Method for enhancing photo-thermal water evaporation capacity of seaweed non-woven fabric

Abstract

The invention relates to a method for enhancing photo-thermal water evaporation capacity of seaweed non-woven fabric, which is characterized by adopting the following process: (1) dispersing GO (graphene oxide) in deionized water with the concentration of 0.8 g / L, adding sodium borohydride with the concentration of 8 g / L, putting the mixed solution on a magnetic stirrer, and stirring at 60 DEG C for 2 hours to obtain rGO dispersion liquid; (2) a silane coupling agent KH570 is added into the rGO dispersion liquid for modification, the mass ratio of the KH570 to the rGO is 10%, standing is conducted for 10 min, then modified rGO is deposited on the surface of the seaweed non-woven fabric through suction filtration, and drying is conducted under the condition of 60 DEG C. Tests show that the light-heat water evaporation capacity of the seaweed non-woven fabric can be remarkably improved by utilizing the method disclosed by the invention.

Description

Technical Field

[0001] The invention relates to a method for enhancing the photothermal water evaporation capacity of a seaweed nonwoven fabric, and belongs to the technical field of textile printing and dyeing. Background Art

[0002] In recent years, the shortage of fresh water resources has become a serious problem facing all mankind. Purifying water that is not suitable for direct use, such as seawater, through membrane separation, distillation, reverse osmosis technology, etc. is an effective way to solve the shortage of fresh water, but it often consumes a large amount of fossil resources and is prone to secondary environmental pollution.

[0003] The light-driven technology, which converts light energy into heat energy through photothermal conversion materials to drive the evaporation of seawater and other materials to produce water vapor, and then condenses the vapor to obtain pure water, has the advantages of being green, safe and sustainable. At present, a variety of photothermal conversion materials with different photothermal conversion mechanisms have been developed, such as carbon-based materials, metal nanoparticles, semiconductors and conductive polymers. Carbon-based materials such as graphene, carbon nanotubes, and carbon black are widely used due to their strong light absorption ability and good chemical and thermal stability.

[0004] Usually, the photothermal conversion material needs to be attached to a base material such as dust-free paper, wood, porous foam, hydrogel, aerogel, etc., in order to better exert its photothermal water evaporation performance. Compared with the above materials, fiber materials have excellent mechanical properties and practicality, are easy to store and transport, and have low large-scale production costs, and are expected to show better performance.

[0005] Alginic acid is a green marine biomass polymer that utilizes Ca 2+ Seaweed fibers and fabrics can be prepared by cross-linking and covalent cross-linking, which have good biocompatibility, degradable absorbency, flame retardancy, high hygroscopicity, gel blocking and metal ion adsorption, and are widely used in textile, medical, sports, military and other fields. Seaweed non-woven fabrics are suitable for use as a substrate for light-heated water evaporation. Summary of the invention

[0006] The present invention uses sodium borohydride to treat graphene oxide (GO) to obtain reduced graphene oxide (rGO), which is then deposited on the surface of seaweed non-woven fabric by suction filtration, so that it has a certain light-heat water evaporation capacity; the surface of rGO is modified by a silane coupling agent (KH570) to further improve the light-heat water evaporation capacity.

[0007] The present invention relates to the following process: (1) GO was dispersed in deionized water at a concentration of 0.8 g / L, sodium borohydride was added at a concentration of 8 g / L, the mixture was placed on a magnetic stirrer and stirred at 60 °C for 2 h to obtain rGO dispersion; (2) Silane coupling agent KH570 was added to the rGO dispersion for modification. The mass ratio of KH570 to rGO was 10%. The rGO was allowed to stand for 10 min. The modified rGO was then deposited on the surface of the seaweed non-woven fabric by suction filtration and dried at 60 °C.

[0008] GO was dispersed in deionized water, a certain amount of sodium borohydride was added, and GO was fully reduced after being placed on a magnetic stirrer and stirred at 60 °C for 2h to obtain rGO dispersion. The π electron energy levels in rGO are closely spaced, and have strong light absorption ability, which can convert light energy into heat energy through lattice vibration. Silane coupling agent KH570 was added to the above rGO dispersion, and the mass ratio of KH570 to rGO was 10%. The surface modification of rGO was completed by standing for 10 min, and then the KH570-modified rGO was deposited on the surface of seaweed non-woven fabric by suction filtration and dried at 60 °C. The silane coupling agent KH570 molecules can bind to the rGO surface and modify it, forming a larger steric hindrance to block the aggregation between rGO, which can not only enhance the effective interaction with the incident light, but also reduce the resistance to the passage of water vapor; in addition, KH570 bound to the rGO surface can limit the direct contact between water and rGO, reduce the contact area with water, and reduce the amount of water filling between the pores, thereby reducing the ineffective loss of heat and improving the water evaporation capacity. DETAILED DESCRIPTION

[0009] The present invention is further illustrated by the following examples and comparative examples.

[0010] Example 1 (1) GO was dispersed in deionized water at a concentration of 0.8 g / L, sodium borohydride was added at a concentration of 8 g / L, the mixture was placed on a magnetic stirrer and stirred at 60 °C for 2 h to obtain rGO dispersion; (2) Silane coupling agent KH570 was added to the rGO dispersion for modification. The mass ratio of KH570 to rGO was 10%. The rGO was allowed to stand for 10 min. The modified rGO was then deposited on the surface of the seaweed non-woven fabric by suction filtration and dried at 60 °C.

[0011] Comparative Example 1 (1) GO was dispersed in deionized water at a concentration of 0.8 g / L, sodium borohydride was added at a concentration of 8 g / L, the mixture was placed on a magnetic stirrer and stirred at 60 °C for 2 h to obtain an rGO dispersion, the total liquid volume being the same as that in Example 1; (2) The rGO dispersion was not modified, and rGO was directly deposited on the surface of the seaweed non-woven fabric same as that in Example 1 by suction filtration, and then dried at 60°C.

[0012] Comparative Example 2 The same volume of deionized water as that in Example 1 was taken, filtered through the surface of the same seaweed nonwoven fabric as that in Example 1 by suction filtration, and dried at 60°C.

[0013] The same amount of deionized water was dripped onto the seaweed nonwoven fabrics obtained in Example 1, Comparative Example 1 and Comparative Example 2, and the fabrics were placed under ultraviolet light and illuminated under the same conditions. After 150 seconds of irradiation, the water evaporation rates of the fabrics were 70.2%, 64% and 42%, respectively; after 210 seconds of irradiation, the water evaporation rates of the fabrics were 88.6%, 77.6% and 59.8%, respectively. It can be seen that the method of the present invention can significantly improve the light-heat water evaporation capacity of the seaweed nonwoven fabric.

[0014] Water evaporation rate (%) = (evaporated water mass / initial water mass) × 100.

Claims

1. The present invention relates to a method for enhancing the photothermal water evaporation capacity of seaweed nonwoven fabrics, characterized in that The following processes are used: (1) GO was dispersed in deionized water at a concentration of 0.8 g / L, sodium borohydride was added at a concentration of 8 g / L, the mixture was placed on a magnetic stirrer and stirred at 60 °C for 2 h to obtain rGO dispersion; (2) Silane coupling agent KH570 was added to the rGO dispersion for modification. The mass ratio of KH570 to rGO was 10%. The rGO was allowed to stand for 10 min. The modified rGO was then deposited on the surface of the seaweed non-woven fabric by suction filtration and dried at 60 °C.