JP4874179B2 - Ultrafiltration membrane, method for producing the same, and method for size separation of nanoparticles - Google Patents

Description

  The present invention relates to an ultrafiltration membrane and a method for producing the same. The present invention also relates to a filtrate and particles that have passed through the ultrafiltration membrane. Furthermore, it is related with the size fractionation method of a nanoparticle.

  In recent years, research on nanoparticles has been carried out energetically, and application to various fields has been actively studied. For example, gold nanoparticles are attracting industrial attention as circuit wiring materials such as semiconductor elements, medical materials using absorption of visible light (plasmon absorption) peculiar to gold nanoparticles, and catalyst materials using semiconductor characteristics. ing. Metal oxide nanoparticles are attracting industrial attention as magnetic materials and the like, and metal sulfides and metal selenium compounds are attracting industrial attention as nanoparticles that exhibit fluorescence depending on the particle size.

  The group of the present inventors has proposed a method of printing a micropattern made of metal nanoparticles in Patent Document 1. A desired pattern is formed on the film surface of the silicone composition, and the metal nanoparticle solution is oozed out from the film and transferred onto a solid substrate to obtain a micropattern composed of gold nanoparticles.

  Non-Patent Document 1 proposes to incorporate gold nanoparticles (2.6 nm) protected with alkylthiol contained in toluene when silica is swollen and apply it to an optical material.

  When metal is made into nanoparticles, various particle size effects such as a melting point drop and a vapor pressure rise appear. For example, the melting point of gold bulk is 1064 ° C., but when the particle diameter is about 2 nm, it can be fused at 200 ° C. Therefore, moldability is improved by using nanoparticles. Non-Patent Document 2 reports that when the particle size is 10 nm or less, the activity of the surface of the particle becomes very high as it approaches 1 nm. Non-Patent Document 3 reports that catalytic activity is exhibited by making gold into ultrafine particles.

  Controlling the particle size is an important issue for efficiently expressing the various functions of the nanoparticles. Patent Document 2 proposes a method for obtaining monodisperse nanoparticles from a synthetic approach. Specifically, a metal-surfactant complex compound is synthesized by a reaction between a metal precursor and a surfactant, and monodispersed metal nanoparticles are formed by thermally decomposing the compound at a high temperature. Thereafter, monodisperse nanoparticles are prepared by adding a poor solvent and further performing a centrifugation step. Patent Document 3 proposes a method of obtaining nanoparticles close to monodispersion by using a liquid phase separation method for micelles having a size of 10 nm or less.

  Patent Document 4 proposes a porous ceramic film having nanometer-order pores by forming a composite film composed of a ceramic phase and a columnar-grown metal phase and etching only the metal phase portion. Yes.

  Non-Patent Document 4 proposes a method for separating nanoparticles (for example, separating particles of 5 nm and 15 nm) by size-exclusion chromatography (SEC).

  In addition, although it is an example of the low molecular compound smaller than a nanoparticle, in nonpatent literature 5, a silicone film | membrane is arrange | positioned on the gold | metal | money board | substrate, and an organic solvent (ethanol) and low on the surface of this silicone film | membrane. Disclosed is an example in which when a mixed solution of molecular compounds (alkyl thiols) is supplied, the low molecular weight compound and the organic solvent reach the gold substrate surface under the silicone film, and the low molecular weight compound and gold react to form a monomolecular film. Has been.

  Non-Patent Document 6 shows that a polyacrylonitrile / polyamide / polydimethylsiloxane three-component composite membrane can separate polyethylene glycol and hexane. Further, Non-Patent Document 7 shows that a two-layer film of polyacrylonitrile and polydimethylsiloxane can take out only hexane from a mixed solution of biflower oil and hexane or a mixed solution of polyisobutylene and hexane. . From these prior arts, it can be seen that the membrane made of polydimethylsiloxane is a filtration membrane having the function of molecular sieve.

Non-patent documents 8 to 13 and Patent document 5 will be described later.
JP 2007-62302 A JP-T-2005-504888 Japanese Patent No. 3303129 Japanese Patent No. 3135110 JP 2006-071497 A Tai, Y., et al., Advanced Materials, 2001, 13, p1611. Kubo, R. et al., Rhys. Lett. 1962, 1, p49. Haruta, M. et al., Catal. Today, 1997, 36, p153. Wilcoxon, JP et al., J. Chem. Phys. 1998, 108, p9137. Kim, IC, et al. Ind. Eng. Chem. Res., 2002, 41, p5523 Stafie, N., et al. J. Membrane Sci., 2004, 228, p103 Balmer, TE et al., Langmuir, 2005, 21, p622. Furukawa, H. et al., Phys. Rev. E, 2003, 68, p031406-1 to 031406-14. Furukawa Hidemitsu et al., Polymer Papers, 2002, 59, p.578-589. Furukawa, H. et al., J. Phys. Soc., 2002, 71, p. 2873-2880. Mitsuhiro Shibayama et al., Latest Trends in Polymer Gels, Chapter 8, CMC Publishing (2004). Campbell, DJ et al., J. Chem. Educ., 1999, 76, p537. Shimizu, T. et al., J. Phys. Chem. B, 2003, 107, p2719.

  As described above, it is extremely important to establish a technique for separating the size of the nanoparticles in order to efficiently express the various functions of the nanoparticles. There are several proposals for the technology for separating nanoparticles as described above. However, at present, the technology for separating nanoparticles having a particle size of about 1 to 10 nm has not yet been put into practical use. In order to separate 1-10 nm nanoparticles with high accuracy, it is necessary to devise in the process of synthesizing nanoparticles (increase the number of processes, etc.) This is because of problems such as complexity. In addition, for nanoparticles having a particle size exceeding 10 nm, a low-cost size separation technique with good operability is desired.

  The present invention has been made in view of the above background, and an object of the present invention is to provide an ultrafiltration membrane or the like that can easily separate the size of nanoparticles at low cost.

The ultrafiltration membrane according to the present invention includes a crosslinked polymer membrane having a three-dimensional network structure and satisfies the following (1) to (3). That is,
(1) The crosslinked polymer film is in a swelling equilibrium with an organic solvent,
(2) The average mesh size 2ξ calculated by multiplying the hydrodynamic radius ξ obtained from the co-diffusion function of the crosslinked polymer film determined by scanning microscopic light scattering method by 2 is 1 nm or more and 20 nm. In the following range,
(3) When a fluid in which particles are dispersed in an organic solvent is supplied onto the crosslinked polymer film, particles having a particle size larger than the maximum mesh size of the crosslinked polymer film are cut off, and the maximum mesh size is The average mesh size is within a value obtained by multiplying 1.3 .

  According to the ultrafiltration membrane according to the present invention, the area and thickness of the membrane can be easily changed, so that the shape and form can be flexibly changed according to the application. Moreover, since the filtration method is employ | adopted, operability is good and can be utilized simply. Moreover, since versatility is high, cost reduction can also be realized.

  According to the present invention, there is an excellent effect that it is possible to provide an ultrafiltration membrane or the like that can easily separate the size of nanoparticles at low cost.

  Hereinafter, an example of an embodiment to which the present invention is applied will be described. It goes without saying that other embodiments may also belong to the category of the present invention as long as they match the gist of the present invention.

  Fig.1 (a) is a typical perspective view for demonstrating an example of the ultrafiltration apparatus which concerns on this embodiment, FIG.1 (b) is Ib-Ib cutting part sectional drawing of Fig.1 (a). . As shown in the figure, the ultrafiltration device 100 includes a swollen crosslinked polymer membrane 11 that functions as an ultrafiltration membrane, a housing 12 and the like. The housing 12 is configured by a cylindrical body having an open bottom surface. The swollen crosslinked polymer film 11 is formed at a location corresponding to the bottom surface of the housing 12. The film thickness of the swollen crosslinked polymer film 11 is not particularly limited, but is preferably 0.05 mm to 50 mm. When the film thickness of the swollen crosslinked polymer film 11 is less than 0.05 mm, the film may be ruptured depending on the weight of the fluid to be supplied. On the other hand, if it exceeds 50 mm, it takes a long time for filtration and the productivity may be inferior. A more preferable range is 0.2 mm to 5 mm.

  The swollen crosslinked polymer film 11 has a three-dimensional network structure and is sufficiently swollen with an organic solvent. 2A and 2B are schematic explanatory views of a three-dimensional network structure of a crosslinked polymer film. The left side of the figure shows the three-dimensional network structure of the crosslinked polymer film before swelling with the organic solvent, and the right side of the figure shows the three-dimensional network structure of the crosslinked polymer film sufficiently swollen with the organic solvent. Is shown. The crosslinked polymer film includes a main chain portion 13, a crosslinked portion 14, and a crosslinking point 15 thereof. When such a crosslinked polymer film 11a is sufficiently swollen with an organic solvent, the organic solvent enters the space portion 16 of the three-dimensional network structure as shown on the left side in the figure. And according to the kind of molecular structure which comprises an organic solvent and a bridge | crosslinking polymer film, the space part 16 enclosed by a mesh | network expands uniformly on an angstrom to nanometer scale order.

  The solvent for swelling the cross-linked polymer film is not particularly limited as long as it is an organic solvent other than water and does not exhibit a chemical reaction with respect to the cross-linked polymer film and can swell. For example, ethanol, acetone, acetonitrile, aniline, benzonitrile, butanol, chlorobenzene, chloroform, cyclohexane, dimethylformamide, ether, isopropanol, methanol, nitrobenzene, pentane, phenol, propanol, α-terpineol, toluene, benzene, heptane, hexane, Octane is mentioned. Preferably, toluene, hexane, octane, α-terpineol and the like can be mentioned. As described above, since the mesh size varies depending on the organic solvent, it is appropriately selected depending on the desired mesh size. To increase the mesh size, select toluene or the like, and to reduce the mesh size, select methanol or the like. The organic solvent to be used is not limited to one type, and a plurality of types may be added or additives may be added as necessary.

  The network size of the swollen crosslinked polymer film 11 can also be adjusted by controlling the ratio of the crosslinking points 15 constituted by the main chain portion 13 and the crosslinked portion 14. As shown in FIG. 2B, the mesh size can be reduced by increasing the crosslinking density. As a result of extensive studies by the present inventors, the concentration of the crosslinking agent should be controlled when a crosslinked polymer film is prepared by the reaction of the crosslinking agent with a polymer compound having a reaction point with the crosslinking agent. It was found that the mesh size can be adjusted easily. When it is desired to increase the mesh size, the concentration of the crosslinking agent to be added is decreased. Conversely, when it is desired to decrease the network size, the concentration of the crosslinking agent to be added is increased.

  The method for forming the three-dimensional network structure in the swollen crosslinked polymer film 11 is not particularly limited, and a known method can be used. Instead of reacting the polymer chain with the crosslinking agent, irradiation with active energy rays such as ultraviolet rays, visible rays, and electron beams induces reactions such as addition reaction, polycondensation, radical polymerization, etc. A network structure may be obtained.

  The average network size of the three-dimensional network structure of the swollen crosslinked polymer film 11 can be calculated by multiplying the hydrodynamic radius ξ obtained by the scanning microscopic light scattering method by 2. The average mesh size in the present embodiment is preferably in the range of 1 nm or more and 20 nm or less. When the thickness is less than 1 nm, the time for filtering the fluid becomes very long, which may result in poor productivity. Further, if the thickness exceeds 20 nm, the crosslinked polymer membrane is swollen, so that it may be difficult to maintain the shape dynamically as a filtration membrane. In such a case, a porous glass filter or the like may be used as a support, and a swollen crosslinked polymer film may be disposed. Of course, if such a problem does not occur, it is possible to classify the size of the nanoparticles according to the present invention using a crosslinked polymer film having an average network size of less than 1 nm and exceeding 20 nm.

  Here, a scanning microscopic light scattering method and a light scattering analyzer used in this measurement method will be described. First, a dynamic light scattering method widely used as a method for measuring the size of particles dispersed in a solution in a solution state will be described. The dynamic light scattering method is a method for analyzing the fine structure inside a solution from 1 μm or less to 0.1 nm from its mobility by measuring the thermal motion occurring inside the solution through the light scattering phenomenon. . A dynamic light scattering method using a visible light laser as a light source is widely used as a method for directly measuring the size of particles dispersed in a solution in a solution state.

  This dynamic light scattering method can be used to analyze the fine network structure of the gel. However, in general, the scattered light from the gel inevitably contains an excessive scattering component caused by the interference of the scattered light due to the inhomogeneity of the network structure inside the gel. There was no way to analyze.

  In order to solve the above problem, a scanning microscopic light scattering method has been developed (see Non-Patent Document 8 and Non-Patent Document 9). In this scanning microscopic light scattering method, it is possible to determine the measurement amount of the statistical average (ensemble average) in which the time average and the spatial average are correctly performed by strictly considering the excessive component of the scattered light caused by the non-uniformity. As a result, a complex fine structure of a transparent sample such as a gel can be analyzed using a visible light laser as a light source. That is, a method for determining an ensemble average correlation function based on a new mathematical formula derived by taking into account multiple scattered light occurring in a non-uniform sample (Non-Patent Document 10), and time-series data of photon pulses measured by light scattering As a result, the light scattering analysis method and the light scattering analysis device for analyzing the fine structure of the non-uniform gel existing in the solvent have been completed. Patent Document 5).

  The above light scattering analysis method includes the observation of scattered light intensity over time, derivation of time average correlation function, derivation of ensemble average autocorrelation function, inverse Laplace transform of ensemble average autocorrelation function, derivation of co-diffusion coefficient, hydrodynamics It consists of the calculation of the radius (ξ) and the average mesh size (2ξ) (Non-Patent Document 9, Non-Patent Document 11). This light scattering analyzer can accurately determine the average network size (2ξ) of the crosslinked polymer film present in the solvent according to the present invention. Here, the calculated average mesh size roughly follows a normal distribution and corresponds to the pore size of the mesh having the highest abundance ratio among the existing mesh sizes. The distribution of the mesh size depends on the type of the crosslinked polymer used, but it is desirable that the average mesh size multiplied by 1.3 is the maximum mesh size. When the maximum mesh size is larger than the value obtained by multiplying the average mesh size by 1.3, the threshold for cutoff is increased, and the particle size distribution of the nanoparticles contained in the filtrate becomes wide.

  Next, a method for separating the size of the nanoparticles using the ultrafiltration device 100 will be described. By supplying a fluid to be filtered 18 in which particles are dispersed in an organic solvent other than water into the housing 12 of the ultrafiltration device 100, particles 22 having a particle size larger than the maximum mesh size of the swollen crosslinked polymer membrane 11 are obtained. Can be cut off. The maximum mesh size varies depending on the mesh size distribution, but is within a value obtained by multiplying the average mesh size observed by the scanning microscopic light scattering method by 1.3. Then, the particles 21 and the organic solvent having a particle size smaller than the maximum mesh size permeate the swollen crosslinked polymer membrane 11 and are accommodated in the filtrate container. From the obtained filtrate 20, particles 21 having a particle size smaller than the maximum mesh size can be obtained. If the particles can be dispersed in an organic solvent other than water and do not chemically react with the swollen crosslinked polymer membrane 1 or do not undergo irreversible adsorption, size separation is possible. However, it is preferable that the physical interaction with the swollen crosslinked polymer film 11 is small from the viewpoint of suppressing the loss of the particle size due to filtration.

  By providing non-polar groups such as alkyl groups on the surface of the particles, particles dispersed in an organic solvent can be easily prepared. Suitable particles include core-shell particles whose shell part is composed of an organic group containing a methylene chain. By introducing an organic group containing a methylene chain into the shell portion, the core-shell particles can be easily nonpolarized. Examples of the organic group containing a methylene chain in the shell part include alkylamine, alkylthiol, and alkyldiol. The alkyl group containing a methylene chain constitutes the outermost layer of the core-shell particle and is dispersed in the organic solvent. Polar functional groups such as amino groups, thiol groups, and dithiol groups are mainly adsorbed on the surface of the metal or metal oxide nanoparticles in the core. Depending on the dielectric constant of the organic solvent used for dispersing the core-shell particles, the polar functional group may be exposed on the outermost surface of the core-shell particles. The shell portion may be a high molecular compound as well as a low molecular organic compound. As a suitable example of a core part, a metal or a metal oxide can be mentioned.

  There are no particular restrictions on the core metal, metal oxide, metal sulfide, and metal selenium compound. Gold, platinum, silver, palladium, rhodium, iridium, ruthenium, osmium, tungsten, nickel, copper, tantalum, bismuth, Lead, zinc, tin, titanium, aluminum, iron and the like, and oxides, sulfides and selenium compounds thereof can be mentioned. The metal may be a mixture of multiple types of metals. Nanoparticles exhibiting fluorescence such as cadmium sulfide and cadmium selenide may be used.

  The bonding form of the core part and the shell part may be not only a chemical bond but also a physical bond such as electrostatic interaction. The organic solvent in which the core-shell particles are dispersed is not particularly limited as long as it is an organic solvent other than water and does not react with the crosslinked polymer film. For example, ethanol, acetone, acetonitrile, aniline, benzonitrile, butanol, chlorobenzene, chloroform, cyclohexane, dimethylformamide, ether, isopropanol, methanol, nitrobenzene, pentane, phenol, propanol, α-terpineol, toluene, benzene, heptane, hexane, Octane is mentioned. Preferably, toluene, hexane, octane, α-terpineol and the like are used. It is not limited to one type of solvent, and may be a mixture of a plurality of organic solvents or an additive such as a dispersant may be added as necessary.

  In the scanning microscopic light scattering method for obtaining the average network size of the swollen crosslinked polymer film, it is preferable that the refractive index of the swollen crosslinked polymer film and the refractive index of the organic solvent used for swelling be equal or as equal as possible. The organic solvent in the filtration target fluid 18 is not necessarily the same as the organic solvent that swells the swollen crosslinked polymer film 11, but as described above, the average network size of the crosslinked polymer film depends on the type of the organic solvent. Since it may vary, it is preferable to use the same solvent or an organic solvent having a similar polarity. When the organic solvent in the filtration target fluid 18 is different from the organic solvent used for the analysis of the average mesh size by the scanning microscopic light scattering method, the volume of the crosslinked polymer film before swelling is measured, and the organic solvent is used as the organic solvent. The soaked volume after swelling can be measured, and an organic solvent that substantially matches the organic solvent used in the above analysis can be used. In the case of a crosslinked polymer film that is isotropically swollen by an organic solvent, measure the area or film thickness of the crosslinked polymer film before swelling, and measure the area or film thickness after swelling immersed in an organic solvent. An organic solvent that substantially matches the organic solvent used in the above analysis can be used. At this time, the organic solvent may be mixed with another organic solvent as necessary, or an additive such as a dispersant may be added.

The particle diameter of the core-shell particles according to this embodiment can be observed with a transmission electron microscope. In the case of core-shell particles in which the shell part is composed of an organic compound or a polymer compound, the core part made of metal, metal oxide, or the like has a higher electron density than the shell part.
For this reason, when observed with a transmission electron microscope, the electron beam transmission of the core part is hindered, and the core part is observed darker than the shell part. In addition, when the boundary of a shell part is not observed clearly, the diameter of a core part may be handled as a particle size of a nanoparticle.

The specific molecular structure of the swollen crosslinked polymer film 11 is not particularly limited as long as the above conditions are satisfied, but those having excellent flexibility have good durability, and the polymer chains in the swollen crosslinked polymer film 11 From the viewpoint of the straightness of the film and the uniformity of the free space in the network structure. Moreover, it is preferable that the swelling crosslinked polymer film 11 according to the present embodiment has a small physical interaction with particles in the fluid to be filtered. From this viewpoint, it is more preferable that the polarity is close to that of the particles to be filtered. When at least a part of the surface portion of the particle to be filtered is an alkyl group, the crosslinked polymer is also preferably nonpolar.

The swollen crosslinked polymer film 11 needs to have a mesh size 17 adjusted so as to have a network structure through which nanoparticles can permeate. Although it cannot be generally stated because it depends on the molecular structure of the crosslinked polymer and the type of organic solvent to be swollen, the crosslinking density is generally 1 × 10 ^{−4 in} number of crosslinking points [units / nm ³ ] per unit volume. / Nm ³ or more and 1 × 10 ¹ piece / nm ³ or less. If it is less than 1 × 10 ⁻⁴ pieces / nm ³ , it may be difficult to hold as a film.

流体力学的半径ξが０．５ｎｍから１０．０ｎｍの範囲である場合、相当する架橋密度は２．４×１０^−４個／ｎｍ^３以上、１．９個／ｎｍ^３以下の範囲となる。 When a polymer film having a three-dimensional crosslinked structure has reached a swelling equilibrium, the value obtained by multiplying the hydrodynamic radius ξ obtained by the scanning microscopic light scattering method by 2 is the average mesh size 2ξ, and the crosslinking point Can be thought of as the distance between. Here, the hydrodynamic radius ξ can be regarded as the radius of the hard sphere formed by the polymer chain constituting the network during cooperative diffusion, so the number of crosslinking points per 1 nm ³ is the crosslinking density Z It can obtain | require from Formula <1> of these.

When the hydrodynamic radius ξ is in the range of 0.5 nm to 10.0 nm, the corresponding crosslinking density is in the range of 2.4 × 10 ⁻⁴ pieces / nm ³ or more and 1.9 pieces / nm ³ or less.

  A general organogel can be used for the swollen crosslinked polymer film. Examples of the polymer resin forming the organogel include polysaccharide derivatives, vinyl polymers, and condensation polymers. Specific examples of the polysaccharide derivative include ethyl cellulose, ethyl hydroxyethyl cellulose gel, cellulose acetate, hydroxypropyl cellulose, cyclodextrin and the like. Also included are oscillating gels utilizing cyclodextrin inclusion. Examples of the vinyl polymer include a polymer resin obtained by thermally or photopolymerizing a monomer or a macromonomer in the presence of a crosslinking agent containing a plurality of vinyl groups, acryloyl groups, and methacryloyl groups.

  Specific examples of the vinyl polymer include poly (styrene), poly (methacrylic acid (2-phenyl-1,3-dioxolan-4-yl) methyl ester) (PDMMA), and poly (N, N-acrylic acid). Dimethylaminoethyl ester), poly (acryloxypropanesulfonic acid), poly (acrylonitrile), poly (N-isopropylacrylamide) (PNIPAm), poly (chloromethylstyrene), poly (divinylbenzene), poly (hydroxyethyl methacrylate) Esters) (PHEMA), poly (vinyl pyridine), poly (vinyl pyrrolidone) (PVP), poly (methyl methacrylate) (PMMA), poly (N-methylolacrylamide), poly (methoxyethylene glycol methacrylate), isobutylene-malein Acid copolymer, polyethylene Emissions, poly (ethylene imine), ethylene - vinyl acetate copolymer, styrene - butadiene copolymer (SBR), poly (tetrafluoroethylene), may be mentioned malonic acid dinitrile and the like. Specific examples of the condensation polymer include poly (siloxane), ladder-type polysiloxane, silica, silicone resin, nylon, polyurethane, polyethylene glycol, polypropylene oxide, poly-L-leucine, polyimide, polyamic acid, and the like. . In addition, 12-hydroxystearic acid or the like that can form an organogel by mixing with a low molecular weight compound with an organic solvent can also be used.

  Alternatively, a monomer or macromonomer may be polymerized in advance to obtain a soluble polymer resin, and an inactive polymer resin may be obtained by irradiating an active energy ray such as an electron beam or ultraviolet light after molding. The molecular weight of the soluble polymer is not particularly limited. For example, the number average molecular weight can be about several hundred to several million. When forming a three-dimensional network structure, it is more preferable that the distribution of the network size is small. From this point of view, it is preferable that the crosslinked polymer film is composed of polymer chains having a single type or a similar structure. In addition, it is preferable to carry out the crosslinking reaction under mild conditions while taking care not to vary the crosslinking conditions depending on the location so that the crosslinking density is uniform.

ただし、この一般式は単に組成を示し、構造を示すものではない。即ち、（ＳｉＲ^６Ｒ^７Ｏ）と（ＳｉＨＲ^８Ｏ）とがランダムに結合していてもよい。 Specific examples of the silicone resin include organopolysiloxane (1) represented by the following general formula (1) and organohydrogenpolysiloxane (2) represented by the following general formula (2).

However, this general formula merely indicates the composition and does not indicate the structure. That is, (SiR ⁶ R ⁷ O) and (SiHR ⁸ O) may be bonded at random.

R ^{1 to} R ⁴ each represent a reactive group having reactivity with an aliphatic or aromatic monovalent hydrocarbon having 1 to 20 carbon atoms or a SiH group, and includes at least two of these reactive groups in one molecule. . R ^{1 to} R ⁴ do not contain a SiH group. Examples of the reactive group having reactivity with the SiH group include an alkoxy group, an alkenyl group, an acryloyloxy group, a methacryloyloxy group, and a vinylphenyl group, and preferably a vinyl group, an acryloyloxy group, a methacryloyloxy group, or a vinyl. It is a phenyl group.

As an aliphatic or aromatic monovalent hydrocarbon having 1 to 20 carbon atoms, a methyl group or a phenyl group is preferable, and a methyl group is more preferable. R ^{1 to} R ⁴ may be the same or different, and R ² and R ³ may be mixed with two or more groups. For example, the organopolysiloxane (1) may have a mixture of a methyl group and a phenyl group as R ^{2 in} one molecule. The same applies to R ³ .

R ^{5 to} R ⁹ represent an aliphatic or aromatic monovalent hydrocarbon having 1 to 20 carbon atoms, preferably a methyl group or a phenyl group, and more preferably a methyl group. Moreover, these R < ⁵ > -R < ⁹ > may be same or different, respectively, and also R < ⁶ >, R < ⁷ >, R < ⁸ > may each contain 2 or more types of groups. For example, the organohydrogenpolysiloxane (2) may have a mixture of a methyl group and a phenyl group as R ^{6 in} one molecule. The same applies to R ⁷ and R ⁸ . l, m, and n each represents an integer corresponding to a molecular weight of about 200 to 50,000, and n is 2 or more.

  Crosslinks with a degree of crosslinking controlled between the reactive groups such as alkenyl groups, acryloyloxy groups, methacryloyloxy groups and vinylphenyl groups of the organopolysiloxane (1) and the SiH groups of the organohydrogenpolysiloxane (2). . The crosslinked polymer membrane according to this embodiment may contain a catalyst and other additives as necessary.

  In order to adjust the mesh size so that particles of a desired size can pass through, as described above, the type of organic solvent, the type of cross-linking agent, the concentration of the cross-linking agent to be added, the cross-linking conditions, the polymer chain to be used, etc. Select. The upper limit of the mesh size of the three-dimensional network structure according to the present embodiment is determined according to the particle size of the size to be cut off by filtration. In the present embodiment, the range that can be collected as the filtrate is smaller than the mesh size.

  FIG. 3 is a cross-sectional explanatory diagram when filtering using the ultrafiltration device 100 according to the present embodiment. In the present embodiment, the filtration target fluid 18 is supplied into the housing 12. In order to make the dispersion liquid easily penetrate the membrane, the dispersion liquid may be pressurized to about 0.01 to 1.0 MPa, for example. The fluid 18 to be filtered penetrates with a concentration gradient as a driving force, and particles and organic solvents smaller than the mesh size can be obtained as a filtrate.

  According to the ultrafiltration membrane of the present embodiment, the mesh size can be uniformly expanded and adjusted by a simple method by swelling the crosslinked polymer membrane with an organic solvent. Moreover, since the area and film thickness of a filtration membrane having such a mesh size can be easily changed, the shape and form can be flexibly changed according to the application. Moreover, since particles larger than the network size of the crosslinked polymer membrane can be cut off by the filtration method, the operability is good and the particles can be easily used. In addition, it is easy to adjust the cut-off threshold value of the particle diameter in the fluid to be filtered to a range of 1 nm to 20 nm. As a result, the size of particles of about 1 nm to 20 nm can be separated very easily. In particular, it has an excellent effect that the size range of 1 nm to 10 nm, which has not been put into practical use, can be easily separated. Moreover, since versatility is high, cost reduction can also be realized.

  In this embodiment, the network size can be easily homogenized by sufficiently swelling the crosslinked polymer film with an organic solvent. Therefore, a system that allows only nanoparticles having a specific particle size or less to pass through can be established, and the size separation of the particles of the fluid to be filtered can be performed with high accuracy.

The ultrafiltration apparatus 100 may be used as a means for removing dust such as a solution resist composition. The resist film pattern has a resolution of the order of several nanometers. Therefore, it is extremely important to remove so-called dust such as nanometer-level particles.
As described above, a method for simply separating the size of 1 to 10 nm nanoparticles has not been put to practical use. The ultrafiltration device 100 according to this embodiment is useful as a means for removing dust such as a resist composition, particularly nanoparticles of 1 to 10 nm.

  In the present embodiment, the cylindrical body is taken as an example of the casing, but is not limited to this. For example, a mesh-like wire net or porous glass may be formed on the bottom, and a crosslinked polymer membrane (ultrafiltration membrane) may be placed thereon. Further, a pressure device may be attached to the ultrafiltration device 100. Thereby, the filtration rate can be increased. Further, a support such as a support film having a pore size larger than the mesh size of the crosslinked polymer film may be laminated on the upper surface and / or the lower surface of the crosslinked polymer film. Further, a plurality of crosslinked polymer films may be laminated. The nanoparticles trapped in the ultrafiltration membrane are recovered by passing an organic solvent that further swells the crosslinked polymer membrane, and the filtration membrane is washed.

[Example]
EXAMPLES Next, the present invention will be described more specifically with reference to examples. However, the scope of the present invention is not limited to the following examples. The reagents and the like described below are generally commercially available unless otherwise specified.

<Measurement of network size of crosslinked polymer film>
The average mesh size (2ξ) of the swollen silicone resin was calculated by a light scattering analyzer based on the scanning microscopic light scattering method. The analysis was performed under the following conditions.
Visible laser wavelength (λ): 5.32 × 10 ⁻⁷ [m]
Laser light output: 250 [mW]
Sample temperature (T): 303 [K]
Observation unit volume: 30 [ μm ³ ]
Scattered light detection angle (θ): 30, 40, 45, 50, 55 °
Unit scanning distance of z axis: 33 [ μm ]
Scattered light sampling time per observation unit volume: 90 [s]
Number of observation unit volumes: 31
Refractive index (n) of organic solvent (toluene): 1.5
Viscosity (η) of organic solvent (toluene): 0.59 [Pa · s]
Observation sample size: 10 [mm] × 10 [mm] × 10 [mm]

ここで、ｑは散乱ベクトルの大きさであり、以下の式＜３＞より求まる。

このとき、Ｅｉｎｓｔｅｉｎ−Ｓｔｏｋｅｓの式を用いると、以下の式＜４＞から流体力学的半径ξが求まる。そして、これに２を乗じることにより平均網目サイズ２ξを決定できる。

ここで、ｋ_Ｂ＝１．３８×１０^−２３［Ｊ／（Ｋ・ｍｏｌ）］はＢｏｌｔｚｍａｎｎ定数である。 Measurement is performed under these conditions, and fast relaxation Γ _c [s ⁻¹ ] due to cooperative diffusion (gel mode) of the gel network is measured from the ensemble average correlation function. From Γ _c , the cooperative diffusion coefficient D _c is obtained by the following formula <2>.

Here, q is the size of the scattering vector, and is obtained from the following formula <3>.

At this time, when the Einstein-Stokes equation is used, the hydrodynamic radius ξ is obtained from the following equation <4>. Then, by multiplying this by 2, the average mesh size 2ξ can be determined.

Here, k _B = 1.38 × 10 ⁻²³ [J / (K · mol)] is a Boltzmann constant.

なお、本実施例においては有機溶媒としてトルエンを用いているが、他の有機溶媒でも同様にして膨潤度を求めることができる。 <Measurement of degree of swelling of crosslinked polymer film>
From the following formula <5>, the weight of the crosslinked polymer film before swelling is W ₀ (g), and the weight of the crosslinked polymer film after being immersed in a sufficient amount of an organic solvent for a sufficient time is W ₁ (g). The degree of swelling S (%) was determined. In this example, the weight of the crosslinked polymer film after 1 day was defined as W ₁ (g).

In this embodiment, toluene is used as the organic solvent, but the degree of swelling can be obtained in the same manner with other organic solvents.

<Measurement of core-shell particle size>
The particle diameter of the core-shell particles was measured using a transmission electron microscope. In this example, as described later, the diameter of the gold nanoparticles in the core portion of the gold nanoparticles coated with decanethiol is used as the particle size of the used nanoparticles. If decanethiol is an all-trans structure, the maximum molecular length is about 1.2 nm. Therefore, the particle size of the decanethiol-coated gold nanoparticles may be considered to be larger than the particle size of the core portion made of gold and smaller than twice the sum of the core portion and the maximum molecular length.

分散は、標準偏差の２乗（ｓ^２）で与えられる。 A specific observation method and a particle size evaluation method will be described. The decanethiol-coated gold nanoparticles dispersed in the solvent toluene were applied to a copper grid with a carbon support film and dried, and then photographed with a transmission electron microscope at 500,000 times magnification. The photograph taken was digitized with a scanner at a resolution of 1200 dpi, and the diameter (X) of the core part of 500 particles was measured. Here, assuming that the diameter of the _n-th core part is _Xn , the average size (X _ave ) and standard deviation (s) of the core part of decanethiol-coated gold nanoparticles are represented by the following formulas <6><7>, respectively. Can be calculated.

The variance is given by the standard deviation squared (s ² ).

Example 1
As an example of the crosslinked polymer film, an example using a silicone resin will be described. The silicone resin was obtained by reacting a base resin with a crosslinking agent. As the base resin, Sylgard 184-A (Lot. No. 30JAN2006) manufactured by DawCorning was used, and as the cross-linking agent, Sylgard 184-B (Lot. No. 30JAN2006) was used. 9.85 g of base resin and 0.15 g of a crosslinking agent were mixed to prepare a crosslinked polymer precursor liquid 10 having a crosslinking agent concentration of 1.5 wt%. As shown in FIG. 4, the crosslinked polymer precursor liquid 10 can have a crosslinked structure by a hydrosilylation reaction between the vinyl group at the terminal of the base resin and dimethyl / methylhydrogensiloxane contained in the crosslinking agent. (Refer nonpatent literature 12).

  FIG. 5 is a schematic cross-sectional view for explaining the manufacturing method of the ultrafiltration device of the first embodiment. The ultrafiltration device 100a includes a swollen silicone film 11a that is a swollen crosslinked polymer film, a housing 12a, and the like. First, the silicon substrate 23 was prepared, and this was cleaned by vacuum ultraviolet irradiation (emission wavelength: 172 nm) for 300 seconds under a reduced pressure of 1 kPa using a xenon excimer lamp (manufactured by USHIO INC.). Then, the silicon substrate 23 with the natural oxide film is dipped in trimethylchlorosilane (manufactured by Aldrich) and dried by blowing nitrogen gas to obtain a hydrophobic silicon substrate 23 on which the trimethylchlorosilane monomolecular film 24 is formed. It was. The smooth surface of the hydrophobic silicon substrate 23 was placed horizontally, and was in close contact with the smooth surface so that the bottom of a silicone rubber cylindrical mold (outer diameter 16 mm, inner diameter 15 mm, height 15 mm) was in contact (FIG. 5). (See (a)).

This cylindrical part is used as a housing 12a, and 0.15 g of the crosslinked polymer precursor liquid 10 is poured into the casing 12a. After confirming that the crosslinked polymer precursor liquid 10 does not leak, it is heated in an oven at 65 ° C. for 12 hours. Went. As a result, a silicone film 10a as a crosslinked polymer film having a diameter of 15 mm and a thickness of 1 mm was obtained. Thereafter, the silicone membrane 10a crosslinked with housing 12a is peeled from the silicon substrate 2 3, one bottom of the housing 12a to obtain what was filled with silicone membrane 10a. Next, the silicone film 10a was immersed in 100 mL of an organic solvent toluene to sufficiently swell the silicone film (polydimethylpolysiloxane (PMDS)).

  Subsequently, the organic solvent toluene was poured into the cylinder from the upper side of the housing 12a, and the toluene was permeated from the swollen silicone film, so that the unreacted base resin and the crosslinking agent were eluted and removed. The swollen gel-like silicone film (swelled crosslinked polymer film) according to Example 1 is hereinafter referred to as “swelled silicone film 1”. The degree of swelling in “swelled silicone film 1” was 1290%. The average mesh size 2ξ of the “swelled silicone film 1” observed with a scanning microscopic light scattering (SMILS) apparatus was 10.43 ± 0.44 nm.

(Example 2)
A silicone film was prepared in the same manner as in Example 1 except that the concentration of the crosslinking agent was 2.0 wt%. Specifically, a silicone film was prepared by preparing a crosslinked polymer precursor liquid 2 in which 9.80 g of the base resin and 0.20 g of the crosslinking agent were mixed. The obtained film is referred to as “swelling silicone film 2”. The degree of swelling of “swelled silicone film 2” swollen with toluene was 589%. The average mesh size 2ξ of “swelled silicone film 2” observed by a scanning microscopic light scattering (SMILS) apparatus was 6.53 ± 0.48 nm.

(Example 3)
A silicone film was prepared in the same manner as in Example 1 except that the concentration of the crosslinking agent was 3.0 wt%. Specifically, a silicone film was prepared by preparing a crosslinked polymer precursor liquid 3 in which 9.70 g of the base resin and 0.30 g of the crosslinking agent were mixed. The obtained film is referred to as “swelling silicone film 3”. The degree of swelling of “swelled silicone film 3” swollen with toluene was 475%. The average mesh size 2ξ of the “swelled silicone film 3” observed by a scanning microscopic light scattering (SMILS) apparatus was 4.06 ± 0.08 nm.

Example 4
A silicone film was prepared in the same manner as in Example 1 except that the concentration of the crosslinking agent was 4.0 wt%. Specifically, a crosslinked polymer precursor liquid 4 in which 9.60 g of base resin and 0.40 g of a crosslinking agent were mixed was prepared to prepare a silicone film. The obtained film is referred to as “swelling silicone film 4”. The degree of swelling of “swelled silicone film 4” swollen with toluene was 372%. The average mesh size 2ξ of the “swelled silicone film 4” observed by a scanning microscopic light scattering (SMILS) apparatus was 2.74 ± 0.37 nm.

(Example 5)
A silicone film was produced in the same manner as in Example 1 except that the concentration of the crosslinking agent was 6.0 wt%. Specifically, a silicone film was prepared by preparing a crosslinked polymer precursor solution 5 in which 9.40 g of base resin and 0.60 g of a crosslinking agent were mixed. The obtained film is referred to as “swelling silicone film 5”. The degree of swelling of “swelled silicone film 5” swollen with toluene was 275%. The average mesh size 2ξ of the “swelled silicone film 5” observed by a scanning microscopic light scattering (SMILS) apparatus was 1.78 ± 0.13 nm.

(Example 6)
A silicone film was prepared in the same manner as in Example 1 except that the concentration of the crosslinking agent was 10.0 wt%. Specifically, a silicone film was prepared by preparing a crosslinked polymer precursor liquid 2 in which 9.00 g of the base resin and 1.00 g of a crosslinking agent were mixed. The obtained film is referred to as “swelling silicone film 6”. The degree of swelling of “swelled silicone film 6” swollen with toluene was 201%. The average mesh size 2ξ of “swelled silicone film 6” observed by a scanning microscopic light scattering (SMILS) apparatus was 1.20 ± 0.23 nm.

  FIG. 6A shows a plot of the degree of swelling against the concentration of the crosslinking agent added to the swollen silicone film according to Examples 1 to 6 above. From the figure, it can be seen that the degree of swelling increases as the concentration of the added crosslinking agent decreases. This suggests that when the crosslink density is lowered, the mesh size of the three-dimensional network structure is increased, and the space 16 for taking in the organic solvent is increased. FIG. 6B shows a plot of the correlation length against the concentration of the crosslinking agent added to the swollen silicone film according to Examples 1-6. From the figure, it can be seen that the correlation length increases as the concentration of the added crosslinking agent decreases. This suggests that the network size of the three-dimensional network structure increases as the crosslinking density decreases. What is necessary is just to manufacture a crosslinked polymer film by controlling the concentration of the crosslinking agent according to the particle size of the particles to be cut off. Of course, the mesh size can also be adjusted by the type of organic solvent.

(Example 7)
<Synthesis of "decyl group-protected gold nanoparticle 1">
Gold nanoparticles having an alkyl group in the shell portion were synthesized according to Non-Patent Document 13. The alkyl group of the modifying group was introduced into the outermost layer of the gold nanoparticle using decanethiol containing a decyl group. A specific synthesis method is as follows. First, 0.66 g (1.2 mmol) of tetraoctylammonium bromide (manufactured by Wako) was dissolved in 160 mL of toluene, and 0.27 g (0.00%) of chloroauric acid tetrahydrate (manufactured by Wako) was dissolved in this solution. 6 mmol) was added. Next, a solution prepared by dissolving decanethiol (manufactured by Wako) 0.10 g (0.6 mmol) in 20 mL of toluene was added and stirred for 10 minutes.

  Further, a solution prepared by dissolving 0.23 g (6.0 mmol) of sodium borohydride (Wako) in 20 mL of deionized water was added and stirred for 12 hours. After 12 hours, stirring was stopped and the mixture was allowed to stand to separate into an organic phase and an aqueous phase. The organic phase was taken out by liquid separation and concentrated to dryness at room temperature using an evaporator. Next, 30 mL of toluene and 300 mL of methanol were added and stirred for 30 minutes. Thereafter, centrifugation was performed at 10,000 rpm for 30 minutes to remove the supernatant. Methanol was added to the dark purple substance collected at the bottom of the centrifuge tube and dispersed again in the solvent. Further, centrifugation at 10,000 rpm was performed for 30 minutes, and the supernatant was removed again. After repeating the washing operation with methanol twice, the dark purple substance at the bottom of the centrifuge tube was dried to dryness at room temperature under reduced pressure to obtain “decyl group-protected gold nanoparticles 1”.

Toluene was added to “decyl group-protected gold nanoparticles 1” to prepare “core-shell particle dispersion 1” containing 5 wt% of “decyl group-protected gold nanoparticles 1”. This “core-shell particle dispersion 1” was applied to a copper grid with a carbon support film and dried, and then 500 particle sizes were measured with a transmission electron microscope. The average particle diameter of the core part of the dodecyl group-protected gold nanoparticles was 2.0 nm, the standard deviation s was 0.8 nm, and the dispersion s ² was 0.7. The maximum size of the core part was 6 nm. FIG. 7A shows the particle size distribution of particles dispersed in “core-shell particle dispersion 1”.

<Synthesis of "decyl group-protected gold nanoparticle 2">
Decyl group-protected gold nanoparticles having a large core part were prepared according to Non-Patent Document 13. That is, the above-mentioned “decyl group-protected gold nanoparticle 1” dried under reduced pressure was placed in a glass container, and the container was placed in an oven. Then, the temperature was increased from room temperature to 160 ^° C. at a temperature rising rate of 2 ° C./min, and heated at 160 ^° C. for 30 minutes. After a predetermined heating time, it was quickly removed from the oven and cooled to room temperature, and then 30 mL of toluene and 300 mL of methanol were added and stirred for 30 minutes. Centrifugation at a rotation speed of 10,000 rpm for 30 minutes and washing by decantation of methanol were repeated twice in the same manner as in the production of “decyl group-protected gold nanoparticle 1”, and concentrated to dryness. Protective gold nanoparticles 2 ”were obtained.

Toluene was added to “decyl group-protected gold nanoparticles 2” to prepare “core-shell particle dispersion 2” containing 5 wt% of “decyl group-protected gold nanoparticles 2”. After applying this “core-shell particle dispersion 2” to a copper grid with a carbon support film and drying it, 500 particles were observed with a transmission electron microscope. As a result, the average particle diameter of the core part of the gold nanoparticle was The standard deviation s was 5.5 nm and the dispersion s ² was 2.8. The maximum particle size of the core part was 11 nm. FIG. 7B shows the particle size distribution of particles dispersed in the “core-shell particle dispersion 2”.

<Preparation of bimodal core-shell particle dispersion>
In order to demonstrate that the swelled silicone membranes according to Examples 1 to 6 are effective as a nanoparticle filter, a solution of gold nanoparticles having two peaks in the particle size distribution (bimodal) was prepared. . The above-mentioned “decyl group-protected gold nanoparticle 1” having an average particle diameter of 2.0 nm and “decyl group-protected gold nanoparticle 2” having an average particle diameter of 5.5 nm are mixed with the same weight, and the content of the nanoparticles is 5 wt. Toluene was added so that it might become%. This solution is referred to as “core-shell particle dispersion 3”. As a result of observing 500 particles with a transmission electron microscope, it was confirmed that the particle size of the gold core portion had a maximum distribution at 2.2 nm and 5.5 nm. The maximum particle size of the core is 9 nm. Using this “core-shell particle dispersion 3”, permeation experiments of the swollen silicon membranes of Examples 1 to 6 were conducted. FIG. 8 shows the particle size distribution of particles dispersed in the “core-shell particle dispersion 3”.

(Example 8)
Using “core-shell particle dispersion 3”, the performance of the swollen silicone membranes produced in Examples 1 to 6 was evaluated. “Core-shell particle dispersion 3” was injected from the upper surface of the housing 12a, and the filtrate after 270 minutes was collected, with the time of injection being 0 minutes. The obtained filtrate was observed with a transmission electron microscope. The average size (X _ave ) and maximum size (D _max ), standard deviation (s), and dispersion (s ² ) of the core part of decanethiol-coated gold nanoparticles that permeated the swollen silicone membrane were evaluated. The results are shown in Table 1.

上記の判定結果から、平均網目サイズ（２ξ）が１０．４３±０．４４ｎｍである「膨潤シリコーン樹脂１」から、最大粒径１０．４ｎｍの被覆粒子が透過したことがわかる。また、平均網目サイズ（２ξ）が６．５３±０．４８ｎｍである「膨潤シリコーン樹脂２」から、最大粒径６．４ｎｍの被覆粒子が透過したことがわかる。また、平均網目サイズ（２ξ）が４．０６±０．０８ｎｍである「膨潤シリコーン樹脂３」から、最大粒径４．９ｎｍの被覆粒子が透過したことがわかる。平均網目サイズに１．３を乗じた値より大きな粒子は、「膨潤シリコーン樹脂１」から「膨潤シリコーン樹脂６」においていずれの場合も確認されなかった。 The evaluation criteria for filtration performance were as follows.
Judgment 1: Film in which decanethiol-coated gold nanoparticles are not permeated, and only organic solvent is permeated Judgment 2: Film having maximum particle diameter (D _max ) of permeated particle core is 4 nm or less Judgment 3: Permeated particle core Film with a maximum particle size of 8 nm or less

From the above determination results, it can be seen that the coated particles having the maximum particle size of 10.4 nm are transmitted from “swelling silicone resin 1” having an average mesh size (2ξ) of 10.43 ± 0.44 nm. Further, it can be seen from the “swelled silicone resin 2” having an average mesh size (2ξ) of 6.53 ± 0.48 nm that coated particles having a maximum particle size of 6.4 nm are transmitted. Further, it can be seen from the “swelled silicone resin 3” having an average mesh size (2ξ) of 4.06 ± 0.08 nm that coated particles having a maximum particle size of 4.9 nm were transmitted. Particles larger than the value obtained by multiplying the average mesh size by 1.3 were not confirmed in any of “swelled silicone resin 1” to “swelled silicone resin 6”.

  FIG. 9A shows the particle size distribution of the particles in the filtrate when the “core-shell particle dispersion 3” is filtered using the “swelled silicone resin 2”. FIG. 9B shows the “core-shell particle dispersion”. 3 "shows the particle size distribution of the particles in the filtrate when filtered using" swelling silicone resin 3 ".

(A) is a typical perspective view for demonstrating an example of the ultrafiltration apparatus which concerns on this embodiment, (b) is Ib-Ib cutting part sectional drawing of Fig.1 (a). (A), (b) is typical explanatory drawing of the three-dimensional network structure of the crosslinked polymer film which concerns on this embodiment. Cross-sectional explanatory drawing at the time of filtration of the ultrafiltration apparatus which concerns on this embodiment. The figure for demonstrating the synthesis method of the crosslinked polymer which concerns on a present Example. The typical sectional view of the ultrafiltration device concerning this example. (A) is a figure which shows the swelling degree of the swelling silicone film | membrane with respect to the crosslinking agent density | concentration which concerns on a present Example, (b) is a figure which shows the correlation length of the silicone film | membrane with respect to the crosslinking agent density | concentration which concerns on a present Example. (A) is a figure which shows the particle diameter distribution of the "core-shell particle dispersion liquid 1" which concerns on a present Example, (b) is a figure which shows the particle diameter distribution of the "core-shell particle dispersion liquid 2" which concerns on a present Example. The figure which shows the particle diameter distribution of the "core-shell particle dispersion liquid 3" which concerns on a present Example. (A) is a diagram showing the particle size distribution of the filtrate obtained by filtering the “core-shell particle dispersion 3” according to this example using the “swelled silicone membrane 2”, and (b) is the “core-shell particle dispersion” according to this example. The figure which shows the particle diameter distribution of the filtrate which filtered "Liquid 3" using "Swelling silicone membrane 3".

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Crosslinked polymer precursor liquid 10a Silicone film 11 Swelling crosslinked polymer film 12 Housing 13 Polymer main chain part 14 Bridged part 15 Crosslinking point 16 Space part 17 Mesh size 18 Filtration target fluid 19 Filtrate container 20 Filtrate 21 smaller than mesh size Particle 22 Particle 23 larger than mesh size Silicon substrate 100 Ultrafiltration device

Claims (9)

An ultrafiltration membrane comprising a crosslinked polymer membrane having a three-dimensional network structure and satisfying the following (1) to (3).
(1) The crosslinked polymer film is in a swelling equilibrium with an organic solvent.
(2) The average mesh size 2ξ calculated by multiplying the hydrodynamic radius ξ obtained from the cooperative diffusion coefficient of the crosslinked polymer film obtained by measurement by a scanning microscopic light scattering method by 2 is 1 nm or more and 20 nm. It is in the following range.
(3) When a fluid in which particles are dispersed in an organic solvent is supplied onto the crosslinked polymer film, particles having a particle size larger than the maximum mesh size of the crosslinked polymer film are cut off, and the maximum mesh size is The average mesh size is within a value obtained by multiplying 1.3 . In the ultrafiltration membrane according to claim 1,
The particles are core-shell particles;
The ultrafiltration membrane, wherein the core part of the core-shell particle is a metal, a metal oxide, a metal sulfide, or a metal selenium compound, and the shell part is an organic group containing a methylene chain. In the ultrafiltration membrane according to claim 1 or 2,
The cutoff threshold of the core-shell particles, or particle size 1.3 nm, ultrafiltration Filtration membrane in the range 26 nm. In the ultrafiltration membrane according to any one of claims 1 to 3 ,
An ultrafiltration membrane, wherein a main component of the crosslinked polymer membrane is a silicone resin. In the ultrafiltration membrane according to any one of claims 1 to 4,
The ultrafiltration membrane, wherein the crosslinked polymer membrane has a thickness of 0.05 mm or more and 50 mm or less . A method for producing an ultrafiltration membrane,
Synthesizing a crosslinked polymer film having a three-dimensional network structure;
Comprising the step of bringing the crosslinked polymer film into a swelling equilibrium with an organic solvent,
Before by adjusting the type of Kieu solvent the crosslinking density of the crosslinked polymer film, scanning microscopic light scattering method is determined by measuring by the crosslinked polymer film hydrodynamic radius obtained from cooperative diffusion coefficient ξ When the average mesh size 2ξ calculated by multiplying 2 by 2 is in the range of 1 nm or more and 20 nm or less and a fluid in which particles are dispersed in an organic solvent is supplied onto the crosslinked polymer film, the crosslinking height A method for producing an ultrafiltration membrane , wherein particles having a particle size larger than the maximum mesh size of the molecular membrane are cut off, and the maximum mesh size is within a value obtained by multiplying the average mesh size by 1.3 . In the manufacturing method of the ultrafiltration membrane of Claim 6 ,
The crosslinked polymer film is obtained by reacting a polymer compound with a crosslinking agent,
A method for producing an ultrafiltration membrane, wherein the crosslinking density is adjusted by the amount of the crosslinking agent added. In the manufacturing method of the ultrafiltration membrane of Claim 6 or 7 ,
The method for producing an ultrafiltration membrane, wherein the crosslinked polymer membrane has a thickness of 0.05 mm or more and 50 mm or less . A method for size separation of nanoparticles,
A crosslinked polymer film having a three-dimensional network structure having a crosslinked structure is brought into a swelling equilibrium with an organic solvent,
By adjusting the kind of the organic solvent and the cross-linking density of the cross-linked polymer film, the hydrodynamic radius ξ determined from the cooperative diffusion coefficient of the cross-linked polymer film determined by scanning microscopic light scattering method is 2 The average network size 2ξ calculated by multiplying by 1 is in the range of 1 nm or more and 20 nm or less, and a fluid in which nanoparticles are dispersed in an organic solvent is supplied to the crosslinked polymer film, whereby the crosslinked polymer A method for size separation of nanoparticles , wherein particles having a particle size larger than the maximum mesh size of the film are cut off, and the maximum mesh size is within a value obtained by multiplying the average mesh size by 1.3 .

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