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CN-121974429-A - Silane modified graphene oxide/polyvinyl alcohol composite aerogel evaporator and preparation method and application thereof

CN121974429ACN 121974429 ACN121974429 ACN 121974429ACN-121974429-A

Abstract

The invention provides a silane modified graphene oxide/polyvinyl alcohol composite aerogel evaporator and a preparation method and application thereof, and relates to the technical field of new energy materials. Subsequently, graphene oxide powder was dispersed into a co-solvent, uniformly distributed by ultrasonic, and then (3-aminopropyl) trimethoxysilane was introduced. And then glutaraldehyde is added, and the mixture is stood at room temperature to complete the crosslinking and gelation processes, so that the GO/SPH hydrogel is formed. Finally, soaking, washing and freeze-drying the obtained hydrogel to obtain the GO/SPH composite aerogel evaporator. The GO/SPH evaporator prepared by the invention realizes extremely high water evaporation rate and solar energy conversion efficiency by utilizing excellent photo-thermal conversion performance of graphene oxide and special rapid water transportation and heat localization capability of PVA three-dimensional porous aerogel.

Inventors

  • YANG SHENGYANG
  • YU YONGHANG

Assignees

  • 扬州大学

Dates

Publication Date
20260505
Application Date
20260126

Claims (9)

  1. 1. The preparation method of the silane modified graphene oxide/polyvinyl alcohol composite aerogel evaporator is characterized by comprising the following steps of: Preparing a cosolvent system, namely completely dissolving polyvinyl alcohol in deionized water, cooling, adding absolute ethyl alcohol, and stirring to form a uniform polyvinyl alcohol/ethanol-water cosolvent system; Step two, dispersing and functionalizing, namely adding graphene oxide powder into the cosolvent system obtained in the step one, performing ultrasonic dispersion, then adding (3-aminopropyl) trimethoxysilane, and continuing ultrasonic treatment to uniformly disperse the graphene oxide powder; Step three, crosslinking and gelation, namely adding glutaraldehyde as a crosslinking agent into the mixed solution in the step two, stirring, standing, and completing the crosslinking and gelation process to obtain silane modified graphene oxide/polyvinyl alcohol hydrogel; and step four, purifying and drying, namely soaking and washing the silane modified graphene oxide/polyvinyl alcohol hydrogel obtained in the step three, and finally, freeze-drying to obtain the GO/SPH composite aerogel evaporator.
  2. 2. The method of claim 1, wherein step one is specifically performed as: Dissolving polyvinyl alcohol in deionized water at a concentration of 2-5 wt%, stirring at 80-95 ℃ until the polyvinyl alcohol is completely dissolved, cooling to room temperature, adding absolute ethyl alcohol, and stirring until the polyvinyl alcohol is uniform, wherein the mass ratio of the ethyl alcohol to the deionized water is 1 (3.5-4.5).
  3. 3. The preparation method according to claim 1, wherein in the second step, the mass ratio of the graphene oxide powder to the polyvinyl alcohol/ethanol-water cosolvent system is (0.1-0.5): 10; The dosage ratio of the addition amount of the (3-aminopropyl) trimethoxysilane to the polyvinyl alcohol/ethanol-water cosolvent system is (0.3-0.7) mL, 10g.
  4. 4. The method of claim 1, wherein in step three, the glutaraldehyde is used in an amount of 420 ul/10 g with respect to the polyvinyl alcohol/ethanol-water co-solvent system.
  5. 5. The preparation method of the graphene oxide powder according to claim 1, wherein in the second step, the ultrasonic dispersion time after adding the graphene oxide powder is 5-15 minutes, and the ultrasonic treatment time after adding the (3-aminopropyl) trimethoxysilane is 3-8 minutes.
  6. 6. The preparation method according to claim 1, wherein in the third step, stirring time after glutaraldehyde addition is 0.5 to 2 minutes, and the standing operation is performed at room temperature for 0.5 to 2 hours.
  7. 7. The method of claim 1, wherein step four is specifically performed as: Soaking the silane modified graphene oxide/polyvinyl alcohol hydrogel obtained in the step three in ultrapure water for 10-20 minutes, repeating for 3-6 times, pre-freezing at a temperature below-50 ℃, and then freeze-drying for 20-30 hours under the condition that the vacuum degree is lower than 10 Pa to obtain the GO/SPH composite aerogel evaporator.
  8. 8. The silane modified graphene oxide/polyvinyl alcohol composite aerogel evaporator prepared by the preparation method of any one of claims 1 to 7.
  9. 9. The use of the silane modified graphene oxide/polyvinyl alcohol composite aerogel evaporator of claim 8 in sea water desalination and water purification.

Description

Silane modified graphene oxide/polyvinyl alcohol composite aerogel evaporator and preparation method and application thereof Technical Field The invention relates to the technical field of new energy materials, in particular to a silane modified graphene oxide/polyvinyl alcohol (GO/SPH) composite aerogel evaporator and a preparation method and application thereof. Background Water resource safety is a foundation stone for sustainable development of human society. However, as industrialization progresses and population continues to grow, the problem of clean water shortage worldwide is becoming more serious. It is estimated that about 50 hundred million people are facing varying degrees of water pressure, and this figure is expected to continue to rise in the next few decades. By 2050, two-thirds of the world population is expected to face water shortage problems. Desalination of sea water is considered as one of the key ways to alleviate water resource shortages in coastal areas, but its treatment scale has remained elusive to meet the increasing demands. The current mainstream seawater desalination technology (such as reverse osmosis) is mature, but still has the problems of high energy consumption, high cost, membrane pollution and the like, so that the popularization and the application of the technology in underdeveloped and remote areas are limited. Under the background, the solar drive interface evaporation technology is an alternative scheme with great prospect by virtue of the advantages of nearly zero energy consumption, environmental friendliness, flexible deployment and the like. However, practical application of the technology is still limited by evaporation rate and energy utilization efficiency, so development of a novel evaporator with high-efficiency photo-thermal conversion and rapid water transportation capability has become a key of current research. Disclosure of Invention Aiming at the problems of low evaporation rate and insufficient photo-thermal conversion efficiency in the existing solar water evaporation technology, the invention designs a silane modified graphene oxide/polyvinyl alcohol composite aerogel evaporator and a preparation method and application thereof. The preparation method of the silane modified graphene oxide/polyvinyl alcohol (GO/SPH) composite aerogel evaporator comprises the following steps: Preparing a cosolvent system, namely completely dissolving polyvinyl alcohol in deionized water, cooling, adding absolute ethyl alcohol, and stirring to form a uniform polyvinyl alcohol/ethanol-water cosolvent system; Step two, dispersing and functionalizing, namely adding graphene oxide powder into the cosolvent system obtained in the step one, performing ultrasonic dispersion, then adding (3-aminopropyl) trimethoxysilane, and continuing ultrasonic treatment to uniformly disperse the graphene oxide powder; Step three, crosslinking and gelation, namely adding glutaraldehyde as a crosslinking agent into the mixed solution in the step two, stirring, standing, and completing the crosslinking and gelation process to obtain silane modified graphene oxide/polyvinyl alcohol (GO/SPH) hydrogel; and step four, purifying and drying, namely repeatedly soaking and washing the silane modified graphene oxide/polyvinyl alcohol (GO/SPH) hydrogel obtained in the step three to remove impurities, and finally obtaining the GO/SPH composite aerogel evaporator through freeze drying. Further, the first specific operation is: Dissolving polyvinyl alcohol in deionized water at a concentration of 2-5 wt%, stirring at a rotation speed of 500 rpm/s at 80-95 ℃ until the polyvinyl alcohol is completely dissolved, cooling to room temperature, adding absolute ethyl alcohol, wherein the mass ratio of the ethyl alcohol to the deionized water is 1 (3-5.5), and stirring at a rotation speed of 50-150 rpm/s until the polyvinyl alcohol is uniform. Further, in the second step: The mass ratio of the graphene oxide powder to the polyvinyl alcohol/ethanol-water cosolvent system is (0.1-0.5) 10; The dosage ratio of the addition amount of the (3-aminopropyl) trimethoxysilane to the polyvinyl alcohol/ethanol-water cosolvent system is (0.3-0.7) mL, 10g. The ultrasonic dispersion time after adding graphene oxide powder is 5-15 minutes, and the ultrasonic treatment time after adding (3-aminopropyl) trimethoxysilane is 3-8 minutes. Further, in step three: the dosage ratio of glutaraldehyde to the polyvinyl alcohol/ethanol-water cosolvent system is 420uL:10g. Stirring time after glutaraldehyde addition is 0.5-2 minutes, standing at room temperature for 0.5-2 hours, and experimental room temperature is 20-25 ℃. Further, the step four specific operation is as follows: Soaking the silane modified graphene oxide/polyvinyl alcohol hydrogel obtained in the step three in ultrapure water for 10-20 minutes, repeating for 3-6 times, pre-freezing at a temperature below-50 ℃, and then freeze-drying for 20-30 hours under the condition that