CN109721893B

CN109721893B - Self-floating heat-insulation water-guide material and preparation method and application thereof

Info

Publication number: CN109721893B
Application number: CN201811473540.6A
Authority: CN
Inventors: 曲久辉; 张唯; 吉庆华; 刘会娟; 刘锐平; 胡承志
Original assignee: Research Center for Eco Environmental Sciences of CAS
Current assignee: Research Center for Eco Environmental Sciences of CAS
Priority date: 2018-12-04
Filing date: 2018-12-04
Publication date: 2020-10-16
Anticipated expiration: 2038-12-04
Also published as: CN109721893A

Abstract

The invention relates to a self-floating heat-insulating water-conducting material and a preparation method and application thereof. The heat-insulating water-guiding material comprises a cross-linking agent, polyvinylpyrrolidone and a heat-insulating material. The invention also provides a preparation method of the heat-insulating and water-conducting material, which comprises the following steps: (1) mixing the cross-linking agent and the polyvinylpyrrolidone to obtain mixed powder; (2) dissolving the mixed powder in an organic solvent to obtain a membrane casting solution; (3) adding the casting solution into a heat insulation material to obtain slurry; (4) and pressing the slurry, and then carrying out phase conversion to obtain the heat-insulating and water-conducting material. The self-floating heat and water insulation and conduction material disclosed by the invention fully combines the heat insulation performance of a heat insulation material, the gaps between cross-linking agents and the water conduction performance of a polymer network, integrates the heat insulation and water conduction performances, can effectively improve the photo-thermal evaporation efficiency of a photo-thermal conversion material, and has sufficient mechanical strength and excellent reutilization property.

Description

Self-floating heat-insulation water-guide material and preparation method and application thereof

Technical Field

The invention relates to the technical field of composite materials, in particular to a self-floating heat-insulating water-guiding material and a preparation method and application thereof.

Background

With the development of human society, water resource shortage is becoming one of global environmental problems. The double predicament of water quantity and water quality type water shortage threatens nearly 40 billion population all over the world, and restricts the development of human society, particularly in regions with undeveloped social economy and deficient natural resources. Therefore, in the front of global energy crisis, it is an urgent need to find a water purification method with low energy consumption and easy popularization. Natural circulation of water is a common natural phenomenon, which encompasses the most widely occurring process of water purification, whereas solar water is the fundamental driving force of natural circulation. Photothermal conversion is the study and enhancement of the natural process by human beings, has the highest conversion efficiency, and is the most important form of solar energy utilization in the human society. Therefore, how to efficiently utilize solar energy to enhance the evaporation of water and improve the quality of water has wide research and application prospects.

Currently, the field of photothermal conversion is mainly focused on the improvement and preparation of light absorbing and photothermal conversion materials. The main photothermal evaporation materials are noble metals such as gold, silver and other nano-fluids and a system based on the plasmon effect formed by further assembling the nano-particles. Besides noble metals, carbon-based materials such as inorganic nanomaterials including Carbon Nanotubes (CNTs) and Graphene (GO) and a macroscopic floating carbon material formed by further assembling the carbon-based materials also have good photo-thermal conversion performance. Although some materials possess on average over 90% solar spectral absorption, the efficiency in practical solar irradiation and large water applications remains insufficient, mainly due to the inability to fully utilize the heat fixed by the photothermal conversion material. Therefore, heat management becomes an important step for practical application of the photothermal conversion material. Therefore, the scholars have proposed a number of porous materials to reduce the heat transfer of the material to the body of water; there are also scholars who better maintain the thermal insulation properties by combining thermal insulation materials with water absorbing materials in the process of maintaining water transport. However, the preparation process of the materials is complex, the mechanical strength is low, and the gap from large-scale application is large.

Disclosure of Invention

Therefore, the technical problem solved by the invention is that in the prior art, the preparation process of the heat-insulating and water-conducting material is complex, the mechanical strength is low, and the large gap is still left from large-scale application.

In order to solve the technical problems, the invention provides a heat-insulating water-guiding material, which is based on heat management, can effectively realize balance between heat management and water transmission, avoids unnecessary heat loss caused by excessive water transmission, and provides a theoretical and material basis for the practical application of the material.

The invention provides the heat and water insulation material which comprises a cross-linking agent, polyvinylpyrrolidone and a heat insulation material.

The invention provides a preparation method of a heat-insulating and water-conducting material, which comprises the following steps:

(1) mixing the cross-linking agent and the polyvinylpyrrolidone to obtain mixed powder;

(2) dissolving the mixed powder in the step (1) in an organic solvent to obtain a membrane casting solution;

(3) adding the casting solution obtained in the step (2) into a heat-insulating material to obtain slurry;

(4) and (4) pressing the slurry obtained in the step (3), and then carrying out phase conversion to obtain the heat and water insulating and conducting material.

The invention provides application of the heat-insulating and water-conducting material in a solar photo-thermal conversion device.

The invention also provides a photothermal conversion device which comprises the heat insulation and water conduction material.

Specifically, the present invention proposes the following technical solutions.

The invention provides a heat-insulating water-guiding material which comprises a cross-linking agent, polyvinylpyrrolidone and a heat-insulating material.

Preferably, in the heat insulating material, the crosslinking agent is one selected from cellulose acetate, polyvinylidene fluoride, and polyacrylonitrile.

Preferably, for the heat and water insulating material, the heat and water insulating material is selected from one of hollow glass beads or polyethylene microspheres, and the particle size of the heat and water insulating material is 10-120 μm, more preferably 30-90 μm, and even more preferably 55-90 μm.

Preferably, for the heat and water insulating material, the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1:0.01-0.4, preferably 1:0.05-0.35, and more preferably 1: 0.0625-0.3125.

Preferably, for the heat and water insulating material, the mass ratio of the cross-linking agent to the heat insulating material is 1:0.7-8.56, preferably 1:1.31-4.88, and more preferably 1: 1.31-2.84.

Preferably, the heat and water insulating and conducting material is a heat and water insulating and conducting material having a three-dimensional network structure and obtained by mixing a cross-linking agent, polyvinylpyrrolidone and a heat insulating material; preferably, the heat-insulating water-conducting material is obtained by phase inversion of the mixture.

Preferably, for the above mentioned heat insulating and water conducting material, the heat insulating and water conducting material is prepared by a method comprising the following steps:

The invention provides a preparation method of the heat-insulating and water-conducting material, which comprises the following steps:

Preferably, in the above production method, in the step (2), the organic solvent is one or more selected from the group consisting of N, N-dimethylacetamide, acetone, and N, N-dimethylformamide.

Preferably, in the above production method, the mass ratio of the crosslinking agent to the organic solvent is 5 to 25:100, preferably 8 to 24:100, and more preferably 14.8 to 23.5: 100.

Preferably, in the above production method, the step (2) further comprises the steps of stirring, sonicating, and defoaming the mixed powder before obtaining the casting solution.

Preferably, in the above production method, the stirring time is 10 to 15 hours.

Preferably, in the above preparation method, the time for the sonication is 30 to 60 minutes.

Preferably, in the above production method, the defoaming time is 24 to 48 hours, preferably 36 to 48 hours.

Preferably, in the above production method, in the step (3), the ratio of the casting solution to the heat insulating material is 2.5 to 7ml:1g, preferably 2.85-4ml:1g of the total weight of the composition.

Preferably, for the above production method, wherein, in the step (4), the pressure of the pressing is 0.01 to 4MPa, preferably 0.10 to 2MPa, more preferably 0.5 to 2 MPa; preferably, the pressing time is 0.5-20min, preferably 0.5-5 min.

Preferably, in the above production process, the phase inversion time in the step (4) is 20 to 40 hours.

Preferably, in the above preparation method, the phase inversion is performed in a thermostatic water bath, and the thermostatic temperature is 20 to 45 ℃.

The invention provides an application of the heat-insulating and water-conducting material or the heat-insulating and water-conducting material prepared by the preparation method in a solar photo-thermal conversion device.

The invention provides a photothermal conversion device which comprises the heat and water insulating and conducting material or the heat and water insulating and conducting material prepared by the preparation method.

Preferably, in the photothermal conversion device described above, the photothermal conversion device further comprises a photothermal conversion film-like material, and preferably, the photothermal conversion film-like material is selected from a photothermal conversion film that does not need to be supported or a photothermal conversion film that is supported by a supporting material.

Preferably, in the photothermal conversion device described above, the support material is selected from one of a nonwoven fabric, absorbent paper, dust-free paper, and filter paper.

Preferably, in the photothermal conversion device, the heat insulating and water conducting material and the photothermal conversion film-shaped material are combined in a wrapping, adhering or attaching manner, or the photothermal conversion powder material is spin-coated or spray-coated on the heat insulating and water conducting material, and preferably, the photothermal conversion powder is selected from one of reduced graphene, graphite, activated carbon, carbon black or carbon nanotubes.

Preferably, the photothermal conversion device described above, wherein the photothermal conversion device is placed in fresh water, seawater, or ethanol.

The invention provides the application of the photothermal conversion device in the fields of desalination, purification, concentration or reduction of water bodies containing organic or inorganic pollution.

The beneficial effects obtained by the invention are as follows:

(1) the self-floating heat and water insulation and guide material prepared by the invention fully utilizes the heat insulation material and the cross-linking agent which are cheap and easy to obtain, realizes the uniform distribution of the heat insulation material through the three-dimensional space net-shaped framework structure of the cross-linking agent, and realizes the double effects of heat insulation and water guide;

(2) the heat-insulating water-guiding material prepared by the invention is self-floating, can float on various water surfaces, and does not need additional auxiliary facilities;

(3) the self-floating heat and water insulation and guide material prepared by the invention fully combines the heat insulation performance of a heat insulation material, the gaps between cross-linking agents and the water guide performance of a polymer network, integrates the heat insulation and water guide performances, and can effectively improve the photo-thermal evaporation efficiency of a photo-thermal conversion material;

(4) the supporting material can load various film-loaded photothermal conversion materials and spray-coating or spin-coating powder materials on the supporting material in the forms of sticking, direct bonding, auxiliary fixing and the like to construct a photothermal conversion device which has strong machinability and functional extensibility;

(5) the heat-insulating water-conducting material has sufficient mechanical strength and excellent reusability.

Drawings

Fig. 1 is a schematic diagram of a light absorption spectrum of the heat-insulating water-conducting material prepared in the first embodiment.

Fig. 2-1 is a schematic scanning electron microscope view of the surface of the heat-insulating water-conducting material prepared in the first embodiment.

Fig. 2-2 is a schematic scanning electron microscope of a cross section of the heat-insulating water-conducting material prepared in the first embodiment.

FIG. 3 is a schematic view of a photothermal conversion device produced in example two.

FIG. 4 shows the photothermal conversion device of example two under simulated light (1 kW/m)²) Schematic diagram of the change in the light evaporation quality.

FIG. 5 shows the photothermal conversion device of example two under simulated light (1 kW/m)²) Graph of net evaporation rate versus time.

FIG. 6 shows the photothermal conversion device of example two under simulated light (1 kW/m)²) Schematic diagram of performance test of the following light evaporation repeated test.

Detailed Description

As described above, in the photothermal conversion technology, the efficiency of photothermal evaporation is not ideal in practical application (normal sunlight, large volume of water body), mainly due to the failure of fully utilizing the heat fixed by the photothermal conversion material. Therefore, heat management becomes an important step for practical application of the photothermal conversion material. In photothermal evaporation processes, water transport and heat management are two important aspects of mass transfer and energy transfer; more importantly, the two are in a competing relationship, i.e., better water transport sacrifices heat management. Therefore, in consideration of the limit of the evaporation rate, the heat-insulating water-conducting material based on heat management effectively realizes the balance between heat management and water transmission, avoids unnecessary heat loss caused by excessive water transmission, and provides a theoretical and material basis for the practical application of the material.

Preferably, in the heat and water insulating and conducting material, the cross-linking agent is selected from one of cellulose acetate, polyvinylidene fluoride and polyacrylonitrile; preferably, the molecular weight of the polyvinylidene fluoride is 50-90 ten thousand.

The cellulose acetate is a cellulose acetate known in the art and has a CAS number of 9004-35-7.

The molecular weight of polyacrylonitrile is 14840-15105.

The polyvinylpyrrolidone has the function of forming holes in the preparation of the heat and water insulating and conducting material, so that the prepared heat and water insulating and conducting material is favorable for transporting, evaporating and dissipating water, and the K value of the polyvinylpyrrolidone is 30.

In a preferred embodiment of the present invention, wherein the heat insulating material is selected from one of hollow glass microspheres or polyethylene microspheres, preferably, the particle size of the heat insulating material is 10-120 μm, more preferably 30-90 μm, and still more preferably 55-90 μm; preferably, the porosity of the thermal insulation material is 30-70%.

In a more preferred embodiment of the present invention, the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1:0.01 to 0.4, preferably 1:0.05 to 0.35, more preferably 1:0.0625 to 0.3125.

Preferably, the mass ratio of the cross-linking agent to the heat insulation material is 1:0.7-8.56, preferably 1:1.31-4.88, and more preferably 1: 1.31-2.84.

The heat-insulating and water-conducting material is a heat-insulating and water-conducting material with a three-dimensional network structure, which is obtained by a mixture containing a cross-linking agent, polyvinylpyrrolidone and a heat-insulating material; preferably, the heat-insulating water-conducting material is obtained by phase inversion of the mixture.

In a preferred embodiment of the present invention, the heat and water insulating and conducting material is prepared by a method comprising the following steps:

In a preferred embodiment of the present invention, the organic solvent is one or more selected from the group consisting of N, N-dimethylacetamide, acetone, and N, N-dimethylformamide.

In a more preferred embodiment of the present invention, the mass ratio of the crosslinking agent to the organic solvent is 5-25:100, preferably 8-24:100, more preferably 14.8-23.5: 100.

In a more preferred embodiment of the present invention, the step (2) further comprises a step of stirring, sonicating and defoaming the mixed powder before obtaining the casting solution.

Preferably, the stirring time is 10 to 15 hours.

Preferably, the time of the sonication is 30 to 60 minutes.

Preferably, the defoaming is static defoaming, and the defoaming time is 24 to 48 hours, preferably 36 to 48 hours.

In a preferred embodiment of the present invention, in step (3), the ratio of the casting solution to the heat insulating material is 2.5-7ml:1g, preferably 2.85-4ml:1 g.

In a more preferred embodiment of the present invention, wherein, in the step (4), the pressure for the pressing is 0.01 to 4MPa, preferably 0.10 to 2MPa, more preferably 0.5 to 2 MPa; preferably, the pressing time is 0.5-20min, preferably 0.5-5 min.

In a preferred embodiment of the present invention, wherein, in the step (4), the time of the phase inversion is 20 to 40 hours, preferably, the phase inversion is performed in a thermostatic water bath, and the thermostatic temperature is 20 to 45 ℃.

The invention realizes the stable dispersion and the glue connection of the heat insulating materials into blocks and the tight interconnection of the heat insulating materials by using the high polymer cross-linking agent as a supporting framework material, thereby generating capillary action water guide between the heat insulating materials and being beneficial to the transportation of water through a pore passage formed by polyvinylpyrrolidone on the cross-linking agent. The self-floating heat-insulation water-guide material prepared by the invention has good water guide performance and excellent heat insulation capability, realizes balance and optimization between the self-floating heat-insulation water-guide material and the self-floating heat-insulation water-guide material, and can effectively improve the photo-thermal conversion efficiency of the photo-thermal conversion film-shaped material.

The invention provides a photothermal conversion device which comprises the heat-insulating and water-conducting material.

In a preferred embodiment of the present invention, the photothermal conversion device further comprises a photothermal conversion film-like material, preferably, the photothermal conversion film-like material is selected from a photothermal conversion film which does not need to be supported or a photothermal conversion film which is supported by a support material, preferably, the support material is selected from one of non-woven fabric, absorbent paper, dust-free paper or filter paper.

In a more preferred embodiment of the present invention, the heat and water insulating material and the photothermal conversion film-shaped material are combined by wrapping, adhering or pasting, or the photothermal conversion powder material is spin-coated or spray-coated on the heat and water insulating material, and preferably, the photothermal conversion powder is selected from one of reduced graphene, graphite, activated carbon, carbon black or carbon nanotubes.

In a more preferred embodiment of the present invention, the photothermal conversion device is placed in fresh water, seawater or ethanol.

The invention provides an application of the self-floating heat-insulating water-conducting material prepared by the scheme in a solar photo-thermal conversion device. The device can convert common liquids such as fresh water, seawater and ethanol into steam under the direct irradiation of sunlight, thereby realizing the separation of solution and solute and having wide application prospect. The scheme for constructing the device comprises that the self-floating heat-insulating and water-conducting material and the photothermal conversion film-shaped material provided by the invention can form a complete photothermal conversion device through a simple combination form of wrapping, pasting or attaching or through spin coating and spraying of photothermal conversion powder material. The photothermal conversion film material mainly comprises various photothermal conversion films made of various materials without support and photothermal conversion film materials taking non-woven fabrics, absorbent paper, dust-free paper or filter paper as support. The wrapping refers to conventional inner and outer wrapping, the sticking refers to various non-waterproof sticking, and the sticking refers to sticking modes (including or not including a foreign tool) in various forms (such as clamping by a clamp and even directly sticking a planar membrane to a self-floating heat and water insulation material in a direct plane). The photothermal conversion powder material mainly comprises reduced graphene, graphite, activated carbon, carbon black and carbon nanotubes.

In the embodiment of the present invention, it is preferable that the photothermal conversion device provided by the present invention is placed on the surface of the liquid such as water, seawater, ethanol, etc. to be free-floating, and the self-floating heat and water insulating material according to the present invention can spontaneously absorb and transport the liquid from the bottom surface of the material to the contact surface with the photothermal conversion material by using the capillary action, so that the photothermal conversion material can simulate the sunlight (1 kW/m)²) The heat energy is generated under the illumination condition, and the heat energy is fully converged on a water-vapor exchange interface, so that the liquid directly contacted with the photothermal conversion material is converted into steam, and the separation of the solution and the solute is realized.

The manufacturers of the raw materials and equipment used in this example, and the equipment and analysis method used in the product analysis are described below, wherein the chemical substances are not indicated as being of the chemical purity grade of conventional reagents, and the experimental equipment is not indicated as being conventional experimental equipment. The information on the raw materials used in the examples and the experimental equipment are shown in tables 1 and 2.

Table 1 information on the raw materials used in the examples

Raw material information	Purity of	Manufacturer of the product
			Hollow glass bead	98％	3MCorporation
Polyethylene microspheres	99％	Duke
			Cellulose Acetate (CA)	CAS:9004-35-7	National medicine group chemical reagent limited company (Hu test)
Polyvinylidene fluoride	Molecular weight of about 60 ten thousand	SHANGHAI 3F NEW MATERIAL TECHNOLOGY Co.,Ltd.
			Polyacrylonitrile	About 150000	Shanghai Wacky chemical reagents Ltd
Polyvinylpyrrolidone	K-30	Shanghai Wacky chemical reagents Ltd

TABLE 2 information of the experimental equipment used in the examples

Example preparation of Heat and Water conducting Material

(1) Uniformly mixing 8g of polyvinylidene fluoride (PVDF) and 1g of polyvinylpyrrolidone (PVP) to obtain mixed powder;

(2) and (2) uniformly dispersing the mixed powder in the step (1) in 49gN, N-dimethylacetamide (DMAc), stirring and dissolving, uniformly mixing for 12 hours, performing ultrasonic treatment for 30 minutes, standing for 48 hours, and defoaming to obtain a yellow transparent casting solution.

(3) Weighing 3g of hollow glass microspheres (with the average particle size of 55 microns), adding 10mL of the casting solution obtained in the step (3) into the hollow glass microsphere powder, continuously stirring uniformly by using a glass rod, and repeatedly beating and kneading by using a pestle to obtain viscous dough-like slurry;

(4) pouring the slurry into a prepared mould (5 x 4 x 0.6cm), pressing under the pressure of 2MPa and keeping for 5min, taking out, transferring into a constant-temperature water bath at 30 ℃ to undergo a phase conversion process, wherein the phase conversion time is 30 hours, and obtaining the heat-insulating and water-conducting material.

The heat-insulating water-conducting material prepared in the first example is measured by using an ultraviolet-visible spectrophotometer, and the absorption spectrum thereof is shown in fig. 1.

As can be seen from fig. 1, the self-floating heat and water insulating and conducting material prepared in the first embodiment shows obvious light absorption at 500nm, and is matched with the absorption characteristics of the silica hollow spheres, and the heat and water insulating and conducting material prepared in the first embodiment indirectly shows that the material has a three-dimensional stacking structure of hollow glass beads.

The heat and water conducting material prepared in the first example was observed by using a Scanning Electron Microscope (SEM), and the results are shown in fig. 2-1 and 2-2.

As can be seen from FIGS. 2-1 and 2-2, the hollow glass beads are preferably cross-linked together by PVDF polymer to form a 3D multi-layer network structure; and at the nodes of this network are just filled with hollow glass microspheres. Therefore, the air closed pores of the glass beads effectively improve the heat insulation performance of the material, and the gaps among the glass beads and the 3D network structure of the PVDF can generate enough capillary action, so that moisture can be effectively transported.

EXAMPLE two preparation of simple photothermal conversion device

The self-floating thermal insulation and water guide material prepared in example 1 was floated on the water surface, and a photothermal conversion film (obtained by dispersing carbon black in a solution of cellulose acetate in N, N-dimethylacetamide, knife coating or spin coating, and phase-converting in water) was attached thereon to obtain a complete photothermal conversion device. The photothermal conversion device is schematically shown in fig. 3, and mainly comprises four components of an open container, water, a self-floating heat-insulating water-conducting material and a photothermal conversion film.

The simple photothermal conversion device obtained in example two was subjected to the following performance measurements:

1) testing of photothermal conversion Performance

The simple photothermal conversion device of example two was used, and the area used was 12cm²The carbon-based photo-thermal conversion film is used for photo-thermal conversion test, and the illumination intensity is controlled to be 1kW/m²The results are shown in FIGS. 4 and 5. Wherein, FIG. 4 shows the mass change in the photothermal conversion experiment under simulated normal sunlightFIG. 5 is a graph of net evaporation rate (light evaporation rate minus dark evaporation rate) during photothermal evaporation.

As can be seen from FIG. 4, as the light was applied, the water evaporated and the mass decreased, and the 50min mass change was about 1.4 g.

As can be seen from FIG. 5, as the photothermal conversion proceeds, the temperature of the material surface increases, and the instantaneous evaporation rate increases, and the steady-state net evaporation rate of 1.3765kg/m is reached at 1250s²H (apparent evaporation rate 1.6 kg/m)²H) compared with the water-dark evaporation rate under the warm and humid conditions of the experimental environment at that time (about 0.24 kg/m)²H), the speed is increased by more than 6 times, and the photo-thermal conversion device prepared in the second embodiment and optimized based on the self-floating heat-insulating water-conducting material is proved to have a good photo-thermal conversion effect under normal sunlight, so that the photo-thermal evaporation rate can be effectively increased.

The steady state net evaporation rate in the examples is calculated as:

in the formula:

instantaneous evaporation rate (kg/m) at time t(s)²·h)；

m_t-50And m_t+50The mass (kg) of water to be evaporated at two instants(s) of t-50 and t +50, respectively;

s is the evaporation area (m)²)；

2) Cyclic testing of photothermal conversion devices

The photothermal conversion device described in example two was subjected to cycle test according to the test method for photothermal conversion performance, and the results are shown in fig. 6.

As can be seen from fig. 6, the photothermal conversion device obtained by using the heat-insulating water-guiding material prepared in the first embodiment basically maintains the photothermal conversion performance at 82.1% after 10 times of recycling, so that the heat-insulating water-guiding material prepared in the first embodiment can effectively improve the photothermal evaporation performance of the photothermal conversion film-shaped material, provides a strong heat collection effect, has sufficient structural strength and performance stability, and can realize stable photothermal conversion in a very simple implementation form (conversion device, second embodiment).

Wherein, the photo-thermal conversion efficiency is calculated, and the calculation formula is shown as formula 1:

in formula 1: eta is the photothermal conversion efficiency;

is the rate at which the mass of the water decreases,

wherein m is_evpIs the change in mass of water (unit: g),

as can be seen from FIG. 3, s is the area of the carbon-based photothermal conversion film (in cm)²)，

t is time (unit: s);

h_1vis the sum of sensible heat and latent heat of liquid water changing into gaseous water at a certain temperature, J/g;

q_sis the intensity of light, W/m²。

According to the formula 1, the photothermal conversion efficiency of the photothermal conversion device with the photothermal conversion material coated on the floating heat and water insulation material can reach 82.1%.

EXAMPLE three preparation of Heat insulating Water conducting Material

(1) Uniformly mixing 8g of polyvinylidene fluoride (PVDF) and polyvinylpyrrolidone (PVP) with different masses to obtain mixed powder, wherein the masses of the polyvinylpyrrolidone are 0.5g, 1.5g, 2g and 2.5g respectively;

(2) uniformly dispersing the mixed powder in the step (1) in 49gN, N-dimethylacetamide (DMAc), stirring, dissolving, uniformly mixing for 12 hours, performing ultrasonic treatment for 30 minutes, standing for 48 hours, and defoaming to obtain a yellow transparent casting solution;

(4) pouring the slurry into a prepared mould (5 x 4 x 0.6cm), pressing and keeping for 5min under the pressure of 2MPa, taking out, transferring into constant-temperature water bath at 30 ℃ to undergo a phase conversion process, wherein the phase conversion time is 30 hours, and obtaining the heat-insulating and water-conducting material.

Floating the prepared heat-insulating water-guiding material on the water surface, adhering a layer of photothermal conversion film on the material, and measuring according to the photothermal conversion performance test method of the conversion device in the second step to obtain the steady-state net evaporation rates of 1.33kg/m²·h、1.35kg/m²·h、1.34kg/m²H and 1.35kg/m²·h。

Example preparation of thermal and Water conducting Material

(2) uniformly dispersing the mixed powder in the step (1) in N, N-dimethylacetamide (DMAc) with different mass, stirring, dissolving and uniformly mixing for 12 hours, performing ultrasonic treatment for 30 minutes, standing for 2 days, and defoaming to obtain yellow transparent casting solution, wherein the DMAc is respectively 34g, 39g, 44g and 54 g;

Floating the prepared heat-insulating water-guiding material on the water surface, and adhering a layer of light on the materialThe thermal conversion film is measured according to the method for testing the photothermal conversion performance of the conversion device in the second embodiment, and the obtained steady-state net evaporation rates are respectively 1.28kg/m²·h、1.31kg/m²·h、1.38kg/m²H and 1.18kg/m²·h。

Example preparation of thermal insulating and Water conducting Material

(2) uniformly dispersing the mixed powder in the step (1) in 49g N, N-dimethylacetamide (DMAc), stirring, dissolving and uniformly mixing for 12 hours, performing ultrasonic treatment for 30 minutes, standing for 2 days, and defoaming to obtain a yellow transparent casting solution;

(3) weighing hollow glass microspheres (with the average particle size of 55 microns) with different masses, adding 10mL of the casting solution obtained in the step (3) into the hollow glass microsphere powder, continuously stirring uniformly by using a glass rod, and repeatedly beating and kneading by using a pestle to obtain viscous paste-like slurry, wherein the hollow glass microspheres are 2g, 2.5g, 3.5g and 4g respectively;

Floating the prepared heat-insulating water-guiding material on the water surface, adhering a layer of photothermal conversion film on the material, and measuring according to the photothermal conversion performance test method of the conversion device in the second step to obtain the steady-state net evaporation rates of 1.11kg/m²·h、1.23kg/m²·h、1.31kg/m²H and 1.08kg/m²·h。

Example preparation of six Heat insulating Water conducting Material

(4) pouring the slurry into a prepared mould (5 x 4 x 0.6cm), pressing and keeping for 5min under different pressures, taking out, transferring into a constant-temperature water bath with the temperature of 30 ℃ to undergo a phase transformation process, wherein the phase transformation time is 30 hours, and obtaining the heat-insulating water-conducting material, wherein the pressures are respectively 0.01Mpa, 0.5Mpa, 1Mpa and 4 Mpa.

Floating the prepared heat-insulating water-guiding material on the water surface, adhering a layer of photothermal conversion film on the material, and measuring according to the photothermal conversion performance test method of the conversion device in the second step to obtain the steady-state net evaporation rates of 1.14kg/m²·h、1.22kg/m²·h、1.34kg/m²H and 1.18kg/m²·h。

Example preparation of seven Heat insulating Water conducting Material

The difference from the first embodiment is that acetic acid (CA) and Polyacrylonitrile (PAN) are used as cross-linking agents to obtain the heat and water insulating material.

Floating the prepared heat-insulating water-guiding material on the water surface, adhering a layer of photothermal conversion film on the material, and measuring according to the photothermal conversion performance test method and the cycle test method of the conversion device in the second step to obtain the steady-state net evaporation rate of 1.36kg/m²H and 1.38kg/m²H, efficiencies of 81.5% and 82%, respectively.

Example preparation of eight Heat insulating Water conducting Material

(3) weighing 3g of hollow glass microspheres, adding 10mL of the casting solution obtained in the step (3) into the hollow glass microsphere powder, continuously stirring uniformly by using a glass rod, and repeatedly beating and kneading by using a pestle to obtain viscous paste-like slurry, wherein the particle sizes of the microspheres are 15 micrometers, 30 micrometers and 90 micrometers respectively;

(4) pouring the slurry into a prepared mould (5 x 4 x 0.6cm), pressing and keeping the pressure at 2Mpa for 5min, taking out, transferring into constant-temperature water bath at 30 ℃ to undergo a phase conversion process, wherein the phase conversion time is 30 hours, and obtaining the heat-insulating and water-conducting material.

Floating the prepared heat-insulating water-guiding material on the water surface, adhering a layer of photothermal conversion film on the material, and measuring according to the photothermal conversion performance test method of the conversion device in the second step to obtain the steady-state net evaporation rates of 1.28kg/m²·h、1.34kg/m²H and 1.38kg/m²·h。

Preparation of device for carrying out nine-stage photothermal conversion

The thermal insulation and water guide material prepared in the first embodiment floats on the water surface, and a photothermal conversion film-shaped material is adhered on the thermal insulation and water guide material to obtain a photothermal conversion device, wherein the photothermal conversion film-shaped material is an unsupported carbon black cellulose acetate film, a carbon black cellulose acetate film coated on a filter paper and a carbon black cellulose acetate film coated on a non-woven fabric.

The various photothermal conversion devices prepared as described above were measured according to the test method for photothermal conversion performance of the conversion device in the second embodiment, and the steady-state net evaporation rates were 1.37kg/m, respectively²·h，1.38kg/m²H and 1.38kg/m²·h。

EXAMPLE preparation of a Ten photothermal conversion device

The thermal insulation and water guide material prepared in the first embodiment floats on the water surface, and a layer of photothermal conversion film is directly attached or wrapped on the thermal insulation and water guide material to obtain the photothermal conversion device.

The various photothermal conversion devices prepared above were measured according to the method for testing photothermal conversion performance of the conversion device in the second embodiment, and the steady-state net evaporation rates obtained were each1.38kg/m²·h，1.38kg/m²·h。

EXAMPLE eleven preparation of photothermal conversion device

And mutually connecting powder materials through a cross-linking agent, and spin-coating or spraying the powder materials on the heat and water insulation and conduction material in the embodiment I, wherein the powder materials are carbon black, graphite, carbon nano tubes, reduced graphene or activated carbon, so as to obtain the photothermal conversion device.

The various photothermal conversion devices prepared as described above were measured according to the test method for photothermal conversion performance of the conversion device in the second embodiment, and the steady-state net evaporation rates were 1.38kg/m, respectively²·h，1.33kg/m²·h，1.38kg/m²·h，1.36kg/m²H and 1.35kg/m²·h。

EXAMPLE twelve Heat-insulating Water-conducting Material

(1) Uniformly mixing 8g of polyvinylidene fluoride (PVDF) and 0.08g of polyvinylpyrrolidone (PVP) to obtain mixed powder;

(2) and (2) uniformly dispersing the mixed powder in the step (1) in 160g of acetone, stirring and dissolving, uniformly mixing for 10 hours, performing ultrasonic treatment for 40 minutes, standing for 24 hours, and defoaming to obtain a yellow transparent casting solution.

(3) Weighing 1.4g of hollow glass microspheres (with the average particle size of 100 microns), adding 10mL of the casting solution obtained in the step (3) into the hollow glass microsphere powder, continuously stirring uniformly by using a glass rod, and repeatedly beating and kneading by using a pestle to obtain viscous dough-like slurry;

(4) pouring the slurry into a prepared mould (5 x 4 x 0.6cm), pressing under the pressure of 0.1MPa and keeping for 0.5min, taking out, transferring into a water bath with constant temperature of 30 ℃ to undergo a phase conversion process, wherein the phase conversion time is 40 hours, and obtaining the heat insulating and water conducting material.

Floating the prepared heat-insulating water-guiding material on the water surface, adhering a layer of photothermal conversion film on the material, and measuring according to the photothermal conversion performance test method of the conversion device in the second step to obtain the steady-state net evaporation rate of 1.07kg/m²·h。

EXAMPLE thirteen preparation of Heat-insulating Water-conducting Material

(1) Uniformly mixing 8g of polyvinylidene fluoride (PVDF) and 3.2g of polyvinylpyrrolidone (PVP) to obtain mixed powder;

(2) and (2) uniformly dispersing the mixed powder in the step (1) in 32g of Dimethylformamide (DMF), stirring and dissolving, uniformly mixing for 15 hours, carrying out ultrasonic treatment for 60 minutes, standing for 36 hours, and defoaming to obtain a yellow transparent casting solution.

(3) Weighing 3g of polyethylene microspheres (with the average particle size of 10 microns), adding 10mL of the casting solution obtained in the step (3) into the polyethylene microsphere powder, stirring uniformly by using a glass rod, and repeatedly beating and kneading by using a pestle to obtain viscous paste-like slurry;

(4) pouring the slurry into a prepared mould (5 x 4 x 0.6cm), pressing under the pressure of 3MPa and keeping for 2min, taking out, transferring into a constant-temperature water bath at 20 ℃ to undergo a phase conversion process, wherein the phase conversion time is 20 hours, and obtaining the heat-insulating and water-conducting material.

Floating the prepared heat-insulating water-guiding material on the water surface, adhering a layer of photothermal conversion film on the material, and measuring according to the photothermal conversion performance test method of the conversion device in the second step to obtain the steady-state net evaporation rate of 1.18kg/m²·h。

Example fourteen preparation of Heat and Water conducting Material

(1) Uniformly mixing 8g of polyvinylidene fluoride (PVDF) and 0.4g of polyvinylpyrrolidone (PVP) to obtain mixed powder;

(2) and (2) uniformly dispersing the mixed powder in the step (1) in 100g of N, N-dimethylacetamide (DMAc), stirring, dissolving, uniformly mixing for 10 hours, performing ultrasonic treatment for 50 minutes, standing for 48 hours, and defoaming to obtain a yellow transparent casting solution.

(3) Weighing 3g of hollow glass microspheres (with the average particle size of 50 microns), adding 10mL of the casting solution obtained in the step (3) into the hollow glass microsphere powder, continuously stirring uniformly by using a glass rod, and repeatedly beating and kneading by using a pestle to obtain viscous dough-like slurry;

(4) pouring the slurry into a prepared mould (5 x 4 x 0.6cm), pressing under the pressure of 4MPa and keeping for 1.5min, taking out, transferring into constant-temperature water bath at 30 ℃ to undergo a phase conversion process, wherein the phase conversion time is 20 hours, and obtaining the heat-insulating water-conducting material.

Floating the prepared heat-insulating water-guiding material on the water surface, adhering a layer of photothermal conversion film on the material, and measuring according to the photothermal conversion performance test method of the conversion device in the second step to obtain the steady-state net evaporation rate of 1.24kg/m²·h。

Example fifteen preparation of Water conducting and insulating Material

(1) Uniformly mixing 8g of polyvinylidene fluoride (PVDF) and 2.8g of polyvinylpyrrolidone (PVP) to obtain mixed powder;

(2) and (2) uniformly dispersing the mixed powder in the step (1) in 100g of N, N-dimethylacetamide (DMAc), stirring, dissolving, uniformly mixing for 15 hours, performing ultrasonic treatment for 60 minutes, standing for 24 hours, and defoaming to obtain a yellow transparent casting solution.

(3) Weighing 3g of hollow glass microspheres (with the average particle size of 120 microns), adding 10mL of the casting solution obtained in the step (3) into the hollow glass microsphere powder, continuously stirring uniformly by using a glass rod, and repeatedly beating and kneading by using a pestle to obtain viscous dough-like slurry;

(4) pouring the slurry into a prepared mould (5 x 4 x 0.6cm), pressing under the pressure of 2MPa and keeping for 3min, taking out, transferring into a constant-temperature water bath at 45 ℃ to undergo a phase conversion process, wherein the phase conversion time is 40 hours, and obtaining the heat-insulating and water-conducting material.

Floating the prepared heat-insulating water-guiding material on the water surface, adhering a layer of photothermal conversion film on the material, and measuring according to the photothermal conversion performance test method of the conversion device in the second step to obtain the steady-state net evaporation rate of 1.36kg/m²·h。

Comparative example preparation of ordinary Water-conducting Heat-insulating Material

(1) Uniformly mixing 8g of polyvinylidene fluoride (PVDF) and 0.04g of polyvinylpyrrolidone (PVP) to obtain mixed powder;

Floating the prepared heat-insulating water-guiding material on the water surface, adhering a layer of photothermal conversion film on the material, and measuring according to the photothermal conversion performance test method of the conversion device in the second step to obtain the steady-state net evaporation rate of 0.98kg/m²·h。

Preparation of ordinary heat-insulating and water-conducting material of comparative example II

(1) Uniformly mixing 8g of polyvinylidene fluoride (PVDF) and 4g of polyvinylpyrrolidone (PVP) to obtain mixed powder;

Floating the prepared heat-insulating water-guiding material on the water surface, adhering a layer of photothermal conversion film on the material, and measuring according to the photothermal conversion performance test method of the conversion device in the second step to obtain the steady-state net evaporation rate of 1.01kg/m²·h。

Preparation of common thermal-insulating water-conducting material

(3) Weighing 5g of hollow glass microspheres (with the average particle size of 55 microns), adding 10mL of the casting solution obtained in the step (3) into the hollow glass microsphere powder, continuously stirring uniformly by using a glass rod, and repeatedly beating and kneading by using a pestle to obtain viscous dough-like slurry;

Preparation of common heat-insulating and water-conducting material

(3) Weighing 1.33g of hollow glass microspheres (with the average particle size of 55 microns), adding 10mL of the casting solution obtained in the step (3) into the hollow glass microsphere powder, continuously stirring uniformly by using a glass rod, and repeatedly beating and kneading by using a pestle to obtain viscous dough-like slurry;

Floating the prepared heat-insulating water-guiding material on the water surface, adhering a layer of photothermal conversion film on the material, and measuring according to the photothermal conversion performance test method of the conversion device in the second step to obtain the steady-state net evaporation rate of 0.92kg/m²·h。

Comparing the first comparative example with the first example, the difference is that the mass of the PVP used in the first comparative example is 0.04g, and the mass of the PVP used in the first example is 1g, namely the mass ratio of the cross-linking agent to the PVP is 1:0.005, which is lower than the mass ratio range of the cross-linking agent to the PVP, when the prepared heat-insulating and water-guiding material is prepared into a photothermal conversion device, the steady-state net evaporation rate obtained in the first example is 1.38kg/m when a photothermal conversion experiment is carried out²H, whereas the steady-state net evaporation rate obtained in comparative example one is 0.98kg/m²H, as can be seen from the comparison between the example one and the comparative example one, the steady-state net evaporation rate is high only when the mass ratio of the crosslinking agent to the PVP is within the mass ratio range of the crosslinking agent to the PVP, and the prepared thermal insulation and water guide material is made into a photothermal conversion device.

Comparing the first example with the second comparative example, the difference is that the mass of the PVP used in the first example is 1g, the mass of the PVP used in the second comparative example is 4g, namely the mass ratio of the cross-linking agent to the PVP is 1:0.5, which is higher than the mass ratio range of the cross-linking agent to the PVP, when the prepared heat-insulating water-guiding material is prepared into a photothermal conversion device, the steady-state net evaporation rate obtained in the first example is 1.38kg/m when a photothermal conversion experiment is carried out²H, whereas the steady-state net evaporation rate obtained for comparative example is 1.01kg/m²H, as can be seen from the comparison between the first example and the second comparative example, although the PVP used in the second comparative example has higher quality, the obtained steady-state net evaporation rate is relatively lower when the photothermal conversion device is made of the obtained thermal insulation and water guide material, and the fact that the use of the second comparative example not only increases the use amount of the PVP, but also has relatively lower steady-state net evaporation rate is indicated, so that the PVP is used in the second comparative exampleThe steady-state net evaporation rate obtained by carrying out a photothermal conversion experiment is higher when the photothermal conversion device is prepared from the heat-insulating water-conducting material obtained by using the crosslinking agent and PVP in a specific mass ratio range.

Comparing the first example with the third comparative example, the difference is that the amount of heat insulating material used is different, the first example uses 3g of hollow glass beads, the third comparative example uses 5g of hollow glass beads, namely the ratio of casting solution to hollow glass beads is 2ml:1g, which is lower than the ratio range of the casting solution to the heat insulating material of the invention, further the heat insulating and water conducting material is prepared, then the photothermal conversion device is prepared according to the method of the second example, and when the photothermal conversion experiment is carried out, the steady-state net evaporation rate obtained by the first example is 1.38kg/m²H, whereas the steady-state net evaporation rate obtained for comparative example three was 1.18kg/m²H, the different influences on the steady-state net evaporation rate caused by using different amounts of heat insulating materials in the preparation of the heat and water insulating and conducting material are shown in the difference of the steady-state net evaporation rates obtained in the first embodiment and the third embodiment, and further the fact that the proportion of the casting solution and the heat insulating material is within a certain range is further shown, the obtained heat and water insulating and conducting material has good heat and water conducting performance, and the obtained steady-state net evaporation rate is high in the photo-thermal conversion experiment.

Comparing the first example with the comparative example, the difference is that 3g of hollow glass microspheres are used in the first example, while 1.33g of hollow glass microspheres are used in the third example, namely the ratio of the casting solution to the hollow glass microspheres is 7.5ml:1g, which is higher than the ratio range of the casting solution to the heat insulating material of the invention, so as to prepare the heat insulating and water conducting material, then the photothermal conversion device is prepared according to the method of the second example, and when the photothermal conversion experiment is carried out, the steady-state net evaporation rate obtained in the first example is 1.38kg/m²H, whereas the steady-state net evaporation rate obtained for comparative example three was 0.92kg/m²H, which shows that if the amount of the casting solution used is large, the thermal insulation performance of the obtained thermal and water insulation material is relatively poor, which is a difference from the data of the steady-state net evaporation rate obtained when the photothermal conversion performance test is performedIt can be seen that, the obtained thermal and water insulation and conduction material has better thermal insulation and conduction performance within a certain proportion range by adopting the casting solution and the thermal insulation material, and further has higher steady-state net evaporation rate when a photothermal conversion experiment is carried out.

As can be seen from the comparison, the thermal insulation and water guide material prepared by adopting the cross-linking agent and the PVP in a specific ratio and the casting solution and the thermal insulation material in a specific ratio has good thermal insulation and water guide performance, and the steady-state net evaporation rate of the prepared photo-thermal conversion device is higher when the photo-thermal conversion device is used for a photo-thermal conversion experiment, so that the photo-thermal evaporation rate is effectively improved.

In conclusion, the heat-insulating water-guiding material disclosed by the invention has enough structural strength and performance stability, can provide a strong heat collection effect, effectively improves the photo-thermal evaporation performance of the photo-thermal conversion film-shaped material, can be repeatedly and continuously used, and is 1kW/m²Under the illumination condition, the photo-thermal conversion material is covered on the self-floating heat-insulating water-conducting material and floats on the water surface, the photo-thermal conversion efficiency of the photo-thermal conversion device can reach 82.1 percent, and the photo-thermal performance can still be kept stable after 10 times of repeated tests. The self-floating heat-insulating water conducting material is not only cheap and easy to prepare in a large scale, but also very easy to further process and combine, and has wide application prospect.

The foregoing is considered as illustrative and not restrictive in character, and that various modifications, equivalents, and improvements made within the spirit and principles of the invention are intended to be included within the scope of the invention.

Claims

1. The heat-insulating and water-conducting material comprises a cross-linking agent, polyvinylpyrrolidone and a heat-insulating material;

the heat insulating material is selected from one of hollow glass micro-beads or polyethylene micro-beads,

the heat-insulating and water-conducting material is prepared by a method comprising the following steps:

2. The heat and water insulating material of claim 1, wherein the cross-linking agent is selected from one of cellulose acetate, polyvinylidene fluoride, or polyacrylonitrile.

3. The heat and water insulating material according to claim 1, wherein the particle size of the heat insulating material is 10 to 120 μm.

4. The heat and water insulating material according to claim 1, wherein the particle size of the heat insulating material is 30 to 90 μm.

5. The heat and water insulating material according to claim 1, wherein the particle size of the heat insulating material is 55-90 μm.

6. The thermally insulating water guiding material according to claim 2, wherein the particle size of the thermally insulating material is 10 to 120 μm.

7. The thermally insulating water guiding material according to claim 2, wherein the particle size of the thermally insulating material is 30-90 μm.

8. The thermally insulating water guiding material according to claim 2, wherein the thermally insulating material has a particle size of 55-90 μm.

9. The heat and water insulating material according to claim 1, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.01-0.4.

10. The heat-insulating water-guiding material according to claim 2, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.01-0.4.

11. The heat and water insulating material according to claim 3, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.01-0.4.

12. The heat and water insulating material according to claim 4, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.01-0.4.

13. The heat and water insulating material according to claim 5, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.01-0.4.

14. The heat and water insulating material according to claim 6, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.01-0.4.

15. The heat and water insulating material according to claim 7, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.01-0.4.

16. The heat and water insulating material according to claim 8, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.01-0.4.

17. The heat and water insulating material according to claim 1, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.05-0.35.

18. The heat-insulating water-guiding material according to claim 2, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.05-0.35.

19. The heat and water insulating material according to claim 3, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.05-0.35.

20. The heat and water insulating material according to claim 4, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.05-0.35.

21. The heat and water insulating material according to claim 5, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.05-0.35.

22. The heat and water insulating material according to claim 6, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.05-0.35.

23. The heat and water insulating material of claim 7, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.05-0.35.

24. The heat and water insulating material according to claim 8, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.05-0.35.

25. The heat and water insulating material according to claim 1, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.0625-0.3125.

26. The heat insulating water guiding material according to claim 2, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.0625-0.3125.

27. The heat and water insulating material according to claim 3, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.0625-0.3125.

28. The heat and water insulating material according to claim 4, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.0625-0.3125.

29. The heat and water insulating material according to claim 5, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.0625-0.3125.

30. The heat and water insulating material according to claim 6, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.0625-0.3125.

31. The heat and water insulating material according to claim 7, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.0625-0.3125.

32. The heat and water insulating material according to claim 8, wherein the mass ratio of the cross-linking agent to the polyvinylpyrrolidone is 1: 0.0625-0.3125.

33. The heat and water insulating material according to any one of claims 1 to 32, wherein the mass ratio of the cross-linking agent to the heat insulating material is 1:0.7 to 8.56.

34. The heat and water insulating material according to any one of claims 1 to 32, wherein the mass ratio of the cross-linking agent to the heat insulating material is 1:1.31 to 4.88.

35. The heat and water insulating material according to any one of claims 1 to 32, wherein the mass ratio of the cross-linking agent to the heat insulating material is 1:1.31 to 2.84.

36. The heat and water insulating material according to any one of claims 1 to 32, wherein the material is a three-dimensional network structure-containing material obtained by mixing a cross-linking agent, polyvinylpyrrolidone and a heat insulating material.

37. The thermally and water conductive material as claimed in claim 33, wherein the thermally and thermally insulating and water conductive material is a thermally and thermally insulating and water conductive material having a three-dimensional network structure obtained by containing a mixture of a cross-linking agent, polyvinylpyrrolidone and a thermally insulating material.

38. The heat insulating and water conducting material according to claim 34, wherein the heat insulating and water conducting material is a heat insulating and water conducting material having a three-dimensional network structure obtained by containing a mixture of a crosslinking agent, polyvinylpyrrolidone and a heat insulating material.

39. The heat insulating and water conducting material according to claim 35, wherein the heat insulating and water conducting material is a heat insulating and water conducting material having a three-dimensional network structure obtained by containing a mixture of a crosslinking agent, polyvinylpyrrolidone and a heat insulating material.

40. The method for preparing the heat and water insulating material of any one of claims 1-39, comprising the steps of:

41. The production method according to claim 40, wherein, in the step (2), the organic solvent is one or more selected from the group consisting of N, N-dimethylacetamide, acetone, and N, N-dimethylformamide.

42. The production method according to claim 40, wherein the mass ratio of the crosslinking agent to the organic solvent is 5-25: 100.

43. The production method according to claim 41, wherein the mass ratio of the crosslinking agent to the organic solvent is 5-25: 100.

44. The production method according to claim 40, wherein the mass ratio of the crosslinking agent to the organic solvent is 8-24: 100.

45. The production method according to claim 41, wherein the mass ratio of the crosslinking agent to the organic solvent is 8-24: 100.

46. The production method according to claim 40, wherein the mass ratio of the crosslinking agent to the organic solvent is 14.8 to 23.5: 100.

47. The production method according to claim 41, wherein the mass ratio of the crosslinking agent to the organic solvent is 14.8 to 23.5: 100.

48. The production method according to claim 40, wherein in the step (2), before obtaining the dope solution, a step of stirring, sonicating and defoaming the mixed powder is further included.

49. The production method according to claim 41, wherein in the step (2), before obtaining the casting solution, a step of stirring, sonicating, and deaerating the mixed powder is further included.

50. The production method according to claim 42, wherein in the step (2), before obtaining the casting solution, a step of stirring, sonicating, and defoaming the mixed powder is further included.

51. The production method according to claim 43, further comprising a step of stirring, sonicating and defoaming the mixed powder before obtaining the dope solution in step (2).

52. The production method according to claim 44, wherein in the step (2), before obtaining the dope solution, a step of stirring, sonicating and defoaming the mixed powder is further included.

53. The production method according to claim 45, wherein in the step (2), before obtaining the dope solution, a step of stirring, sonicating and defoaming the mixed powder is further included.

54. The production method according to claim 46, wherein in the step (2), before obtaining the dope solution, a step of stirring, sonicating and defoaming the mixed powder is further included.

55. The method of claim 48, wherein the stirring time is 10-15 hours.

56. The method of claim 49, wherein the stirring time is 10-15 hours.

57. The method of claim 50, wherein the stirring time is 10-15 hours.

58. The method of claim 48, wherein the sonication time is between 30 and 60 minutes.

59. The method of claim 55, wherein the sonication time is between 30 and 60 minutes.

60. The production method according to claim 48, wherein the defoaming time is 24 to 48 hours.

61. The process of claim 55, wherein the time for debubbling is 24-48 hours.

62. The production method according to claim 58, wherein the defoaming time is 24 to 48 hours.

63. The production method according to claim 48, wherein the defoaming time is 36 to 48 hours.

64. The process of claim 55, wherein the time for debubbling is 36-48 hours.

65. The production method according to claim 58, wherein the defoaming time is 36 to 48 hours.

66. The production method according to any one of claims 40 to 65, wherein, in step (3), the ratio of the casting solution to the heat insulating material is 2.5 to 7ml:1g of the total weight of the composition.

67. The production method according to any one of claims 40 to 65, wherein, in step (3), the ratio of the casting solution to the heat insulating material is 2.85 to 4ml:1g of the total weight of the composition.

68. The production method according to any one of claims 40 to 65, wherein, in the step (4), the pressure of the pressing is 0.01 to 4 MPa.

69. The production method according to any one of claims 40 to 65, wherein, in the step (4), the pressure of the pressing is 0.10 to 2 MPa.

70. The production method according to any one of claims 40 to 65, wherein, in the step (4), the pressure of the pressing is 0.5 to 2 MPa.

71. The production method according to claim 66, wherein, in the step (4), the pressure of the pressing is 0.01 to 4 MPa.

72. The production method according to claim 68, wherein, in the step (4), the time for the pressing is 0.5 to 20 min.

73. The production method according to claim 69, wherein, in the step (4), the time for the pressing is 0.5 to 5 min.

74. The production method according to claim 71, wherein, in the step (4), the time for the pressing is 0.5 to 20 min.

75. The production method according to any one of claims 40 to 65, wherein, in step (4), the phase inversion time is 20 to 40 hours.

76. The production method according to claim 66, wherein, in the step (4), the phase inversion time is 20 to 40 hours.

77. The production method according to claim 68, wherein, in the step (4), the phase inversion time is 20 to 40 hours.

78. The production method according to claim 72, wherein, in the step (4), the phase inversion time is 20 to 40 hours.

79. The production method according to any one of claims 40 to 65, wherein the phase inversion is carried out in a thermostatic water bath, and the thermostatic temperature is 20 to 45 ℃.

80. The preparation method according to claim 66, wherein the phase inversion is performed in a thermostatic water bath, and the thermostatic temperature is 20-45 ℃.

81. The preparation method of claim 68, wherein the phase inversion is performed in a thermostatted water bath at a temperature of 20-45 ℃.

82. The preparation method of claim 72, wherein the phase inversion is performed in a thermostatic water bath, and the thermostatic temperature is 20-45 ℃.

83. The preparation method according to claim 75, wherein the phase inversion is performed in a thermostatic water bath, and the thermostatic temperature is 20-45 ℃.

84. Use of the thermally insulating water conducting material of any one of claims 1 to 39 in a solar photothermal conversion device.

85. Use of the thermally and water-conducting material prepared by the preparation method of any one of claims 40-83 in a solar photothermal conversion device.

86. A photothermal conversion device comprising the thermally insulating water guiding material of any one of claims 1 to 39.

87. A photothermal conversion device comprising the heat insulating water guiding material produced by the production method according to any one of claims 40 to 83.

88. The photothermal conversion device of claim 86, wherein the photothermal conversion device further comprises a photothermal conversion film-like material.

89. The photothermal conversion device of claim 87, wherein the photothermal conversion device further comprises a photothermal conversion film-like material.

90. The photothermal conversion device according to claim 88, wherein the photothermal conversion film-like material is selected from a photothermal conversion film that does not need to be supported or a photothermal conversion film that is supported using a supporting material.

91. The photothermal conversion device according to claim 89, wherein the photothermal conversion film-like material is selected from a photothermal conversion film that does not need to be supported or a photothermal conversion film that is supported using a supporting material.

92. The photothermal conversion device according to claim 90, wherein the support material is selected from one of a nonwoven fabric, absorbent paper, dust-free paper, and filter paper.

93. The photothermal conversion device according to claim 91, wherein the support material is selected from one of a nonwoven fabric, absorbent paper, dust-free paper, and filter paper.

94. The photothermal conversion device of any one of claims 88-93, wherein the heat and water insulating material is combined with the photothermal conversion film-like material by wrapping, pasting, or attaching, or the photothermal conversion powder material is spin-coated or spray-coated on the heat and water insulating material.

95. The photothermal conversion device of claim 94, wherein the photothermal conversion powder is selected from one of reduced graphene, graphite, activated carbon, carbon black, or carbon nanotubes.

96. The photothermal conversion device of any of claims 88-93, wherein the photothermal conversion device is placed in fresh water, seawater, or ethanol.

97. The photothermal conversion device of claim 94 wherein the photothermal conversion device is placed in fresh water, seawater, or ethanol.

98. The photothermal conversion device of claim 95 wherein the photothermal conversion device is placed in fresh water, seawater, or ethanol.

99. Use of the photothermal conversion device of any of claims 86-95 in the field of desalination, purification, concentration or reduction of water containing organic or inorganic contaminants.