WO2018131709A1

WO2018131709A1 - Base member having increased surface hydrophobicity or hydrophilicity

Info

Publication number: WO2018131709A1
Application number: PCT/JP2018/000972
Authority: WO
Inventors: 宮原　鐘一; 伸也田光; 昌宏仲山
Original assignee: 仲山貴金属鍍金株式会社
Priority date: 2017-01-16
Filing date: 2018-01-16
Publication date: 2018-07-19
Also published as: TW201841741A; JPWO2018131709A1; JP2020023052A

Abstract

[Problem] To provide an industrially easily practicable surface modification method for a base member by which a surface of the base member can be modified to exhibit a wide range of hydrophobicity or hydrophilicity including ultra hydrophobicity and ultra hydrophilicity. [Solution] A surface modification method for a base member comprises performing: a step of subjecting a surface of a base member to a chemical surface roughening treatment or a physical surface roughening treatment, such as a surface roughening treatment using a plating treatment, to convert the base member into a base member having a continuous fine irregular face on a surface thereof; and a step of forming a self-assembled monolayer on the surface of the base member having the continuous fine irregular face.

Description

Substrate with improved surface hydrophobicity or hydrophilicity

The present invention relates to a substrate having a surface modified so as to increase the hydrophobicity or hydrophilicity of the surface and a method for producing the same. More specifically, the present invention relates to a surface of a substrate formed of a solid material such as a metal material, a ceramic material, or a synthetic resin material from a super-water-repellent to a super-hydrophilic property using a method that can be easily carried out industrially. The present invention relates to a surface modification method that can be modified so as to exhibit desired water repellency or hydrophilicity, and a substrate whose surface properties are modified by the method.

In recent years, an integrated chemical and biochemical analysis system called μ-TAS (Total Analysis System) has been developed to analyze trace body fluids (eg, blood), various trace components, and conduct chemical reactions between trace components. It has come to be used. This μ-TAS forms a micro flow channel (micro channel) on the surface of a small-sized substrate (chip) such as glass, and uses the micro flow channel as a reaction container to biochemically analyze a small amount of sample. It is an instrument developed mainly for carrying out reactions and chemical reactions. When supplying a sample liquid such as a small amount of body fluid to the above minute flow path, it is desirable that the surface of the flow path (especially the bottom surface of the flow path) has high hydrophilicity, and leakage of the sample liquid from the flow path. In order to prevent this, it is desirable that the wall portion (bank portion) around the channel has high water repellency. Therefore, in order to produce a highly practical μ-TAS, it is necessary to apply a treatment for locally modifying the surface characteristics of various substrates made of solid materials to be water-repellent or hydrophilic. .

Various methods are known for modifying the surface properties of a substrate made of a solid material. As a typical method, a self-assembled monolayer (commonly known as SAM) is formed on the surface of the substrate. There is a method of forming. For example, Patent Document 1 discloses a surface property modification method capable of modifying the surface properties of a metal substrate so as to exhibit high water repellency.

In Patent Document 1, a substrate-adsorbing compound having an adsorptive group exhibiting adsorptivity to a solid surface and a chain hydrophobic group, a functional group, and a chain hydrophobic group are substantially adsorbed on the solid surface. A self-assembled unit consisting of an adsorbing compound and a non-adsorbing compound on the surface of a solid such as a metal substrate and having a functional group exposed on the surface. A method for modifying a solid surface by forming a layer film (SAM) is described. In the example of this patent document 1, the water contact angle ranges from 88 ° to 132 ° by applying the above modification to the surface of a glass plate having a gold surface with a water contact angle of 25 °. There is a description that a modified surface can be obtained.

On the other hand, Patent Document 2 discloses a surface property modification method capable of modifying a surface property of a substrate in a wide range so as to exhibit desired physical properties from superhydrophobic to superhydrophilic.

Patent Document 2 discloses a metal composite substrate having a shape of a removal trace-like hole of a supramolecular organization having a fractal surface structure, and a surface of which is flake-like, and a self-assembled monolayer provided on the surface. A functional metal composite substrate comprising a functional thin film that is either (SAM) or a polymer thin film is disclosed. As a method of manufacturing the above-mentioned metal composite substrate, a fullerene structure (supermolecular structure) produced using a fullerene derivative having a specific chemical structure is used as a template, and this structure is transferred to a metal material. Thus, a method of forming a substrate having a shape of a removal trace-like hole of a supramolecular organization is disclosed.

Patent Document 2 has a description that the metal composite substrate produced by the method disclosed therein exhibits controlled wettability from super / high hydrophilicity to super / high water repellency, As an example, an example is disclosed in which a metal composite substrate is produced by using the method described in this document and the contact angle with water is measured. Specifically, it can be seen that a substrate having surface characteristics exhibiting super-water-repellency of about 157 ° can be obtained from super-hydrophilicity having a contact angle with water of about 11 °. In [0051] of this document, when the contact angle with water is used as an index, water repellency is defined as 90 ° or more, high water repellency when 110 ° or more but less than 150 °, and super water repellency when 150 ° or more. is doing. However, there is no detailed description on the super / high hydrophilicity.

JP 2007-270278 A JP 2010-99817 A

As described above, in Patent Document 2, by utilizing the method disclosed therein, a substrate having a controlled wettability from the super / high hydrophilicity to the super / high water repellency can be produced on the surface. There is a description to the effect, and examples thereof are also described. However, as described above, the method described in Patent Document 2 uses a fullerene structure (supermolecular structure) in which fullerene derivatives are organized as a template to transfer the structure of the supermolecular structure to a metal material. The porous metal substrate is produced by a method of obtaining a removal trace-like pore shape of a supramolecular structure having a fractal surface structure, and the surface is a flaky metal. It is a composite substrate. Therefore, this metal composite substrate manufacturing method is an industrially easy method for expressing wettability controlled from super / high hydrophilicity to super / high water repellency on the surface of the substrate itself made of various materials. I can't say that.

Therefore, the main object of the present invention is to industrially develop the wettability controlled as desired from the super / high hydrophilicity to the super / high water repellency on the surfaces of various prefabricated substrates. It is to provide an easily available method.

The inventor of the present invention has continued research to develop an industrially easy-to-use method for developing controlled wettability from the super / high hydrophilicity to the super / high water repellency on the substrate surface. . As a result of the research, first, a continuous fine uneven surface (rough surface) is formed on the substrate surface by performing precious metal plating treatment under conditions different from the plating treatment conditions for forming a normal smooth plating layer on the substrate surface. And a method of forming a self-assembled monolayer (Self-Assembled Monolayer, SAM) on the surface of the noble metal plating layer thus formed with continuous and fine irregularities. The present inventors have found that the hydrophobicity or hydrophilicity of the substrate surface can be remarkably increased.

The inventor then formed a base metal plating layer having a continuous fine uneven surface on the substrate surface instead of the noble metal plating layer having the continuous fine uneven surface, and then It has also been found that a thin noble metal plating layer having a continuous fine irregular surface on the surface of the substrate can also be produced by utilizing the method for forming a noble metal plating layer thereon. That is, also by this method, when a self-assembled monolayer is laminated on the surface of a thin noble metal plating layer having continuous fine irregularities generated on the surface of the substrate, similarly, the hydrophobicity or hydrophilicity of the substrate surface is increased. It has been found that it can be significantly increased.

The inventor further forms a base metal plating layer having a continuous fine uneven surface on the substrate surface instead of the noble metal plated layer having a continuous fine uneven surface, and self-organizes on the base metal plated layer. It has also been found that the hydrophobicity or hydrophilicity of the substrate surface can be remarkably enhanced by a method of directly forming a monomolecular film.

The present inventor continued further research, and as a result, a precious metal or base metal plating layer having a continuous fine uneven surface was formed on the surface of the substrate, and self-organized on the uneven surface of the surface of the plated layer. Not only by the method of forming a monomolecular film, but by using various general chemical roughening treatments (eg, chemical etching) or physical roughening treatments (eg, laser irradiation treatment, plasma treatment) Even after forming a continuous fine uneven surface on the substrate surface, a method of generating a self-assembled monolayer on the fine uneven surface of the substrate can significantly increase the hydrophobicity or hydrophilicity of the substrate surface. I also found what I can do.

That is, the structure of the supramolecular structure is transferred to a metal material by using the fullerene structure (supermolecular structure) in which fullerene derivatives are organized as described in Patent Document 2 as a template. A porous substrate manufactured by the above method, which has a shape of a removal trace-like hole of a supramolecular structure having a fractal surface structure, and even if the surface is not a flaky metal composite substrate, it is industrially implemented. Even if a substrate surface having continuous fine irregularities formed by roughening plating treatment that is easy to use is used, or is formed by using normal chemical roughening treatment or physical roughening treatment By using a substrate surface having a typical fine uneven surface, a SAM can be generated on the continuous fine uneven surface, and the substrate can be formed in a desired manner from super / high hydrophilicity to super / high water repellency. Surface characteristics It has been found that can be converted to a substrate having.

Therefore, according to the present invention, by subjecting the surface of the substrate to chemical roughening or physical roughening, the substrate is converted into a substrate having a continuous fine uneven surface on the surface, and There is provided a substrate with a modified surface, which is obtained by subjecting a surface of the substrate having a continuous fine uneven surface to a treatment for generating a self-assembled monolayer. As a precaution, the supramolecule formed by organizing fullerene derivatives as described in Patent Document 2 is used in the chemical roughening treatment or physical roughening treatment in the present invention. It does not include a process for producing a substrate having the shape of a removal trace-like pore of a supramolecular structure having a porous and fractal surface structure obtained by transferring the structure as a template.

Further, according to the present invention, the surface of the substrate is subjected to a chemical surface roughening treatment or a physical surface roughening treatment to convert the substrate into a substrate having a continuous fine uneven surface on the surface. There is also provided a method for increasing the hydrophobicity or hydrophilicity of a substrate surface, comprising a step and a step of subjecting the surface of the substrate to a surface having a continuous fine irregular surface to form a self-assembled monolayer. As a precaution, the fullerene derivative as described in Patent Document 2 is also formed in the chemical roughening treatment or the physical roughening treatment in the above method of the present invention. This method does not include a process for producing a substrate having a shape of removal trace-like pores of a supramolecular structure having a porous and fractal surface structure obtained by transferring the supramolecular structure as a template.

In accordance with the present invention, by forming a self-assembled monolayer on the surface of the substrate on which a continuous fine uneven surface is formed on the surface by a normal chemical roughening treatment or physical roughening treatment, The reason why the surface of the substrate is remarkably improved in hydrophobicity or hydrophilicity as compared with the case where the self-assembled monolayer is simply laminated on the surface is not clear at present, but the present inventor The substrate surface is roughened, and continuous fine irregularities are formed on the surface. As a result, a hydrophobic group or a hydrophilic group is formed at or near one end of the self-assembled monolayer. It is estimated that this is because the amount of the substrate-adhering molecules provided on the surface of the substrate (that is, the number of molecules actually adhering to the substrate) significantly increased.

In addition, as the surface area increases, the amount of the constituent molecules of the self-assembled monolayer adhering to the substrate surface increases, and the self-assembled monolayer is not hindered by the fine uneven structure of the continuous fine uneven surface. The constituent molecules of the molecular film (SAM) can be densely attached to the fine concavo-convex surface with high orientation, and the hydrophobic group or functional group provided at the other end is aligned and exposed to the outside. It is estimated that this is because the SAM film (several μm thick) is formed, and as a result, the effects shown in Young's formula or Wenzel's formula appear.

In the present specification, according to the definition described in Patent Document 2, the contact angle with water is used as an index, the water repellency is 90 ° or more, the water repellency is 110 ° or more and less than 150 °, and the water repellency is high. The super water-repellent property is 150 ° or more. Similarly, when the contact angle with water is used as an index, the case of less than 90 ° is defined as hydrophilic, the case of less than 70 °, 30 ° or more is defined as highly hydrophilic, and the case of less than 30 ° is defined as superhydrophilic. To do.

The preferred embodiments of the substrate having improved hydrophobicity or hydrophilicity on the surface of the present invention and the production method thereof will be described below.
(1) Chemical roughening treatment or physical roughening treatment is performed by plating treatment (chemical plating treatment), chemical etching (substrate surface is subjected to chemical corrosion agent, electrolytic polishing or high temperature heating in vacuum, etc.) The treatment selected from the group consisting of anodizing treatment, anodizing treatment, and laser irradiation, or a combination thereof.
(2) Chemical roughening treatment or physical roughening treatment is performed by laminating a base metal plating layer having continuous fine unevenness by base metal plating treatment on the substrate surface, and a base metal having continuous fine unevenness. This is a treatment performed in combination with a lamination treatment of a noble metal plating layer on the surface of the plating layer.
(3) The chemical roughening treatment or the physical roughening treatment is a noble metal plating treatment represented by at least a gold plating treatment.
(4) The chemical roughening treatment or the physical roughening treatment is at least a noble metal plating treatment represented by a gold plating treatment, and the thickness of the noble metal plating layer to be generated is in the range of 0.05 to 10 μm. Preferably, it is in the range of 0.1-6 μm, particularly preferably in the range of 0.5-5 μm.
(5) The substrate is a metal substrate such as an aluminum plate, a stainless steel plate, a copper plate, or a titanium metal plate.
(6) The substrate is a ceramic substrate such as a glass plate or a silica plate. (7) The substrate is a plastic substrate.
(8) The base is a metal base, a ceramic base, or a plastic base provided with a noble metal layer or subjected to base metal plating or noble metal plating.
(9) The average value of the full width at half maximum and height of the convex portions constituting the continuous fine uneven surface is in the range of 0.005 to 100 μm, preferably 0.01 to 10 μm, particularly preferably 0.05 to 5 μm. It is in the range.
(10) The convex part which comprises a continuous fine uneven surface has a substantially cone shape.
(11) The substrate is a plate-shaped substrate, a rod-shaped substrate, or a tubular substrate.
(12) The self-assembled monolayer has a thiol group at one end and a hydrophilic group at the other end, a disulfide compound having a carboxyl group at both ends, a carboxyl group at one end, Selected from the group consisting of a compound having a bromine atom at the other end and a thiol compound, alkanethiol compound produced by the reaction of thiourea, and a compound having a carboxyl group at one end and a hydrophobic group at the other end It is made up of compounds.
(13) The self-assembled monolayer has a thiol group at one end, a hydrophilic group at the other end, a disulfide compound having a carboxyl group at both ends, a carboxyl group at one end, It is composed of a sulfur atom-containing compound selected from the group consisting of thiol compounds produced by the reaction of a compound having a bromine atom at the other end with thiourea, and has a hydrophilic surface with an enhanced surface of the self-assembled monolayer Indicates.
(14) The self-assembled monolayer is composed of an alkanethiol compound or a compound having a carboxyl group at one end and a hydrophobic group at the other end, and the surface of the self-assembled monolayer is increased. The hydrophobicity is shown.

By using the method of the present invention, “a fullerene structure in which fullerene derivatives are organized (supermolecular tissue) is used as a template, and the structure of the supramolecular tissue is transferred. Porous substrate with a fractal surface structure and the shape of traces of supramolecular structures, and without using a flaky metal composite substrate. A self-assembled monolayer (SAM) is formed on the surface using a method of forming continuous fine irregularities by chemical or physical roughening, including plating that is easy to implement As a result, the hydrophobicity or hydrophilicity of the substrate is increased, and as a result, it is possible to produce a substrate having desired surface characteristics from super / high hydrophilicity to super / high water repellency.

The surface of the gold foil with a smooth surface is used as a base, and the surface of the base is subjected to a plating treatment using a gold plating solution containing potassium gold cyanide at a concentration of 10 g / L in terms of gold and a current density of 2 A / dm ^2. 4 is an electron micrograph (× 3000) of the surface of a substrate on which a gold plating layer having continuous fine irregularities is generated, and then a self-assembled monolayer is formed on the irregular surface. It is a figure which shows the result of having observed the contact angle of the water droplet with the microscope, after dripping 5 microliters of pure waters on the surface of the base | substrate of FIG. The surface of the gold foil with a smooth surface is used as a base, and the surface of the base is plated with a gold plating solution containing potassium gold cyanide at a concentration of 5 g / L in terms of gold and the current density is 100 mA / dm ^2. 4 is an electron micrograph (× 3000) of the surface of a substrate on which a gold plating layer having continuous fine irregularities is generated, and then a self-assembled monolayer is formed on the irregular surface. It is a figure which shows the result of having observed the contact angle of the water droplet with the microscope, after dripping 5 microliters of pure waters on the surface of the base | substrate of FIG. The surface of the gold foil with a smooth surface is used as a base, and the surface of the base is plated with a gold plating solution containing potassium gold cyanide at a concentration of 2 g / L in terms of gold and the current density is 3 A / dm ^2. 4 is an electron micrograph (× 3000) of the surface of a substrate on which a gold plating layer having continuous fine irregularities is generated, and then a self-assembled monolayer is formed on the irregular surface. It is a figure which shows the result of having observed the contact angle of the water droplet with the microscope, after dripping 5 microliters of pure waters on the surface of the base | substrate of FIG. The surface of the platinum foil having a smooth surface is used as a base, and the surface of the base is subjected to a plating treatment using a platinum plating solution containing dinitrodiamine platinum at a concentration of 10 g / L in terms of platinum and a current density of 3 A / dm ^2. 4 is an electron micrograph (× 3000) of the surface of a substrate in which a platinum plating layer having continuous fine irregularities is generated, and then a self-assembled monolayer is formed on the irregular surface. It is a figure which shows the result of having observed the contact angle of the water droplet with the microscope, after dripping 5 microliters of pure waters on the surface of the base | substrate of FIG. It is an electron micrograph of the fine uneven surface of the plating layer which consists of the lamination nickel plating layer and thin gold plating layer which were generated on the base in Example 8. It is a laser microscope photograph (3D photograph) of the surface of a stearic acid self-assembled monolayer on the surface of an etched copper plate (etched for 45 seconds) produced in Example 9. It is a laser microscope photograph (3D photograph) of the surface of a stearic acid self-assembled monolayer on the surface of an etched copper plate (etched for 75 seconds) produced in Example 10. It is a laser microscope photograph (3D photograph) of the surface of a stearic acid self-assembled monolayer on the surface of an etched titanium plate (etched for 10 minutes) produced in Example 11.

Next, various materials and processing methods for carrying out the present invention will be described in detail.

The substrate used in the present invention is made of a material that shows a solid at a normal temperature, and is generally a precious metal such as gold or platinum, a metal such as iron, copper, nickel, titanium (titanium metal), a base metal such as brass, or glass. The substrate is made of ceramic such as silica, but depending on the purpose, a substrate made of plastic or various composite materials can be used. These substrates may be pretreated (including the formation of a film) using a plating treatment or the like in advance if desired. Since specific examples of the substrate are described in Patent Document 1 and Patent Document 2, the description of these Patent Documents is described in this specification.

The substrate may be a plate-shaped substrate, a rod-shaped substrate, or a tubular substrate. The plate-like substrate may have a flat surface, or may have an entire or partial curved surface. In addition, various structures may be formed on the surface of the substrate like a chemical / biochemical analysis integrated system called μ-TAS (Total Analysis System).

In the present invention, there is no particular limitation on the means for forming a continuous fine uneven surface on the surface of the substrate, and a chemical roughening treatment (including chemical plating treatment) or a physical rough surface that can be easily adopted as a normal industrial treatment. Is used.

The chemical roughening treatment or physical roughening treatment that can be used in the present invention includes the above-described plating treatment (especially chemical plating treatment) and chemical etching treatment (especially using chemicals to roughen the substrate surface). Treatment), anodization treatment, laser irradiation treatment, and the like, but are not limited thereto. The plating treatment is usually a treatment for forming a plating layer having a smooth surface, but the plating conditions (chemical composition of the plating solution, chemical component concentration in the plating solution, current density, plating treatment time, etc.) are adjusted. Those skilled in the art know that a plating layer having a non-smooth surface is formed. Further, various chemical roughening treatments or physical roughening treatments may be used in combination.

In addition, after a base metal plating layer (eg, nickel plating layer) having continuous fine irregularities on the surface of a base such as a metal base is generated in advance, a thin noble metal plating layer is then formed on the surface of the base metal plating layer. A method of forming a noble metal plating layer in which continuous minute irregularities are finally formed on the surface can be advantageously used. When this method is used, the amount of expensive noble metal used can be suppressed, so that the method of the present invention is a very advantageous method for industrial implementation.

When the roughening treatment is a noble metal plating treatment typified by a gold plating treatment, the thickness of the produced noble metal plating layer is preferably in the range of 0.05-10 μm, more preferably 0.1 It is in the range of −6 μm, particularly preferably in the range of 0.5-5 μm.
Further, the average value of the full width at half maximum and the height of the convex portions constituting the continuous fine irregular surface formed on the substrate surface is preferably in the range of 0.005 to 100 μm, more preferably It is in the range of 0.01-10 μm, particularly preferably in the range of 0.05-5 μm.

A chain molecule having a hydrophobic group or hydrophilic group at one end or in the vicinity thereof and a polar group having a strong affinity for the substrate surface in the other end or in the vicinity or in the molecule is mainly used as a liquid phase. The method of forming a self-assembled monolayer (SAM) on the surface of a substrate by reacting with a substrate has been known for some time as a technique for modifying the surface characteristics of the substrate. For example, the above-mentioned Patent Document 1 and Patent Document There is a detailed description in 2. Therefore, the contents described in Patent Document 1 and Patent Document 2 are described in this specification.

Examples of compounds (chain molecules) constituting the self-assembled monolayer formed on the roughened substrate of the present invention include the following compounds.

A compound having a thiol group at one end and a hydrophilic group at the other end;
Disulfide compounds having carboxyl groups at both ends;
A thiol compound formed by the reaction of a compound having a carboxyl group at one end and a bromine atom at the other end with thiourea;
An alkanethiol compound and a compound having a carboxyl group at one end and a hydrophobic group at the other end.

In order for the surface of the self-assembled monolayer provided on the roughened substrate to exhibit enhanced hydrophilicity, a self-assembled monolayer is provided with a thiol group at one end. It is formed by the reaction of a compound with a hydrophilic group at the other end, a disulfide compound with a carboxyl group at both ends, a compound having a carboxyl group at one end and a bromine atom at the other end, and thiourea It is desirable to comprise a sulfur atom-containing compound selected from the group consisting of thiol compounds.

In order for the surface of the self-assembled monolayer provided on the roughened substrate to exhibit an increased hydrophobicity, the self-assembled monolayer may be converted to an alkanethiol compound or a carboxyl at one end. It is desirable to comprise a compound having a group and a hydrophobic group at the other end.

[Example 1]
A gold foil having a smooth surface was used as a base, and the surface of the base was plated using the following gold plating solution to form a gold plating layer having continuous fine irregularities on the surface.
Gold plating solution composition (pH 6-8):
Potassium cyanide potassium 10g / L (as gold)
Potassium dihydrogen phosphate 60g / L
Potassium citrate 60g / L
Temperature: 60 ° C
Current density: 2 A / dm ²
Energizing time: 5 minutes

Next, the octadecanethiol 3 mM solution was used, and the substrate containing the above gold plating layer was immersed in this solution for 48 hours and then dried, so that the self-organized monomolecule of octadecanethiol was formed on the uneven surface of the gold plating layer of the substrate. A membrane was formed. FIG. 1 shows an electron micrograph (× 3000) of the obtained substrate surface. It is observed that continuous fine irregularities are formed on the surface.
FIG. 2 shows the result of observing the contact angle of water droplets with a microscope after 5 μL of pure water was dropped on the surface of the substrate shown in FIG. As can be seen from FIG. 2, the observed contact angle was 157 °.

[Example 2]
By performing the same plating treatment as in Example 1 except that the gold concentration of the gold plating solution composition was changed to 5 g / L and the current density was changed to 100 mA / dm ² , the gold plating layer (thickness) having unevenness on the surface : About 3 μm) was obtained, and then a self-assembled monolayer was formed on the surface of the substrate by the method described in Example 1. FIG. 3 shows an electron micrograph (× 3000) of the obtained substrate surface. It is observed that continuous fine irregularities (average value of half width and height of convex portion: about 1 μm) are formed on the surface.
The result of observing the contact angle of the substrate surface shown in FIG. 3 with water by the method described in Example 1 is shown in FIG. As can be seen from FIG. 4, the observed contact angle was 147 °.

[Example 3]
Except for changing the gold concentration of the gold plating solution to 2 g / L and changing the current density to 3 A / dm ² , the same plating treatment as in Example 1 was performed to generate a gold plating layer having irregularities on the surface. After obtaining the substrate, a self-assembled monolayer was formed on the surface of the substrate by the method described in Example 1. FIG. 5 shows an electron micrograph (× 3000) of the obtained substrate surface. It is observed that continuous fine irregularities are formed on the surface.
FIG. 6 shows the result of observing the contact angle of the surface of the substrate shown in FIG. 5 with water by the method described in Example 1. As can be seen from FIG. 6, the observed contact angle was 161 °.

[Example 4]
Using a platinum foil having a smooth surface as a base, the following platinum plating solution was applied to the surface of the base, and a platinum plating layer having irregularities was formed by plating.
Platinum plating solution composition (pH 9-10):
Dinitrodiamine platinum 10g / L (as platinum)
Ammonium nitrate 100g / L
Sodium nitrite 10g / L
Ammonium hydroxide 55g / L
Potassium citrate 60g / L
Temperature: 90 ° C
Current density: 3 A / dm ²
Energizing time: 5 minutes

Next, a 3 mM octadecanethiol solution was used, and the platinum plating layer-forming substrate was immersed in this solution for 48 hours and then dried to form a self-assembled monolayer on the uneven surface of the platinum plating layer of the substrate. . FIG. 7 shows an electron micrograph (× 3000) of the obtained substrate surface. It is observed that continuous fine irregularities are formed on the surface.
FIG. 8 shows the result of observing the contact angle of water droplets with a microscope after 5 μL of pure water was dropped on the surface of the substrate shown in FIG. As can be seen from FIG. 8, the observed contact angle was 137 °.

[Example 5]
An aluminum plate with a smooth surface is used as a base, and the surface of the base is subjected to anodization and alkali etching to form a continuous fine uneven surface, and the aluminum plate with the uneven surface formed is immersed in a stearic acid solution. By doing so, a self-assembled monolayer was formed. When the contact angle of the surface of the obtained self-assembled monolayer with respect to water was observed by the same method as in Example 1, a contact angle exceeding 150 ° was observed.

[Example 6]
Using a brass plate having a smooth surface and nickel plating having a thickness of 0.5 to 3 μm, an uneven surface was formed on the surface of the substrate by laser treatment. The substrate on which the irregular surface was formed was immersed in 3 mM 15-carboxy-1-pentadecanethiol (ethanol solution) for 16 hours to form a self-assembled monolayer. When pure water was dropped by the same method as in Example 1 on the surface of the obtained self-assembled monolayer, the water spread quickly. Therefore, the contact angle with water was determined to be less than 15 °.

[Example 7]
Using a brass plate having a smooth surface and nickel plating having a thickness of 0.5 to 3 μm, an uneven surface was formed on the surface of the substrate by laser treatment. The substrate on which the uneven surface was formed was immersed in 3 mM 2-aminoethanethiol (ethanol solution) for 16 hours to form a self-assembled monolayer. When pure water was dropped by the same method as in Example 1 on the surface of the obtained self-assembled monolayer, the water spread quickly. Therefore, the contact angle with water was determined to be less than 15 °.

[Example 8]
On the surface (contact angle: 90 ° or less) of a smooth stainless steel plate (SUS304 plate), a first nickel plating layer is first formed using a wood bath and a watt bath, and then a second layer using a chloride bath. By generating a nickel plating layer of the eye, a multilayer nickel plating layer having continuous fine irregularities on the surface is generated, and then a continuous layer of a thin layer is formed using a cyanide plating bath on the surface of the multilayer nickel plating layer. A gold plating layer (thickness: about 0.1 μm) having fine irregularities was generated. An electron micrograph of the surface of the gold plating layer of the obtained substrate is shown in FIG. It is observed that continuous fine irregularities (the height of the main convex portion: about 0.9 μm to about 1.6 μm) are generated on the surface.
Using the same processing as in Example 1, a self-assembled monomolecular film of octadecanethiol was formed on the surface of the gold plating layer on the substrate on which the laminated nickel plating layer and the thin gold plating layer were sequentially formed. It was.
After 5 μL of pure water was dropped on the surface of the self-assembled monolayer on the substrate by the same method as in Example 1, the contact angle of the water droplet was observed with a microscope. It was confirmed that the average value of the measurement of the first time).

[Example 9]
The surface of a copper plate with a smooth surface (contact angle: 90 ° or less) was etched at 50 ° C. for 45 seconds using an aqueous etchant solution (ammonium persulfate 100 g / L, 2-methylpyridine 5 g / L, methylsulfonic acid 20 g / L). Etching was performed to obtain a copper plate having a roughened surface. Next, a self-assembled monolayer of stearic acid was formed on the roughened surface of the copper plate. FIG. 10 shows a laser micrograph (3D photograph) of the surface of the self-assembled monolayer of the obtained copper plate.
After 5 μL of pure water was dropped on the surface of the self-assembled monolayer on the copper plate by the same method as in Example 1, the contact angle of the water droplet was observed with a microscope. As a result, the contact angle was 134 °. It was confirmed.

[Example 10]
A self-assembled monolayer of stearic acid was formed on the surface of the copper plate in the same manner as in Example 9 except that the etching time was changed to 75 seconds. A laser micrograph (3D photograph) of the surface of the self-assembled monolayer of the obtained copper plate is shown in FIG.
After 5 μL of pure water was dropped on the surface of the self-assembled monolayer on the copper plate by the same method as in Example 1, the contact angle of the water droplet was observed with a microscope. As a result, the contact angle was 148 °. It was confirmed.

[Example 11]
The surface of the titanium metal plate having a smooth surface (contact angle: 90 ° or less) is etched at 120 ° C. for 10 minutes using an aqueous etchant solution (hydrofluoric acid 10% by mass, nitric acid 30% by mass). A roughened titanium metal plate was obtained. Next, a self-assembled monolayer of stearic acid was formed on the roughened surface of the titanium metal plate. FIG. 11 shows a laser micrograph (3D photograph) of the surface of the self-assembled monomolecular film of the obtained titanium metal plate.
After dropping 5 μL of pure water onto the surface of the self-assembled monolayer on the titanium metal plate by the same method as in Example 1, the contact angle of the water droplet was observed with a microscope. It was confirmed that.

Claims

By subjecting the surface of the substrate to a chemical or physical surface roughening treatment, the substrate is converted into a substrate having a continuous fine uneven surface on the surface; A substrate with a modified surface, which is obtained by subjecting a surface having a fine uneven surface to a process for producing a self-assembled monolayer.
2. The substrate according to claim 1, wherein the chemical roughening treatment or the physical roughening treatment is a treatment selected from the group consisting of plating treatment, chemical etching, anodizing treatment, and laser irradiation, or a combination thereof.
The substrate according to claim 1, wherein the chemical roughening treatment or the physical roughening treatment comprises at least a gold plating treatment.
The chemical surface roughening treatment or the physical surface roughening treatment is carried out by laminating a base metal plating layer having continuous fine unevenness by base metal plating treatment on the surface of the substrate, and a base metal plating layer having continuous fine unevenness. The base | substrate of Claim 1 which is a process performed by the combination with the lamination | stacking process of the noble metal plating layer to the surface.
The substrate according to any one of claims 1 to 3, wherein the substrate is a metal substrate or a ceramic substrate.
6. The substrate according to any one of claims 1 to 5, wherein the average value of the half width and height of the convex portions constituting the irregular surface is in the range of 0.005 to 100 μm.
The substrate according to any one of claims 1 to 6, wherein the substrate is a plate-shaped substrate, a rod-shaped substrate, or a tubular substrate.
A self-assembled monolayer that has a thiol group at one end and a hydrophilic group at the other end, a disulfide compound that has a carboxyl group at both ends, a carboxyl group at one end, and the other end A compound selected from the group consisting of a thiol compound, an alkanethiol compound produced by the reaction of a compound having a bromine atom with thiourea, and a compound having a carboxyl group at one end and a hydrophobic group at the other end The substrate according to any one of claims 1 to 7, which is configured.
A self-assembled monolayer that has a thiol group at one end and a hydrophilic group at the other end, a disulfide compound that has a carboxyl group at both ends, a carboxyl group at one end, and the other end A compound comprising a sulfur atom-containing compound selected from the group consisting of thiol compounds formed by the reaction of a compound having a bromine atom with thiourea, and having an improved hydrophilic property on the surface of the self-assembled monolayer Item 8. The substrate according to any one of Items 1 to 7.
The self-assembled monolayer is composed of an alkanethiol compound or a compound having a carboxyl group at one end and a hydrophobic group at the other end, and the surface of the self-assembled monolayer is enhanced. The substrate according to any one of claims 1 to 7, which exhibits properties.
A step of subjecting the surface of the substrate to a chemical roughening treatment or a physical roughening treatment to convert the substrate into a substrate having a continuous fine uneven surface on the surface; A method for increasing the hydrophobicity or hydrophilicity of a substrate surface, comprising a step of performing a treatment for generating a self-assembled monolayer on a surface having a continuous fine uneven surface.
The method according to claim 11, wherein the chemical roughening treatment or the physical roughening treatment is a treatment selected from the group consisting of plating treatment, chemical etching, and laser irradiation or a combination thereof.