 after water treatment.

[0026] Figure 10 CIE coordinates corresponding to the photoluminescence spectra of the fiber obtained in Example 1 after water treatment. DETAILED DESCRIPTION

[0027] The present application is described below in conjunction with examples, which are only used to explain the present application and are not intended to limit the scope of the present application.

[0028] Example 1

[0029] A preparation method of a room temperature phosphorescent sodium alginate functional fiber, comprising the following steps:

[0030] (1) At room temperature, 500 parts by weight of sodium alginate fiber prepared by wet spinning is placed in 50 parts by weight of dilute hydrochloric acid with pH of 3, and after stirring uniformly, 500 parts by weight of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and 300 parts by weight of N-hydroxysuccinimide are added, and stirring is continued to activate the sodium carboxylate group of sodium alginate into active ester to prepare a mixed solution, which is ready for use;

[0031] (2) 50 parts by weight of 1-aminopyrene is dissolved in 20 parts by weight of tetrahydrofuran solution, and ultrasonic oscillation treatment is carried out at room temperature, and it is slowly added to the mixed solution obtained in step 1) under vigorous stirring, and stirring is continued for 24 hours;

[0032] (3) The sodium alginate fiber in the solution after stirring in step 2) is washed with tetrahydrofuran, and after deionized washing, vacuum drying is carried out, and the room temperature phosphorescent sodium alginate functional fiber is obtained.

[0033] Example 2

[0034] A preparation method of a room temperature phosphorescent sodium alginate functional fiber, comprising the following steps:

[0035] (1) At room temperature, 500 parts by weight of sodium alginate fiber prepared by wet spinning is placed in 75 parts by weight of 2-morpholinoethanesulfonic acid buffer solution with pH of 4, and after stirring uniformly, 600 parts by weight of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and 200 parts by weight of N-hydroxysuccinimide are added, and stirring is continued to activate the sodium carboxylate group of sodium alginate into active ester to prepare a mixed solution, which is ready for use;

[0036] (2) 80 parts by weight of 1-aminopyrene is dissolved in 20 parts by weight of tetrahydrofuran solution, and ultrasonic oscillation treatment is carried out at room temperature, and it is slowly added to the mixed solution obtained in step 1) under vigorous stirring, and stirring is continued for 24 hours;

[0037] (3) The sodium alginate fiber in the solution after stirring in step 2) is washed with tetrahydrofuran, and after deionized washing, vacuum drying is carried out, and the room temperature phosphorescent sodium alginate functional fiber is obtained.

[0038] Example 3

[0039] A preparation method of a room temperature phosphorescent sodium alginate functional fiber, comprising the following steps:

[0040] (1) At room temperature, 500 parts by weight of sodium alginate fiber prepared by wet spinning was placed in 25 parts by weight of 2-morpholinoethanesulfonic acid buffer solution with pH of 4, and after stirring uniformly, 400 parts by weight of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and 300 parts by weight of N-hydroxysuccinimide were added, and stirring was continued, so that the sodium carboxylate groups of the sodium alginate were activated into active esters to prepare a mixed solution, which was ready for use;

[0041] (2) 120 parts by weight of 1-aminopyrene was dissolved in 40 parts by weight of tetrahydrofuran solution, and ultrasonic oscillation treatment was carried out at room temperature, and the solution was slowly added to the mixed solution obtained in step 1) under vigorous stirring, and stirring was continued for 24 h;

[0042] (3) The sodium alginate fiber in the solution after stirring in step 2) was washed with tetrahydrofuran, and after deionization and washing, vacuum drying was carried out, and the sodium alginate fiber was obtained.

[0043] Figures 1-3 The luminescence photographs of the fibers obtained in Examples 1-3 under ultraviolet lamp irradiation and after stopping irradiation are shown in the figures, and it can be seen from the figures that the three kinds of fibers all exhibit super-long lifetime room temperature phosphorescence, and the three kinds of fibers all exhibit afterglow with excitation wavelength response and delay time response. The fiber obtained in Example 1 exhibits yellowish white afterglow after stopping 254 nm ultraviolet light excitation, and as the afterglow duration time increases, the afterglow color changes from yellowish white to yellowish green, while after stopping 365 nm ultraviolet light excitation, it exhibits orange red afterglow, and the afterglow color produces obvious red shift as the excitation wavelength increases. The fiber obtained in Example 2 and the fiber obtained in Example 3 also exhibit afterglow with excitation wavelength response and time response, and among them, the fiber obtained in Example 1 exhibits the best super-long lifetime room temperature phosphorescence property.

[0044] Figure 4 and Figure 5 The photoluminescence spectra and corresponding CIE coordinates of the fibers obtained in Examples 1-3 (D1-D3) are shown in the figures, and it can be seen that the fluorescence emission wavelength ranges of the three kinds of fibers are all 380-410 nm, and under the excitation of ultraviolet lamp, they exhibit blue-violet fluorescence.

[0045] Figure 6 and Figure 7 The delayed luminescence spectra and corresponding CIE coordinates of the fibers obtained in Examples 1-3 (D1-D3) are shown in the figures, and it can be seen that the room temperature phosphorescence emission wavelength ranges of the three kinds of fibers are all 450-800 nm, and after stopping ultraviolet light excitation, the three kinds of fibers exhibit afterglow from blue-green to red.

[0046] Figure 8The phosphorescent lifetime of the fibers obtained in Examples 1 to 3 (D1 to D3) can be seen to be super-long, and the lifetime of the fiber obtained in Example 2 is significantly shorter than that of the fibers obtained in Examples 1 and 3, with the longest lifetime reaching 1236 ms.

[0047] The fiber obtained in Example 1 also exhibits water-responsive fluorescent properties, as shown in Figure 9 and 10 When the fiber obtained in Example 1 encounters water, a new emission peak at 494 nm is generated, and the fluorescent color changes from blue-purple to blue-green. This water-responsive fluorescent property is a reversible process, and when the fiber obtained in Example 1 is dried again, it returns to the initial state.

[0048] The above merely describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing room-temperature phosphorescent sodium alginate functional fibers, characterized in that, Includes the following steps: 1) At room temperature, 500 parts by weight of sodium alginate fiber prepared by wet spinning was placed in 75 parts by weight of 2-morpholine ethanesulfonic acid buffer solution with pH 4. After stirring evenly, 600 parts by weight of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 200 parts by weight of N-hydroxysuccinimide were added. Stirring was continued to activate the sodium carboxylate group of sodium alginate into an active ester, and a mixed solution was prepared for use. (2) Dissolve 80 parts by weight of 1-aminopyrene in 20 parts by weight of tetrahydrofuran solution, perform ultrasonic vibration treatment at room temperature, and slowly add it to the mixture obtained in step 1) under vigorous stirring, and continue stirring for 24 hours. (3) Wash the sodium alginate fiber in the solution after stirring in step 2) with tetrahydrofuran, then wash with deionized water and dry under vacuum to obtain the final product.

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