CN-115928323-B - PVDF-HFP/PDMS (polyvinylidene fluoride-high frequency-spectrum/polydimethylsiloxane) composite fiber membrane with high radiation cooling performance and preparation method thereof

Abstract

The invention belongs to the field of radiation cooling material design, and relates to a high radiation cooling performance composite fiber membrane PVDF-HFP/PDMS and a preparation method thereof, which is characterized in that, the mixed solution of polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) and Polydimethylsiloxane (PDMS) is prepared into the composite fiber membrane with uniform single nanofiber and excellent radiation cooling effect. The preparation method has the advantages of simple preparation method, environmental friendliness, large-size preparation, easiness in large-scale production and the like, and solves the problems that the conventional radiation cooling material is not excellent enough in daytime cooling effect, and is mostly hydrophobic, flexible, stretch-resistant and the like.

Inventors

• TANG SHAOCHUN
• WU YIPENG
• ZHANG RONG

Assignees

• 南京大学

Dates

Publication Date

20260508

Application Date

20220107

Claims (1)

1. 1. A preparation method of a high-radiation cooling composite fiber membrane PVDF-HFP/PDMS is characterized by dissolving 6g of PVDF-HFP powder in a mixed solvent of acetone and DMF, wherein the mass of the acetone and the mass of the DMF are 12g respectively, stirring and heating the mixed solution in a water bath environment at 45 ℃ for 5 hours, then mixing the mixed solution with 3.3gPDMS and stirring the mixed solution at room temperature for 30 minutes to obtain PVDF-HFP/PDMS and using the PVDF-HFP/PDMS for electrostatic spinning, regulating the spinning temperature to 40 ℃, the voltage to 20kV, the distance between a needle head and a roller to 12cm, the rotating speed of the roller to 200rpm, the pushing speed to 2mL/h and the spinning time to 15 hours, and finally obtaining the composite fiber membrane PVDF-HFP/PDMS; The composite fiber membrane has high reflectivity of 98.86% in a wave band of 0.3-2.5 mu m, middle infrared emissivity of 0.967 in a wave band of 8-13 mu m, and can achieve a cooling effect of 6.4 ℃ under the irradiation of 738W/m 2 sunlight and a cooling effect of about 7.1 ℃ at night without sunlight.

Description

PVDF-HFP/PDMS (polyvinylidene fluoride-high frequency-spectrum/polydimethylsiloxane) composite fiber membrane with high radiation cooling performance and preparation method thereof Technical Field The invention belongs to the field of radiation cooling materials, and particularly relates to a high-radiation cooling performance composite fiber membrane PVDF-HFP/PDMS and a preparation method thereof. Background The traditional cooling technology (such as air conditioner, fan, etc.) consumes additional energy, further aggravates the emission of greenhouse gases, and influences the sustainable development of human society. The novel passive radiation cooling technology is characterized in that the special selective reflection and emission characteristics of the functional material are utilized, and the heat of the novel passive radiation cooling technology radiates to cold outer space through an atmospheric window of 8-13um in a medium infrared radiation mode, so that the cooling of the novel passive radiation cooling technology is realized. The novel passive cooling technology can realize automatic cooling without consuming extra energy, has no pollution gas emission, and can be widely applied to the fields of intelligent wearing fabrics, building cooling, biomedical treatment and the like. However, achieving efficient diurnal radiative cooling remains a significant challenge. Because the material can continuously absorb certain heat in the form of visible light under the daytime sun irradiation, the sunlight absorptivity of only a few percent can offset and even exceed the cooling effect from infrared radiation. Therefore, the high sunlight reflection and the middle infrared emission of the radiation functional material are key to realizing efficient daytime cooling. At present, the passive radiation cooling material mostly adopts micro-nano technology such as electron beam lithography, magnetron sputtering and the like to prepare photonic crystals, multi-layer photonic structures, dielectrics, polymer-polymer medium composite materials and the like on a metal mirror surface, and the problems of complex preparation technology, high cost and the like still exist. Recently, the patent CN110117427A adopts a multilayer structure to realize 95% of reflectivity of a wave band of 0.3-2.5 mu m and infrared emission of a wave band of 8-13 mu m of 0.93 so as to achieve the effect of radiation cooling in daytime, the implementation and the preparation process are complex, the cooling efficiency is still to be further improved, and the radiation cooling nano functional composition prepared in the patent CN110330818A has infrared selectivity, but the infrared emissivity of the wave band of 8-13 mu m is only 0.89-0.92. Therefore, the existing radiation cooling material still has the problems of high cost, complex preparation process, further improvement of radiation cooling performance and the like, and the comprehensive performance of the material cannot be considered, such as wear resistance, water resistance, air permeability and the like. In view of the above, a high-emissivity cooling performance composite fiber film which is easy to manufacture in a large scale at low cost, has excellent cooling performance and is washable is urgently needed to be developed. Disclosure of Invention The invention aims to provide a preparation method of a composite fiber membrane with high radiation cooling performance, which solves the problems of poor daytime cooling effect, high cost, poor hydrophobicity and the like of radiation cooling materials. The invention aims to reduce the material cost, improve the radiation cooling effect and the water resistance, so that the radiation cooling effect is widely applied to the fields of wearable fabrics, building cooling and the like. The technical scheme of the invention is that in order to achieve the purpose, the invention is realized by the following technical scheme: A high-radiation cooling performance composite fiber membrane PVDF-HFP/PDMS and a preparation method thereof, wherein a-CF 3 group in PVDF-HFP has high infrared emissivity in a wave band of 8-13 mu m, si-O-Si bonds in PDMS solution also have high infrared emissivity in a wave band of 8-13 mu m, and in addition, the nanofiber structure prepared by an electrostatic spinning process effectively scatters and endows the fiber membrane with high solar reflectance. Therefore, the PVDF-HFP/PDMS composite fiber membrane prepared by the method has both high infrared emissivity and high solar reflectance, and realizes high-efficiency radiation cooling. The PVDF-HFP powder is dissolved in an organic solvent and then mixed with PDMS to prepare a PVDF-HFP/PDMS composite solution, and then the PVDF-HFP/PDMS composite fiber membrane with high radiation cooling performance is obtained through an electrostatic spinning method. The method comprises the following specific steps: (1) Dissolving a proper amount of PVDF-HFP powder into an organic