JP4366687B2 - Method and apparatus for controlling amount of adsorption by light irradiation - Google Patents

Description

  The present invention relates to a method for reversibly changing the amount of a substance adsorbed on a porous adsorbent, and an apparatus therefor.

  As a method for reversibly changing the amount of adsorption of a substance adsorbed on a porous adsorbent, a pressure swing cycle adsorption (PSA) technique or a heating swing cycle adsorption (TSA) technique has been conventionally known. Japanese Patent Publication No. 2001-327829 (Patent Publication 1) describes a substance separation / purification apparatus (pressure swing adsorption apparatus) using PSA technology, and Japanese Patent Laid-Open No. 2003-175111 (Patent Publication 2). Describes a method for separating and purifying substances (thermal swing adsorption method) using TSA technology.

However, in order to use such separation / purification methods and adsorbent regeneration methods in fields such as microreactors and on-site separation devices that are promising recently, it is necessary to reduce the size and size of the devices. On the other hand, pressure swing cycle adsorption technology and heating swing cycle adsorption technology have the problem of pressure loss of the device and the necessity of excessive energy, and there is a limit to miniaturization and miniaturization of the device. Application to such a field was difficult.
JP 2001-327829 A JP 2003-175111 A

  The present invention has been made in view of the above-described problems of the prior art, and is a method for reversibly changing the amount of adsorption of a substance adsorbed on a porous adsorbent, and includes a pressure swing cycle adsorption technique and a heating swing cycle. It is an object of the present invention to provide a method in which the size and size of an apparatus can be easily reduced as compared with an adsorption technique, and an apparatus for carrying out the method.

  As a result of intensive studies to achieve the above object, the present inventors have determined that the adsorbed amount of the adsorbed substance on the porous adsorbent that absorbs light having a predetermined wavelength is irradiated with light having that wavelength. It is surprisingly different between the case where the light is irradiated (hereinafter referred to as “light irradiation state”) and the case where the light is not irradiated (hereinafter referred to as “light irradiation stopped state”), and the light irradiation state and the light irradiation stopped state. It has been found that the adsorption amount can be reversibly and actively changed by repeating the above, and the present invention has been completed.

That is, the adsorption amount control method of the present invention is:
A porous material comprising a silica-based mesoporous material that has an adsorption performance for an adsorbed substance and a dye that absorbs light having a predetermined wavelength and is incorporated in the skeleton of the silica-based mesoporous material. A first step of adsorbing the adsorbed substance to the porous adsorbent while irradiating the adsorbent with light having the predetermined wavelength at a first irradiation amount;
A second step of increasing or decreasing the irradiation amount of light having the predetermined wavelength as a second irradiation amount, and decreasing or increasing the amount of adsorption of the adsorbed substance in the porous adsorbent;
It is the control method of the adsorption amount by light irradiation characterized by including these.

Further, the adsorption amount control device of the present invention includes:
A porous material comprising a silica-based mesoporous material that has an adsorption performance for an adsorbed substance and a dye that absorbs light having a predetermined wavelength and is incorporated in the skeleton of the silica-based mesoporous material. An adsorbent,
A light irradiation device for irradiating the porous adsorbent with light having the predetermined wavelength;
A processing vessel in which the porous adsorbent is disposed;
A light shielding container for shielding the inside of the processing container from light other than light irradiated from the light irradiation device;
A pipe connected to the processing container, for introducing a fluid containing an adsorbed substance into the processing container and / or discharging the fluid from the processing container;
It is a control apparatus of the adsorption amount by light irradiation characterized by comprising.

  In the present invention, either the first irradiation amount or the second irradiation amount may be zero, and the first step is in the light irradiation stopped state and the second step is in the light irradiation state. In the second step, the adsorption amount of the substance to be adsorbed decreases. When the first step is in the light irradiation state and the second step is in the light irradiation stop state, the adsorption amount of the adsorbed substance increases in the second step. Will be. In addition, both the first step and the second step may be in a light irradiation state, and when the second irradiation amount is larger than the first irradiation amount, the adsorption amount of the substance to be adsorbed in the second step is If the second irradiation amount is smaller than the first irradiation amount, the adsorption amount of the substance to be adsorbed increases in the second step.

  In addition, although the reason why the adsorption amount reversibly changes by changing the light irradiation amount in the present invention is not necessarily clear, the present inventors infer as follows. That is, when irradiation with light having a wavelength is started or the irradiation amount is increased for a porous adsorbent that absorbs light having a predetermined wavelength, a non-radiative transition to a ground state of a molecule excited by light absorption or The temperature inside the porous adsorbent is slightly increased by the reversible photoreaction, and thereby the amount of the adsorbed substance that can be adsorbed on the porous adsorbent (adsorption equilibrium amount) is decreased. On the other hand, when the irradiation of such light is stopped or the irradiation amount is reduced, the temperature inside the porous adsorbent quickly decreases to a temperature without such non-radiative transition or reversible photoreaction, thereby causing porous adsorption. The amount of adsorbed substance that can be adsorbed on the agent (adsorption equilibrium amount) increases. And the transient change of the equilibrium state of the adsorption performance of the porous adsorbent by such light irradiation is not accompanied by an irreversible so-called photochemical reaction, but is caused by a reversible so-called physical adsorption property change. Therefore, the present inventors infer that the adsorption amount reversibly changes by repeating the light irradiation state and the light irradiation stop state. Note that the rise in temperature inside the porous adsorbent in the present invention is a slight temperature change in a minute region near the surface of the porous adsorbent, and the temperature rise of the entire system in the conventional heating swing cycle adsorption technique. Are quite different and differ greatly in terms of time to reach equilibrium, energy loss, local control, and the like. In addition, the present inventors speculate that the amount of adsorption reversibly changes also due to the increase or decrease of the amount of the transient structural change component of the dye due to the increase or decrease of the light irradiation amount or the polarity change of the porous adsorbent surface.

  In addition, in the present invention, light that is excellent in remoteness and easy to control in a minute region is used, so that the apparatus is downsized, miniaturized, and speeded up compared to the pressure swing cycle adsorption technology and the heating swing cycle adsorption technology. Is possible.

  According to the adsorption amount control method of the present invention, it is possible to reversibly and actively change the adsorption amount of a substance adsorbed on the porous adsorbent by a highly versatile technique called light irradiation. According to the adsorption amount control device of the present invention, the adsorption amount control method of the present invention can be implemented efficiently and reliably, and the conventional pressure swing cycle adsorption technology and heating swing cycle adsorption technology can be used. Compared to this, the apparatus can be miniaturized and miniaturized.

  Hereinafter, the control method and control device for the amount of adsorption by light irradiation according to the present invention will be described in detail with reference to the drawings in accordance with preferred embodiments thereof.

  FIG. 1 is a schematic cross-sectional view showing an embodiment of an adsorption amount control device of the present invention suitable for carrying out the adsorption amount control method by light irradiation of the present invention. In FIG. 1, reference numeral 1 denotes a porous adsorbent that has an adsorption performance for a substance to be adsorbed and absorbs light having a predetermined wavelength, and the porous adsorbent 1 is disposed inside a processing vessel 2. ing. Moreover, the light irradiation part 31 of the light irradiation apparatus 3 for irradiating the porous adsorbent 1 with the light L having a predetermined wavelength is disposed close to the processing container 2, and the light irradiation part 31 is a light irradiation apparatus. 3 drive units 32. The processing container 2 and the light irradiation unit 31 are disposed inside the light shielding container 4 for shielding the inside of the processing container 2 from light other than the light L emitted from the light irradiation device 3. A pipe 5 for introducing fluid into the pipe and a pipe 6 for discharging fluid from the inside of the processing container 2 are connected to the processing container 2. First, the main components of the apparatus for controlling the amount of adsorption by light irradiation according to the present invention will be described in detail.

(Porous adsorbent (porous base))
The porous adsorbent 1 according to the present invention may be any adsorbent capable of adsorbing light having a predetermined wavelength and having adsorption performance with respect to a predetermined adsorbed substance. It is preferable that the porous base material has an adsorption performance and a dye that absorbs light having a predetermined wavelength, but the porous base material itself absorbs light having a predetermined wavelength. It may consist of.

  Examples of porous base materials that have adsorption performance for such substances to be adsorbed include metals such as aluminum and tantalum; silica, alumina, titania, zirconia, ceria, tin oxide, barium oxide, nickel oxide. Metal oxides (including semi-metal oxides) such as ruthenium oxide, vanadium oxide, and indium oxide; complex oxides such as titanosilicate and barium titanate; and carbonaceous materials such as activated carbon. When used, a metal oxide that is transparent to visible light, such as silica and alumina, is preferable because the room for selection becomes wide. Further, since the carbonaceous material such as activated carbon itself is a material that efficiently absorbs visible light, when using visible light as light having a predetermined wavelength, a porous base made of a carbonaceous material is used as it is. Can be used as a porous adsorbent.

The pore diameter (average pore diameter), specific surface area and the like of the porous base constituting the porous adsorbent according to the present invention are not particularly limited and are appropriately selected according to the target substance to be adsorbed. From the viewpoint of improving the efficiency, it is preferable that the average pore diameter is not less than the molecular size of the adsorbed substance and the specific surface area is made as large as possible. From such a viewpoint, the porous base according to the present invention preferably has an average pore diameter of about 0.3 nm to 50 nm and a specific surface area of about 100 m ² / g or more. A mesoporous material is particularly preferred.

  That is, a silica-based mesoporous material particularly suitable as a porous base material according to the present invention is produced using a surfactant as a template and a silica source as a raw material, and a skeleton in which silicon atoms are bonded via oxygen atoms. Based on -Si-O-, it has a highly crosslinked network structure. Such a silica-based material only needs to have silicon atoms and oxygen atoms as main components, and at least a part of the silicon atoms may form a carbon-silicon bond at two or more organic groups. . Examples of such an organic group include, but are not limited to, divalent or higher organic groups generated by removing two or more hydrogens from hydrocarbons such as alkanes, alkenes, alkynes, benzenes, and cycloalkanes. Instead, the organic group may have an amide group, amino group, imino group, mercapto group, sulfone group, carboxyl group, ether group, acyl group, vinyl group or the like.

  The silica-based mesoporous material suitable for the present invention has mesopores having a central pore diameter of about 1 to 50 nm in the pore size distribution curve. In the case of having such mesopores, a functional organic compound having a large molecular diameter can easily enter the pores, and the diffusion of molecules within the pores can be performed quickly, so that the efficiency can be improved. Good adsorption separation tends to be possible. The central pore diameter is a curve (pore diameter distribution curve) in which a value (dV / dD) obtained by differentiating the pore volume (V) with respect to the pore diameter (D) is plotted against the pore diameter (D). ) At the maximum peak, and can be determined by the method described below. That is, the silica-based mesoporous material is cooled to a liquid nitrogen temperature (−196 ° C.), nitrogen gas is introduced, the adsorption amount is determined by a constant volume method or a gravimetric method, and then the pressure of the introduced nitrogen gas is gradually increased. Increase and plot the amount of nitrogen gas adsorbed against each equilibrium pressure to obtain an adsorption isotherm. Using this adsorption isotherm, a pore size distribution curve can be obtained by a calculation method such as Cranston-Inklay method, Pollimore-Heal method, BJH method or the like.

The silica-based mesoporous material suitable for the present invention preferably contains 60% or more of the total pore volume in the range of ± 40% of the center pore diameter in the pore size distribution curve. A silica-based mesoporous material that satisfies this condition means that the pore diameter is very uniform. The specific surface area of the silica mesoporous material is not particularly limited, but is preferably 700 m ² / g or more. The specific surface area can be calculated as a BET specific surface area from the adsorption isotherm using the BET isotherm adsorption equation.

  Furthermore, the silica-based mesoporous material suitable for the present invention preferably has one or more peaks at a diffraction angle corresponding to a d value of 1 nm or more in the X-ray diffraction pattern. The X-ray diffraction peak means that a periodic structure having a d value corresponding to the peak angle is present in the sample. Therefore, having one or more peaks at a diffraction angle corresponding to a d value of 1 nm or more means that the pores are regularly arranged at intervals of 1 nm or more.

  Further, the pores of the silica-based mesoporous material suitable for the present invention are formed not only on the surface of the porous material but also on the inside. The arrangement state (pore arrangement structure or structure) of the pores in such a porous body is not particularly limited, but is preferably a 2d-hexagonal structure, a 3d-hexagonal structure, or a cubic structure. Such a pore arrangement structure may have a disordered pore arrangement structure.

Here, that the porous body has a hexagonal pore arrangement structure means that the arrangement of the pores is a hexagonal structure (S. Inagaki, et al., J. Chem. Soc., Chem. Commun. S. Inagaki, et al., Bull. Chem. Soc. Jpn., 69, 1449; 1996, Q. Huo, et
al., Science, 268, 1324, 1995). In addition, a porous body having a cubic pore arrangement structure means that the arrangement of the pores is a cubic structure (JCVartuli, et al.
al., Chem. Mater., 6, 2317, 1994; see Q. Huo, et al., Nature, 368, 317, 1994). In addition, the porous body having a disordered pore arrangement structure means that the arrangement of the pores is irregular (PTTanev, et
al., Science, 267, 865, 1995; SABagshaw, et al., Science, 269, 1242, 1995; R. Ryoo, et al., J. Phys. Chem., 100, 17718, 1996). The cubic structure is preferably Pm-3n, Im-3m or Fm-3m symmetric. The symmetry is determined based on a space group notation.

  The silica-based mesoporous material suitable for the present invention may be used as a powder having an average particle size of about 0.01 to 3 μm, but may be molded and used as necessary. Any molding means may be used, but extrusion molding, tablet molding, rolling granulation, compression molding, CIP and the like are preferable. The shape can be determined according to the use mode and method, and examples thereof include a columnar shape, a crushed shape, a spherical shape, a honeycomb shape, an uneven shape, and a corrugated shape.

  A silica-based mesoporous material suitable for the present invention is produced, for example, by the following method. That is, first, a silica precursor and a surfactant are mixed in a solvent to obtain a porous precursor in which a surfactant is introduced into the silica precursor.

  The silica raw material used here is not particularly limited as long as it can form a silicon oxide (including a silicon composite oxide) by reaction, but from the viewpoint of reaction efficiency and physical properties of the obtained silicon oxide, alkoxy It is preferable to use silane, sodium silicate, layered silicate, silica, or any mixture thereof, and it is more preferable to use alkoxysilane.

  As the alkoxysilane, tetraalkoxysilane having 4 alkoxy groups, trialkoxysilane having 3 alkoxy groups, or dialkoxysilane having 2 alkoxy groups can be used. The type of alkoxy group is not particularly limited, but those having a relatively small number of carbon atoms in the alkoxy group (such as those having about 1 to 4 carbon atoms) such as methoxy group, ethoxy group, propoxy group, butoxy group, etc. This is advantageous in terms of reactivity. Further, when the alkoxysilane has 3 or 2 alkoxy groups, an organic group, a hydroxyl group, or the like may be bonded to the silicon atom in the alkoxysilane, and the organic group is an amino group, a mercapto group, or the like. It may further have a functional group.

  Examples of tetraalkoxysilane include tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, and dimethoxydiethoxysilane. Examples of trialkoxysilane include trimethoxysilanol, triethoxysilanol, and trimethoxymethylsilane. , Trimethoxyvinylsilane, triethoxyvinylsilane, 3-glycidoxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, phenyl Trimethoxysilane, phenyltriethoxysilane, γ- (methacryloxypropyl) trimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane Orchids. Examples of dialkoxysilane include dimethoxydimethylsilane, diethoxydimethylsilane, diethoxy-3-glycidoxypropylmethylsilane, dimethoxydiphenylsilane, and dimethoxymethylphenylsilane.

  Although the said alkoxysilane can also be used independently, it can also be used in combination of 2 or more types. Moreover, the alkoxysilane having 2 to 4 alkoxy groups described above can be used in combination with a monoalkoxysilane having one alkoxy group. Examples of the monoalkoxysilane that can be used in this way include trimethylmethoxysilane, trimethylethoxysilane, and 3-chloropropyldimethylmethoxysilane.

  Alkoxysilane produces a silanol group by hydrolysis, and the resulting silanol groups condense to form a silicon oxide. In this case, an alkoxysilane having a large number of alkoxy groups in the molecule has many bonds generated by hydrolysis and condensation. Therefore, it is preferable to use tetraalkoxysilane having a large number of alkoxy groups as alkoxysilane, and it is particularly preferable to use tetramethoxysilane or tetraethoxysilane as the tetraalkoxysilane from the viewpoint of reaction rate.

Examples of sodium silicate include sodium metasilicate (Na ₂ SiO ₃ ), sodium orthosilicate (Na ₄ SiO ₄ ), sodium disilicate (Na ₂ Si ₂ O ₅ ), and sodium tetrasilicate (Na ₂ Si _4). O ₉ ) and the like. As the sodium silicate, in addition to such a single substance, water glass (Na ₂ O · nSiO ₂ , n = 2 to 4) or the like having a different composition depending on the case can be used.

Furthermore, as layered silicate (layered silicate), kanemite (NaHSi ₂ O ₅ .3H ₂ O), sodium disilicate crystal (α, β, γ, δ-Na ₂ Si ₂ O ₅ ), macatite (Na ₂ Si ₄ O ₉ .5H ₂ O), ialite (Na ₂ Si ₈ O ₁₇ .xH ₂ O), magadiite (Na ₂ Si ₁₄ O ₁₇ .xH ₂ O), Kenyanite (Na ₂ Si ₂₀ O _41. xH ₂ O) and the like. Further, a layer obtained by treating clay minerals such as sepiolite, montmorillonite, vermiculite, mica, kaolinite and smectite with an acidic aqueous solution to remove elements other than silica can be used as the layered silicate.

In addition, as silica, Ultrasil (Ultrasil), Cab-O-Sil (Cabot), HiSil (Pittsburgh)
Precipitating silica such as Plate Glass); colloidal silica; fumed silica such as Aerosil (Degussa-Huls).

  The above silica raw materials can be used alone or in combination of two or more. However, when two or more types of silica raw materials are used, it is preferable to use a single silica raw material because the reaction conditions during production may be complicated.

  The surfactant used together with the silica raw material is not particularly limited, and may be any of cationic, anionic, and nonionic, specifically, alkyltrimethylammonium, alkyl Ammonium, dialkyldimethylammonium, benzylammonium chlorides, bromides, iodides or hydroxides; fatty acid salts, alkylsulfonates, alkylphosphates, polyethylene oxide nonionic surfactants, primary alkylamines, etc. Can be mentioned. These surfactants may be used alone or in combination of two or more.

Among the above surfactants, examples of the polyethylene oxide nonionic surfactant include a polyethylene oxide nonionic surfactant having a hydrocarbon group as a hydrophobic component and polyethylene oxide as a hydrophilic portion. . Such surfactants, for example, is represented by the general formula _{C n H 2n + 1 (OCH} 2 CH 2) m OH, n is 10 to 30, m can be used favorably those which are 30 . As such a surfactant, an ester of a fatty acid such as oleic acid, lauric acid, stearic acid, palmitic acid and sorbitan, or a compound obtained by adding polyethylene oxide to these esters can also be used.

Further, as such a surfactant, a triblock copolymer type polyalkylene oxide may be used. Examples of such surfactants include those composed of polyethylene oxide (EO) and polypropylene oxide (PO) and represented by the general formula (EO) _x (PO) _y (EO) _x . x and y represent the number of repetitions of EO and PO, respectively, x is preferably 5 to 110, y is preferably 15 to 70, x is preferably 13 to 106, and y is more preferably 29 to 70. Examples of the triblock copolymer include (EO) ₁₉ (PO) ₂₉ (EO) ₁₉ , (EO) ₁₃ (PO) ₇₀ (EO) ₁₃ , (EO) ₅ (PO) ₇₀ (EO) ₅ , (EO). ₁₃ (PO) ₃₀ (EO) ₁₃ , (EO) ₂₀ (PO) ₃₀ (EO) ₂₀ , (EO) ₂₆ (PO) ₃₉ (EO) ₂₆ , (EO) ₁₇ (PO) ₅₆ (EO) ₁₇ , ( EO) ₁₇ (PO) ₅₈ (EO) ₁₇ , (EO) ₂₀ (PO) ₇₀ (EO) ₂₀ , (EO) ₈₀ (PO) ₃₀ (EO) ₈₀ , (EO) ₁₀₆ (PO) ₇₀ (EO) ₁₀₆ , (EO) ₁₀₀ (PO) ₃₉ (EO) ₁₀₀ , (EO) ₁₉ (PO) ₃₃ (EO) ₁₉ , (EO) ₂₆ (PO) ₃₆ (EO) ₂₆ . These triblock copolymers are available from BASF, Aldrich, etc., and triblock copolymers having desired x and y values can be obtained at a small scale production level.

Also, a star diblock copolymer in which two polyethylene oxide (EO) chains-polypropylene oxide (PO) chains are bonded to two nitrogen atoms of ethylenediamine can be used. Examples of such star diblock copolymers include those represented by the general formula ((EO) _x (PO) _y ) ₂ NCH ₂ CH ₂ N ((PO) _y (EO) _x ) ₂ . Here, x and y represent the number of repetitions of EO and PO, respectively, x is preferably 5 to 110, y is preferably 15 to 70, x is 13 to 106, and y is 29 to 70. preferable.

Among such surfactants, since a silica-based mesoporous material having high crystallinity can be obtained, a salt (preferably a halide) of alkyltrimethylammonium [C _p H _{2p + 1} N (CH ₃ ) ₃ ]. Salt) is preferably used. In that case, the alkyl group in the alkyltrimethylammonium preferably has 8 to 22 carbon atoms. Examples include octadecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, dodecyltrimethylammonium bromide, decyltrimethylammonium bromide, octyltrimethylammonium bromide, docosyltrimethylammonium chloride, and the like. It is done.

  In addition, water, an organic solvent (acetone, alcohol, etc.), a mixed solvent of water and an organic solvent, and the like can be used as a solvent for obtaining a porous precursor by introducing a surfactant into a silica raw material. It is preferable to use water or a mixed solvent containing water as a main component.

  A specific method for obtaining a porous precursor by introducing a surfactant into a silica raw material is not particularly limited, but the following method is preferable. That is, a silica raw material is added and mixed in a solution containing a surfactant to form a complex in which surfactant ions are introduced into the silica raw material, and the silica raw material is subjected to a condensation reaction (hydrolysis and dehydration condensation). . Accordingly, when layered silicate is used as the silica raw material, surfactant ions enter between the layers of the layered silicate. On the other hand, when a silica raw material other than the layered silicate is used, micelles in which surfactants are regularly arranged in an aqueous solution are formed, and the silica raw material is gathered around the micelle. And the silanol group (-OH) produced | generated by the hydrolysis of the silica raw material in the composite is dehydrated and condensed, and the porous precursor having a two-dimensional or three-dimensional network structure in which the silica raw material bond is partially formed The body is obtained.

  In that case, it is preferable that the density | concentration of surfactant in a solution is 0.05-1 mol / L. When this concentration is less than the lower limit, surfactant ions are not sufficiently introduced into the silica raw material, and pore formation tends to be incomplete. On the other hand, when the upper limit is exceeded, unreacted and in solution There is a tendency that the amount of the surfactant remaining in the surface increases and the uniformity of the pores decreases. Moreover, it is preferable that the dispersion amount of the silica raw material in a solution is 0.0055-0.33 mol / L in conversion of Si density | concentration. If the amount of dispersion is less than the lower limit, the amount of the unreacted surfactant remaining in the solution tends to increase and the uniformity of the pores tends to decrease. The agent ions are not sufficiently introduced into the silica raw material and the pore formation tends to be incomplete. Furthermore, it is preferable that the number of moles of skeleton-forming atoms such as Si is 0.02 to 10 times the number of moles of the surfactant. The reaction temperature is not particularly limited and is preferably 0 to 100 ° C, more preferably 20 to 80 ° C. More specific reaction conditions are preferably determined as appropriate based on the type of silica raw material used.

  That is, when alkoxysilane is used as the silica raw material, it is preferable to prepare a surfactant solution having an alkaline pH of 8 or higher or an acidic pH of 6 or lower, and adding the alkoxysilane to this solution. Since the added alkoxysilane is hydrolyzed and dehydrated and condensed in the solution, the powder is deposited several seconds to several tens of minutes after the addition. After that, the solution is further stirred and the condensation reaction of the alkoxysilane is further advanced and matured, and then left as necessary to stabilize the system, and the resulting precipitate is filtered and washed as necessary. Thereby, a porous body precursor is obtained.

  Also, when using alkoxysilane as a silica raw material, first, the oligomer is hydrolyzed and dehydrated in an acidic or alkaline solution in the absence of a surfactant to form an oligomer, and then the resulting oligomer is made alkaline. Alternatively, it may be added to an acidic surfactant solution for further condensation reaction, and this is preferable because the degree of polymerization tends to be improved. Furthermore, when obtaining a silica-based mesoporous material in which a dye to be described later is incorporated into the skeleton, an oligomer of alkoxysilane is formed in an acidic solution and then the oligomer is added to an alkaline surfactant solution. , Which is particularly preferable because a larger amount of the dye can be introduced into the skeleton.

When silica raw material other than alkoxysilane (layered silicate, sodium silicate or silica) is used as the silica raw material, the silica raw material is first dispersed in an alkaline surfactant solution having a pH of 9.5 or higher. After cutting off part of the Si— (O—Si) ₄ bond formed in the raw material, the pH of the surfactant solution is adjusted to be in the range of 7 to 9.5 to condense the silica raw material. It is preferable to react. After that, the solution is further stirred and the condensation reaction of the silica raw material is further advanced and matured, and then left as necessary to stabilize the system, and the resulting precipitate is filtered and washed as necessary. Thereby, a porous body precursor is obtained. If the pH of the surfactant solution exceeds 9.5, the yield of the porous body obtained due to insufficient dehydration condensation of silanol groups tends to decrease. On the other hand, if the pH is less than 7, There is a tendency that acid ions are easily deposited as amorphous silica gel.

  Next, the silica mesoporous material suitable for the present invention is obtained by removing the surfactant contained in the porous material precursor obtained as described above. Examples of the method for removing the surfactant as described above include, for example, (i) a method of removing the surfactant by baking the porous body precursor at 300 to 1000 ° C., and (ii) an organic compound having high solubility in the surfactant. Method of removing the surfactant by immersing the porous precursor in a solvent, (iii) Ion exchange method in which the porous precursor is immersed in an acidic solution and heated to exchange the surfactant with hydrogen ions, etc. Can be mentioned.

(Dye)
The porous adsorbent according to the present invention is preferably composed of the above-mentioned porous base and a dye that absorbs light having a predetermined wavelength. The dye that can be used in the present invention is not particularly limited, and is appropriately selected depending on the light to be irradiated, the porous base material to be combined, and the like. Examples of such dyes include azo dyes, toluidine dyes, anthraquinone dyes, indigoid dyes, sulfur dyes, triphenylmethane dyes, pyrazolone dyes, stilbene dyes, diphenylmethane dyes, xanthene dyes, alizarin dyes, acridine dyes, quinoneimine dyes (azine dyes). Oxazine dyes, thiazine dyes), thiazole dyes, methine dyes, nitro dyes, nitroso dyes, cyanine dyes and the like. Disperse Red 1 [manufactured by Aldrich, Inc. from the viewpoint that the higher the absorption efficiency, the higher the change efficiency. Intramolecular charge transfer such as compound name: 4- (N-2-hydroxyethyl-N-ethyl) amino-4′-nitroazobenzene], Disperse Orange 3 [compound name: 4- (4-nitrophenylazo) aniline] Type of Dyes (monoazo dyes, disazo dyes, trisazo dyes, tetrakisazo dyes, polyazo dyes), cyanine dyes are preferred.

  In the porous adsorbent according to the present invention, such a dye is preferably uniformly present at least near the surface of the porous base, and the specific method for combining them is not particularly limited. For example, (I) the dye may be incorporated into the skeleton of the porous base, or (II) the dye may be supported on the surface of the porous base, but the detachment of the dye is more reliable. The former (I) is more preferable from the viewpoint that the difference in the adsorption amount due to the presence or absence of light irradiation tends to be larger.

  When a dye is incorporated into the skeleton of the porous base, (i) the raw material of the porous base (for example, silica raw material that is a raw material of the silica-based mesoporous material) A method of obtaining a porous adsorbent in which a dye is incorporated into the skeleton using a conjugate, or (ii) a porous adsorbent in which a dye is incorporated into the skeleton by mixing the dye with the raw material of the porous base Although the method to obtain can be employ | adopted, the former (i) is more preferable from a viewpoint which tends to be able to incorporate more pigment | dyes more reliably. Thus, the content of the dye incorporated in the skeleton of the porous adsorbent is preferably about 2 to 30% by weight of the porous adsorbent. If the pigment content is less than the lower limit, the difference in the amount of adsorption due to the presence or absence of light irradiation tends not to be sufficiently large. It tends to be.

  In addition, when the dye is supported on the surface of the porous base, (1) the dye is chemically adsorbed on the surface of the porous base, or (2) the dye is physically attached to the surface of the porous base. The former (1) is more preferable from the viewpoint of tending to carry the dye more reliably. As a specific method, for example, a porous base is impregnated in a solution in which a dye having a hydroxyl group (or a reactive functional group) is dissolved, and remains on the inner surface of the mesopores under acidic or basic conditions. A method of chemically adsorbing with a silanol group is exemplified. In addition, as the latter method of physically adsorbing, a method of recovering a porous base on which a dye is physically adsorbed by removing the solution after impregnating a porous base in a dye solution, Examples thereof include a method of physically mixing the porous base material with a ball mill or the like. The amount of the dye supported on the surface of the porous adsorbent in this way is preferably about 2 to 30% by weight of the porous adsorbent. If the amount of the dye supported is less than the lower limit, the difference in the amount of adsorption due to the presence or absence of light irradiation tends not to be sufficiently large. On the other hand, if the amount exceeds the upper limit, the adsorption performance of the porous adsorbent decreases and the adsorption amount is insufficient It tends to be.

(Irradiated light and light irradiation device)
The light L applied to the porous adsorbent 1 may be any light that is efficiently absorbed by the porous adsorbent 1 used, and the wavelength is not particularly limited. Therefore, the light L applied to the porous adsorbent 1 may be any of light having a wavelength in the visible light region, light having a wavelength in the ultraviolet region, and light having a wavelength in the infrared region. In the case of a porous adsorbent containing a dye, it is appropriately selected according to the dye used), but light having a wavelength in the visible light region is more preferable from the viewpoint of the device configuration and price.

  Moreover, the light L irradiated to the porous adsorbent 1 may be monochromatic light such as light emitted from various laser devices or continuous light emitted from various LEDs and lamps. Therefore, the light irradiation device 3 is not particularly limited, and various laser devices, various LEDs, various light sources such as various lamps (light irradiation unit 31) and their driving devices (driving unit 32) can be used as appropriate, but at a low price. It is more preferable to use an array of LEDs from the viewpoint of facilitating size reduction and compactness.

  Furthermore, you may use sunlight as the light L irradiated to the porous adsorbent 1, In that case, not the light source as the light irradiation apparatus 3, but the porous adsorbent 1 in the processing container 2 only when sunlight is required. It is preferable to use a window or an optical waveguide that can be guided to the above.

  In the present invention, the irradiation amount of the light L applied to the porous adsorbent 1 is controlled. Such control may be mechanical control by a control means (not shown) such as a computer, or Manual control may also be used.

(Processing vessel, shading vessel and piping)
The processing container 2 shown in FIG. 1 only needs to be capable of efficiently transmitting the light L emitted from the light irradiation device 3, and for example, a glass container or the like is appropriately used. Moreover, the light shielding container 4 should just shield the inside of the processing container 2 from light other than the light L emitted from the light irradiation apparatus 3, For example, a stainless steel container etc. are used suitably. In FIG. 1, since the light irradiation unit 31 is disposed outside the processing container 2, the processing container 2 needs to be able to transmit the light L. In the case of being disposed inside, it is not necessary, and the processing container 2 may also serve as the light shielding container 4. Moreover, it is preferable that the light shielding container 4 also serves as a thermostat so that the temperature in the processing container 2 is kept constant.

  Furthermore, the material of the pipes 5 and 6 connected in the processing container 2 is not particularly limited, and for example, a glass tube or the like is appropriately used. In FIG. 1, a pipe 5 for introducing a fluid into the processing container 2 and a pipe 6 for discharging the fluid from the processing container 2 are separately provided. However, the present invention is not limited to this. Alternatively, a single pipe may serve as introduction and discharge of fluid. In addition, such a pipe is provided with a fluid supply source (not shown) containing a substance to be adsorbed and a discharge fluid recovery device through means (not shown) for controlling the flow of fluid such as a pump and a valve. It is preferably connected to (not shown).

(Adsorption amount control method by light irradiation)
Next, the method for controlling the amount of adsorption by light irradiation according to the present invention will be described in detail with reference to FIG. In addition, the control method of the adsorption amount by light irradiation of the present invention is not limited to the case where it is implemented by the apparatus shown in FIG.

  In the present invention, first, the adsorbed substance is adsorbed on the porous adsorbent 1 in a state where the fluid containing the adsorbed substance is introduced into the reaction vessel 2. At that time, the light L is emitted from the light irradiation device 3 with the first irradiation amount, but the first irradiation amount may be zero.

  Next, when the irradiation amount of the light L irradiated to the porous adsorbent 1 is increased, the amount of the adsorbed substance that can be adsorbed to the porous adsorbent 1 by the porous adsorbent 1 absorbing more light L. (Adsorption equilibrium amount) decreases, and the adsorbed material is released from the porous adsorbent 1 until the decreased adsorption equilibrium amount is reached. On the other hand, when the irradiation amount of the light L applied to the porous adsorbent 1 is reduced or zero, the amount of adsorbed substance (adsorption equilibrium amount) that can be adsorbed on the porous adsorbent 1 increases, and the increased adsorption. The adsorbed substance is further adsorbed on the porous adsorbent 1 until the equilibrium amount is reached.

  The transient change in the equilibrium state of the adsorption performance of the porous adsorbent 1 due to such light irradiation does not involve an irreversible so-called photochemical reaction, but is caused by a reversible change in so-called physical adsorption characteristics. Is. Therefore, when the light irradiation state and the light irradiation stop are repeated, or the light irradiation amount is repeatedly changed, the adsorption amount reversibly changes, and when the light irradiation amount increases, it corresponds to the difference in the adsorption equilibrium amount. When the amount of adsorbed material is released from the porous adsorbent 1 and the amount of light irradiation decreases, the amount of adsorbed material corresponding to the difference in adsorption equilibrium amount is further adsorbed on the porous adsorbent 1. It becomes.

  Further, when the adsorbed substance is adsorbed in a state where the porous adsorbent 1 is irradiated with a lot of light L, the adsorbed substance is adsorbed as compared with the case where the adsorbed substance is adsorbed in a state where the irradiation amount of the light L is reduced or zero. Since the speed is improved, it is possible to change the adsorption speed together with the adsorption amount by controlling the irradiation amount of the light L.

  As described above, according to the method for controlling the amount of adsorption by light irradiation according to the present invention, it is possible to reversibly and quickly change the amount of adsorption of the adsorbed substance on the porous adsorbent, It is useful as a separation / purification method and a method for regenerating a porous adsorbent.

(Adsorbed substances and applications)
The substance to be adsorbed that is an object of the present invention is not particularly limited as long as it is a substance that is efficiently adsorbed by the porous adsorbent 1 to be used. Examples of such adsorbed substances include gaseous components such as hydrogen, carbon monoxide, carbon dioxide, nitrogen, hydrocarbon (gas), and halomethane, and liquid components such as water, hydrocarbon (liquid), and gasoline. Is mentioned. Therefore, the present invention is useful as a system that achieves hydrogen separation, carbon monoxide separation, carbon dioxide separation, nitrogen separation, hydrocarbon separation, removal of harmful substances such as halomethane, and humidity control.

  Further, in the present invention, light that is excellent in remoteness and easy to control in a minute region (for example, a diameter of 1 μm or less) is used. , Miniaturization and high speed are possible. Therefore, the present invention is particularly useful for an on-board separation / purification apparatus for vehicle installation, an on-site separation / purification apparatus for home use, a microreactor separation / purification apparatus, a μ-TAS (Total analysis system), a substance sustained release system, and the like. .

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example.

(Example 1)
Azo dye {Disperse Red 1 (DR1) [compound name: 4- (N-2-hydroxyethyl-N-ethyl) amino-4'-nitroazobenzene]} manufactured by Aldrich Co.} and alkoxysilane {tetraethoxysilane (TEOS)} As a conjugate with the following structural formula:

で表されるアゾベンゼン骨格を有するアルコキシシラン(DR1UPTEOS)を用いた。そして、DR1UPTEOS０．０８１ｇとTEOS０．９０３ｇとの混合物｛DR1UPTEOS：TEOS=1:30(モル比)｝にアセトン０．７６ｇ及び０．０１規定塩酸０．８３ｇを添加し、攪拌した。最初はTEOSとアセトンに溶解したDR1UPTEOSが分散していたが、１時間程度の反応で均一な溶液に変化し、３時間程度反応させたところTEOS及びDR1UPTEOSの加水分解及び脱水縮合によるオリゴマー形成に伴う粘性の増加が観察された。

An alkoxysilane having an azobenzene skeleton represented by the formula (DR1UPTEOS) was used. Then, 0.76 g of acetone and 0.83 g of 0.01 N hydrochloric acid were added to and stirred with a mixture {DR1UPTEOS: TEOS = 1: 30 (molar ratio)} of DR81UPTEOS 0.081 g and TEOS 0.903 g. At first, DR1UPTEOS dissolved in TEOS and acetone was dispersed, but after about 1 hour of reaction, it turned into a homogeneous solution, and when reacted for about 3 hours, it accompanied with oligomer formation by hydrolysis and dehydration condensation of TEOS and DR1UPTEOS. An increase in viscosity was observed.

On the other hand, 0.7 mL of 2.02 M aqueous sodium hydroxide solution was mixed with 90 mL of distilled water, and trimethylstearyl ammonium chloride {[CH ₃ (CH ₂ ) ₁₇ N (CH ₃ ) ₃ ] Cl (C18TMACl)} 0. After adding 200 g and heating to 40 ° C. to dissolve, it was kept at room temperature.

  Subsequently, when the said oligomer solution was dripped at the obtained alkaline surfactant aqueous solution, stirring vigorously, the solution became cloudy simultaneously with dripping. The mixture was further stirred at room temperature for about 2.5 hours, and then filtered using a Kiriyama funnel. The filtrate was almost colorless and transparent, and when the obtained red powder (porous precursor) was rinsed with water and acetone, the filtrate showed a slight pink color during the acetone rinse.

  Subsequently, in order to remove C18TMACl as a template from the obtained porous precursor, the porous precursor was suspended in a solution obtained by adding 2.0 g of concentrated hydrochloric acid to 100 mL of ethanol and stirred at room temperature for about 7 hours. Then, it filtered using the Kiriyama funnel. Furthermore, the obtained powder was rinsed with ethanol, water, and acetone, air-dried, and then vacuum-dried overnight to obtain a porous adsorbent according to the present invention.

(Example 2)
The porous adsorbent according to the present invention is the same as in Example 1 except that a mixture of DR1UPTEOS 0.229 g and TEOS 0.852 g {DR1UPTEOS: TEOS = 1: 10 (molar ratio)} is used as a mixture of DR1UPTEOS and TEOS. Got.

(Comparative Example 1)
A porous adsorbent for comparison was obtained in the same manner as in Example 1 except that only 0.933 g of TEOS was used instead of the mixture of DR1UPTEOS and TEOS. In addition, when the oligomer solution was dropped into the surfactant aqueous solution, the solution became cloudy, and the obtained powder was a white powder.

(Infrared absorption spectrum measurement)
Infrared (IR) absorption spectra of the porous adsorbents obtained in Examples 1 and 2 were measured by the KBr method using a Fourier transform infrared spectrometer (manufactured by Nicolet: Avatar 360). Infrared absorption spectra of the porous adsorbents obtained in Example 1 and Example 2 are shown in FIGS. 2 (a) and 2 (b), respectively. From the results shown in FIGS. 2 (a) and 2 (b), it was confirmed that the porous adsorbents obtained in Examples 1 and 2 were based on a silica skeleton and were introduced with an azo dye. .

(X-ray diffraction measurement)
The X-ray diffraction (XRD) patterns of the porous adsorbents obtained in Examples 1 and 2 and Comparative Example 1 were measured using an X-ray diffractometer (manufactured by Rigaku: RINT-TTR). The X-ray diffraction patterns of the porous adsorbents obtained in Comparative Example 1, Example 1 and Example 2 are shown in FIGS. 3 (a), 3 (b) and 3 (c), respectively. From the results shown in FIGS. 3 (a), (b), and (c), the porous adsorbents obtained in Examples 1 and 2 and Comparative Example 1 have diffraction peaks, and have a periodic structure. It was confirmed that. Moreover, it is guessed from the indexing that it is a two-dimensional hexagonal structure.

(Measurement of isothermal adsorption of nitrogen)
For the porous adsorbents obtained in Examples 1 and 2 and Comparative Example 1, isothermal adsorption measurement of nitrogen was performed at 77K using a fully automatic gas adsorption amount measuring device (manufactured by Yuasa Ionics: Autosorb 1-AG). did. The obtained isothermal adsorption curve of nitrogen is shown in FIG.

The isotherm during adsorption and desorption was on the same curve for any porous adsorbent, and no hysteresis was observed. From this, it was confirmed that reversible physical adsorption occurred. Moreover, in any porous adsorbent, P / P ₀ is about 0.3, indicating a sudden rise in the amount of adsorption characteristic of mesopores, confirming that it is a good silica-based mesoporous material. It was.

(Specific surface area)
About the porous adsorbent obtained in Examples 1-2 and Comparative Example 1, when specific surface area was calculated | required by BET (Brunauer-Emmett-Teller) method, in any porous adsorbent, 500-750 m < ² > / g. It was about.

(Pore size distribution)
About the porous adsorbent obtained in Examples 1-2, the pore distribution curve was calculated | required from the adsorption curve using BJH (Barrett-Joyner-Halenda) method based on the Kelvin formula. The pore size distributions of the porous adsorbents obtained in Example 1 and Example 2 are shown in FIGS. 5 (a) and 5 (b), respectively. From the results shown in FIGS. 5A and 5B, it was confirmed that the pore diameters of the porous adsorbents obtained in Examples 1 and 2 were centered on 2 nm.

(Light irradiation adsorption test on the amount of benzene adsorbed)
A halogen adsorption light source (HOYASHOT HL100E) and a cold light guide for light irradiation (manufactured by Suruga Seiki Co., Ltd .: VFGS) were attached to the vapor adsorption measuring apparatus (BELSORP-18 manufactured by Nippon Bell Co.) shown in FIG. And the light irradiation adsorption test regarding the adsorption amount of benzene shown below was conducted using the porous adsorbent obtained in Comparative Example 1. In addition, 10 mg of porous adsorbent 1 is disposed inside a glass processing container 2 having a capacity of 17 mL, and centered on visible light having a wavelength of 380 to 780 nm with a maximum irradiation power of 390 mW (guide outlet) from the cold light 3. The porous adsorbent 1 was irradiated with the irradiation light L. Moreover, the light irradiation part 31 of the processing container 2 and the cold light 3 is arrange | positioned inside the 25 degreeC constant temperature water tank (light-shielding container) 4 made from stainless steel, and 43 mL of glass is provided in the processing container 2 via the valve 10. A preparatory chamber (pipe) 11 is connected. Further, a container 14 in which benzene 13 is stored inside through a valve 12, a pump 16 and a pressure gauge 17 are connected through the valve 15 to the preliminary chamber 11.

  First, after the entire system was sufficiently deaerated, benzene vapor having a predetermined initial pressure (pressure: 9 Torr) was introduced into the preliminary chamber 11. Subsequently, after closing the valve 12 and the valve 15, the valve 10 is opened to introduce benzene vapor into the processing container 2, and the amount of benzene adsorbed on the porous adsorbent 1 is in an equilibrium state without irradiation with light L. Left until. Next, the irradiation of the light L was started when the adsorption amount of benzene reached a sufficient equilibrium state, and the irradiation of the light L was stopped after a predetermined time, and the pressure change in the processing container 2 during that time was measured.

  FIG. 7 schematically shows the result of using the porous adsorbents obtained in Examples 1 and 2, that is, the state of pressure change that changes due to light irradiation. Regardless of which porous adsorbent is used, when light irradiation is started after reaching the equilibrium state, the pressure increases as shown in FIG. 7, and the increase stops after about 30 seconds to 1 minute, and light irradiation is performed. The pressure in the state became constant (FIG. 7: ON state). Next, when the light irradiation was stopped, the pressure began to decrease again, and again returned to the initial equilibrium state in about 30 seconds to 1 minute (FIG. 7: OFF state). This phenomenon was reproduced in the same way even if the light irradiation was repeatedly started and stopped (desorbed once and then performed again). Note that the increase in pressure is caused by the release of benzene adsorbed inside the porous adsorbent. On the other hand, when light irradiation is stopped, the original equilibrium state is restored. Is adsorbed. Since such a phenomenon occurred, it was confirmed that the adsorption characteristics of the porous adsorbent reversibly change by light irradiation, and adsorption / desorption can be actively controlled by light irradiation.

  Such a phenomenon was observed in the porous adsorbents obtained in Examples 1 and 2, but was not observed in the porous adsorbent obtained in Comparative Example 1. Therefore, light absorption by the dye was not observed. It was confirmed that it plays an important role in this phenomenon.

  Next, using the porous adsorbents obtained in Examples 1 and 2, a light irradiation adsorption test was performed in a state where initial equilibrium pressures were different. The initial equilibrium pressure is set to the following three patterns: (i) the pressure at the rising portion of the first adsorption amount on the adsorption isotherm (several Torr), (ii) the adsorption amount with respect to the relative pressure once slightly before the flat amount The test was conducted with the pressure (ten torr) and (iii) the pressure of the flat part (50 to 60 Torr). In addition, the light irradiation power was changed at the same time, and the difference in behavior was also compared. The obtained results are shown in FIG.

  From the comparison of the results shown in FIG. 8, it was confirmed that the porous adsorbent obtained in Example 2 had a greater change in the equilibrium state under any conditions. That is, it was confirmed that when the amount of the introduced dye was larger, the amount of change in the adsorption amount due to light irradiation was larger, and the change in the amount of adsorption was larger in proportion to the dye concentration. When the porous adsorbent obtained in Example 2 is used, a maximum of about 36% of benzene is released to the outside by light irradiation, and the same amount of benzene is again put inside after stopping the light irradiation. Re-adsorption was possible.

  Moreover, when the dependence on the light irradiation power is compared, the amount of change tends to increase as the power increases, and the dependence is more pronounced in the porous adsorbent obtained in Example 2. Was confirmed.

  The difference due to the difference between the initial equilibrium pressure of several Torr and tens of Torr was not confirmed in any of the porous adsorbents obtained in Examples 1 and 2, but the initial equilibrium pressure was 50 to 60 Torr. In some cases, the amount of change was lower in any porous adsorbent.

  Further, when the valve 10 was opened and benzene vapor was introduced into the processing vessel 2, the pressure change until the adsorption amount of benzene on the porous adsorbent 1 was in an equilibrium state with the light L irradiated was measured. In the case where the initial pressure in the preliminary chamber 11 is 35 Torr or less, it was confirmed that the adsorption rate in the light irradiation state is faster than the light irradiation stop state until the equilibrium state is reached. On the other hand, when the initial pressure in the preliminary chamber 11 was about 90 Torr, which was close to the saturated vapor pressure (95.1 Torr @ 25 ° C.), no difference was observed in the adsorption rate.

(Comparative Example 2)
Porous adsorbent for comparison (organic-inorganic hybrid type silica system having benzene in silica skeleton) by the same production method as Synthesis Example 1 [Preparation of porous particles] described in JP-A- 2003-263999 Mesoporous material) was obtained. When the obtained porous adsorbent was subjected to a light irradiation adsorption test on the amount of benzene adsorbed in the same manner as described above, no change in the amount of adsorption due to light irradiation was confirmed.

(Example 3)
The porous adsorbent obtained in Comparative Example 1 was adsorbed with an azo dye (Aldrich DR1) by the following method to obtain a porous adsorbent according to the present invention. That is, 62 mg of DR1 was dissolved in 100 mL of ethanol, and then 40 mg of the porous adsorbent obtained in Comparative Example 1 was suspended in the resulting solution and stirred for 1 hour, and then the adsorbed porous adsorbent The porous adsorbent according to the present invention was obtained by filtration, air drying, and vacuum drying. When the obtained porous adsorbent was subjected to a light irradiation adsorption test on the amount of benzene adsorbed in the same manner as described above, a change in the amount of adsorption due to light irradiation of about 14% was confirmed.

(Example 4)
The porous adsorbent obtained in Comparative Example 1 was physically loaded with an azo dye (Aldrich DR1) by the following method to obtain a porous adsorbent according to the present invention. That is, the porous adsorbent according to the present invention was obtained by sufficiently mixing 40 mg of the porous adsorbent obtained in Comparative Example 1 and 10 mg of DR1 in a mortar. When the obtained porous adsorbent was subjected to a light irradiation adsorption test on the amount of benzene adsorbed in the same manner as described above, a change in the amount of adsorption due to light irradiation of about 17% was confirmed.

(Example 5)
A porous adsorbent according to the present invention was obtained in the same manner as in Example 3 except that the blue dye toluidine (Aludrich Toluidine Blue O) was used as the dye. When the obtained porous adsorbent was subjected to a light irradiation adsorption test on the amount of benzene adsorbed in the same manner as described above, a change in the amount of adsorption due to light irradiation of about 15% was confirmed.

  As described above, according to the adsorption amount control method of the present invention, the adsorption amount of the substance adsorbed on the porous adsorbent can be reversibly and actively changed by a versatile technique called light irradiation. It becomes possible. According to the adsorption amount control device of the present invention, the adsorption amount control method of the present invention can be implemented efficiently and reliably, and the conventional pressure swing cycle adsorption technology and heating swing cycle adsorption technology can be used. Compared to this, the apparatus can be miniaturized and miniaturized. Therefore, the present invention is particularly useful for an on-board separation / purification apparatus for vehicle installation, an on-site separation / purification apparatus for home use, a microreactor separation / purification apparatus, a μ-TAS (Total analysis system), a substance sustained release system, and the like. .

1 is a schematic cross-sectional view showing an embodiment of an adsorption amount control device of the present invention suitable for carrying out the adsorption amount control method by light irradiation of the present invention. FIG. 2A and FIG. 2B are graphs showing infrared absorption spectra of the porous adsorbents obtained in Example 1 and Example 2, respectively. 3 (a), 3 (b) and 3 (c) are graphs showing X-ray diffraction patterns of the porous adsorbents obtained in Comparative Example 1, Example 1 and Example 2, respectively. It is a graph which shows the isothermal adsorption curve of nitrogen of the porous adsorbent obtained in Examples 1-2 and Comparative Example 1. 5A and 5B are graphs showing the pore size distribution of the porous adsorbents obtained in Example 1 and Example 2, respectively. It is a schematic diagram which shows the structure of the vapor | steam adsorption measuring apparatus used for the light irradiation adsorption test regarding the adsorption amount of benzene. It is a typical graph which shows the mode of the pressure change which changes with light irradiation at the time of using the porous adsorbent obtained in Examples 1-2. It is a graph which shows the result of the light irradiation adsorption test regarding the adsorption amount of benzene using the porous adsorbent obtained in Examples 1-2.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Porous adsorbent, 2 ... Processing container, 3 ... Light irradiation apparatus, 31 ... Light irradiation part, 32 ... Light irradiation apparatus drive part, 4 ... Light-shielding container, 5, 6 ... Pipe, L ... Irradiation light.

Claims (2)

A porous material comprising a silica-based mesoporous material that has an adsorption performance for an adsorbed substance and a dye that absorbs light having a predetermined wavelength and is incorporated in the skeleton of the silica-based mesoporous material. A first step of adsorbing the adsorbed substance to the porous adsorbent while irradiating the adsorbent with light having the predetermined wavelength at a first irradiation amount;
A second step of increasing or decreasing the irradiation amount of light having the predetermined wavelength as a second irradiation amount, and decreasing or increasing the amount of adsorption of the adsorbed substance in the porous adsorbent;
A method for controlling the amount of adsorption by light irradiation. A porous material comprising a silica-based mesoporous material that has an adsorption performance for an adsorbed substance and a dye that absorbs light having a predetermined wavelength and is incorporated in the skeleton of the silica-based mesoporous material. An adsorbent,
A light irradiation device for irradiating the porous adsorbent with light having the predetermined wavelength;
A processing vessel in which the porous adsorbent is disposed;
A light shielding container for shielding the inside of the processing container from light other than light irradiated from the light irradiation device;
A pipe connected to the processing container, for introducing a fluid containing an adsorbed substance into the processing container and / or discharging the fluid from the processing container;
A device for controlling the amount of adsorption by light irradiation.

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