CN113289876B

CN113289876B - Preparation method of metal protective film with self-repairing function and super-amphiphobic function

Info

Publication number: CN113289876B
Application number: CN202110482450.9A
Authority: CN
Inventors: 李凌杰; 雷惊雷; 刘雷; 武佳乐; 唐春燕; 潘嘉燕
Original assignee: Chongqing University
Current assignee: Chongqing University
Priority date: 2021-04-30
Filing date: 2021-04-30
Publication date: 2022-07-29
Anticipated expiration: 2041-04-30
Also published as: CN113289876A

Abstract

The invention provides a preparation method of a metal protective film with self-repairing function and super-amphiphobic function. The functional metal protective film of the present invention is produced by dip-coating a film and then curing the film. The method is suitable for surface protection of metal materials with various shapes and sizes. The metal protective film prepared by the invention has a lasting self-repairing function and a super-amphiphobic function, not only can quickly repair various scratches, grinding marks and other mechanical damages, but also can resist pollution and damage of various environmental media, and has a great practical application value. The method has the characteristics of simple process, convenient operation, environmental protection, easy large-scale industrial treatment and the like.

Description

Preparation method of metal protective film with self-repairing function and super-amphiphobic function

Technical Field

The invention belongs to the technical field of surface engineering, and particularly relates to a preparation method of a metal protective film with self-repairing function and super-amphiphobic function.

Background

Metals such as aluminum, magnesium, zinc, iron, titanium, nickel, copper and alloys thereof are widely used in various fields of national economy. The metal materials are active in chemical property, are very easy to corrode, and are also easy to be damaged by mechanical damage such as scraping and abrasion and pollution of various environment media in the using process, so that the service quality and the service life of the metal materials are seriously influenced.

In order to effectively inhibit the corrosion of metal materials, various metal surface protection techniques have been developed. However, the existing metal protective films generally only can inhibit different types of corrosion, but do not have the effect on mechanical damage and pollution damage in the service process. Even though a self-repairing film layer technology capable of overcoming mechanical damage of the film layer to a certain extent is developed recently, for example, a patent technology 'CN 104947099B a preparation method of a metal surface film with rapid self-repairing capability'; and a super-hydrophobic and super-oleophobic super-amphiphobic membrane layer technology which can overcome the pollution and damage of environmental media to a certain extent, for example, the patent technology 'CN 107779030B is a preparation method of a high-strength aluminum alloy durable super-amphiphobic surface'. However, these films have single function, and only can solve a certain problem in the metal service process, but cannot completely and fundamentally solve all the problems. Therefore, the technical problem to be solved by the technical staff in the art is how to provide a metal protective film with self-repairing function and super-amphiphobic function, so as to comprehensively and effectively solve the problems of corrosion, mechanical damage and pollution damage in the service of metal.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a preparation method of a metal protective film with self-repairing function and super-amphiphobic function.

The invention adopts the following technical scheme: a preparation method of a metal protective film with self-repairing function and super-amphiphobic function comprises the following steps:

dipping, pulling and film forming: completely immersing the cleaned metal workpiece in a #1 immersion liquid, pure water, a #2 immersion liquid, pure water, a #3 immersion liquid and pure water at 60-80 ℃ for 10-20 minutes respectively, wherein the pulling speeds are 0.05-0.1 mm/s, 5mm/s, 0.1-0.5 mm/s, 5mm/s, 0.5-1.0 mm/s and 5mm/s respectively; repeating the steps for 6-8 times, soaking the workpiece in 60-80 ℃ No. 1 soaking liquid for 5-10 minutes, and then pulling out the workpiece at the speed of 0.01-0.05 mm/s;

curing treatment: and (3) curing the metal workpiece treated in the step (i) at the temperature of 100-120 ℃ for 10-12 hours to finish the preparation of the metal protective film.

Further, the composition of the impregnation liquid is as follows:

#1 impregnating solution is prepared by uniformly mixing an aluminum phosphate solution and a commercially available polytetrafluoroethylene emulsion in a volume ratio of 1: 1-3; the preparation process of the aluminum phosphate solution comprises the following steps: mixing Al (OH) ₃ Powder and H at a concentration of 60 wt% ₃ PO ₄ Mixing according to a molar ratio of 3:1, stirring for 3 hours at 100 ℃, then adding 5 times of water by mass, and stirring uniformly to obtain an aluminum phosphate solution;

#2 immersion fluid was made of SiO ₂ The nano particles are ultrasonically dispersed in a 10-15 g/L aqueous solution of polymethacrylic acid salt; SiO 2 ₂ The particle size of the nano particles is 10-30 nanometers, and the content of the nano particles is 1-3 g/L; the molecular weight of the polymethacrylic acid is 5000-20000;

#3 the impregnating solution consists of a 3-8 g/l polyethyleneimine brine solution; the molecular weight of the polyethyleneimine is 150000-300000.

Furthermore, the concentration of the brine in the #2 steeping liquor and the #3 steeping liquor is 0.05-0.20 mol/L, and the type of the salt is soluble chloride, sulfate or nitrate of sodium, potassium, magnesium, calcium and barium.

The metal workpiece is a metal of aluminum, magnesium, zinc, iron, titanium, nickel, copper, and alloys thereof, and is not limited by shape and size.

Compared with the prior art, the invention has the following beneficial effects:

1. the invention synergistically exerts the binding effect of the aluminum phosphate component, the surface energy reducing effect of the polytetrafluoroethylene component, the non-covalent bond effect between the polymethacrylic acid and the polyethyleneimine component and the SiO effect in the three impregnating solutions ₂ The nano particles have the effect of enhancing the mechanical strength and the effect of promoting film formation of salt components, and a film layer with good binding force, strong non-covalent bond effect, low surface energy and high mechanical strength is prepared, so that the film layer is endowed with excellent protective performance, self-repairing function and super-amphiphobic function; not only can effectively inhibit corrosion, but also can quickly and completely repair various mechanical damages such as scratches, grinding marks and the like, and resist the pollution and the damage of various environmental media, thereby having great practical application value.

2. The invention is suitable for surface protection of various metals with various sizes and shapes, and can effectively improve the service quality and service life of metals such as aluminum, magnesium, zinc, iron, titanium, nickel, copper and the like and alloys thereof in different application fields.

3. The method has the characteristics of simple process, convenient operation, environmental protection, easy large-scale industrial treatment and the like.

Drawings

FIG. 1 is a self-repairing functional display of the film layer obtained in example 1.

FIG. 2 is a super-amphiphobic functional display of the membrane layer obtained in example 1.

Detailed Description

The present invention will be described in further detail with reference to specific examples.

It should be noted that these examples are only for illustrating the present invention, and not for limiting the present invention, and the simple modification of the method based on the idea of the present invention is within the protection scope of the present invention.

Example 1:

the preparation method of the protective film with the self-repairing function and the super-amphiphobic function on the surface of the AZ31 magnesium alloy specifically comprises the following steps:

dipping, pulling and film forming: dipping and drawing the film into a film by using a dipping and drawing machine. The cleaned magnesium alloy workpiece was completely immersed in 60 ℃ of #1 immersion liquid, pure water, #2 immersion liquid, pure water, #3 immersion liquid, and pure water for 20 minutes each at a pull rate of 0.1mm/s, 5mm/s, 0.2mm/s, 5mm/s, 0.8mm/s, and 5mm/s, respectively, and the above steps were repeated 6 times, and then the workpiece was immersed in 60 ℃ of #1 immersion liquid for 10 minutes and pulled at a rate of 0.05 mm/s.

The #1 impregnation liquid is formed by uniformly mixing an aluminum phosphate solution and a commercially available polytetrafluoroethylene emulsion according to the volume ratio of 1: 3; the preparation process of the aluminum phosphate solution comprises the following steps (in other examples): mixing Al (OH) ₃ Powder and H in a concentration of 60 wt% ₃ PO ₄ Mixing according to a molar ratio of 3:1 and a molar ratio of 3:1, stirring for 3 hours at 100 ℃, then adding 5 times of water by mass, and stirring uniformly to obtain the aluminum phosphate solution. #2 impregnating solution was made of SiO with a particle size of about 15 nm ₂ The nano particles are dispersed in a saline solution containing 10 g/L polymethacrylic acid (molecular weight is 5000) and sodium chloride with concentration of 0.075 mol/L by ultrasound with the content of 3g/L and mixed to obtain the nano particles. #3 the impregnating solution was a saline solution of magnesium nitrate with a concentration of 0.05 mol/L containing 3g/L polyethyleneimine (molecular weight 150000).

Curing treatment: curing the magnesium alloy workpiece treated in the step one at 100 ℃ for 12 hours to obtain a film layer with the thickness of about 120 microns.

The performance and function of the film layer was checked as follows (same test method for other examples):

a. and (3) testing the protection performance: the electrochemical impedance spectrum is adopted to test the protective performance of the film layer, the test is carried out on an Autolab PGSTAT302N type electrochemical workstation of Switzerland Vantone, and the test frequency range is 10 ^-2 ～10 ⁵ Hz, an applied sinusoidal AC signal amplitude of 20mV, and a corrosive medium of simulated sweat (0.5 wt% NaCl, 0.1 wt% lactic acid and 0.1 wt% urea)pH 6.5), the test temperature was room temperature. The film resistance is obtained by analyzing and fitting a test result by using self-contained software of an instrument, and the larger the film resistance is, the better the protective performance is.

b. Self-repairing function test: a scratch of about 110 microns in width was scribed on the film layer with a razor blade and the time required for complete repair of the scratch was recorded by observing the scratch's change in natural atmospheric conditions through a digital material microscope, Leica DM4000M, germany.

c. Testing the super-amphiphobic function: the water and oil repellency of the surface of a workpiece is evaluated by measuring the contact angle of 2 mu L of water drops (pure water) and oil drops (n-hexane) on the surface of the workpiece by using a German Dataphysics OCA20 video optical contact angle measuring instrument, the surface with the contact angle of more than 150 degrees is considered as an ultraphobic surface, and the ultraphobic effect of the surface with the larger contact angle is better.

d. And (3) testing the durability: the durability is tested by testing the protective performance, the self-repairing function and the super-amphiphobic function of the film layer after repeated scratching, abrasive paper abrasion and high-temperature damage and soaking in an organic solvent. The repeated scratching is to make a scratch of about 110 microns wide on the film layer by a blade, and repeatedly scratch the same position 10 times. Scratch sandpaper abrasion one side of the film was placed against 1000# sandpaper and pulled under 5.0kPa for a distance of 10 cm. The high temperature destruction is to place the film sample in an environment of 100 ℃ for 10 h. The organic solvent soaking test is to soak the film layer sample in ethanol and acetone, which are the most commonly used organic solvents, for 12 hours.

The performance and function test results of the film layer show that: the resistance value of the film layer of the magnesium alloy workpiece treated by the method of the invention is up to 278.60 MOmega cm ² Thus showing that the film layer has excellent protective performance. Referring to fig. 1(a), there are black scratches of 110 microns width; referring to fig. 1(b), scratches can be completely repaired by self within 2 hours, which shows that the film layer has the characteristics of high self-repairing speed and high self-repairing degree. Referring to fig. 2(a), the contact angle of a water drop on the surface of the film layer is 156.2 °; referring to fig. 2(b), the contact angle of the oil drop on the surface of the membrane layer is 152.5 °, which shows that the membrane layer has the super-amphiphobic function.

The durability results show that: damage forms such as repeated scratching, abrasive paper abrasion, high-temperature damage, organic solvent soaking and the like have little influence on the protective performance, the self-repairing function and the super-amphiphobic function of the film layer (the change of specific test results is less than 3 percent), and the film layer performance and the function have excellent durability.

Examples 2, 3 and 4:

the same method as the preparation steps, performance and function test of the protective film in example 1, but different metal materials as the objects of protection (see table 1), different compositions of the impregnation solution (see table 1), different preparation conditions (see table 2), and different results of performance and function test (see table 3).

TABLE 1 composition of the metallic materials and impregnating solutions used in the examples

Table 2 film preparation conditions for each example

Table 3 film layer performance and functional test results corresponding to each embodiment

According to the film performance and function test results corresponding to the embodiments in table 3, it can be shown that the film prepared by the embodiments has excellent protective performance, self-repairing function and super-amphiphobic function, and the performances and functions have excellent durability.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the technical solutions, and those skilled in the art should understand that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all that should be covered by the claims of the present invention.

Claims

1. A preparation method of a metal protective film with self-repairing function and super-amphiphobic function is characterized by comprising the following steps:

Curing treatment: curing the metal workpiece treated in the step one at the temperature of 100-120 ℃ for 10-12 hours to finish the preparation of the metal protective film;

wherein, the composition of the impregnation liquid is as follows:

#3 the impregnating solution consists of a 3-8 g/l polyethyleneimine brine solution; the molecular weight of the polyethyleneimine is 150000-300000;

the concentration of brine in the #2 steeping liquor and the #3 steeping liquor is 0.05-0.20 mol/L, and the type of salt is any one of soluble chlorides, sulfates and nitrates of sodium, potassium, magnesium, calcium and barium.

2. The method for preparing the metal protective film with the self-repairing function and the super-amphiphobic function according to claim 1, wherein the metal is aluminum, magnesium, zinc, iron, titanium, nickel, copper or an alloy thereof, and is not limited by shape and size.