Sodium alginate phase change material with triple stimulus response and its preparation method

Abstract

This invention relates to the field of biomaterials and stimulus-responsive materials, specifically to a sodium alginate phase change material with triple stimulus-responsive properties and its preparation method. The sodium alginate phase change material of this invention is an ion-liquid crystal biomaterial obtained by mixing sodium alginate and a double-chain azobenzene quaternary ammonium salt compound in an aqueous phase, followed by shaking, centrifugation to remove the supernatant, and freeze-drying. The sodium alginate phase change material prepared by this invention exhibits phase changes under three external stimuli: light, humidity, and force. The sodium alginate phase change material prepared by this invention can be used as an advanced intelligent self-healing material in biological and biomedical fields.

Description

Technical Field

[0001] This invention relates to the fields of biomaterials and stimulus-responsive materials, and mainly to a sodium alginate phase change material with triple stimulus-responsive properties and its preparation method. Background Technology

[0002] Phase change is an important property in materials chemistry, capable of altering the physicochemical properties of materials. For example, under heating conditions, the phase change from solid to liquid can endow solid materials with processability and repairability. While most materials undergo phase changes dependent on temperature, temperature-induced phase changes can sometimes bring numerous adverse effects. Taking high-temperature phase changes as an example, this process requires high-temperature resistant equipment, and the high temperatures can also damage the properties of the material, especially for organic functional materials.

[0003] In fields such as biology and biomedicine, phase changes can endow biomaterials with self-healing capabilities and can also be used to regulate their physicochemical properties. However, using temperature changes to achieve phase changes in biomaterials is not advisable, as temperature variations can damage the function of biological tissues. Therefore, in these fields, there is a need to develop biomaterials with isothermal phase change capabilities, where phase changes can be achieved through other external stimuli. Among commonly used external stimuli, light, humidity, and force stimulation offer advantages such as ease of control, no waste, and minimal physical damage, making them relatively ideal external stimulation methods.

[0004] Most currently developed isothermal phase change organic and biofunctional materials utilize the photoisomerization of azobenzene molecules to drive phase changes. Azobenzene molecules can convert absorbed light energy into mechanical energy, driving the transition between cis and trans isomers. Through rational material design, the conformational change of azobenzene molecules can effectively drive phase changes in materials. However, most isothermal phase change materials based on azobenzene photoisomerization only respond to light stimulation, belonging to single-stimulus-responsive functional materials. To date, no azobenzene materials have been reported that can effectively undergo phase changes under three external stimuli: light, humidity, and force. This limits the application of azobenzene materials as multifunctional self-healing materials in related fields.

[0005] Sodium alginate is a abundant biological resource in nature, a polysaccharide molecule with a large number of negatively charged structures. Due to the lack of stimulus-responsive functional groups, sodium alginate alone is difficult to respond effectively to external stimuli. Furthermore, due to its inherent biomolecular characteristics, sodium alginate is also unsuitable for use as a isothermal phase change biomaterial. However, effectively utilizing the negative charge in the sodium alginate molecule and modifying it with positively charged azobenzene molecules to prepare sodium alginate phase change materials with triple stimulus-responsive properties (light, humidity, and force) would be of great significance for expanding the applications of sodium alginate and azobenzene-based materials in basic research and technological fields. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a sodium alginate phase change material with triple stimulus response properties and a method for preparing the same.

[0007] The technical solution of the present invention is as follows:

[0008] This invention provides a sodium alginate phase change material with triple stimulus response properties, the raw materials for which include sodium alginate and a double-chain azobenzene quaternary ammonium salt compound.

[0009] In this invention, the sodium alginate is a mixture of polysaccharide polymers with the molecular formula (C6H7O6Na)n.

[0010] In this invention, the azobenzene quaternary ammonium salt compound containing a double-chain structure is N,N-dimethyl-N-(4-(4-((4-n-octoxyphenyl)diazepine)phenoxy)n-butyl)-3,6,9,12-tetraoxatridecylammonium bromide.

[0011] In this invention, the method for preparing the sodium alginate phase change material with triple stimulus response properties includes:

[0012] At room temperature, an aqueous solution of sodium alginate was mixed with an aqueous solution of a double-chain azobenzene quaternary ammonium salt compound. The mixture was shaken, and the supernatant was discarded after centrifugation. The resulting condensed product was washed with water and then freeze-dried to obtain a sodium alginate phase change material with triple stimulus response properties.

[0013] In the present invention, in the preparation method of the sodium alginate phase change material with triple stimulus response properties, the concentration of the sodium alginate aqueous solution is 30-40 mmol / L, based on the sodium alginate repeating monosaccharide unit being C6H7O6Na, and the concentration of the aqueous solution of the double-chain azobenzene quaternary ammonium salt compound is 5-15 mmol / L.

[0014] In the present invention, in the preparation method of the sodium alginate phase change material with triple stimulus response properties, in the mixed solution, the sodium alginate is calculated as C6H7O6Na as the repeating monosaccharide unit of sodium alginate, and the molar ratio of sodium alginate to the double-chain azobenzene quaternary ammonium salt compound is 1:1 to 1:3.

[0015] In the preparation method of the sodium alginate phase change material with triple stimulus response properties in this invention, the freeze-drying time is 8 hours.

[0016] In this invention, after preparing the sodium alginate phase change material with triple stimulus response properties, the process further includes inducing the sodium alginate phase change material with triple stimulus response properties to undergo a phase change under room temperature conditions through light, humidity and force stimulation.

[0017] In this invention, the photoinduced phase transition process of the sodium alginate phase change material with triple stimulus response properties includes: ultraviolet light irradiation to induce the sodium alginate phase change material with triple stimulus response properties to undergo a transition from a liquid crystal state to a disordered fluid state; and visible light irradiation to induce the sodium alginate phase change material with triple stimulus response properties to undergo a transition from a disordered fluid state to a liquid crystal state.

[0018] In this invention, during the photoinduced phase transition process of the sodium alginate phase change material with triple stimulus response properties: the ultraviolet light irradiation conditions are a wavelength of 365 nm and an intensity of 30 mW / cm². 2 The exposure time was 10 minutes; the visible light irradiation conditions were a wavelength of 520 nm and an intensity of 90 mW / cm². 2 Time: 10 minutes.

[0019] In this invention, the humidity-induced phase transition process of the sodium alginate phase change material with triple stimulus response properties includes: humidity treatment to induce the sodium alginate phase change material with triple stimulus response properties to undergo a transition from a liquid crystal state to a disordered fluid state; and drying treatment to induce the sodium alginate phase change material with triple stimulus response properties to undergo a transition from a disordered fluid state to a liquid crystal state.

[0020] In this invention, during the humidity-induced phase transition process of the sodium alginate phase change material with triple stimulus response properties: the humidity treatment conditions are 100% relative humidity for 30 minutes; the drying treatment conditions are less than 50% relative humidity for 1 hour.

[0021] In this invention, the mechanotropic phase change process of the sodium alginate phase change material with triple stimulus response properties includes: humidity treatment to induce the sodium alginate phase change material with triple stimulus response properties to undergo a transition from a liquid crystal state to a disordered fluid state, and the resulting disordered fluid state material undergoes a rapid transition from a disordered fluid state to a liquid crystal state under shear force stimulation.

[0022] This invention provides a sodium alginate phase change material with triple stimulus response properties and its preparation method. The sodium alginate phase change material with triple stimulus response properties and its preparation method have the following characteristics:

[0023] 1. The sodium alginate phase change material with triple stimulus response properties obtained in this invention is an ionic liquid crystal material formed by sodium alginate and a double-chain azobenzene quaternary ammonium salt compound.

[0024] 2. The sodium alginate phase change material obtained by this invention has triple stimulus response properties and can generate a reversible phase transition between liquid crystal state and disordered fluid state under ultraviolet light and visible light stimulation.

[0025] 3. The sodium alginate phase change material obtained by this invention has triple stimulus response properties and can produce a reversible phase transition between liquid crystal state and disordered fluid state under humidity and drying treatment.

[0026] 4. The sodium alginate phase change material obtained by the present invention, which has triple stimulus response properties, can rapidly transform from a disordered fluid state to a liquid crystal state under shear force stimulation after humidity treatment.

[0027] 5. The sodium alginate phase change material with triple stimulus response properties obtained by the present invention can be used as a self-healing material in related fields such as biology and biomedicine. Attached Figure Description

[0028] Figure 1 Comparison of small-angle X-ray scattering (SAXS) images of the sodium alginate phase change material with triple stimulus response properties described in Example 1 before and after ultraviolet light irradiation and after visible light irradiation.

[0029] Figure 2 Comparison of small-angle X-ray scattering (SAXS) images of the sodium alginate phase change material with triple stimulus response properties described in Example 1 before and after humidity treatment and after drying treatment.

[0030] Figure 3 Comparison of small-angle X-ray scattering (SAXS) images of the sodium alginate phase change material with triple stimulus response properties described in Example 1 after humidity treatment and after shear force stimulation. Detailed Implementation

[0031] This invention provides a sodium alginate phase change material with triple stimulus-response properties and its preparation method. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the same result. It should be noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments. Those skilled in the art can obviously make modifications or appropriate alterations and combinations to the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0032] The present invention will be further illustrated below with reference to the embodiments:

[0033] Example 1:

[0034] At room temperature, 1 mL of a 30 mmol / L sodium alginate aqueous solution (based on the repeating monosaccharide unit C6H7O6Na) and 3 mL of a 10 mmol / L N,N-dimethyl-N-(4-(4-((4-n-octyloxyphenyl)diazeninyl)phenoxy)n-butyl)-3,6,9,12-tetraoxatridecylammonium bromide aqueous solution were mixed. The mixture was shaken and centrifuged at a relative centrifugal force of 6124 g for 10 minutes. The supernatant was discarded, and the resulting condensed layer was washed with water and freeze-dried for 8 hours to obtain the sodium alginate phase change material with triple stimulus response properties described in this invention. Testing showed that the sodium alginate phase change material with triple stimulus response properties prepared in this invention is a liquid crystal material with a nematic phase structure.

[0035] The prepared sodium alginate phase change material with triple stimulus response properties exhibits X-ray small-angle scattering (SAS) spectra before UV irradiation, after 10 minutes of UV irradiation, and after 10 minutes of visible light irradiation, as shown in the figures. Figure 1 As shown, according to Figure 1 The results show that the prepared sodium alginate phase change material with triple stimulus response can undergo a reversible phase transition between liquid crystal state and disordered fluid state under ultraviolet and visible light stimulation.

[0036] The prepared sodium alginate phase change material with triple stimulus response properties exhibits X-ray small-angle scattering (SAS) spectra before humidity treatment, after standing for 30 minutes at 100% relative humidity, and after standing for 1 hour at relative humidity less than 50%, as shown below. Figure 2 As shown, according to Figure 2 The results show that the prepared sodium alginate phase change material with triple stimulus response can undergo reversible phase transitions between liquid crystal and disordered fluid states under high humidity and dry conditions.

[0037] The prepared sodium alginate phase change material with triple stimulus response properties, after standing for 30 minutes at 100% relative humidity, exhibits X-ray small-angle scattering (SAS) spectra before and after shear force stimulation, as shown below. Figure 3 As shown, according to Figure 3 The results showed that the sodium alginate phase change material with triple stimulus response properties prepared by the study could rapidly transform into a liquid crystal state under shear force stimulation, even when the disordered fluid state generated under high humidity conditions was transformed into a liquid crystal state.

[0038] Comparative Example 1:

[0039] At room temperature, 1 mL of sodium alginate aqueous solution with a concentration of 30 mmol / L (calculated as sodium alginate repeating monosaccharide unit C6H7O6Na) and 1.5 mL of N,N-dimethyl-N-(4-(4-((4-n-octyloxyphenyl)diazeninyl)phenoxy)n-butyl)-3,6,9,12-tetraoxatridecylammonium bromide aqueous solution with a concentration of 10 mmol / L were mixed. The mixture was shaken and then centrifuged in a centrifuge at a relative centrifugal force of 6124 g for 10 minutes. The supernatant was discarded, and the resulting condensed layer was washed with water and then freeze-dried for 8 hours to obtain sodium alginate material containing an azobenzene structure.

[0040] The sodium alginate material containing an azobenzene structure prepared in Comparative Example 1 was found to be unable to produce a triple phase transition response under three stimuli: light, humidity, and force. Therefore, it is not a phase transition material with triple stimulus response properties.

[0041] Comparative Example 2:

[0042] At room temperature, 1 mL of 60 μmol / L sodium carboxymethyl cellulose (based on 500 glycosyl units, with each glycosyl unit containing one negative charge) and 3 mL of 10 mmol / L N,N-dimethyl-N-(4-(4-((4-n-octyloxyphenyl)diazeninyl)phenoxy)n-butyl)-3,6,9,12-tetraoxatridecylammonium bromide aqueous solution were mixed. The mixture was shaken and centrifuged at 6124 g for 10 minutes. The supernatant was discarded, and the resulting precipitate was washed with water and freeze-dried for 8 hours to obtain a cellulose material containing an azobenzene structure. The obtained cellulose material containing an azobenzene structure was found to be crystalline at room temperature.

[0043] The cellulose material containing azobenzene structure prepared in Comparative Example 2 was found to be unable to completely transform into a disordered fluid state under ultraviolet light irradiation, and unable to undergo phase change under the stimulation of humidity and force. It is not a phase change material with triple stimulus response properties.

[0044] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several improvements without departing from the principle of the present invention, and these improvements should also be considered within the scope of protection of the present invention.

Claims

1. A sodium alginate phase change material having a triple stimulus responsive property and a method for preparing the same, characterized by, The preparation raw material includes sodium alginate and double chain structure azobenzene quaternary ammonium salt compound, the sodium alginate is the mixture of polysaccharide polymer with molecular formula (C6H7O6Na)n, and the double chain structure azobenzene quaternary ammonium salt compound is N,N -dimethyl- N - (4- (4- ( (4-n-octyloxyphenyl) diazenyl) phenoxy) n-butyl) -3, 6, 9, 12-tetraoxatridecyl ammonium bromide, wherein the preparation method of the sodium alginate phase change material with triple stimulus response property comprises the following steps: mixing sodium alginate aqueous solution and double chain structure azobenzene quaternary ammonium salt compound aqueous solution under room temperature condition, oscillating the mixed solution, centrifuging the oscillated mixed solution, discarding the supernatant, washing the obtained coagulation layer product with water, and freeze-drying the product, thereby obtaining the sodium alginate phase change material with triple stimulus response property, wherein in the mixed solution, the sodium alginate is C6H7O6Na, and the molar ratio of the sodium alginate to the double chain structure azobenzene quaternary ammonium salt compound is 1:1~1:

3.

2. The method for preparing sodium alginate phase change material with triple stimuli-responsive properties according to claim 1, characterized in that, The aqueous solution of sodium alginate is calculated based on the repeating monosaccharide unit of sodium alginate, C6H7O6Na, and has a concentration of 30-40 mmol / L, and the aqueous solution of the double-chain structure azobenzene quaternary ammonium salt compound has a concentration of 5-15 mmol / L.

3. The method for preparing sodium alginate phase change material with triple stimulus response properties as described in claim 1, characterized in that, The time of the freeze-drying treatment is 8 hours.

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