CN102304741B

CN102304741B - Anodic oxidation method for preparing aluminum-based super-hydrophobic film

Info

Publication number: CN102304741B
Application number: CN201110282445.XA
Authority: CN
Inventors: 吴若梅; 梁叔全; 喻亚
Original assignee: Hunan University of Technology
Current assignee: Hunan University of Technology
Priority date: 2011-09-22
Filing date: 2011-09-22
Publication date: 2014-05-07
Anticipated expiration: 2031-09-22
Also published as: CN102304741A

Abstract

The invention belongs to the field of preparation technology of super-hydrophobic surface and provides an anodic oxidation method for preparing an aluminum-based porous super-hydrophobic surface. The method comprises the following steps: performing mechanical polishing on an aluminum alloy board, removing surface defects and oxidation films, washing with ethanol and deionized water, and drying; preparing electrolyte consisting of 1.803 mol/L of sulfuric acid, 0.068 mol/L of potassium dichromate, 0.079 mol/L of oxalic acid, 2.57 mol/L of sodium chloride and 1.37 mol/L of glycerin; then electrifying by taking the aluminum board as an anode and graphite as a cathode for reaction, wherein the current density is controlled to 1.2 A/dm<2> and the reaction time is 30-40 min; washing the reacted aluminum board with distilled water, and drying or naturally airing; placing the aluminum board in 1 wt% stearic acid ethanol solution to soak for 20-30 min and then taking out the aluminum board; washing the aluminum board with a proper amount of alcohol; taking out the aluminum board and cleaning with clean water; and drying at the room temperature in the atmospheric environment for 24-28 hours under the relative humidity of 60-75% to prepare the porous aluminum alloy super-hydrophobic surface.

Description

Anodic oxidation method for preparing aluminum-based super-hydrophobic film

Technical field

The present invention relates to prepare the method for aluminium base super hydrophobic surface in atmosphere at room temperature environment.

Background technology

Aluminium alloy is a most widely used class non-ferrous metal structured material in industry, is widely used in Aeronautics and Astronautics, automobile, machinofacture, boats and ships and chemical industry.There is good electroconductibility, thermal conductivity, working plasticity, corrosion stability and higher intensity.But the metallic surface that conventional aluminium alloy surface treatment method obtains does not have self-cleaning property, easily contaminated, and also the long-term protective value in the caustic soln environment such as acid, alkali, salt is also short of.Therefore, the stronger more stable and long-term protective value of research better novel aluminium alloy means of defence or approach be the important topic in metallic substance protection field always.Super-hydrophobic coat has unique surface property, as self-cleaning, and didirtresistance, hydrophobicity etc., super hydrophobic surface, for metallic substance, can play automatically cleaning, suppresses surface corrosion and surface oxidation and reduce the effect of rubbing factor.Some researchs both domestic and external in the recent period show, some corrosive acid, alkali, salts solution have the contact angle about the same with pure water and roll angle in super-hydrophobic metallic surface, super-hydrophobic metallic surface a little tilts, the liquid such as corrosive acid, alkali, salt will tumble from super-hydrophobic metallic surface, this means that super hydrophobic surface can reduce the chance that corrosive liquid contacts with metallic substance effectively, contribute to improve the erosion resistance of metallic substance, this provides a new developing direction to undoubtedly the Protective Research of metallic substance.Superhydrophobic surface of aluminum alloy is really used in actual industrial and agricultural production and daily life, and its preparation technology is crucial, is also basis.In recent years, developed the technology that some prepare superhydrophobic surface of aluminum alloy, as chemical Vapor deposition process, electrochemical deposition method, polyelectrolyte alternating deposit method, hard anodizing method, plasma method, chemical method for etching etc.But, existing these methods otherwise use expensive material as surface can be extremely low fluorinated siloxane, or need special processing units as plasma processing equipment or complicated technological process, thereby cost is higher, is difficult to industrialization.It is high that the present invention has designed a kind of hardness, corrosion stability, and wear resistance, tint permanence is good; Treatment process is simple, easy to operate, and liquid waste disposal is easy; Less energy consumption, cost is lower; Oxidization time is short, and the preparation method that production efficiency is high easily undergoes technological transformation and reforms under existing installation and condition.

Summary of the invention

Technical problem to be solved by this invention is to provide the preparation method at aluminum alloy surface structure super-drainage structure that a kind of technique is simple and cost is low.

In order to solve the problems of the technologies described above, the preparation method who builds super-drainage structure in aluminum alloy surface provided by the invention, comprises the steps:

(1) homogeneous surface smooth aluminum alloy plate materials is carried out to mechanical polishing and polishing, remove surface imperfection and oxide film, use washed with de-ionized water 15 minutes, and dry;

(2) preparation electrolytic solution is the sulfuric acid of 1.803 mol/L, the potassium bichromate of 0.068 mol/L, oxalic acid, the sodium-chlor of 2.57 mol/L and the glycerine of 1.37 mol/L of 0.079 mol/L;

(3), then take aluminium plate as anode, graphite is that cathodal closing reacts.Controlling current density is 1.2 A/dm ², the reaction times is 30 min.Reacted aluminium plate is cleaned and dried with distilled water or naturally do;

(4) then aluminium flake being put into massfraction is that 1% stearic acid ethanolic soln soaks, and reduces its surface free energy, and the time is approximately 30 min, under room temperature (approximately 25 ℃), carries out;

(5) after the time of immersion 20-30 min, taking out, with appropriate straight alcohol cleaning, take out and with clear water, wash down, is 60 ~ 75% in relative humidity, under atmosphere at room temperature environment, is dried 24 hours.

The preparation method at aluminum alloy surface structure super-drainage structure who adopts technique scheme, electrolytic solution used is: sulfuric acid, heavy complex acid potassium, oxalic acid, sodium-chlor and drier oil.Surface-coated material used is: stearic acid, ethanol.Super-hydrophobic base material can be pure aluminum or aluminum alloy.The contact angle of super-hydrophobic aluminum alloy surface and water is between 150o～165o, and water droplet is less than 15o in the roll angle of material surface.The superhydrophobic property of super-hydrophobic aluminum alloy surface is stable, in temperature range, is to place half a year in 0～40 ℃, the relative humidity environment that is 30%～70%, and considerable change does not occur superhydrophobic property.

In sum, preparation method's operating procedure with super-hydrophobic aluminium alloy of the present invention is simple, favorable reproducibility, without any expensive device, do not need complicated chemical treating process yet, can in traditional technology, improve, there is good industrial applications prospect.

accompanying drawing explanation:

Fig. 1. the scanning electron microscope (SEM) photograph of the super-hydrophobic aluminum alloy surface that the embodiment of the present invention 1 obtains;

Fig. 2. the contact angle test pattern of the super-hydrophobic aluminum alloy surface that the embodiment of the present invention 1 obtains and water.

embodiment:

Embodiment 1:

First, aluminum alloy plate materials is carried out to mechanical polishing and polishing, remove surface imperfection and oxide film, clean respectively 15 minutes with ethanol and deionized water.Preparation electrolytic solution is the sulfuric acid of 1.803 mol/L, the potassium bichromate of 0.068 mol/L, oxalic acid, the sodium-chlor of 2.57 mol/L and the glycerine of 1.37 mol/L of 0.079 mol/L.Then take aluminium plate as anode, graphite is that cathodal closing reacts.Controlling current density is 1.2 A/dm ², the reaction times is 30 min.Reacted aluminium plate is cleaned and dried with distilled water or naturally do; In the stearic acid ethanolic soln that is 1% at massfraction, soaking 30 minutes, is 60 ~ 75% in relative humidity, under atmosphere at room temperature environment, is dried 24 hours, can prepare aluminium alloy porous super hydrophobic surface.The wettability of testing this coatingsurface with OCA20 contact angle tester, result shows that the contact angle of this surface and water is 158 ± 2o.

Embodiment 2:

First, aluminum alloy plate materials is carried out to mechanical polishing and polishing, remove surface imperfection and oxide film, clean respectively 15 minutes with ethanol and deionized water.Preparation electrolytic solution is the sulfuric acid of 1.37 mol/L, the potassium bichromate of 0.054 mol/L, oxalic acid, the sodium-chlor of 2.6mol/L and the glycerine of 1.37 mol/L of 0.079 mol/L.Then take aluminium plate as anode, graphite is that cathodal closing reacts.Controlling current density is 1.3 A/dm ², the reaction times is 35 min.Reacted aluminium plate is cleaned and dried with distilled water or naturally do; In the stearic acid ethanolic soln that is 1% at massfraction, soaking 30 minutes, is 60 ~ 75% in relative humidity, under atmosphere at room temperature environment, is dried 25 hours, can prepare aluminium alloy porous super hydrophobic surface.The wettability of testing this coatingsurface with OCA20 contact angle tester, result shows that the contact angle of this surface and water is 160 ± 2o.

Embodiment 3:

First, aluminum alloy plate materials is carried out to mechanical polishing and polishing, remove surface imperfection and oxide film, clean respectively 15 minutes with ethanol and deionized water.Preparation electrolytic solution is the sulfuric acid of 1.803 mol/L, the potassium bichromate of 0.06 mol/L, oxalic acid, the sodium-chlor of 2.57 mol/L and the glycerine of 1.37 mol/L of 0.079 mol/L.Then take aluminium plate as anode, graphite is that cathodal closing reacts.Control current density is 1.4A/dm ², the reaction times is 35 min.Reacted aluminium plate is cleaned and dried with distilled water or naturally do; In the stearic acid ethanolic soln that is 1% at massfraction, soaking 30 minutes, is 60 ~ 75% in relative humidity, under atmosphere at room temperature environment, is dried 26 hours, can prepare aluminium alloy porous super hydrophobic surface.The wettability of testing this coatingsurface with OCA20 contact angle tester, result shows that the contact angle of this surface and water is 156 ± 2o.

Embodiment 4

First, aluminum alloy plate materials is carried out to mechanical polishing and polishing, remove surface imperfection and oxide film, clean respectively 15 minutes with ethanol and deionized water.Preparation electrolytic solution is the sulfuric acid of 1.803 mol/L, the potassium bichromate of 0.054 mol/L, oxalic acid, the sodium-chlor of 2.5 mol/L and the glycerine of 1.37 mol/L of 0.079 mol/L.Then take aluminium plate as anode, graphite is that cathodal closing reacts.Controlling current density is 1.5 A/dm ², the reaction times is 40 min.Reacted aluminium plate is cleaned and dried with distilled water or naturally do; In the stearic acid ethanolic soln that is 1% at massfraction, soaking 30 minutes, is 60 ~ 75% in relative humidity, under atmosphere at room temperature environment, is dried 28 hours, can prepare aluminium alloy porous super hydrophobic surface.The wettability of testing this coatingsurface with OCA20 contact angle tester, result shows that the contact angle of this surface and water is 151 ± 2o.

Claims

1. a method that adopts anodic oxidation method for preparing aluminum-based super-hydrophobic film, is characterized in that, comprises the steps:

(2) preparation electrolytic solution is the sulfuric acid of 1.803 mol/L, the potassium bichromate of 0.068 mol/L, oxalic acid, the sodium-chlor of 2.57 mol/L and the glycerine of 1.37 mol/L of 0.079 mol/L; Then take aluminum alloy plate materials as anode, graphite is that cathodal closing reacts; Controlling current density is 1.2 A/dm ², the reaction times is 30 min;

(3) reacted aluminum alloy plate materials cleaned and dried with distilled water or naturally do; And then to put into massfraction be that 1% stearic acid ethanolic soln soaks, reduce its surface free energy, the time is 30 min; Under room temperature (25 ℃), carry out;

(4) after immersion 30 min, taking out, with appropriate straight alcohol cleaning, take out and with clear water, wash down, is 60 ~ 75% in relative humidity, under atmosphere at room temperature environment, is dried 24 hours;

The aluminum alloy sheet material surface of processing through aforesaid method is lead, and the contact angle of surface and water is between 150o ~ 166o, and water droplet is less than 10o in surperficial roll angle.