Titanium dioxide-based fluid-cellulose acetate electrospinning membrane for radiative cooling and preparation method thereof

Abstract

The present invention relates to a titanium dioxide-based fluid-cellulose acetate electrospun membrane for radiative cooling and a method for preparing the same. The present invention first uses an ion exchange method to prepare the titanium dioxide-based fluid, then modifies cellulose acetate with the titanium dioxide-based fluid. Finally, an electrospinning method is used to produce a cellulose acetate-titanium dioxide-based fluid composite fiber film for daytime radiative cooling. The titanium dioxide-based fluid modifies the cellulose acetate structure, significantly enhancing the mechanical strength and radiative cooling efficiency of the composite fiber membrane. Due to the titanium dioxide-based fluid's high enthalpy change, high solar reflectivity, and UV absorption properties, the resulting fabric produces a large temperature difference between the fabric and human skin when exposed to direct sunlight, achieving a superior radiative cooling effect.

Description

Technical Field

[0001] The present invention relates to the field of radiation cooling textiles, and in particular to a titanium dioxide fluid-cellulose acetate electrospinning membrane for radiation cooling and a preparation method thereof. Background Art

[0002] Normal body temperature is crucial for physiological metabolism and organ function. Once body temperature is disturbed and thermal homeostasis is disrupted, heat stress can induce related diseases and even be life-threatening. Heating, ventilation, and air-conditioning systems are commonly used to create a comfortable indoor thermal environment and achieve personal thermophysiological comfort. However, this energy-intensive environmental control system runs counter to the goals of energy conservation and low carbon emissions and fails to take into account people working outdoors in high temperatures. Therefore, there is an urgent need for textile-based personal cooling technologies that can control the local microclimate around the human body and maintain human safety and comfort in an energy-efficient and sustainable society. Passive daytime radiative cooling is a new type of cooling that requires no additional energy consumption and can cool objects by reflecting sunlight and radiant heat at mid-infrared wavelengths. Common flexible substrates used for radiative cooling (i.e., polydimethylsiloxane or polyimide films) have poor air permeability and are difficult to degrade. Therefore, an integrated textile design approach is needed to promote the synergistic effects of radiation, conduction, and evaporative cooling to minimize heat absorption and maximize heat dissipation. Summary of the Invention

[0003] In view of the above problems, the object of the present invention is to provide a titanium dioxide-based fluid-cellulose acetate electrospinning membrane for radiative cooling and a preparation method thereof.

[0004] The technical solution of the present invention to solve the above technical problems is as follows:

[0005] Preparation method of titanium dioxide fluid-cellulose acetate electrospinning membrane for radiation cooling,

[0006] The specific steps include:

[0007] Step 1: preparing a cellulose acetate solution, adding 5 wt% titanium dioxide-based fluid nanoparticles to the cellulose acetate solution and stirring the mixture to obtain a spinning solution;

[0008] Step 2: electrospinning the spinning solution obtained in step 1 to obtain an electrospinning membrane;

[0009] Step 3: Place the obtained electrospun membrane in an oven to dry and remove the residual solvent to obtain a titanium dioxide-based fluid-cellulose acetate electrospun membrane for radiation cooling.

[0010] Furthermore, the titanium dioxide-based fluid nanoparticles in step 1 are prepared by an ion exchange method, and are titanium dioxide solvent-free nanofluids with titanium dioxide as the inner core and polysiloxane quaternary ammonium salt and sodium nonylphenol polyoxyethylene ether sulfate as the outer shell.

[0011] Furthermore, the cellulose acetate solution in step 1 is 12 wt %, and is prepared by the following method: dissolving cellulose acetate powder in a mixed solvent of acetone-N,N-dimethylformamide, and then continuously stirring at 25 degrees for 2 hours.

[0012] Furthermore, in step 1, the solvent is N,N-dimethylformamide and acetone in a volume ratio of 2:1.

[0013] The titanium dioxide-based fluid-cellulose acetate electrospinning membrane for radiation cooling is prepared by the above method.

[0014] The beneficial effects of the present invention are as follows: the present invention utilizes titanium dioxide fluid to modify cellulose acetate, greatly enhancing the mechanical strength and radiative cooling efficiency of the composite fiber membrane. When prepared into clothing for use, due to the high enthalpy change characteristics of the titanium dioxide fluid, the titanium dioxide fluid will absorb heat above room temperature of 32°, reduce viscosity and undergo phase transition, resulting in a large temperature difference between the human skin and the body. At the same time, the titanium dioxide fluid has the characteristics of high solar reflectivity and ultraviolet light absorption, which can achieve a better radiative cooling effect. At the same time, the flowing titanium dioxide fluid will be more evenly dispersed in the cellulose acetate matrix, enhancing the mechanical strength, air permeability and flexibility of the composite fiber membrane. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a preparation flow chart of the present invention;

[0016] Figure 2 This is a test sample of the titanium dioxide-based fluid-cellulose acetate electrospun film prepared in Example 1;

[0017] Figure 3 This is a scanning electron micrograph of the titanium dioxide-based fluid-cellulose acetate electrospun film prepared in Example 1;

[0018] Figure 4 This is a differential scanning calorimeter of the titanium dioxide-based fluid-cellulose acetate electrospun film prepared in Example 1;

[0019] Figure 5 Infrared reflection spectra of polymer films prepared in Examples 1-5;

[0020] Figure 6 This is a graph showing the radiation intensity of the titanium dioxide-based fluid-cellulose acetate electrospun film prepared in Example 1 changing with time outdoors;

[0021] Figure 7 This is a temperature diagram of the cellulose acetate-titanium dioxide fluid electrospun films prepared in Examples 1-5 changing with time outdoors. DETAILED DESCRIPTION

[0022] The principles and features of the present invention are described below in conjunction with specific embodiments. The embodiments are only used to explain the present invention and are not used to limit the scope of the present invention.

[0023] Example 1

[0024] Preparation of a titanium dioxide-based fluid-cellulose acetate precursor solution: Dissolve an appropriate amount of cellulose acetate powder in a mixed solvent of acetone and N,N-dimethylformamide (2:1 by volume) and stir continuously at 25°C for 2 hours to prepare a uniform cellulose acetate solution (12 wt%). Add a 5 wt% titanium dioxide-based fluid and stir until uniform.

[0025] Preparation of titanium dioxide fluid-cellulose acetate film: The spinning solution obtained by the above configuration is electrospun to obtain an electrospun membrane. The obtained electrospun membrane is placed in an oven at 60°C to dry and remove

[0026] Example 2

[0027] Preparation of titanium dioxide-based fluid-cellulose nanofiber precursor solution: Dissolve an appropriate amount of cellulose nanofiber powder in a mixed solvent of acetone and N,N-dimethylformamide (2:1 by volume) and stir continuously at 25 degrees for 2 hours to prepare a uniform cellulose nanofiber solution (12 wt%). Add 5 wt% titanium dioxide-based fluid and stir until uniform.

[0028] Preparation of titanium dioxide-based fluid-cellulose nanofibers: The spinning solution obtained by the above configuration is electrospun to obtain an electrospun membrane. The obtained electrospun membrane is placed in an oven at 60°C to remove residual solvent;

[0029] Example 3

[0030] Preparation of titanium dioxide-based fluid-microcrystalline cellulose precursor solution: Dissolve an appropriate amount of cellulose acetate powder in a mixed solvent of acetone and N,N-dimethylformamide (2:1 by volume) and stir continuously at 25°C for 2 hours to prepare a uniform microcrystalline cellulose solution (12 wt%). Add 5 wt% silicon dioxide-based fluid and stir until uniform.

[0031] Preparation of titanium dioxide fluid-microcrystalline cellulose film: The spinning solution obtained by the above configuration is electrospun to obtain an electrospun membrane. The obtained electrospun membrane is placed in an oven at 60°C to remove residual solvent;

[0032] Example 4

[0033] Preparation of titanium dioxide-based fluid-carboxymethyl cellulose precursor solution: Dissolve an appropriate amount of carboxymethyl cellulose powder in a mixed solvent of acetone and N,N-dimethylformamide (2:1 by volume) and stir continuously at 25 degrees for 2 hours to prepare a uniform carboxymethyl cellulose solution (12 wt%). Add 5 wt% titanium dioxide-based fluid and stir evenly.

[0034] Preparation of titanium dioxide fluid-carboxymethyl cellulose film: The spinning solution obtained by the above configuration is electrospun to obtain an electrospun membrane. The obtained electrospun membrane is placed in an oven at 60°C to remove residual solvent;

[0035] Example 5

[0036] Preparation of titanium dioxide-based fluid-hydroxypropyl methylcellulose precursor solution: Dissolve an appropriate amount of hydroxypropyl methylcellulose powder in a mixed solvent of acetone and N,N-dimethylformamide (2:1 volume ratio) and stir continuously at 25 degrees for 2 hours to prepare a uniform hydroxypropyl methylcellulose solution (12 wt%). Add 5 wt% titanium dioxide-based fluid and stir evenly.

[0037] Preparation of titanium dioxide-based fluid-hydroxypropyl methylcellulose film: The spinning solution obtained by the above configuration is electrospun to obtain an electrospun membrane. The obtained electrospun membrane is placed in an oven at 60°C to remove residual solvent;

[0038] pass Figure 2-7 Analysis and morphology analysis show that the fiber interlaced structure of cellulose acetate-titanium dioxide fluid film is relatively dense and the fiber diameter is relatively uniform; differential scanning calorimetry analysis shows that titanium dioxide fluid has high enthalpy change performance, and the higher the solid content, the greater the enthalpy change; infrared analysis confirms that titanium dioxide fluid modified materials make a greater contribution to the reflectivity of polysaccharide composite fiber film, and the composite fiber membrane of silicon dioxide fluid and cellulose acetate has the highest infrared reflectivity; cooling effect display proves that titanium dioxide fluid modified film has significant radiation cooling effect in practical application, among which the composite fiber membrane composed of titanium dioxide fluid and cellulose acetate has the best cooling effect.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a titanium dioxide-based fluid-cellulose acetate electrospinning membrane for radiative cooling, characterized in that: The following steps are involved: Step 1: preparing a cellulose acetate solution, adding 5 wt% titanium dioxide fluid nanoparticles to the cellulose acetate solution and stirring uniformly to obtain a spinning solution; the titanium dioxide fluid nanoparticles in step 1 are prepared by an ion exchange method, and the titanium dioxide solvent-free nanofluid has titanium dioxide as an inner core and polysiloxane quaternary ammonium salt and nonylphenol polyoxyethylene ether sodium sulfate as an outer shell; Step 2: electrospinning the spinning solution obtained in step 1 to obtain an electrospinning membrane; Step 3: Place the obtained electrospun membrane in an oven to dry and remove the residual solvent to obtain a titanium dioxide-based fluid-cellulose acetate electrospun membrane for radiation cooling.

2. The method for preparing a titanium dioxide-based fluid-cellulose acetate electrospinning membrane for radiative cooling according to claim 1, characterized in that: The cellulose acetate solution in step 1 is 12 wt % and is prepared by the following method: dissolving cellulose acetate powder in a mixed solvent of acetone and N,N-dimethylformamide, and then continuously stirring at 25 degrees for 2 hours.

3. The method for preparing a titanium dioxide-based fluid-cellulose acetate electrospinning membrane for radiative cooling according to claim 2, characterized in that: In the step 1, the solvent is N,N-dimethylformamide and acetone in a volume ratio of 2:

1.

4. Titanium dioxide fluid-cellulose acetate electrospinning membrane for radiative cooling, characterized in that: Prepared by any one of the methods of claims 1-3.

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