CN115074007A

CN115074007A - Inorganic-organic composite super-hydrophilic coating and preparation method and application thereof

Info

Publication number: CN115074007A
Application number: CN202210516075.XA
Authority: CN
Inventors: 吴笑梅; 高强; 李强
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2022-05-12
Filing date: 2022-05-12
Publication date: 2022-09-20
Anticipated expiration: 2042-05-12
Also published as: CN115074007B

Abstract

The invention discloses an inorganic-organic composite super-hydrophilic coating as well as a preparation method and application thereof, belonging to the technical field of coatings. The super-hydrophilic coating is prepared by adding phyllosilicate mineral into water, stirring at room temperature and performing ultrasonic treatment to obtain a uniformly mixed suspension; and adding the water-based polymer into the mixture, stirring the mixture in a water bath at the temperature of between 50 and 90 ℃ for reacting for 2 to 5 hours to obtain a polymer solution after intercalation modification, and then adding the nano inorganic powder, the dispersing agent and the defoaming agent into the mixture to react to obtain the modified polymer. The contact angle of the super-hydrophilic coating can reach 0 degrees, and the time for reaching 0 degrees is 0.5 s. The inorganic-organic composite super-hydrophilic coating prepared by the invention is environment-friendly and low in cost, and the prepared coating has excellent water resistance and ultraviolet aging resistance, better mechanical property and bonding force, is suitable for large-area construction and application, and is beneficial to accelerating the development and application of super-hydrophilic technology.

Description

Inorganic-organic composite super-hydrophilic coating and preparation method and application thereof

Technical Field

The invention relates to a super-hydrophilic coating and a preparation method thereof, in particular to an inorganic-organic composite super-hydrophilic coating and a preparation method and application thereof, belonging to the field of super-hydrophilic coatings.

Background

Wettability is the most important core in many engineering and technologies, and one of the extreme wet states, super-hydrophilicity, is the contact angle between liquid and film is nearly 0 degree, and the research progress is always of interest to researchers. The super-hydrophilic coating has the effect that the acting force on water drops in the material is far greater than the tension of the surface of the material, so that the water drops are uniformly spread and form a water film, the surface contact of pollutants and the material is prevented, and meanwhile, the pollutants on the surface of the material can be removed by means of wind blowing, rainwater washing and the like, and the self-cleaning purpose is realized. Therefore, the super-hydrophilic self-cleaning coating with simple preparation conditions and excellent durability is developed and has high application value.

The super-hydrophilic coating is divided into three categories of organic polymer coating, inorganic coating and organic-inorganic composite according to chemical components.

Organic polymer super hydrophilic coating generally refers to some natural or artificial water soluble polymers rich in hydrophilic functional groups, such as hydroxyl, carboxyl, amine and sulfonic acid groups. These hydrophilic groups can form hydrogen bonds or electrostatic attraction with water molecules, resulting in the formation of a continuous or quasi-continuous water film layer. In the research article, "bioinsed adhesive coatings from polyethylene and titanium acid additives exhibiting anti-contamination, self-cleaning, and antibacterial capabilities (Ren JL, Zhu JT. JOURNAL. COLLOID AND INTERFACE SCIENCE.2021.06.032Volume602 Page 406-414)" the authors succeeded in depositing a biomimetic adhesive superhydrophilic coating with a contact angle OF less than 10 ° on the substrate surface by optimizing the mass ratio OF polyethyleneimine to tannic acid, which coating has excellent antibacterial activity and self-cleaning capability.

The super-hydrophilic inorganic coating can be classified into two types. The first is made of an inherently hydrophilic material (e.g. SiO) ₂ Graphene oxide, etc.) in various forms, including solid, hollow or mesoporous nanoparticles, nanoflakes, and nanorods. The second being made of, for example, TiO ₂ Or a photo-induced super-hydrophilic material such as ZnO, which, after exposure to uv light for a period of time, reduces the contact angle to below 10 ° to a super-hydrophilic state. Chinese patent application CN1687249A disclosesA method for preparing super-hydrophilic coating, which coats titanium dioxide sol on the surface of base material, and the surface shows super-hydrophilic performance after high temperature calcination and ultraviolet irradiation.

The organic polymer super-hydrophilic coating has lasting and stable hydrophilic effect, but has the disadvantages of easy swelling in water, no resistance to solvent and ultraviolet radiation, no aging resistance, and poor hardness and wear resistance. Inorganic super-hydrophilic coatings, e.g. nano-SiO ₂ 、TiO ₂ High temperature calcination is often required to improve the hydrophilicity of the surface and the bonding force between particles. In addition, the gaps between the particles tend to absorb dust, lowering the surface energy and destroying the structure, making it impossible to produce a long-term stable superhydrophilic coating. Compared with other methods, the inorganic-organic composite coating has the advantages of both organic and inorganic coatings, makes up for deficiencies in performance, generates a synergistic effect, and is becoming a hotspot of research on super-hydrophilic coatings. The Chinese invention patent application CN111574899A discloses an organic-inorganic hybrid antifogging coating and a preparation method thereof, and the method mixes acrylate and silica sol and prepares a super-hydrophilic coating with a water contact angle of 3-6 degrees after curing at room temperature.

At present, inorganic organic super-hydrophilic coatings are mainly prepared by compounding inorganic nano silicon dioxide, titanium dioxide and other powder with hydrophilic organic solvents. However, the nano powder and the polymer matrix are in point contact, so that the bonding force of the inorganic powder and the organic polymer interface is weak, the powder is easily abraded and washed away, the roughness of the coating is damaged, the mechanical property is not ideal, and the super-hydrophilic property of the coating is not maintained for a long time in a use environment.

Chinese patent application 202111640947.5 discloses a UV-curable super-hydrophilic antifogging coating, a preparation method and an application thereof, wherein the coating comprises the following components in parts by weight: 30-70 parts of UV resin oligomer, 20-50 parts of acrylic monomer, 10-30 parts of surfactant and 1-5 parts of modified two-dimensional nano material; the raw materials for preparing the modified two-dimensional nano material comprise a two-dimensional nano material and a modifier; the modifier is selected from acrylic acid modifier or acrylate modifier. The two-dimensional nano material is selected from more than one of nano zirconium phosphate, modified graphene, montmorillonite, talcum powder or titanium dioxide nanosheets. However, the two-dimensional nano material and the UV resin oligomer are simply and physically mixed, no chemical bond is formed between the powder and the polymer, the interface bonding force of the coating is improved to a limited extent, and the mechanical property of the coating cannot be improved; moreover, the technology needs to carry out a specific ultraviolet curing technology to obtain the super-hydrophilic surface, and the cost is high.

Disclosure of Invention

Aiming at the problems in the field of super-hydrophilic coatings at present, the mechanical property and the water resistance of the coatings are poor, and the micro-nano composite structures on the surfaces are easy to damage, so that the service life of the coatings is short.

The invention also aims to provide application of the inorganic-organic composite super-hydrophilic coating in preparation of an inorganic-organic composite super-hydrophilic coating.

In order to achieve the purpose, the invention is realized by the following technical scheme:

an inorganic-organic composite super-hydrophilic coating is characterized in that layered silicate minerals are added into water, stirred and ultrasonically treated at room temperature to obtain a uniformly mixed suspension; adding the water-based polymer into the mixture, stirring the mixture in a water bath at 50-90 ℃ for reacting for 2-5 hours to obtain a polymer solution after intercalation modification, and then adding the nano inorganic powder, the dispersing agent and the defoaming agent into the mixture to react to obtain the modified polymer solution; the water-based polymer is any one or more of polyvinyl alcohol, polyethylene glycol and polyacrylic acid.

In order to further achieve the purpose of the invention, preferably, the raw material formula comprises the following components in percentage by mass: 5-30% of nano inorganic powder, 2-10% of layered silicate mineral, 5-15% of water-based polymer, 43.5-87.8% of water, 0.1-1% of dispersant and 0.1-0.5% of defoamer, wherein the sum of the mass percentages of the components is 100%; the nano inorganic powder is one or more of silicon dioxide, titanium dioxide and zinc oxide.

Preferably, the size of the nano inorganic powder is 5-100 nm.

Preferably, the phyllosilicate mineral is any one or more of montmorillonite, mica and kaolinite.

Preferably, the mass ratio of the nano inorganic powder to the layered silicate mineral is in a range of 0.5-15: 1.

preferably, the dispersant is one or more of sodium tripolyphosphate, sodium hexametaphosphate, sodium dodecyl sulfate and polyacrylamide.

Preferably, the defoaming agent is any one or more of silicone resin, dimethyl silicone oil and emulsified silicone oil.

The preparation method of the inorganic-organic composite super-hydrophilic coating comprises the following steps:

step 1, adding a phyllosilicate mineral into pure water, stirring for 30-60 min at room temperature, and carrying out ultrasonic treatment for 15-30 min to obtain a uniformly mixed suspension;

step 2, adding a water-based polymer into the suspension, and stirring and reacting for 2-5 hours in a water bath kettle at the temperature of 50-90 ℃ to obtain a polymer solution after intercalation modification;

and 3, sequentially adding nano inorganic powder, a dispersing agent and a defoaming agent into the polymer solution, and stirring for 30-60 min by controlling the heating temperature of a water bath to be 50-90 ℃ to obtain the inorganic-organic composite super-hydrophilic coating.

The application of the inorganic-organic composite super-hydrophilic coating in preparing the inorganic-organic composite super-hydrophilic coating is characterized in that: coating the obtained inorganic-organic composite super-hydrophilic coating on the surface of a matrix by adopting a film forming process to obtain an inorganic-organic composite super-hydrophilic coating; the time required for the static contact angle of the obtained inorganic-organic composite super-hydrophilic coating to change to 0 ℃ is 0.5-2 s.

Preferably, the substrate is cleaned before coating and then dried for standby, and the substrate is a cement-based material, a concrete substrate or a glass substrate; the substrate is sequentially ultrasonically cleaned for more than 20 minutes by acetone, ethanol and ultrapure water; the drying is carried out in a blast drying oven with the temperature of above 60 ℃; for a large-area substrate, the drying is carried out under a natural condition after the substrate is cleaned by a high-pressure water gun; the film forming process is one or more of spraying, blade coating, spin coating and dip coating;

the adhesive tape adhesion of the obtained inorganic-organic composite super-hydrophilic coating is 1-3 grades, the pencil hardness grade is H-5H, the maximum loss amount after the abrasive paper is worn for 100 times is only 6.8mg, and the surface still has super-hydrophilicity after the abrasive paper is worn for 100 times; after the coating is subjected to a water and acid resistance test for one week and is placed outdoors for natural aging for 6 months, the super-hydrophilic state of the surface is maintained.

Compared with the prior art, the invention has the following advantages:

1) the invention introduces the phyllosilicate into the super-hydrophilic coating, and greatly improves the mechanical property and the water resistance of the composite coating due to the strong interface action between the lamellar structure of the phyllosilicate and the polymer. The adhesive tape adhesion of the coating is 1-3 grade, the pencil hardness grade is H-5H, the maximum loss after the abrasive paper is worn for 100 times is only 6.8mg, and the surface still has super-hydrophilicity after the mechanical wear resistant period is 100 times. After one week of water and acid resistance and 6 months of natural aging, the super-hydrophilic state of the surface can be still maintained.

2) Generally speaking, intercalation modification is not beneficial to super-hydrophilicity of the coating, because the higher the intercalation degree is, the better the mechanical property and water resistance of the coating is, but the polymer wraps the powder, so that the roughness is reduced, and the hydrophilicity of the coating is reduced. Adding a phyllosilicate mineral into water, and combining ultrasonic treatment to obtain a uniformly mixed suspension; and adding the aqueous polymer, and stirring and reacting in a water bath at the temperature of 50-90 ℃ for 2-5 hours under strict control to obtain a polymer solution after intercalation modification, wherein the prepared coating has super-hydrophilicity, and the mechanical water resistance and other properties of the coating are obviously improved.

3) The hydrophilic lamellar natural minerals doped in the invention have wide sources in nature, can effectively replace part of nano inorganic powder, and reduce the cost of the coating. When the water-based solvent is added, the dispersibility and the compatibility of the coating can be effectively improved, and the stability of the coating is effectively improved.

4) The preparation method of the inorganic-organic composite super-hydrophilic coating is simple, the reaction time is short, and complex equipment and reaction conditions of high-temperature calcination are not needed.

5) The inorganic-organic composite super-hydrophilic coating prepared by the invention is environment-friendly, has low cost, is particularly suitable for large-area construction application, and is beneficial to accelerating the development and application of super-hydrophilic technology.

Drawings

FIG. 1 shows the contact of the coating prepared in example 1 with water droplets.

FIG. 2 shows the contact of the coating prepared in example 2 with water droplets.

FIG. 3 shows the contact of the coating prepared in example 3 with water droplets.

FIG. 4 shows the contact of the coating prepared in example 4 with water droplets.

FIG. 5 is a graph showing the change in water contact angle value of the coating obtained in example 3 depending on the number of times of rubbing with sandpaper.

FIG. 6 is a graph showing the change in contact angle after immersion of the coating obtained in example 4 in water as a function of immersion time.

Figure 7 is an XRD pattern of the coating prepared in example 3.

Detailed Description

The present invention will be further described with reference to specific embodiments to illustrate and explain the present invention, but the embodiments of the present invention are not limited thereto.

Example 1

A preparation method of an inorganic-organic composite super-hydrophilic coating comprises the following steps:

1) 10.0g of mica was weighed out accurately and placed in 79.8ml of deionized water to form a suspension, stirred at room temperature for 30min and sonicated for 15 min. Then 5.0g of polyethylene glycol is added into the solution, the temperature is set to 80 ℃ in a water bath, and the solution is stirred for 2 hours at the rotating speed of 1500r/min to form a compound solution.

2) Weighing 5.0g of nano SiO ₂ Dissolving the particles in the solution, sequentially adding 0.1g of sodium hexametaphosphate dispersant and 0.1g of silicone resin defoaming agent, stirring in a water bath at 80 ℃ for 30min, and performing ultrasonic treatment at room temperature for 15min to obtain the super-hydrophilic composite coating for coating.

3) 2ml of the dope was sucked up by a dropper, and spin-coated on a glass substrate by a spin coater at a rotation speed of 500 r. And finally, drying the coating in a vacuum drying oven at 60 ℃ for 30min and curing to obtain the super-hydrophilic coating.

Example 2

A preparation method of an inorganic-organic super-hydrophilic coating comprises the following steps:

1) accurately weighing 2.0g of mica, placing the mica into 62.8ml of deionized water to form a suspension, stirring the suspension for 30min at room temperature, and carrying out ultrasonic treatment for 15 min. Then 5.0g of polyethylene glycol is added into the solution, the temperature is set to 80 ℃ in a water bath, and the solution is stirred for 2 hours at the rotating speed of 1500r/min to form a compound solution.

2) Weighing 30.0g of nano ZnO particles, dissolving in the solution, sequentially adding 0.1g of sodium hexametaphosphate dispersant and 0.1g of dimethyl silicone oil defoamer, stirring in a water bath at 80 ℃ for 30min, and performing ultrasonic treatment at room temperature for 15min to obtain the super-hydrophilic composite coating for coating.

Example 3

1) accurately weighing 5.0g of montmorillonite, placing the montmorillonite into 84.8ml of deionized water to form a suspension, stirring for 30min at room temperature, and carrying out ultrasonic treatment for 15 min. Then 5.0g of PVA grains are added into the solution, the temperature is set to 80 ℃ in a water bath, and the solution is stirred for 2 hours at the rotating speed of 1500r/min to form a compound solution.

2) Weighing 5.0g of nano SiO ₂ Dissolving the particles in the solution, sequentially adding 0.1g of sodium dodecyl sulfate and 0.1g of dimethyl silicone oil defoaming agent, stirring in a water bath at 80 ℃ for 30min, and carrying out ultrasonic treatment at room temperature for 15min to obtain the super-hydrophilic composite coating for coating.

Example 4

1) 5.0g of kaolin is accurately weighed and placed into 84.8ml of deionized water to form a suspension, stirred for 30min at room temperature and subjected to ultrasonic treatment for 15 min. Then 5.0g of PVA grains are added into the solution, the temperature is set to 80 ℃ in a water bath, and the solution is stirred for 2 hours at the rotating speed of 1500r/min to form a compound solution.

2) Weighing 5.0g of nano TiO ₂ Dissolving the particles in the solution, sequentially adding 0.1g of sodium tripolyphosphate dispersant and 0.1g of silicone resin defoamer, stirring in a water bath at 80 ℃ for 30min, and performing ultrasonic treatment at room temperature for 15min to obtain the super-hydrophilic composite coating for coating.

TABLE 1

TABLE 2

Table 1 shows the indexes of the adhesive property and the mechanical property of the matrix coating in examples 1-4, and the adhesive tape adhesion of the coating is 1-3 grade, the pencil hardness grade is H-5H, and the maximum loss amount of the abrasive paper after 100 times of abrasion is only 6.8 mg.

Table 2 shows the initial contact angles of the coatings of the substrates of examples 1 to 4 as 3.2 °, 0.0 °, 0.0 °, 1.2 °, respectively. The coating was placed outdoors and after 6 months of natural aging the change in contact angle of the surface was 5.0 °, 0.0 °, 2.1 °, 3.5 °. Although the contact angle is slightly increased in part, the whole contact angle is still less than 5 degrees, and the surface still has super-hydrophilic property.

Fig. 1 shows the contact condition of the coating prepared in example 1 with a water drop, and it can be seen from the figure that the prepared coating becomes a super-hydrophilic coating, and the contact angle of the water drop with the surface is 3.2 °.

FIG. 2 is a graph showing the contact condition of the coating prepared in example 2 with a water drop, from which it can be seen that the prepared coating becomes a super-hydrophilic coating, and the contact angle of the water drop with the surface is 0 deg..

Fig. 3 shows the contact condition of the coating prepared in example 3 with a water drop, and it can be seen from the figure that the prepared coating becomes a super-hydrophilic coating, and the contact angle of the water drop with the surface is 0 °.

Fig. 4 shows the contact condition of the coating prepared in example 4 with a water drop, and it can be seen from the figure that the prepared coating becomes a super-hydrophilic coating, and the contact angle of the water drop with the surface is 1.2 °.

FIG. 5 is a graph showing the change in water contact angle value of the coating obtained in example 3 depending on the number of times of rubbing with sandpaper. It can be seen that although the WCA value of the coating of example 3 tends to increase with increasing number of abrasion tests, the magnitude of the increase is relatively small, and 150 rubs with sandpaper are followed by a WCA value which remains superhydrophilic at 5 deg.. This is because the powder on the surface of the coating of example 3 is abraded by a small amount, and the micro-nano composite structure on the surface of the coating is not damaged substantially. This shows that the super-hydrophilic coating prepared by the experiment shows good mechanical wear resistance, and has practical significance for producing and using super-hydrophilic surfaces.

FIG. 6 is a graph showing the change in contact angle after immersion of the coating obtained in example 4 in water as a function of immersion time. The graph reflects that the water contact angle of the surface of the coating of the example 4 has no obvious change until the surface can reach 0 DEG during the soaking process in the aqueous solution with the pH value of 7 for 5 days, and the coating shows good water resistance.

According to the invention, a lamellar structure of a phyllosilicate mineral is used for adsorbing polymer molecules for intercalation modification, fig. 7 is an XRD (X-ray diffraction) diagram of the coating prepared in example 3, as shown in fig. 7, the diffraction peak 2 theta of the (001) surface of pure montmorillonite in the diagram is 5.883 degrees, and d001 is 1.500nm, while the diffraction peak of montmorillonite (001) after MMT and PVA composite coating is 2 theta 5.726 degrees, the diffraction peak position shifts towards a small angle direction, and the layer spacing is enlarged, so that the PVA molecular chain enters into MMT layers, the binding power and the mechanical property of inorganic matters and organic binders can be greatly improved, the super-hydrophilic coating can have excellent antifouling property for a long time, and the service life of the super-hydrophilic coating is greatly prolonged.

Different from the simple physical mixing between most nano powder and polymers, the layered nano material prepared by the invention forms chemical bonds due to the intercalation reaction between the layered nano material and the polymers, so that the interface bonding force between the layered nano material and the polymers is greatly improved, and the mechanical property of the coating is more excellent. Compared with the friction resistance of a coating prepared by the method and the application disclosed in Chinese patent application 202111640947.5, the ultra-hydrophilic antifogging coating prepared by the UV curing ultra-hydrophilic antifogging coating can only bear 10-12 times, the ultra-hydrophilic coating prepared by the layered silicate intercalation modification method disclosed by the invention can bear 150 times of friction resistance, still has ultra-hydrophilicity, greatly improves the mechanical property, and prolongs the service life of the ultra-hydrophilic coating. As can be seen from the drawings of the above examples, the inorganic-organic composite super-hydrophilic coating prepared by the invention has excellent water resistance, simple coating preparation process, short reaction time and no need of complex equipment and reaction conditions of high-temperature calcination. The coating is green and environment-friendly, has low cost, is also suitable for large-area construction application, and is favorable for accelerating the development and application of a super-hydrophilic technology.

In the prior art, after the surface reaches a super-hydrophilic state through the roughness, the surface cannot be maintained for a long time, and the durability of the coating is poor, so that the coating cannot have good antifouling and self-cleaning performances for a long time. According to the invention, the micro-nano composite structure is formed by the phyllosilicate mineral and the nano inorganic powder, so that the higher roughness of the coating is realized, and the higher surface energy of the coating is realized by using a hydrophilic organic matter as a binder, so that the super-hydrophilic performance of the coating is realized. The lamellar structure of the phyllosilicate mineral is utilized to adsorb polymer molecules for intercalation modification, so that the phyllosilicate mineral has better compatibility with an organic binder in the coating, thereby greatly improving the binding power of an inorganic substance and the organic binder and the binding power of the coating and a matrix. The adhesive tape of the inorganic-organic composite super-hydrophilic coating prepared by the invention has the adhesion grade of 1-3, the pencil hardness grade of H-5H, and the contact angle between the surface and water after the abrasive paper abrasion period of 100-150 times is 5-10 degrees. After the coating is soaked in water for one week, the surface contact angle is 0-5 degrees. The super-hydrophilic coating has excellent wear resistance, water resistance and aging resistance, the service life of the coating is prolonged, and the coating has long-term antifouling self-cleaning performance.

The above embodiments are not intended to limit the technical solution of the present invention in any form, and any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An inorganic-organic composite super-hydrophilic coating is characterized in that layered silicate minerals are added into water, stirred and ultrasonically treated at room temperature to obtain a uniformly mixed suspension; adding the water-based polymer into the mixture, stirring the mixture in a water bath at 50-90 ℃ for reacting for 2-5 hours to obtain a polymer solution after intercalation modification, and then adding the nano inorganic powder, the dispersing agent and the defoaming agent into the mixture to react to obtain the modified polymer solution; the water-based polymer is any one or more of polyvinyl alcohol, polyethylene glycol and polyacrylic acid.

2. The inorganic-organic composite superhydrophilic coating of claim 1, characterized in that: the raw material formula comprises the following components in percentage by mass: 5-30% of nano inorganic powder, 2-10% of layered silicate mineral, 5-15% of water-based polymer, 43.5-87.8% of water, 0.1-1% of dispersant and 0.1-0.5% of defoamer, wherein the sum of the mass percentages of the components is 100%; the nano inorganic powder is one or more of silicon dioxide, titanium dioxide and zinc oxide.

3. The inorganic-organic composite superhydrophilic coating of claim 2, characterized in that: the size of the nano inorganic powder is 5-100 nm.

4. The inorganic-organic composite superhydrophilic coating of claim 1, characterized in that: the phyllosilicate mineral is one or more of montmorillonite, mica and kaolinite.

5. The inorganic-organic composite superhydrophilic coating of claim 1, characterized in that: the mass ratio of the nano inorganic powder to the layered silicate mineral is within the range of 0.5-15: 1.

6. the preparation method of the inorganic-organic composite super-hydrophilic coating according to claim 1, characterized in that: the dispersing agent is one or more of sodium tripolyphosphate, sodium hexametaphosphate, sodium dodecyl sulfate and polyacrylamide.

7. The preparation method of the inorganic-organic composite super-hydrophilic coating according to claim 1, characterized in that: the defoaming agent is any one or more of silicone resin, dimethyl silicone oil and emulsified silicone oil.

8. The method for preparing the inorganic-organic composite super-hydrophilic coating according to any one of claims 1 to 7, characterized by comprising the steps of:

9. The use of the inorganic-organic composite superhydrophilic coating of claims 1-7 for the preparation of an inorganic-organic composite superhydrophilic coating, wherein: coating the obtained inorganic-organic composite super-hydrophilic coating on the surface of a matrix by adopting a film forming process to obtain an inorganic-organic composite super-hydrophilic coating; the time required for the static contact angle of the obtained inorganic-organic composite super-hydrophilic coating to change to 0 ℃ is 0.5-2 s.

10. The use of the inorganic-organic composite superhydrophilic coating of claim 9 in the preparation of an inorganic-organic composite superhydrophilic coating, wherein: the matrix is cleaned before coating and then dried for later use, and the matrix is a cement-based material, a concrete matrix or a glass matrix; the substrate is sequentially ultrasonically cleaned for more than 20 minutes by acetone, ethanol and ultrapure water; the drying is carried out in a blast drying oven with the temperature of above 60 ℃; for a large-area substrate, the drying is carried out under a natural condition after the substrate is cleaned by a high-pressure water gun; the film forming process is one or more of spraying, blade coating, spin coating and dip coating;