Photo-thermal effect membrane material based on bacterial cellulose as well as preparation method and application of photo-thermal effect membrane material

Abstract

The invention relates to a bacterial cellulose-based photothermal effect membrane material and a preparation method and application thereof, the photothermal effect membrane material is formed by combining two layers of bacterial cellulose components, and the bacterial cellulose component at the lower layer is foamed bacterial cellulose. The bacterial cellulose component on the upper layer is a bacterial cellulose film containing a powdery photothermal effect material, and the thickness of the prepared photothermal effect film material is smaller than 1 mm. Compared with the prior art, the method has the advantages that the powdery photothermal effect material is organized and distinguished into a flexible foaming film with a heat insulation function and a cellulose film mixed with the photothermal material through two solid states of a bacterial cellulose film and flexible foaming, and the conversion from light energy to heat energy and the storage of the heat energy are realized through compounding; based on the heating principle of the photothermal effect, heating can be achieved without depending on any energy form input except light energy.

Description

Technical Field

[0001] The present invention relates to the technical field of heating materials, and in particular to a photothermal effect membrane material based on bacterial cellulose, and a preparation method and application thereof. Background Art

[0002] Traditional heating devices require the combustion of organic fuels to generate heat energy. The equipment has defects such as heavy weight, complex structure, large volume, high operating risk, and unstable heat source, which limits the scalability and applicability of the technology. Photothermal materials are a type of material that converts absorbed light energy into thermal energy. With the development of optical technology, photothermal materials are increasingly used in the fields of chemical industry, energy, sensing and life health, becoming a new type of material that cannot be ignored in the field of materials science research.

[0003] The research on the photothermal effect of inorganic materials has developed earlier and is relatively mature. The research researchers are mainly concerned with metal nanomaterials based on plasma local heating mechanism, metal oxide semiconductors based on non-radiative relaxation mechanism, and carbon-based materials based on molecular thermal vibration mechanism. Among them, the research on the photothermal effect of metal materials is relatively early, and it is also one of the more mature photothermal materials currently developed. This type of metal mainly includes Au nanomaterials, Ag nanomaterials, Pt nanoparticles, Al nanoparticles, CuS nanosheets, etc.

[0004] In recent years, researchers have found that some narrow-bandgap semiconductor material systems can also produce significant thermal effects, making inorganic semiconductor materials a new type of photothermal material. Such materials include Ti2O3 nanoparticles, black TiO2, MoO3 quantum dots, and metal oxide semiconductors such as Fe3O4.

[0005] In addition, carbon-based materials represented by graphene have strong absorption capacity brought by their conjugated structure, thus having efficient light-to-heat conversion capabilities. Materials such as graphene, graphene oxide, carbon nanotubes, graphite, carbon black, and carbon dots have also attracted the attention of researchers in recent years.

[0006] Many current studies have used MXenes and other substrates to prepare corresponding interfacial evaporation films, which have achieved 84% solar steam conversion efficiency under 1 sun irradiation under experimental conditions. For example, CN117700828A discloses a double-layer MXene-based aerogel composite phase change film and its preparation method and application.

[0007] However, the existing photothermal effect materials have the following two problems to be solved:

[0008] (1) Powdered photothermal materials are not easy to be processed, and traditional composite methods will greatly interfere with the efficiency of the photothermal effect;

[0009] (2) Due to the extremely high thermal conductivity of photothermal effect materials, it is difficult to store heat for utilization, and the heat generated by the photothermal effect is often dispersed throughout the entire illuminated surface and is difficult to be transmitted to the specific location that needs to be heated; Summary of the invention

[0010] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a photothermal effect membrane material based on bacterial cellulose and a preparation method and application thereof.

[0011] The purpose of the present invention can be achieved by the following technical solutions:

[0012] One of the technical solutions of the present invention is to provide a photothermal effect membrane material based on bacterial cellulose, which is composed of two layers of bacterial cellulose components, wherein the bacterial cellulose component in the lower layer is foamed bacterial cellulose, and the bacterial cellulose component in the upper layer is a bacterial cellulose film containing powdered photothermal effect material.

[0013] In some specific embodiments, the powdered photothermal effect material includes carbon nanotubes, Mxenes, and mesoporous carbon spheres.

[0014] In some specific embodiments, the thickness of the bacterial cellulose-based photothermal effect membrane material is less than 1 mm.

[0015] The photothermal effect film material based on bacterial cellulose provided by the present invention is physically combined with the bacterial cellulose itself, and the composite stacking organization of bacterial cellulose is used to form a powdered photothermal effect material that is not easy to shape, and realizes the thermal energy conversion and utilization of solar energy. When the ambient light irradiates the bacterial cellulose film on the upper layer to generate heat, the lower foamed bacterial cellulose matrix layer is used to isolate the heat from dissipating outward, so that the generated heat can be conducted through the bacterial cellulose film on the upper layer to the object located above the bacterial cellulose film.

[0016] The second technical solution of the present invention is to provide a method for preparing a photothermal effect membrane material based on bacterial cellulose as described in one of the above technical solutions, comprising the following steps:

[0017] S1, mixing bacterial cellulose solution, glycerol, sodium alginate solution, PVA (polyvinyl alcohol) solution, tributyl phosphate solution, and powdered photothermal effect material aqueous dispersion to obtain a first mixed solution;

[0018] Mixing bacterial cellulose solution, glycerol, sodium alginate solution, PVA (polyvinyl alcohol) solution, and protein powder to obtain a second mixed solution;

[0019] S2, freezing the first mixed solution obtained in step S1, adding an excess of CaCl2 solution to carry out a spheroidization reaction, and obtaining a gel solution;

[0020] The second mixed solution obtained in step S1 is whipped to a foaming state, and after freezing, an excess amount of CaCl2 solution is added to perform a spheroidization reaction to obtain a foaming gel solution;

[0021] S3, placing the gel solution obtained in step S2 on the foaming gel solution, heating and reacting, and obtaining a photothermal effect membrane material based on carbon nanotube composite bacterial cellulose.

[0022] In some specific embodiments, in step S1, in the first mixed solution, the ratio of bacterial cellulose, glycerol, sodium alginate solution, PVA (polyvinyl alcohol) solution, tributyl phosphate solution, and powdered photothermal effect material aqueous dispersion is 0.60wt%: 1wt%: 0.30wt%: 0.30wt%; (0.1-0.20)wt%; (1.5-3)wt%;

[0023] Among them, the bacterial cellulose solution uses a bacterial cellulose solution with a mass fraction of 1.2wt%, the sodium alginate solution uses a sodium alginate solution with a mass fraction of 0.2wt%, the PVA solution uses a PVA solution with a mass fraction of 0.05wt%, and the powdered photothermal effect material aqueous dispersion uses a carbon nanotube aqueous dispersion with a concentration of 10mg / mL.

[0024] In some specific embodiments, in step S1, in the second mixed solution, the ratio of bacterial cellulose solution, glycerol, sodium alginate solution, PVA solution, and protein powder is (0.6-1.20) wt%: (1-2) wt%: 0.30 wt%: 0.60 wt%: (0.0001-0.0002) wt%;

[0025] The bacterial cellulose solution uses a bacterial cellulose solution with a mass fraction of 1.2 wt %, the sodium alginate solution uses a sodium alginate solution with a mass fraction of 0.2 wt %, and the PVA solution uses a PVA solution with a mass fraction of 0.05 wt %.

[0026] In some specific embodiments, in step S2, in the treatment of the first mixed solution, the freezing temperature is (-70 to -80)°C, and the freezing time is (2 to 5) min;

[0027] The temperature of the spheroidization reaction is 20°C;

[0028] In some specific embodiments, in step S2, in the processing of the second mixed liquid, beating the second mixed liquid to a foaming state means beating the second mixed liquid until it becomes white and the foam is uniform, and then stopping beating;

[0029] The freezing temperature is (-70~-80)℃, and the freezing time is (25-35)min;

[0030] The temperature of the spheroidization reaction was 20°C.

[0031] In some specific embodiments, in step S2, the CaCl2 solution uses a CaCl2 solution with a mass fraction of 0.02 wt%.

[0032] In some specific embodiments, in step S3, the mass ratio of the gel solution to the foaming gel solution is 1:(1-2).

[0033] In some specific embodiments, in step S3, the heating temperature is 120° C. and the heating time is 90 min.

[0034] The third technical solution of the present invention is to provide an application of a photothermal effect membrane material based on bacterial cellulose as described in one of the above technical solutions in photothermal catalysis and photothermal power generation materials.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) The present invention organizes the powdered photothermal effect material through two solid states of bacterial cellulose film and flexible foaming, distinguishes the flexible foaming film with heat insulation function and the cellulose film mixed with photothermal material, and realizes the conversion of light energy into heat energy and the preservation of heat energy through compounding. The prepared photothermal effect film material is based on the heating principle of photothermal effect and can achieve heat generation without relying on any energy input other than light energy.

[0037] (2) The present invention uses bacterial cellulose as a substrate to simultaneously meet the requirements of heat storage and material fixation, and replaces the heating logic of energy storage-conversion used in previous gas tanks, fuels, etc., realizing instant conversion and instant use of heat, solving the problems of heat energy dissipation and directional transmission, breaking away from the limitations of the performance exploration of the material itself, and having a broader prospect of use.

[0038] (3) The photothermal effect film material prepared by the present invention is a film material with a thickness not exceeding 1 mm. It has the property of being bendable while maintaining the heating function, and is also water-resistant and oil-resistant, and has strong scalability in application. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the folding of the photothermal effect film material prepared by the present invention. DETAILED DESCRIPTION

[0040] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0041] In the following examples, unless otherwise specified, raw materials or processing techniques are conventional commercially available raw materials or conventional processing techniques in the art.

[0042] The source of the bacterial cellulose liquid used in the examples is: bacterial cellulose aqueous dispersion produced by Qihong Technology Co., Ltd.

[0043] Embodiment 1:

[0044] 1. Preparation of mother liquor

[0045] Sodium alginate mother solution: weigh 10g of sodium alginate, dissolve it in 500mL of deionized water, place it in a 60℃ water bath, and stir until it is completely dissolved. After cooling, store it in a refrigerated environment at 4℃ and away from light.

[0046] PVA (polyvinyl alcohol) mother solution: weigh 5g of PVA, dissolve it in 100mL of deionized water, place it in a water bath at 85℃, and stir until it is completely dissolved. After cooling, store it at room temperature.

[0047] CaCl2 solution: weigh 20g of anhydrous CaCl2, dissolve it in 1L of deionized water, and stir at room temperature until it is completely dissolved. After cooling, store it in a sealed container at room temperature.

[0048] 2. Preparation of photothermal effect material film

[0049] (1) Weigh 50 g of 1.2 wt% bacterial cellulose homogenate, 1 g of glycerol, 15 mL of sodium alginate mother solution, 6 mL of PVA mother solution, and 0.12 g of tributyl phosphate, and add deionized water to make the final solution 100 g. Add 20 mL of 10 mg / mL carbon nanotube aqueous dispersion to the solution, mix well, place the solution in a conical flask, seal it with a sealing film, and store it in a refrigerated environment at 4°C.

[0050] (2) Take 10g, 20g, 30g, 40g, and 50g of the above solution respectively and place them in five 9cm diameter culture dishes. Place them in a -76℃ freezer for 3min. After freezing, immerse the culture dishes in a CaCl2 solution until the solution in the culture dishes is completely spheroidized at 20℃ and the solution is peeled off from the culture dishes in a gelatinous state.

[0051] (3) Take out the gel solution and absorb the excess CaCl2 solution to obtain a thin film gel.

[0052] 3. Preparation of aerogel / foaming layer

[0053] (1) Weigh 50 g of 1.2 wt% bacterial cellulose homogenate, 2 g of glycerol, 15 mL of sodium alginate mother solution, 12 mL of PVA mother solution, and 0.12 mg of freeze-dried protein powder, and add deionized water to make the final solution 100 g. After mixing evenly, place the solution in a conical flask, seal it with a sealing film, and store it in a refrigerated environment at 4°C.

[0054] (2) Place the above solution in a beaker and use a stirrer to beat the material until it becomes foamy. Stop when the material becomes white and the foam is uniform. Take a certain amount of foam and spread it evenly on the bottom of a 9 cm culture dish so that its average thickness reaches 6 mm, and quickly place it in a -76°C environment and freeze it for 30 minutes.

[0055] (3) After freezing, place each culture dish in a CaCl2 solution until it is completely thawed and the spheroidization reaction and gelation are completed at 20°C to obtain a foaming gel. Place the foaming gel in a culture dish or a round container with a similar shape and a smooth surface.

[0056] 4. Material Composite

[0057] The above-mentioned thin film gel is placed on the foaming gel (the mass ratio of the thin film gel to the foaming gel is about 1:1.5) and placed in an oven, heated at a constant temperature of 120°C for 90 minutes, and after drying, placed in an environment of 80°C for drying for 120 minutes and stored in a dark and ventilated manner to prepare a photothermal effect membrane material based on carbon nanotube composite bacterial cellulose.

[0058] The prepared photothermal effect film material can be used in environments with background temperature requirements, sufficient light and high heating requirements, such as working under good sunlight. It can also realize heating functions that do not rely on heat and oxygen in high-altitude plateaus, mountains and other areas, and can be used to heat food, clothing, or living areas.

[0059] Test Example 1:

[0060] After the photothermal effect film material prepared by the present invention is unfolded, the initial temperature is 18 degrees Celsius, which is the same as the ambient temperature. After receiving one sun's light, it can reach a peak temperature of 68.7 degrees Celsius in about 8 minutes. This shows that the photothermal effect film material prepared by the present invention can start to generate heat only by receiving light, and can also start to heat the objects contacted by the material.

[0061] Test Example 2:

[0062] like Figure 1 As shown, without destroying the structure of the photothermal effect film material, it can be cut and folded to maximize the area receiving light to increase the heating efficiency per unit time. The photothermal conversion efficiency can theoretically reach 97%, and is close to 80% in the experiment.

[0063] Test Example 3:

[0064] When the initial temperature of the object is 38.7°C and the ambient temperature is 20°C, the object is wrapped with a 0.2 mm thick photothermal effect film material, which can keep the temperature of the object above 30°C for about 5 minutes.

[0065] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A photothermal effect membrane material based on bacterial cellulose, characterized in that: It is composed of two layers of bacterial cellulose components, wherein the bacterial cellulose component in the lower layer is foamed bacterial cellulose, and the bacterial cellulose component in the upper layer is a bacterial cellulose film containing powdered photothermal effect material.

2. The photothermal effect membrane material based on bacterial cellulose according to claim 1, characterized in that: The powdered photothermal effect material includes carbon nanotubes, Mxenes, and mesoporous carbon spheres.

3. The photothermal effect membrane material based on bacterial cellulose according to claim 1, characterized in that: The thickness of the bacterial cellulose-based photothermal effect membrane material is less than 1 mm.

4. A method for preparing a photothermal effect membrane material based on bacterial cellulose as claimed in any one of claims 1 to 3, characterized in that: The steps include: S1, mixing bacterial cellulose solution, glycerol, sodium alginate solution, PVA solution, tributyl phosphate solution, and powdered photothermal effect material aqueous dispersion to obtain a first mixed solution; Mixing the bacterial cellulose solution, glycerol, sodium alginate solution, PVA solution, and protein powder to obtain a second mixed solution; S2, freezing the first mixed solution obtained in step S1, adding an excess of CaCl2 solution to carry out a spheroidization reaction, and obtaining a gel solution; The second mixed solution obtained in step S1 is whipped to a foaming state, and after freezing, an excess amount of CaCl2 solution is added to perform a spheroidization reaction to obtain a foaming gel solution; S3, placing the gel solution obtained in step S2 on the foaming gel solution, heating and reacting, and obtaining a photothermal effect membrane material based on carbon nanotube composite bacterial cellulose.

5. The preparation method according to claim 1, characterized in that: In step S1, in the first mixed solution, the ratio of bacterial cellulose, glycerol, sodium alginate solution, PVA solution, tributyl phosphate solution, and powdered photothermal effect material aqueous dispersion is 0.60wt%: 1wt%: 0.30wt%: 0.30wt%; (0.1-0.20)wt%; (1.5-3)wt%; The bacterial cellulose solution is a 1.2 wt% bacterial cellulose solution, the sodium alginate solution is a 0.2 wt% sodium alginate solution, the PVA solution is a 0.05 wt% PVA solution, and the powdered photothermal effect material aqueous dispersion is a 10 mg / mL carbon nanotube aqueous dispersion. In the second mixed solution, the ratio of bacterial cellulose solution, glycerol, sodium alginate solution, PVA solution and protein powder is (0.6-1.20) wt%: (1-2) wt%: 0.30 wt%: 0.60 wt%: (0.0001-0.0002) wt%; The bacterial cellulose solution uses a bacterial cellulose solution with a mass fraction of 1.2 wt %, the sodium alginate solution uses a sodium alginate solution with a mass fraction of 0.2 wt %, and the PVA solution uses a PVA solution with a mass fraction of 0.05 wt %.

6. The preparation method according to claim 1, characterized in that: In step S2, in the treatment of the first mixed solution, the freezing temperature is (-70 to -80)°C and the freezing time is (2 to 5) minutes; The temperature of the spheroidization reaction is 20°C; In the processing of the second mixed liquid, beating the second mixed liquid until it is in a foamy state means beating the second mixed liquid until it becomes white and the foam is uniform, then stopping beating; The freezing temperature is (-70~-80)℃, and the freezing time is (25-35)min; The temperature of the spheroidization reaction was 20°C.

7. The preparation method according to claim 1, characterized in that: In step S2, the CaCl2 solution uses a CaCl2 solution with a mass fraction of 0.02wt%.

8. The preparation method according to claim 1, characterized in that: In step S3, the mass ratio of the gel solution to the foaming gel solution is 1:(1-2).

9. The preparation method according to claim 1, characterized in that: In step S3, the heating temperature is 120°C and the heating time is 90 minutes.

10. Use of the photothermal effect membrane material based on bacterial cellulose as claimed in any one of claims 1 to 3 in photothermal catalysis and photothermal power generation materials.

Images