JPH1177908A - Polymer ultra-fine particle attraction structure and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide polymer ultra-fine particle attraction structure usable for functional material such as electronic material, optical material or the like or specifically sensor, diagnosing test carrier or the like, and a method for manufacturing it. SOLUTION: The polymer ultra-fine particle attraction structure comprises chargeable polymer ultra-fine particles substantially uniformly dispersed and attracted on a chargeable polymer thin film formed on a surface of a base plate. The method for manufacturing it comprises the steps of forming a chargeable polymer thin film on a base plate, then dipping chargeable polymer ultra- fine particles in dispersion liquid, and substantially uniformly dispersing the particles by electrostatic interaction to attract the particles on the film. The thin film is preferably obtained by alternately laminating at least one layer of water soluble polymer having cationic charge and one layer of water soluble polymer having anionic charge.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer ultrafine particle adsorbing structure and a method for producing the same, and more particularly to a functional material such as an electronic material and an optical material, various sensors, and a carrier for a diagnostic reagent. The present invention relates to a molecular ultrafine particle adsorption structure and a method for producing the same.

[0002]

2. Description of the Related Art Ultrafine polymer particles having a large surface area have been expected to be applicable in many fields such as paints, adhesives, stationary phases for chromatography, cosmetics and pharmaceuticals. Various monodisperse latexes such as polystyrene latex and acrylic latex have been put to practical use.

[0003] Such an aggregate of ultrafine polymer particles is prepared by coating an emulsion / dispersion of ultrafine polymer particles on a substrate, or by adsorbing ultrafine polymer particles on a substrate by electrodeposition coating. Aggregated and deposited materials have been put to practical use. However, the aggregate of the ultrafine polymer particles produced by such a method has a problem that the dispersion uniformity of the ultrafine particles is insufficient and the characteristics as the ultrafine particles are not functionally exhibited.

On the other hand, as a technique for laminating ultrafine particles using electrostatic interaction as a driving force, there has been reported a method of producing an ultrathin film using an electrostatic compounding method of a charged polymer. Such a method is, specifically, a linear polymer, a protein, or a metal alkoxide or (Chem. Lett., P. 125,
1996), oxide particles such as silica (Chem. Lett., 125
P. 1997) using electrostatic interaction.

Further, formation of polystyrene fine particles with formation of a monolayer on the water surface and evaporation of the solvent (JP-A-6-277501, JP-A-8-229474, Langmuir, vol. 12, p. 1303, 1996), application of an electric field ( Science, vol. 272, p. 706, 1996), etc., are being studied. The aggregate of polymer ultrafine particles obtained by these technologies
For decorative applications (JP-A-8-234007) and optical applications (J.Colloid
Application to Interface Sci., Vol. 144, No. 2, p. 538, 1991) is being studied.

[0006] However, all of the above-mentioned technologies accumulate and laminate polymer ultrafine particles in a close-packed or agglomerated state. No method has been realized in which the substrate is adsorbed on the substrate while the substrate is being made to adhere to the substrate.

Accordingly, an object of the present invention is to provide a polymer ultrafine particle adsorbing structure in which polymer ultrafine particles are substantially uniformly dispersed without agglomeration and adsorbed on a substrate in a single layer, and a method for producing the same. To provide.

[0008]

Means for Solving the Problems As a result of intensive studies in view of the above-mentioned object, the present inventors have found that a charged polymer ultra-fine particle is electrostatically interconnected on a charged polymer thin film formed on a substrate. It has been discovered that by adsorbing substantially uniformly the action as the main driving force, it is possible to obtain a polymer ultrafine particle adsorption structure that can be used for electronic materials, optical materials, etc., including carriers for sensors and reagents. Thus, the present invention has been completed.

That is, the polymer ultrafine particle-adsorbing structure of the present invention is formed on a charged polymer thin film formed on a substrate surface.
The present invention is characterized in that the charged polymer ultrafine particles are substantially uniformly dispersed and adsorbed.

Further, in the method for producing a polymer ultrafine particle adsorption structure according to the present invention, the substrate on which the chargeable polymer thin film is formed is immersed in a dispersion of the chargeable polymer ultrafine particles, The charged polymer ultrafine particles are substantially uniformly dispersed and adsorbed thereon by electrostatic interaction.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

[1] Configuration of polymer ultrafine particle adsorption structure (1) Chargeable polymer ultrafine particles The charged polymer ultrafine particles used in the present invention are in the presence of a surfactant or a protective colloid or in the absence of a surfactant. Below,
It can be prepared by emulsion polymerization. By the emulsion polymerization method, polymer ultrafine particles having high sphericity can be obtained. Materials include polystyrene, polymethyl methacrylate, methacrylate / acrylate copolymer, styrene / acrylate copolymer, polyvinyl acetate, vinyl acetate / methacrylate copolymer, vinyl acetate / acrylate Copolymer, styrene / butadiene copolymer (SB), acrylonitrile /
Butadiene copolymer (NB), methyl methacrylate /
Butadiene copolymer (MB), polybutadiene, polychloroprene, a blend thereof, or a ternary or higher copolymer thereof can be given.

The above-mentioned charged ultrafine polymer particles are charged by the charge of a functional group, a polymerization initiator fragment, a surfactant, or a protective colloid bonded to the surface. Ultrafine particles of anionic polymer having a functional group such as a carboxyl group, a hydroxyl group, or a sulfone group on the surface or an anionic surfactant bonded thereto exhibit anionic properties, and have a functional group such as an amino group or a quaternary ammonium base or a cationic group on the surface. The cationic polymer ultrafine particles to which the surfactant is bound show cationicity.

The average particle size of the charged ultrafine polymer particles can be generally from several nm to several tens of μm, but it is preferable to reduce the variation in particle size from the viewpoint of workability and dispersibility. The average particle size is preferably in the range of 10 nm to 10 μm,
A range of 3 μm is more preferred, and a range of 70 nm to 2 μm is most preferred. The particle size can be measured by an electron microscope, a laser light scattering method, or the like.

Although the degree of monodispersity of the charged ultrafine polymer particles varies depending on the application of the ultrafine polymer particle adsorbing structure, the particle size distribution (CV) value of the ultrafine polymer particles is 20 in each case.
% Or less, and more preferably 15% or less. Particularly when a high degree of monodispersity is required, C.
The V. value is preferably 5% or less, more preferably 3% or less.
If the CV value exceeds 20%, the dispersion of the particle size becomes large, and the structure of the aggregate of ultrafine polymer particles becomes ununiform. The particle size distribution (CV) is obtained from the measured value of the average particle size (R) and the standard deviation (SD) as follows: CV = SD / R (%)
It is calculated by the following equation.

The charged polymer ultrafine particles are preferably used by suspending in water as a dispersion medium or a solution in which a water-soluble polymer, a surfactant or a water-soluble salt is dissolved in water. Commercially available dispersions of such charged polymer ultrafine particles include, for example, STANDEX SC, IMMUTEXG, and MPP (all manufactured by Nippon Synthetic Rubber Co., Ltd.), Estapol (Rhone Poulin), and Polybead ( Funakoshi Co., Ltd.) and the like.

(2) Chargeable polymer thin film The chargeable polymer thin film formed on the substrate adsorbs the charged polymer ultrafine particles in a single layer and covers the unevenness of the substrate to flatten the surface.

The chargeable polymer thin film has a certain thickness and a uniform charge distribution on the surface.
It is preferable to form them by alternately laminating at least one layer each of a cationic water-soluble polymer and an anionic water-soluble polymer. The obtained laminate forms a complex, is insoluble in water, and is stable. The thickness of the chargeable polymer thin film is preferably from 3 nm to 1 μm, more preferably from 5 nm to 0.1 μm.

The chargeable polymer forming the thin film is a polymer in which an ionic functional group is bonded to a polymer such as polyvinyl, polyacrylate, polymethacrylate, and polystyrene. Examples of the ionic functional group include an alkali metal salt such as a sulfonic acid group, a carboxyl group, and a phosphoric acid group or an alkaline earth metal salt (anionic);
And quaternary ammonium bases (cationic). Specific examples of such a charged polymer will be described below.

(A) The following formula (1):

Embedded image (Where n is an integer representing the degree of polymerization).

(B) The following formula (2):

Embedded image (Where n is an integer representing the degree of polymerization).

(C) The following equation (3):

Embedded image (Where n is an integer representing the degree of polymerization) 2-acrylic acid 2-trimethylammonium ethyl ester chloride represented by the formula:

(D) The following formula (4):

Embedded image (Where n is an integer representing the degree of polymerization).

(E) The following formula (5):

Embedded image (Where n is an integer representing the degree of polymerization).

As a method for forming the above-mentioned charged polymer thin film, a method for applying the above-mentioned charged polymer on the surface of the substrate, preferably, a solution of a cationic polymer and an anionic charged polymer solution is alternately applied to the surface of the substrate. There is a method of applying (drying) on the top, a method of kneading a chargeable polymer with another plastic material and molding.

At the time of forming the charged polymer thin film, an alkali metal is used to promote the separation of the electric charge in the water-soluble polymer chain in water and to increase the rate of adsorption and deposition on the substrate surface or thin film surface. And an electrolyte such as a halide of an alkaline earth metal.
The coexistence of the electrolyte improves the particle adsorption speed and dispersibility as compared with the case where no electrolyte is added. Specific examples of the electrolyte include LiCl, LiBr, LiI, NaCl, NaBr, NaI, KCl,
_{KBr, KI, MgCl 2, MgBr} 2, MgI 2, CaCl 2, CaBr 2,
Examples thereof include CaI _{2 and the} like, and monovalent salts such as NaCl, NaBr, KCl 3 and KBr are preferred. The concentration of the electrolyte is preferably in the range of 0.01 to 10M, more preferably in the range of 0.02 to 5M. If it is less than 0.01M, the effect due to coexistence is small, and if it exceeds 10M, it becomes excessive, which is not preferable.

(3) Substrate Materials for the substrate include, for example, glass, plastic, metal, ceramics, carbonaceous materials such as graphite and carbon fiber, or silicates of clay minerals such as mica, kaolin and montmorillonite, and the like. And a complex. The shape of the substrate is not particularly limited as long as the surface is sufficiently smooth.

[2] Method for Producing Polymer Ultrafine Particle Adsorbed Structure In order to produce a polymer ultrafine particle adsorbed structure, a substrate having a chargeable polymer thin film formed in a liquid in which charged polymer ultrafine particles are dispersed is used. Is preferred. For example, when a cationic polymer ultrafine particle is used, a substrate having a thin film (or a surface layer thereof) made of an anionic water-soluble polymer is immersed in a liquid in which the cationic polymer ultrafine particle is dispersed. Are adsorbed on the surface by electrostatic interaction. In the case of using anionic ultrafine polymer particles, when a substrate having a thin film (or a surface layer thereof) made of a cationic water-soluble polymer is immersed, the anionic polymer is similarly subjected to electrostatic interaction. Ultrafine particles are adsorbed on the surface.

The dispersion concentration of the charged polymer ultrafine particles is 1 × 10
Range of ^{7-10 15} cells / ml are preferred. The amount of adsorption increases with increasing dispersion concentration. The dispersion medium is preferably water, particularly pure water, but does not impair the chargeability of the charged polymer ultrafine particles,
Other polar solvents that do not infiltrate can be used.

The immersion temperature is preferably in the range of about 0 to 60 ° C. in order to promote the adsorptivity of the charged polymer ultrafine particles. When the dispersion medium is water, the immersion temperature is more preferably in the range of about 1 to 30 ° C, and further preferably in the range of about 1 to 15 ° C. If the temperature is too high, the charged polymer ultrafine particles may easily associate in the dispersion depending on the type, and the charged polymer ultrafine particles are substantially uniformly dispersed and do not adsorb to the thin film.

The immersion time is preferably in the range of 1 minute to 3 hours in order to achieve a desired adsorption amount of the charged polymer ultrafine particles. In this range, the amount of adsorption increases as the immersion time elapses. However, depending on other immersion conditions, immersion may be performed for a longer time, and it is assumed that the amount of adsorption after reaching the adsorption equilibrium hardly changes.

In the present invention, the charged ultrafine polymer particles are adsorbed in a substantially uniform dispersion state in order to functionally exhibit the characteristics of the ultrafine polymer particles as single particles. Here, “substantially uniform” means that a considerable number of the adsorbed ultrafine particles are not substantially in contact with each other, and the distance between the particles does not need to be constant. Specifically, assuming that the percentage of the charged polymer ultrafine particles adsorbed on the charged polymer thin film adsorbed as single particles is the single particle ratio, the single particle ratio is 30% or more. Is preferable, and particularly preferably 40% or more. When adsorbed at a single particle rate of 30% or more, the polymer ultrafine particle layer becomes a single layer.

The substrate on which the polymer thin film is formed is immersed in a dispersion of charged polymer ultrafine particles for a predetermined period of time, taken out, and allowed to stand at room temperature or under heating, or to stand still or an inert gas such as nitrogen or argon or air. Air is blown and dried. Since the polymer ultrafine particles have a large specific surface area, the surface area of the polymer ultrafine particle adsorption structure increases in accordance with the amount of adsorption.

[0033]

EXAMPLES The present invention will be specifically described based on the following examples, but the present invention is not limited thereto.

Example 1 A quartz crystal microbalance (QCM, 9 MHz) was used as a substrate.
), And using this substrate as a cationic water-soluble polymer, polyallylamine hydrochloride (weight average molecular weight Mw: 8,500
~ 11,000) and a 0.02mol% aqueous solution of sodium polystyrenesulfonate (weight average molecular weight Mw: 70,000) as an anionic water-soluble polymer.
Dip three times at 20 ° C, and apply a thickness of about 6 nm on the surface of the gold electrode of QCM.
Polymer thin film was formed. Each aqueous solution contains 2
M NaCl was added. In order to make the polymer thin film surface cationic, the last immersion liquid was an aqueous solution of polyallylamine hydrochloride.

Next, polystyrene ultrafine particles having an average particle size of 548 nm (surface charge anionic, polybead (Funakoshi Co., Ltd.)
(A) 19 × 10 ¹⁰ / ml, (b) 3.8 × 10
The polymer thin film-coated electrode was placed in a liquid at 20 ° C. dispersed in pure water at a concentration of ¹⁰ cells / ml and (c) 7.6 × 10 ⁹ cells / ml.
Immersion for 60 minutes, during which time the frequency change ΔF
Monitored by The adsorption weight Δm / S (ng / cm ² ) of polystyrene ultrafine particles per unit area of the electrode surface is
Based on the frequency change ΔF monitored by the QCM, the following relational expression (6): −ΔF = 0.87 × Δm (6) (where ΔF represents the frequency change and Δm is the adsorption weight (ng))
Represents ) And the electrode surface area S (0.32 cm ² ). The results are shown in FIG. As is clear from FIG. 1, the adsorption amount of the polystyrene ultrafine particles rapidly increased by immersion for a short time.

3.8 × 10 ¹⁰ polystyrene ultra-fine particles / ml
The polystyrene ultrafine particle-adsorbed structure prepared by immersing the polymer thin film-coated electrode in water dispersed at a concentration of 60 minutes for 60 minutes is dried, and the polystyrene ultrafine particles on the thin film surface are subjected to SEM (5,000
Times) observed. The results are shown in FIG.

FIG. 2 shows that the polystyrene ultrafine particles adsorbed on the surface of the polymer thin film in a dispersed state (with no adjacent fine particles in contact with each other) had a single particle ratio of about 56%. The polystyrene ultrafine particles were not desorbed even when the air flow or the water flow was applied to the surface of the polystyrene ultrafine particle adsorption structure, and the stable structure was maintained.

Example 2 Ultrafine polystyrene particles having an average particle size of 548 nm were dispersed in pure water at a concentration of 3.8 × 10 ¹⁰ particles / ml, and the same polymer thin film-coated electrode as in Example 1 was used as shown in Table 1. Each was immersed at a temperature in the range of 4040 ° C. for 60 minutes to prepare a polystyrene ultrafine particle adsorption structure. Ultrafine polystyrene particles on the surface of the thin film were observed by SEM (5,000 times). From the SEM photograph, it was found that the single particle ratio of the polystyrene ultrafine particles was about 30% or more of the surface of the polymer thin film.

[0039]

Example 3 Ultrafine polystyrene particles having an average particle diameter of (a) 780 nm, (b) 548 nm, and (c) 84 nm (Polybead, Funakoshi Co., Ltd.)
Was prepared in the same manner as in Example 1 except that a liquid prepared by dispersing a polystyrene solution at a concentration of 3.8 × 10 ¹⁰ particles / ml in pure water was used. The frequency change of the surface was monitored by QCM, and the adsorption weight (ng / ng /
cm ² ) was calculated in the same manner as in Example 1. The results are shown in FIG.

As is apparent from FIG. 3, the amount of adsorbed polystyrene fine particles increased with the elapse of the immersion time, and the amount of adsorption increased dramatically as the average particle size of the polystyrene fine particles increased.

Example 4 When forming a charged polymer thin film, the concentrations of NaCl added to the aqueous charged polymer solution were 2M, (b) 0.2M, and (c)
0 M (no addition), and the dispersion concentration of the polystyrene ultrafine particles (average particle size: 548 nm) in the immersion liquid is 3.8 × 10 ¹⁰ particles /
A polystyrene ultrafine particle adsorption structure was produced in the same manner as in Example 1 except that the amount was changed to ml. QCM for surface frequency change
And the adsorption weight (ng
/ Cm ² ) was calculated in the same manner as in Example 1. Fig. 4 shows the results.
Shown in

As apparent from FIG. 4, as the amount of added NaCl increased, the amount of polystyrene fine particles adsorbed during the same immersion time increased. In the case without NaCl (c),
The polystyrene ultrafine particles of the polystyrene ultrafine particle adsorption structure produced by immersion for 60 minutes were observed by SEM (5,000 times). FIG. 5 shows the results. The single particle ratio of the polystyrene ultrafine particles calculated from FIG. 5 was 64%.

Example 5 A polystyrene ultrafine particle-adsorbing structure prepared under the same conditions as in Example 1 (concentration of polystyrene ultrafine particles used: 3.8)
An aqueous solution (containing 2 M NaCl) containing 0.02 mol% of polyallylamine hydrochloride (weight average molecular weight: 8,500 to 11,000) as a cationic water-soluble polymer on the surface of (× 10 ¹⁰ / ml, immersed for 60 minutes) And an aqueous solution (2 M NaCl) containing 0.02 mol% of sodium polystyrene sulfonate (weight average molecular weight: 70,000) as an anionic water-soluble polymer
) At 15 ° C. alternately to form a second polymer thin film having a thickness of about 5 nm comprising three layers of polyallylamine hydrochloride and two layers of sodium polystyrenesulfonate. However, the uppermost layer was a layer of polyallylamine hydrochloride so that the surface became cationic.

Ultrafine polystyrene particles having an average particle size of 548 nm
The polystyrene ultrafine particle adsorption structure coated with the second polymer thin film is immersed in a liquid at 15 ° C. dispersed in pure water at a concentration of 3.8 × 10 ¹⁰ particles / ml for 0 to 60 minutes to adsorb polystyrene ultrafine particles. On the surface of the structure, a combination of the second chargeable polymer thin film and the ultrafine polystyrene particles was laminated. During that time, the frequency change was monitored by QCM, and the adsorption weight (ng / cm ² ) of the polystyrene ultrafine particles was calculated in the same manner as in Example 1. FIG. 6 shows the results. As is clear from FIG. 6, the adsorption amount of the polystyrene ultrafine particles increased with the elapse of the immersion time.

The polystyrene ultrafine particles adsorbed on the surface of the second charged polymer thin film by immersion for 60 minutes were observed by SEM (10,000 times). FIG. 7 shows the results. FIG.
As is clear from the figure, the second layer of polystyrene ultrafine particles was substantially uniformly dispersed and adsorbed on the second layer of the polymer thin film. However, in FIG. 7, since the second charged polymer thin film is substantially transparent, the polystyrene ultrafine particles in the lower layer appear as dark particles, and the polystyrene ultrafine particles in the upper layer appear as bright particles.

[0047]

As described in detail above, according to the present invention,
A polymer ultrafine particle-adsorbed structure in which polymer ultrafine particles are substantially uniformly dispersed and adsorbed (in a single layer) on a polymer thin film formed on a substrate can be obtained easily and quickly. The polymer ultrafine particle-adsorbed structure on which the polymer ultrafine particles having high monodispersity is adsorbed can be used for various sensors, test carriers for diagnosis and the like, or electronic materials and optical applications.

[Brief description of the drawings]

FIG. 1 shows the immersion time and frequency change of a polymer thin film-coated electrode in dispersions of polystyrene ultrafine particles at various concentrations, and the weight of polystyrene ultrafine particles adsorbed on the polystyrene ultrafine particle adsorption structure obtained in Example 1. 6 is a graph showing a relationship with the graph.

FIG. 2 is a SEM photograph (magnification: 5,000) of the surface of the polystyrene ultrafine particle-adsorbed structure obtained in Example 1.

FIG. 3 shows the immersion time and frequency change of the polymer thin film-coated electrode in dispersions of polystyrene ultrafine particles having various average particle diameters, and the polystyrene ultrafine particles of the polystyrene ultrafine particle adsorption structure obtained in Example 3. It is a graph which shows the relationship with an adsorption weight.

FIG. 4 shows a polystyrene ultrafine particle-adsorbed structure obtained in Example 4, when an electrode coated with a polymer thin film formed by adding various concentrations of NaCl is immersed in a polystyrene ultrafine particle dispersion. 4 is a graph showing the relationship between immersion time, frequency change, and the adsorption weight of polystyrene ultrafine particles.

FIG. 5 is a SEM photograph (magnification: 5,000 times) of the surface of the polystyrene ultrafine particle-adsorbed structure obtained in Example 4.

FIG. 6 shows the relationship between the immersion time of a second layer of polystyrene ultrafine particles in a dispersion liquid, the frequency change, and the weight of polystyrene ultrafine particles adsorbed on the polystyrene ultrafine particle-adsorbed structure obtained in Example 5. It is a graph.

FIG. 7 is a SEM photograph (magnification: 10,000 times) of the surface of the polystyrene ultrafine particle-adsorbed structure obtained in Example 5.

Claims (13)

[Claims] 1. An ultrafine polymer particle adsorbing structure, wherein charged ultrafine polymer particles are substantially uniformly dispersed and adsorbed on a charged thin polymer film formed on a surface of a substrate. . 2. The ultrafine polymer particle adsorbing structure according to claim 1, wherein the charged ultrafine polymer particles are adsorbed in a single layer. 3. The polymer ultrafine particle adsorbing structure according to claim 1, wherein the charged polymer ultrafine particles adsorbed on the charged polymer thin film are adsorbed by a single particle. A polymer ultrafine particle adsorbing structure, characterized in that the ratio of the particles is 30% or more. 4. The polymer ultrafine particle adsorbing structure according to claim 1, wherein said charged ultrafine polymer particles have an average particle size of 10 nm to 10 μm. Fine particle adsorption structure. 5. The structure for adsorbing ultrafine polymer particles according to claim 1, wherein a combination of the chargeable polymer thin film and the chargeable polymer ultrafine particle layer on the surface of the substrate is 2 or more. A structure for adsorbing ultrafine polymer particles, comprising at least two layers. 6. The ultrafine polymer particle-adsorbing structure according to claim 1, wherein the charged polymer thin film comprises a water-soluble polymer having a cationic charge and an anionic charge. And a water-soluble polymer having at least one layer alternately laminated thereon. 7. The method for producing a polymer ultrafine particle adsorption structure according to claim 1, wherein the substrate on which the chargeable polymer thin film is formed is placed in a dispersion of the chargeable polymer ultrafine particles. Wherein the charged polymer ultrafine particles are substantially uniformly dispersed by electrostatic interaction and adsorbed on the charged polymer thin film. 8. The method according to claim 7, wherein the charged ultrafine polymer particles are adsorbed in a single layer. 9. The method for producing a polymer ultrafine particle-adsorbed structure according to claim 7, wherein a single particle ratio of the charged polymer ultrafine particles is 30% or more. 10. The method for producing a polymer ultrafine particle-adsorbing structure according to claim 7, wherein the charged polymer ultrafine particles have an average particle size of 10 nm to 10 μm. Method. 11. The method for manufacturing a polymer ultrafine particle-adsorbing structure according to any one of claims 7 to 10, comprising the charged polymer thin film and the charged polymer ultrafine particle layer on the substrate surface. A method comprising laminating two or more combinations. 12. The method for producing an ultrafine polymer particle adsorption structure according to any one of claims 7 to 11, wherein the charged polymer thin film comprises a water-soluble polymer having a cationic charge, and an anionic polymer. A water-soluble polymer having the above-mentioned charge is alternately laminated at least one layer at a time. 13. The method for producing a polymer ultrafine particle adsorption structure according to claim 12, wherein, when forming the charged polymer thin film, an electrolyte is allowed to coexist in a solution of the water-soluble polymer. Features method.