JPH02101193A - Formation of thin film - Google Patents

Abstract

PURPOSE:To form a thin film of an inorg. material and/or an org. material having superior adhesive strength on an electrode by dispersing the inorg. material and/or the org. material each having a limited particle size range in an aq. micelle soln. of a surfactant having chargeability by electrolysis to form colloid and by carrying out electrolysis in the micelle soln. CONSTITUTION:A surfactant having chargeability by electrolysis and represented by the formula is dissolved in water to the critical micelle concn. or above to prepare an aq. micelle soln. and an inorg. material and/or an org. material each having 50Angstrom -0.5mum primary particle size is dispersed in the micelle soln. to form colloid. The inorg. and org. materials may be any materials insoluble in water. A supporting electrolyte such as NaCl is added to the colloidal soln., suspended and dispersed under ultrasonic waves or by stirring. Electrodes are then immersed in the micelle soln. and electrolysis is carried out. The surfactant is positively charged, the micelle breaks and a thin film of the inorg. material and/or the org. material dispersed in the micelle soln. is formed on one of the electrodes with satisfactory adhesion.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention forms a film of water-insoluble organic or inorganic particles by an electrochemical method, and forms a film of water-insoluble organic or inorganic particles on an electrode with good adhesion. It relates to a method of forming.

[Conventional technology]

There has been no method for forming water-insoluble organic or inorganic particles on an electrode in an aqueous solution.

As a wet method for forming an organic film, an LB film and an electrolytic polymerization method are known. LB film is a method in which molecules containing hydrophilic and hydrophobic groups are spread on the surface of water and collected onto a substrate.The molecules that can be deposited are limited, and the deposition of inorganic particles, etc. Can not.

The electrolytic polymerization method is a method in which an organic substance is dissolved in an aqueous or organic solvent and electrolyzed to deposit a polymerized film on an electrode. Until now, organic materials have been limited to molecules with unsaturated bonds, and films of inorganic materials have not been formed.

Recently, a wet method for forming organic pigment films has been proposed by Saji et al. (J, Am, Cp em, S).

c, 109.5881. (1987), Chem.
.

Leff 893 (IQ88)) reported a micelle electrolysis method.

We have already found that it is possible to form films of other water-insoluble organic particles and water-insoluble inorganic particles using this micelle electrolysis method.

In these micelle electrolysis methods, water-insoluble organic and inorganic substances are dispersed or solubilized in surfactant micelles that have the property of being charged by electrolysis, and then the micelles are destroyed by electrolysis, and the organic and inorganic substances are transferred to the electrode. It is precipitated on top.

[Problem to be solved by the invention]

Thin film formation by micelle electrolysis involves depositing particulate material in a solution onto an electrode, and is an extremely low energy film formation method. For this reason, the fine particles dispersed in the solution are stuck on the electrode, and the adhesion is very weak, and even when the electrode is pulled out of the micelle solution, the film formed part peels off. There was a problem with this.

An object of the present invention is to improve the adhesion of this film-formed portion.

[Means to solve the problem]

In order to solve these problems, the present invention aims to: 1. Disperse a water-insoluble organic material, an inorganic material, or a mixed material of an organic material and an inorganic H into an aqueous micelle solution of a surfactant that has the property of being electrolytically charged. In the micelle electrolysis method in which organic material, inorganic 441+, or a mixture of organic and inorganic materials (I1) is produced on the electrode by electrolyzing the micelles, the primary It is characterized in that the diameter of the particles is 50A to 0.5 μm.

As a result of intensive research, we discovered that among films formed by micellar electrolysis, there are films that adhere well to electrodes and films that adhere poorly to the electrodes. Observation with an electron microscope revealed that there were many particles with primary particle diameters exceeding Q,51zm in the film with poor adhesion;
It was discovered that the film was formed using particles with a secondary particle diameter of 0.5 μm or less.

The reason for this is presumed to be due to the cohesive force of the particles. That is, as the particles become finer, the interfacial free energy increases, which makes them thermodynamically unstable and the particles tend to aggregate. It was presumed that this would increase the adhesion between the particles of the film and between the particles and the electrode.

Next, the thin film forming method of the present invention will be explained in order.

The surfactant of the present invention has a low critical micelle concentration and easily forms micelles, and is charged by electrolysis, which causes repulsion between the electrode and the surfactant that forms the micelles, causing the micelles to collapse and become trapped inside. It is sufficient if the contained particles are deposited on the electrode. For example, the general formula CM (
C9H5) 2]M: Ti5V, Cr, Fe, Co,
Ni5Ru.

There are surfactants containing Os and Pd, and commercially available ones include ferrocenyl PEG into which ferrocene is introduced.

This surfactant is dissolved in water to a level exceeding the critical micelle concentration, and an inorganic material, an organic material, or a mixture thereof is dispersed therein. Any water-insoluble material may be used as these materials.

After this, the supporting electrolyte is added. As a supporting electrolyte, N
aC,9,Na,,so,l,LiBr,LiSO4
etc.

After preparing the micelle solution, it is suspended and dispersed using ultrasound or stirring.

Next, the electrodes are immersed in this solution to perform electrolysis. The electrolytic potential differs depending on the type of surfactant, but ferrocenyl PE
When using G, +0.
It is best to do this at 2V or higher.

+0.2V is the oxidation potential of ferrocenyl PEG,
The surfactant becomes positively charged, the micelles collapse, and a film of material dispersed in the micelle solution is formed on the electrode.

Next, a detailed explanation will be given using examples.

[Example 1] As a surfactant, ferrocenyl PEG (manufactured by Doguchi Kagaku) having a metallocene group into which Fe was introduced was used. 1 g of a 3mM aqueous solution of ferrocenyl PEG was prepared. Furthermore, 0.0% LiBr was added as a supporting electrolyte. 1M/Ω was added.

In the container, a phthalocyanine pigment monochlorocopper phthalocyanine was selected as an organic material and ground in a sand mill until the maximum particle size of the primary particles was 0.4 μm or less. Particle size was measured using an electron microscope. 3 g of this phthalocyanine was added to the micelle solution and dispersed using an ultrasonic homogenizer. Next, the SCE was immersed into this solution using a platinum plate as a counter electrode, a saturated calomel electrode as a reference electrode, and an ITO glass electrode as a sample electrode, and the electric field potential was adjusted to
C.

E, +〇, 5V and electrolyzed for 30 minutes. Through these operations, a film of monochlorocopper phthalocyanine was formed on the ITO to a film thickness of 4,000 μm. This substrate was washed under running water, dried with an air blower, and baked at 2.degree. C. for 1 hour.

As an adhesion test, when Scotch Tub was pasted on this substrate and then peeled off, the monochlorocopper phthalocyanine film did not peel off at all.

[Comparative example]

To a micelle solution prepared in the same manner as in Example 1, 3 g of monochlorocopper phthalocyanine before pulverization using a sand mill was added. The maximum primary particle size of phthalocyanine was 10 μm, and more than 70% of the particles had a primary particle size of 1 μm or more. The particle size was determined to +1111 using an electron microscope. This phthalocyanine was dispersed in the micelle solution using an ultrasonic homogenizer.

A film of monochlorocopper phthalocyanine was formed on an ITO (=J) glass substrate in the same manner as in Example.

However, when the substrate was removed from the dispersion solution, half of the film peeled off.

[Example 2] 1f! of a 10 mM solution of ferrocenyl PEG! Making,
Among these, as an inorganic material, the average primary particle size is 0.05 μm.
20g of carbon powder and 0.0g of LiBr as supporting electrolyte.
], M were added and dispersed using an ultrasonic homogenizer. Using this dispersion solution, I
A carbon film was formed on a TOfNI glass substrate. This substrate was washed by immersion in still water and dried with warm air.

During these two steps, the carbon film did not peel off and was formed with good adhesion.

[Comparative Example 2] Carbon powder having an average primary particle size of 3 μm was dispersed in a micelle solution in the same manner as in Example 2.

A carbon film was formed on the ITO-coated glass in the same manner as in Example 1, but the adhesion of the carbon film was poor (and the film could not be formed completely).

〔Effect of the invention〕

As can be seen from the above examples, by setting the particle size of the material dispersed in the micelle electrolysis method to 0.5 μm or less, it was possible to form a thin film with good adhesion regardless of whether the material was organic or inorganic.

The present invention has made it possible to form films of various functional fine particles with good adhesion.

that's all Applicant: Seiko Epson Corporation

Claims (1)

[Claims] 1. A water-insoluble organic material, an inorganic material, or a mixed material of an organic material and an inorganic material is dispersed into a colloid in a micellar aqueous solution of a surfactant that has the property of being charged by electrolysis, and electrolysis is performed in the micellar aqueous solution. , a micelle electrolysis method in which an organic material, an inorganic material, or a mixture of an organic material and an inorganic material is deposited on an electrode by electrolyzing micelles, characterized in that the diameter of the primary particles of the material is 50 Å to 0.5 μm. Thin film formation method.