阅读说明：本技术 一种快速制备氧化铜/聚四氟乙烯超双疏性涂层的方法 (Method for rapidly preparing copper oxide/polytetrafluoroethylene super-amphiphobic coating ) 是由 于思荣 吕哲馨 尹晓丽 周雪 宋锴星 于 2019-10-11 设计创作，主要内容包括：本发明涉及一种快速制备氧化铜/聚四氟乙烯复合超双疏性涂层的方法,依次包括如下步骤：(1)基体材料表面的预处理(砂纸打磨,碱洗或酸洗,丙酮、无水乙醇、去离子水超声清洗,烘干)；(2)配制包含组份A与组份B的化学置换制膜乳液；(3)化学置换反应沉积铜/聚四氟乙烯复合涂层；(4)热氧化处理固化沉积的铜/聚四氟乙烯复合涂层,即可得到具有树枝状微纳米结构的氧化铜/聚四氟乙烯复合超双疏性涂层。本发明所制备的氧化铜/聚四氟乙烯复合超双疏性涂层具有超疏水性、超疏油性、热稳定性和耐腐蚀性等特性。本发明制备方法简单快速,成本低,环境友好,所制得的超双疏性表面性能稳定,适合工业化生产。(The invention relates to a method for rapidly preparing a copper oxide/polytetrafluoroethylene composite super-amphiphobic coating, which sequentially comprises the following steps: (1) pretreating the surface of the base material (sanding, alkali washing or acid washing, ultrasonic cleaning of acetone, absolute ethyl alcohol and deionized water, and drying); (2) preparing chemical displacement membrane preparation emulsion containing a component A and a component B; (3) depositing a copper/polytetrafluoroethylene composite coating by chemical displacement reaction; (4) and curing the deposited copper/polytetrafluoroethylene composite coating through thermal oxidation treatment to obtain the copper oxide/polytetrafluoroethylene composite super-amphiphobic coating with the dendritic micro-nano structure. The copper oxide/polytetrafluoroethylene composite super-amphiphobic coating prepared by the invention has the characteristics of super hydrophobicity, super oleophobicity, thermal stability, corrosion resistance and the like. The preparation method is simple and quick, low in cost and environment-friendly, and the prepared super-amphiphobic surface has stable performance and is suitable for industrial production.)

1. A method for rapidly preparing a copper oxide/polytetrafluoroethylene composite super-amphiphobic coating sequentially comprises the following steps:

(1) pretreatment of the surface of a substrate

Any one of metal materials such as aluminum, magnesium, zinc, iron and alloys thereof is used as a base material, the base material is cut into required sizes according to use or design requirements, impurities such as dust and rust on the surface of the base material are ground by sand paper, the ground sample is sequentially placed into acetone, absolute ethyl alcohol and deionized water to be subjected to ultrasonic cleaning for 5-15min, impurities and pollutants such as dust, rust and oil stain on the surface of the base material are further removed, and then the base material is placed into a constant-temperature blast drying box to be dried at 30-100 ℃ for later use; if the impurities and pollutants are not easy to polish, alkaline washing with 3-10% sodium hydroxide solution for 30s-2min or acid washing with 20-30% nitric acid solution for 30s-2 min; then sequentially putting into acetone and absolute ethyl alcohol for ultrasonic cleaning for 5-15 min;

(2) preparing chemical displacement membrane-making emulsion by adopting mixed solution method

Taking the following components in parts by mass: 5-40 parts of soluble inorganic salt containing copper ions such as copper sulfate pentahydrate, copper nitrate or copper chloride, 1-3 parts of sodium chloride or potassium chloride and 40-200 parts of deionized water or pure water, and uniformly stirring to prepare a film-making emulsion component A;

taking the following components in parts by mass: 10-50 parts of water-soluble PTFE emulsion as a film-making emulsion component B;

mixing the film-making emulsion component A and the component B, and uniformly stirring to form stable emulsion;

(3) chemical displacement reaction deposition Cu/PTFE composite coating

Dipping the substrate pretreated in the step (1) into the chemical displacement membrane-making emulsion prepared in the step (2), wherein the dipping time is 30s-8min, generating a reddish Cu/PTFE composite coating on the surface of the substrate material, and taking out the substrate for later use; bubbles are generated in the reaction process, when the mass parts of all the components of the chemical displacement membrane preparation emulsion are small, the dipping time is close to the upper limit of a time window for 8min, and when the mass parts of all the components of the chemical displacement membrane preparation emulsion are large, the dipping time is close to the lower limit of the time window for 30 s;

(4) thermal oxidation film formation treatment

And (3) putting the substrate sample covered with the Cu/PTFE composite coating on the surface in the step (3) into a heating furnace such as a muffle furnace or a tube furnace for thermal oxidation treatment, wherein the gas atmosphere is air or oxygen, the heating rate is properly controlled until the reddish Cu/PTFE composite coating on the surface of the substrate is oxidized into the blackish CuO/PTFE composite coating, the thermal treatment temperature is 150-380 ℃, the heat preservation time is 1-5 h, and after the thermal oxidation treatment is finished, taking out the sample for air cooling to room temperature or cooling to room temperature along with the furnace, so that the CuO/PTFE composite super-amphiphobic coating with the dendritic micro-nano structure and super-hydrophobicity, super-lipophobicity, thermal stability and corrosion resistance can be prepared.

Technical Field

The invention relates to the technical field of metal material surface modification, super-hydrophobic surface and material protection. The method is characterized in that the service life of metal materials such as aluminum materials, magnesium materials, zinc materials, iron materials and the like is prolonged and the functional application is improved by means of the hydrophobic, oleophobic, self-cleaning and anti-corrosion characteristics of the super-amphiphobic surface.

Background

Metals and alloys thereof are important engineering materials and play an irreplaceable role in industrial development and social progress. Aluminum is the most abundant metal element in the earth's crust, and because of its light weight, high specific strength, and good electrical and thermal conductivity, it has a wide application in the fields of aerospace, military and civil ship, machine manufacturing, electronic devices, etc. In the process of vigorously implementing the ocean strategy and building the ocean forcing nation in China, the development and the construction of ocean equipment and engineering do not leave the support and the guarantee of key materials such as aluminum, aluminum alloy and the like. However, because of the high reactivity of the aluminum element, when the aluminum element is in a complex marine environment, the aluminum element is inevitably seriously affected by marine chemical corrosion and biofouling, the service life of the material is shortened, and the maintenance cost is increased.

With the continuous update of anticorrosion and antiscaling technologies, there are some mature marine anticorrosion and antiscaling technologies, such as alloy element doping, corrosion inhibitors, cathode protection, antifouling paints, etc., but these technologies have the problems of time consumption, high cost, environmental pollution, large bulk toxicity, etc., and thus, there is a need for developing new marine anticorrosion and antiscaling materials and new technologies with low cost, short production cycle, environmental protection, and long duration. The bionic super-wetting surface inspired by nature has the characteristics of hydrophobicity, oleophobicity, scale prevention, self cleaning and corrosion prevention, and provides a new means and idea for the marine corrosion and pollution prevention technology.

Increasing the roughness and reducing the surface of the substrate according to the theory of the preparation of surfaces with special wettabilitySurface energy is two requirements. Currently, there are many methods for improving surface roughness, such as chemical etching, laser etching, sol-gel, vapor phase chemical deposition, electrochemical deposition, etc.; the method for reducing the surface energy of the substrate is inorganic (ZnO, CuO or TiO with a micro-nano structure)₂、SiO₂Etc.) and organic (containing-CH)₂-、-CH₃、-CF₂-、-CF₂H、-CF₃Iso-hydrophobic groups). For organic modifiers, alkanes, silicones, fluorinated carbon compounds are all common raw materials for preparing superhydrophobic surfaces; wherein, the fluorine-containing polymer (such as polytetrafluoroethylene PTFE) has extremely low intermolecular force of fluorine-carbon chains, extremely low surface energy, low friction and high temperature corrosion resistance, so that the fluorine-containing polymer can be widely applied to the field of hydrophobic non-stick.

According to the existing research, the intrinsic hydrophobic contact angle of the fluorine-containing polymer is 90-110 degrees, but the requirement of the surface of super-hydrophobicity (the static contact angle is more than 150 degrees) is not met, so that the super-hydrophobic effect is realized by combining other technical means. Chinese patent (No. CN104072792B, No. 7/4 in 2017) discloses a preparation method of a super-hydrophobic polytetrafluoroethylene film; firstly, uniformly stirring 15-40 parts of PTFE emulsion, 40-54 parts of ultrapure water, 8-25 parts of zinc acetate and 1-20 parts of sodium chloride or potassium chloride; preparing a membrane on a substrate by adopting a dip coating method, drying, calcining at the temperature of 380 ℃ for 20-40 minutes after the membrane is dried, and soaking for 30 minutes by using 1mol/L acetic acid solution to obtain the super-hydrophobic polytetrafluoroethylene membrane, wherein the contact angle is 150.5-155.6 degrees, and the rolling angle is less than 30 degrees; adding zinc acetate and chloride salt into PTFE emulsion, obtaining polytetrafluoroethylene with a micro-and nano-structure by utilizing a phase separation principle and a dip coating film making mode, carrying out corrosion treatment on the polytetrafluoroethylene with acetic acid after calcination treatment, and taking down a cross-linked and cured polytetrafluoroethylene film from a substrate to obtain a porous polytetrafluoroethylene film with a micro-nano structure; the technical method is simple, easy for large-scale production, good in surface wear resistance, capable of being repaired and reused, and the reaction principle of the method is mainly that zinc acetate generates zinc oxide at the decomposition temperature to prepare the roughness required by the super-hydrophobic film. Chinese patent (No. CN103992701B, granted on 2016, 9, 7) discloses a preparation method of a super-hydrophobic polymer composite coating containing nano-particles; firstly, mixing a coupling agent, a hydrolysis promoter and deionized water, carrying out normal-temperature hydrolysis, adding nanoparticles, reacting for 0.25-5 h at 50-100 ℃ under magnetic stirring, and carrying out post-treatment to obtain modified nanoparticle powder (aluminum oxide and silicon dioxide); sieving the modified nano particle powder, mixing with fluoropolymer emulsion (polytetrafluoroethylene and fluorinated ethylene propylene), diluting with diluent, stirring, coating on a metal substrate, curing at high temperature, annealing, and cooling to room temperature; the invention emphasizes and provides a simple method for preparing a super-hydrophobic polymer composite coating containing nano particles, the nano particles are modified by a coupling agent, the pH adjusting process in the nano particle hydrophobic treatment process is omitted, the modified nano particles are added into a polymer composite film coating, and the purpose of stabilization is achieved through the interaction of the bonding of the nano particles and the coupling agent and the long chain of the fluorine-containing polymer molecule. Chinese patent (application publication No. CN102776548A, application publication date 2012, 11 month 14) discloses a composite electroplating method for preparing a super-hydrophobic film layer on a steel surface; firstly, grinding, polishing and activating steel, then carrying out composite electroplating treatment on the steel in a composite plating solution (comprising a nickel-phosphorus plating solution and nano polytetrafluoroethylene particles), forming a layer of micro-nano structure on the surface of the steel, and finally transferring the steel into a vacuum furnace for heat treatment; the invention emphasizes that the method is suitable for surface treatment of various steel materials and has wide application range. Chinese patent (application publication No. CN103964701A, application publication date 2014 8/6) discloses a method of preparing a super-hydrophobic coating by hydrolyzing a silane coupling agent in an alcohol-water solvent under appropriate temperature and pH conditions, reacting with silica sol to generate silica particles grafted with organic groups, mixing with a certain volume of PTFE emulsion and an auxiliary agent to prepare sol-gel, and using a dip-coating method; although the patent technologies can prepare the PTFE-containing super-hydrophobic surface, the technical methods have the defects of high cost, more environmental pollutants, more process steps, complex control conditions of all processes, need of support of specific instruments and equipment, poor coating uniformity and substrate binding property and the like, and are not suitable for large-scale industrial application. In addition, the surface coatings prepared by these techniques have super-hydrophobicity and the super-amphiphobic problem is not mentioned.

The process for preparing the super-hydrophobic surface is different from the technical method, and the super-amphiphobic surface with good super-hydrophobicity, super-oleophobic property, thermal stability and corrosion resistance is simply, quickly and efficiently prepared on aluminum and other substrates through a two-step method of emulsion chemical replacement and thermal oxidation film formation. The preparation method and the technical process are simple, the cost is low, and the prepared copper oxide (CuO)/Polytetrafluoroethylene (PTFE) composite structure is stable; in addition, the method can be applied to the surfaces of aluminum materials, magnesium, zinc, iron and other metal materials, and is suitable for industrial production.

Disclosure of Invention

The invention aims to develop a method for simply and quickly preparing a functional super-amphiphobic coating with good super-hydrophobicity, super-oleophobic, thermal stability, corrosion resistance and other characteristics.

In order to achieve the purpose, the method for quickly preparing the dendritic micro-nano structure copper oxide/polytetrafluoroethylene composite super-amphiphobic coating sequentially comprises the following steps:

(1) pretreatment of the surface of a substrate

Any one of metal materials such as aluminum, magnesium, zinc, iron and alloys thereof is used as a base material, the base material is cut into required sizes according to use or design requirements, sand paper is used for polishing off dust and rust impurities on the surface of the base material, the polished sample is sequentially placed into acetone, absolute ethyl alcohol and deionized water for ultrasonic cleaning for 5-15min, impurities and pollutants such as dust, rust, oil stain and the like on the surface of the base material are further removed, and then the base material is placed into a constant-temperature blast drying box and dried at 30-100 ℃ for later use; if the impurities and pollutants are not easy to polish, alkali washing in alkaline water washing solution of 3-10% sodium hydroxide for 30s-2min or acid washing in acid washing solution of 20-30% nitric acid for 30s-2min can be used; then sequentially putting into acetone and absolute ethyl alcohol for ultrasonic cleaning for 5-15 min;

(2) preparing chemical displacement membrane-making emulsion by adopting mixed solution method

Taking the following components in parts by mass: 5-40 parts of soluble inorganic salt containing copper ions such as copper sulfate pentahydrate, copper nitrate or copper chloride, 1-3 parts of sodium chloride or potassium chloride and 40-200 parts of deionized water or pure water, and uniformly stirring to prepare a film-making emulsion component A;

taking the following components in parts by mass: 10-50 parts of water-soluble PTFE emulsion as a film-making emulsion component B;

mixing the film-making emulsion component A and the component B, and uniformly stirring to form stable emulsion;

(3) chemical displacement reaction deposition Cu/PTFE composite coating

Dipping the substrate pretreated in the step (1) into the chemical displacement membrane-making emulsion prepared in the step (2), wherein the dipping time is 30s-8min, generating a reddish Cu/PTFE composite coating on the surface of the substrate material, and taking out the substrate for later use; bubbles are generated in the reaction process, when the mass parts of all the components of the chemical displacement membrane preparation emulsion are small, the dipping time is close to the upper limit of a time window for 8min, and when the mass parts of all the components of the chemical displacement membrane preparation emulsion are large, the dipping time is close to the lower limit of the time window for 30 s;

(4) thermal oxidation film formation treatment

And (3) putting the substrate sample covered with the Cu/PTFE composite coating on the surface in the step (3) into a heating furnace such as a muffle furnace or a tube furnace for thermal oxidation treatment, wherein the gas atmosphere is air or oxygen, the heating rate is properly controlled, the red Cu/PTFE composite coating on the surface of the substrate is directly oxidized into the black CuO/PTFE composite coating, the thermal treatment temperature is 150-380 ℃, the heat preservation time is 1-5 h, and after the thermal oxidation treatment is finished, the substrate sample can be directly taken out for air cooling to room temperature or cooled to room temperature along with the furnace, so that the dendritic micro-nano structure CuO/PTFE composite super-amphiphobic coating with super-hydrophobicity, super-lipophobicity, thermal stability and corrosion resistance can be prepared.

The forming principle of the super-amphiphobic coating is as follows: firstly, carrying out a simple physical or chemical cleaning process on the surface of a base material to obtain a base surface with certain roughness, high cleanliness and multiple active centers on the surface of the base material, so as to improve the bonding property of a deposited coating and the base in the subsequent steps and reduce the influence of impurities and pollutants on the coating; in the prepared chemical displacement membrane preparation emulsion, the reaction mainly takes place that copper ions in a matrix material displacement solution are copper simple substances and are adsorbed on the surface of a matrix material to form a deposited reddish Cu/PTFE composite coating; in the direct thermal oxidation process, reddish copper deposited in the Cu/PTFE composite coating on the surface of the matrix is oxidized into blackish copper oxide under a certain temperature condition, polytetrafluoroethylene which forms a composite structure with the copper oxide is also cured under a heated condition, and finally a CuO/PTFE composite super-amphiphobic coating is generated on the surface of the matrix.

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

(1) the method adopts common chemical reagents and materials, quickly prepares the stable and reliable super-amphiphobic surface in a simple and low-cost two-step preparation mode, omits the independent operation of low surface energy modification in the conventional preparation of the super-hydrophobic surface, and has more direct whole process and higher controllability;

(2) the preparation principle of the invention is simple and direct, the matrix material generates displacement reaction in the chemical displacement membrane-making emulsion, and no pollution and toxic substances are generated, thereby avoiding the harm to human body and environment;

(3) the microstructure of the invention is mainly a CuO/PTFE composite dendritic micro-nano structure generated by thermal oxidation, the structure is stable, and the super hydrophobicity, super oleophobicity and thermal stability of the coating are ensured;

(4) the processing process adopted by the invention has no special requirements on the shape and the size of the sample, increases the popularization and application of the invention, and can be popularized to the surfaces of other metal materials such as magnesium, zinc, iron and the like.

Drawings

FIG. 1 is an SEM image of a CuO/PTFE composite super-amphiphobic coating;

FIG. 2 is an XRD pattern of a CuO/PTFE composite super-amphiphobic coating;

FIG. 3 is a contact angle of a CuO/PTFE composite super-amphiphobic coating to deionized water;

FIG. 4 is a contact angle of a CuO/PTFE composite super-amphiphobic coating to ethylene glycol;

FIG. 5 is a graph showing the relationship between the heat-insulating time of the CuO/PTFE composite super-amphiphobic coating and the contact angles of water and glycol in the heat-insulating process at 260 ℃;

FIG. 6 is a graph of the relationship between the soaking time of the CuO/PTFE composite super-amphiphobic coating in a sodium chloride solution with the mass fraction of 3.5% and the contact angles of water and glycol.

Detailed Description

The invention is described in detail below with reference to the attached drawing figures:

the invention aims to develop a method for simply and quickly preparing a copper oxide/polytetrafluoroethylene composite super-amphiphobic coating with a dendritic micro-nano structure, and the method improves the service life and functional application of a matrix material by virtue of good super-hydrophobicity, super-oleophobic property, thermal stability and corrosion resistance of the surface of the copper oxide/polytetrafluoroethylene composite super-amphiphobic coating.

In order to achieve the purpose, the invention takes pure aluminum and 6061 aluminum alloy as research objects, and prepares the copper oxide/polytetrafluoroethylene composite super-amphiphobic coating on the surface of the matrix.