CN108545797B

CN108545797B - Flexible composite material for seawater desalination and preparation method thereof

Info

Publication number: CN108545797B
Application number: CN201810319162.XA
Authority: CN
Inventors: 焦世惠; 方振兴; 庞广生
Original assignee: Jilin University
Current assignee: Jilin University
Priority date: 2018-04-11
Filing date: 2018-04-11
Publication date: 2021-05-07
Anticipated expiration: 2038-04-11
Also published as: CN108545797A

Abstract

The invention discloses a flexible composite material for seawater desalination and a preparation method thereof, belonging to the technical field of inorganic material preparation processes. The flexible composite material for seawater desalination is formed by taking carbonized melamine sponge as a support body and loading tungsten oxide nano materials in the sponge. Ultrasonically dispersing a tungsten oxide nano material in deionized water, adding a piece of melamine sponge, absorbing water dispersion of the tungsten oxide nano material into the pore canal by utilizing the porous structure and the super-strong water absorption performance of the melamine sponge, and then carbonizing the melamine sponge absorbed with the tungsten oxide nano material at high temperature under the nitrogen protection condition to obtain the flexible composite material for seawater desalination. The method has simple preparation process, cheap and easily available reaction raw materials, and skillfully utilizes the structure and the performance of the raw materials to prepare the flexible composite material with practical application. The prepared composite material can be used for seawater desalination and has stable repeatability.

Description

Flexible composite material for seawater desalination and preparation method thereof

Technical Field

The invention belongs to the technical field of inorganic material preparation processes, and particularly relates to a flexible composite material for seawater desalination and a preparation method thereof.

Background

At present, shortage of fresh water resources is one of the most urgent global challenges (Science,2011,333, 712-. Two common approaches to solve the water resource shortage are reverse osmosis technology and solar seawater desalination technology (Nature nanotechnology 2015,10, 459-. Since solar energy is the most abundant energy source available to human beings, compared with the seawater desalination by reverse osmosis technology, the seawater desalination by solar energy has many advantages, such as no consumption of conventional energy, no pollution, high purity of obtained fresh water, etc. In recent years, the development of solar seawater desalination technology is promoted by strong light absorption Materials such as graphene, gold nanoparticles, amorphous carbon and the like (Chemistry of Materials,2017,29, 5629-. However, the problems of reducing the cost of the material and preventing the performance of the material from being degraded still remain to be solved. For example, metal nanoparticles having a plasmon resonance effect are very expensive and may be dropped off after long-term use in water, which undoubtedly increases the use cost of the seawater desalination composite material and reduces the service life thereof. Therefore, in recent years, the development and design of low-cost materials for seawater desalination become the goal of many researchers. At present, researchers at home and abroad have designed various composite materials capable of improving the seawater desalination efficiency: wood block/exfoliated graphene bilayer structures (ACS applied materials & interfaces,2017,9, 7675-. However, most of these light-absorbing materials are complicated and complicated to prepare, and the reaction conditions are difficult to control accurately, which limits their mass production. The invention provides a low-cost melamine sponge as a base material, and a flexible composite material which can be used for seawater desalination is prepared by compounding a tungsten oxide nano material with the melamine sponge under the condition of nitrogen, and the preparation method is low in preparation cost and simple and feasible.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a flexible composite material for seawater desalination and a preparation method thereof, the provided method is to ultrasonically disperse a tungsten oxide nano material in deionized water, absorb aqueous dispersion of the tungsten oxide nano material into pore channels of the tungsten oxide nano material by utilizing the porous structure and strong water absorbability of melamine sponge, and finally carbonize at high temperature under the protection of nitrogen to prepare the composite material capable of floating in water, so that the problem that the melamine sponge sinks when absorbing water is solved, and simultaneously the water evaporation efficiency of the composite material is improved.

The specific technical scheme is as follows:

a flexible composite material for seawater desalination is prepared by using carbonized melamine sponge as a support body, and loading tungsten oxide nano materials in the sponge.

The tungsten oxide nano material is preferably a tungsten oxide nano wire.

A preparation method of a flexible composite material for seawater desalination comprises the steps of ultrasonically dispersing a tungsten oxide nano material in deionized water, adding melamine sponge, absorbing water dispersion of the tungsten oxide nano material into a pore channel of the tungsten oxide nano material, and then carrying out high-temperature carbonization on the melamine sponge adsorbed with the tungsten oxide nano material under the condition of nitrogen protection to obtain the flexible composite material for seawater desalination.

In the above method for preparing the flexible composite material for seawater desalination, the high-temperature carbonization is preferably performed at 400-600 ℃; the carbonization time is preferably 2 hours or more.

In the above method for preparing a flexible composite material for seawater desalination, the tungsten oxide nano material is ultrasonically dispersed in deionized water, and the concentration of the obtained dispersion liquid is preferably 5 mg/mL.

Has the advantages that:

the method has simple preparation process, cheap and easily available reaction raw materials, and skillfully utilizes the structure and the performance of the raw materials to prepare the flexible composite material with practical application. The prepared composite material can be used for seawater desalination and has stable repeatability.

Drawings

Fig. 1 is a macro photograph of the composite prepared in example 1.

Fig. 2 is a macro photograph of the composite prepared in example 2.

Fig. 3 is a macro photograph of the composite prepared in example 3.

Fig. 4 is a macro photograph of the composite prepared in example 4.

FIG. 5 is a graph of the UV-VIS near IR absorption spectrum of the composite material prepared in example 1.

Fig. 6 is a graph showing the effect of water evaporation on the tungsten oxide/carbon sponge prepared in example 1.

Fig. 7 is a graph showing the effect of the cycle performance test on the composite material prepared in example 1.

FIG. 8 is a graph showing the deformation resistance test process of the composite material prepared in example 1.

Detailed Description

Example 1

The newly prepared tungsten oxide nano-wires of 50mg are ultrasonically dispersed in 10mL of deionized water, then the blocky melamine sponge is put into the deionized water, the water dispersion of the tungsten oxide nano-materials is absorbed into the pore canals of the melamine sponge by utilizing the porous characteristic and the strong water absorption property of the melamine sponge, the melamine sponge absorbed with the tungsten oxide nano-materials is put into a muffle furnace, and the melamine sponge is carbonized for 2 hours at 500 ℃ under the protection of nitrogen. The flexible composite material which can float in water and can desalt seawater by using sunlight can be prepared.

Example 2

The newly prepared tungsten oxide nano-wires of 50mg are ultrasonically dispersed in 10mL of deionized water, then the blocky melamine sponge is put into the deionized water, the water dispersion of the tungsten oxide nano-materials is absorbed into the pore canals of the melamine sponge by utilizing the porous characteristic and the strong water absorption property of the melamine sponge, the melamine sponge absorbed with the tungsten oxide nano-materials is put into a muffle furnace, and the melamine sponge is carbonized for 2 hours at 400 ℃ under the protection of nitrogen. The flexible composite material which can float in water and can desalt seawater by using sunlight can be prepared. (if the temperature is low, e.g. 300 ℃, the melamine sponge cannot be carbonized)

Example 3

The newly prepared tungsten oxide nano-wires of 50mg are ultrasonically dispersed in 10mL of deionized water, then the blocky melamine sponge is put into the deionized water, the water dispersion of the tungsten oxide nano-materials is absorbed into the pore canals of the melamine sponge by utilizing the porous characteristic and the strong water absorption property of the melamine sponge, the melamine sponge absorbed with the tungsten oxide nano-materials is put into a muffle furnace, and the melamine sponge is carbonized for 2 hours at the temperature of 600 ℃ under the protection of nitrogen. The flexible composite material which can float in water and can desalt seawater by using sunlight can be prepared. (if the temperature is higher, the composite material obtained by carbonization does not have good flexibility and can greatly limit the wide application of the composite material when the temperature exceeds 600℃.)

Example 4

The newly prepared tungsten oxide nano-wires of 50mg are ultrasonically dispersed in 10mL of deionized water, then the blocky melamine sponge is put into the deionized water, the water dispersion of the tungsten oxide nano-materials is absorbed into the pore canals of the melamine sponge by utilizing the porous characteristic and the strong water absorption property of the melamine sponge, the melamine sponge absorbed with the tungsten oxide nano-materials is put into a muffle furnace, and the melamine sponge is carbonized for 4 hours at 500 ℃ under the protection of nitrogen. The flexible composite material which can float in water and can desalt seawater by using sunlight can be prepared.

Example 5

The flexible composite material prepared in example 1 is applied to seawater desalinationThe test comprises the following specific processes: the flexible composite material was placed in a beaker containing 100mL of deionized water, and the beaker was placed on a Sadolis electronic balance with a power of 2kW/cm²Was irradiated with simulated sunlight (xenon lamp) and one reading was taken from the balance and recorded every minute. The change curve of the reaction system mass with time is shown in fig. 6, and for comparison, the change curve of the mass of pure seawater during evaporation and the change curve of the mass of seawater during evaporation under the action of carbon sponge are also plotted in fig. 6. As can be seen from the figure, the tungsten oxide/carbon sponge prepared in example 1 has a very good effect of promoting the evaporation of seawater.

Example 6

The experimental process of example 5 is repeated 10 times, and the change rate of the seawater quality in each experiment is recorded, as shown in fig. 7, it can be seen that the speed of promoting seawater evaporation of the sample prepared by the invention is kept stable in the repeated 10 times of use, which indicates that the sample prepared by the invention can be recycled and has stable performance.

Example 7

The flexible composite prepared in example 1 was tested for deformation resistance. The specific process is shown in fig. 8: the composite material is deformed by applying an external bending stress, and can be immediately restored to the original shape after the external force is removed, which shows that the composite material prepared by the invention has good deformation resistance.

Claims

1. A flexible composite material for seawater desalination is composed of carbonized melamine sponge as supporting body and tungsten oxide nano material loaded in the sponge.

2. A method for preparing the flexible composite material for seawater desalination of claim 1, comprising the steps of ultrasonically dispersing tungsten oxide nano-materials in deionized water, adding melamine sponge, absorbing aqueous dispersion of the tungsten oxide nano-materials into pore canals of the tungsten oxide nano-materials, and then carbonizing the melamine sponge absorbed with the tungsten oxide nano-materials at high temperature under the protection of nitrogen to obtain the flexible composite material for seawater desalination; the high-temperature carbonization is carried out for more than 2 hours at 400-500 ℃.

3. The method for preparing the flexible composite material for seawater desalination as claimed in claim 2, wherein the concentration of the dispersion obtained by ultrasonically dispersing the tungsten oxide nano material in deionized water is 5 mg/mL.