JP2005272532A - Meso configuration, mesoporous body and method for producing meso configuration - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a meso configuration having highly controlled orientation and a mesoporous body and to provide a method for producing the same. <P>SOLUTION: The method for producing a meso configuration comprises an irradiation process of linearly polarized ultraviolet light, with which a polymer liquid crystal film having a photo-crosslinkable part and a liquid crystal group on the side chain is irradiated with linearly polarized ultraviolet light, then a heat treatment process for heat-treating the film after the irradiation process and a meso configuration formation process for immersing the film after the heat treatment process in a mixed solution containing a surfactant and a silane compound and forming the meso configuration containing the surfactant and silica on the film after the heat treatment process. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mesostructured body, a mesoporous body, and a method for producing a mesostructured body.

Mesostructures synthesized by a sol-gel method using a surfactant aggregate as a template have attracted attention for applications such as reaction catalysts, separation, and low dielectric constant materials.
Under such circumstances, the following method for producing a mesostructure has been proposed (see Patent Document 1). That is, a polysilane film is formed on a substrate, and this film is irradiated with ultraviolet polarized light to form an alignment film. Then, a mixed solution of the surfactant and the silane compound is prepared, and the alignment film is immersed in the mixed solution. Then, silica is deposited on the alignment film so as to follow the molecular alignment of the film, and as a result, a mesostructure having a high orientation is obtained.

However, this is because the alignment film is formed by irradiating the polysilane film with ultraviolet polarized light to anisotropically cut the main chain of the polysilane. As the strength was weak.
Therefore, when this alignment film is immersed in a mixed solution of a surfactant and a silane compound, the alignment film is partially dissolved by the solution, and as a result, the mesostructure alignment is not sufficiently controlled. There was a point.
JP 2003-327729 A

  The present invention has been completed based on the above-described circumstances, and an object thereof is to provide a mesostructured body, a mesoporous body, and a method for producing the same, in which orientation is highly controlled.

  As a means for achieving the above object, the invention of claim 1 is directed to a linearly polarized ultraviolet light which irradiates a linearly polarized ultraviolet light on a polymer liquid crystal film having a liquid-crosslinkable portion and a liquid-crosslinkable portion on a side chain. An irradiation step, a heat treatment step for heat-treating the film after the irradiation step, and a surface activity on the film after the heat treatment step by immersing the film after the heat treatment step in a mixed solution containing a surfactant and a silane compound. A mesostructured body production process comprising forming a mesostructured body containing an agent and silica.

  According to a second aspect of the present invention, there is provided a first ultraviolet light irradiation step of irradiating a polymer liquid crystal film having a liquid-crosslinkable site and a liquid crystal group in a side chain with a linearly polarized ultraviolet light, and a film after the first irradiation step. A heat treatment step for heat treating the film, a second ultraviolet light irradiation step for irradiating the film after the heat treatment step with ultraviolet light, and a film after the second ultraviolet light irradiation step for a mixed solution containing a surfactant and a silane compound. A mesostructured body production method comprising a mesostructured body forming step of immersing and forming a mesostructured body containing a surfactant and silica on the film after the second ultraviolet light irradiation step. .

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the heat treatment temperature is a temperature at which the polymer liquid crystal exhibits a liquid crystal phase.

  According to a fourth aspect of the present invention, a polymer liquid crystal film having a photocrosslinkable site in the side chain and a liquid crystal group is cross-linked by linearly polarized ultraviolet light, and silica is used on the film with a surfactant organic tissue as a template. It is a mesostructured body deposited by the sol-gel method.

  In the invention of claim 5, a polymer liquid crystal film having a photocrosslinkable site and a liquid crystal group in the side chain is cross-linked by linearly polarized ultraviolet light, and silica is used on the film with a surfactant organic tissue as a template. It is a mesoporous body obtained by depositing by a sol-gel method and further removing the surfactant.

<Invention of Claim 1>
As shown in the schematic diagram of FIG. 1, the polymer liquid crystal film 3 having a liquid-crosslinkable portion and a liquid crystal group on the side chain is irradiated with linearly polarized ultraviolet light 5. Then, only the side chain group 1A sensitive to the linearly polarized ultraviolet light 5 among the side chain groups 1 is photocrosslinked. That is, only the side chain group 1A located in parallel (//) with respect to the direction of electric field vibration of ultraviolet light is selectively photocrosslinked to form a polymer liquid crystal film 3 having uniaxial orientation (FIG. 1A). ), See FIG. FIG. 1B schematically shows a state in which a four-membered ring is formed by photocrosslinking of two double bonds.

  Then, the polymer liquid crystal film 3 is heat-treated. Then, the side chain group 1B that has not been cross-linked by ultraviolet light is aligned so as to have the same orientation as the cross-linked side chain group 1A due to its liquid crystallinity due to the influence of the already cross-linked side chain group 1A. (See FIG. 1C).

Next, when the polymer liquid crystal film 3 is immersed in a mixed solution containing a surfactant and a silane compound, the surfactant as a template is arranged in a nanostructure due to the uniaxial orientation of the side chain group 1 of the polymer liquid crystal film 3. It is deposited on the film while being oriented to have. Then, mesoporous silica (mesoporous body) is deposited on the template, and a mesostructured body 7 made of a surfactant and silica is formed on the polymer liquid crystal film 3.
According to this manufacturing method, the liquid crystallinity of the side chain group 1 is exhibited in the heat treatment step, and the degree of orientation of the side chain group 1 is increased. Therefore, the nanostructure arrangement of the mesostructured body 7 is highly controlled by this highly oriented side chain group 1.
Furthermore, according to this manufacturing method, since the polymer liquid crystal film 3 immersed in the mixed solution is photocrosslinked, the film strength is high. Therefore, it is stable even in a mixed solution, and the uniaxial orientation of the side chain group 1 is not easily impaired. Therefore, the nanostructure arrangement of the mesostructured body 7 can be controlled to a higher degree.

<Invention of Claim 2>
According to the manufacturing method of this claim, after heat-treating the polymer liquid crystal film, ultraviolet rays are further irradiated in the second ultraviolet light irradiation step. That is, in the schematic diagram of FIG. 2, (A), (B), and (C) are the same as (A), (B), and (C) of FIG. 1, but as shown in FIG. The subsequent film is further irradiated with ultraviolet rays 9. Note that FIG. 2E corresponds to FIG.
Since the cross-linking degree of the polymer liquid crystal film 3 is increased by the irradiation of the ultraviolet ray 9, the film stability in the mixed solution containing the surfactant and the silane compound is remarkably improved, and the uniaxial orientation of the side chain group 1 is improved. Furthermore, it becomes difficult to be damaged. Therefore, the nanostructure arrangement of the mesostructured body 7 can be controlled to a higher degree.

<Invention of Claim 3>
According to the structure of this claim, the heat treatment temperature is set to a temperature at which the polymer liquid crystal exhibits a liquid crystal phase. At the temperature at which the liquid crystal phase is developed, the uncrosslinked side chain groups easily flow, and thus the liquid crystal is easily aligned.

<Invention of Claim 4>
Since the mesostructured body according to the present invention is deposited on a stable crosslinked polymer liquid crystal film in a sol-gel mixed solution, the nanostructure alignment is high.

<Invention of Claim 5>
The mesoporous body according to the present invention is deposited on a stable crosslinked polymer liquid crystal film in a mixed solution of the sol-gel method, and further has a surfactant removed, so that the nanostructure alignment is high.

Hereinafter, the present invention will be described in detail.
First, an irradiation process of linearly polarized ultraviolet light that irradiates linearly polarized ultraviolet light onto a polymer liquid crystal film having a liquid-crosslinkable site and a liquid crystal group in the side chain, and a heat treatment process that heat-treats the film after the irradiation process A mesostructure formation step of immersing the film after the heat treatment step in a mixed solution containing the surfactant and the silane compound to form a mesostructure body containing the surfactant and silica on the film after the heat treatment step. A first manufacturing method provided will be described.

First, the irradiation process of linearly polarized ultraviolet light will be described.
The polymer liquid crystal used in this step is not particularly limited. For example, a polymer liquid crystal having a side chain with a liquid crystal group (mesogen) such as an aromatic hydrocarbon group and a substituent having a double bond between carbon atoms is used. Specifically, for example, a polymer liquid crystal having a photocrosslinkable moiety represented by the general formula (1) or (2) can be given.

  Here, the substituent R is not particularly limited, but a hydrogen atom, a halogen atom, a cyano group, an alkyl group, a phenyl group, or the like is preferable. The alkyl group is preferably a lower alkyl group having 4 or less carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group.

  X is not particularly limited, but a range of 1 to 20 is preferable, and 6 to 12 is particularly preferable.

  A is none, an oxygen atom, a sulfur atom, or a group represented by —COO— or —OCO—.

  Although Q will not be specifically limited if it is a liquid crystal group, For example, the liquid crystal group of the following formula | equation (Q1)-(Q15) is mentioned.

ビフェニル

Biphenyl

フェニルピリジン

Phenylpyridine

安息香酸フェニル

Phenyl benzoate

安息香酸ビフェニル

Biphenyl benzoate

トラン

Trang

アゾキシベンゼン

Azoxybenzene

アゾベンゼン

Azobenzene

シクロヘキシルフェニル

Cyclohexylphenyl

シクロヘキシルピリミジン

Cyclohexyl pyrimidine

シクロヘキシルカルボン酸フェニル

Cyclohexylcarboxylic acid phenyl

シクロヘキシルカルボン酸ビフェニル

Cyclohexylcarboxylic acid biphenyl

ベンジリデンアニリン

Benzylideneaniline

コレステリル

Cholesteryl

コレスタニル

Cholestanyl

コレスタジエニル

Cholestadienyl

In the above formulas (Q1) to (Q15), the substituents R, R ₁ , R ₂ and R ₃ are groups in which hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkyl group having 1 to 6 carbon atoms is substituted with halogen. Represents an alkoxy group having 1 to 6 carbon atoms, a halogen group, a nitro group, an amino group, or a cyano group. Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. , N-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group and the like are preferable. Examples of the group in which an alkyl group having 1 to 6 carbon atoms is substituted with halogen include- CF ₃ is preferable, and examples of the alkoxy group having 1 to 6 carbon atoms include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, n Pentoxy, n- hexoxy and the like. The halogen group is preferably fluorine, chlorine, bromine or iodine.
In (Q1), (Q3), (Q4), (Q5), (Q6), (Q7), (Q11), and (Q12), R ₁ and R ₂ , R ₁ , R _2, and R ₃ are the same substituent. May be different.

  B is none, an oxygen atom, a sulfur atom, or a group represented by —COO— or —OCO—.

  Although P will not be specifically limited if it is a photocrosslinkable group, For example, the photocrosslinkable group of the following formula | equation (P1)-(P10) is mentioned.

シンナモイル基

Cinnamoyl group

シンナミリデン基

Cinnamylidene group

カルコン残基

Chalcone residues

２，５−ジメトキシスチルベン残基

2,5-dimethoxystilbene residue

スチリルピリジニウム残基

Styrylpyridinium residue

アントラセン残基

Anthracene residue

イソクマリン残基

Isocoumarin residue

２−ピロン残基

2-pyrone residue

α−フェニルマレイミド

α-Phenylmaleimide

チミン残基

Thymine residue

In the above formulas (P1) to (P10), the substituents R, R ₁ and R ₂ are hydrogen, a group having 1 to 6 carbon atoms, a group having 1 to 6 carbon atoms substituted with halogen, 1 to 6 alkoxy groups, halogen groups, nitro groups, amino groups, and cyano groups. Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, and n- A butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, and the like are preferable. Examples of the group in which an alkyl group having 1 to 6 carbon atoms is substituted with a halogen include -CF ₃ Preferred examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, and an n-pento group. A xyl group, an n-hexoxy group, and the like are preferable. The halogen group is preferably fluorine, chlorine, bromine or iodine.
In (P6), R ₁ and R ₂ may be the same or different. In (P5), X means a well-known anion that is not particularly limited, such as a halogen ion (fluorine, chlorine, bromine, or iodine).

  n is not particularly limited, but is preferably about 5 to 10000, more preferably 10 to 10000, and particularly preferably 100 to 1000 in order to produce a uniform polymer film by various casting methods. .

  The molecular weight of the polymer is preferably in the range of 10,000 to 1,000,000 in terms of weight average molecular weight. This is because when the weight average molecular weight is within this range, the film strength of the polymer liquid crystal film becomes strong, and stability in a mixed solution containing a surfactant and silica described later is improved.

  The method for forming the polymer liquid crystal film is not particularly limited, and a known method can be adopted. For example, a method in which a transparent crystal plate such as quartz, glass plate, Si wafer, sodium fluoride, or the like, or a transparent polymer film such as polystyrene or polymethyl methacrylate is used as a support, and the film is formed on the support by, for example, spin casting. That is, a method of forming a thin film on a support by dropping a polymer organic solvent solution onto the support and rotating the support at a high speed can be employed. Further, a method such as spray coating can be widely adopted.

The film thickness of the polymer liquid crystal film is not particularly limited, but is preferably 50 to 200 nm in order not to cause side chain association during heat treatment (resulting in disturbance of the side chain orientation) (here) The association means that the side chain groups are folded by heat and contracted).
In order to adjust the film thickness, for example, there is a method of adjusting the evaporation rate by changing the concentration of the solution to be spin-cast, the number of rotations at the time of spin-cast, or mixing a solvent with a high boiling point such as toluene. is there.

  Moreover, although it does not specifically limit as a wavelength of the linearly polarized ultraviolet light (Linearly Polarized Ultra Violet; LPUV) in this process, Preferably, it is the range of 200-400 nm. More preferably, it is the light absorption wavelength region of each crosslinking group, and is preferably within the range of ± 10 nm of the maximum light absorption wavelength (λmax). This is because, in this wavelength range, the photocrosslinking reaction efficiency of the crosslinkable group is good, and the exposure amount of ultraviolet light is small.

The exposure amount of linearly polarized ultraviolet light is preferably in the range of 0.05 to 10 Jcm ⁻² . This is because when the exposure amount is within this range, sufficient uniaxial orientation can be imparted to the polymer liquid crystal.

  Next, a heat treatment process for heat-treating the film after the irradiation process will be described. The heat treatment temperature is not particularly limited, but is preferably an intermediate temperature between the start point and the end point of any one of the liquid crystal states of the polymer liquid crystal such as nematic, smectic A, smectic B, smectic C, and cholesteric. It is preferable. Of the polymer liquid crystals that take a plurality of liquid crystal states, an intermediate temperature between the start point and the end point of the nematic liquid crystal state is particularly preferable.

  By setting the liquid crystal temperature, fluidity is imparted to the side chain of the polymer liquid crystal, and as a result, the side chain that has not been crosslinked by ultraviolet light is easily aligned due to the influence of the already crosslinked side chain. Because it becomes.

  The heat treatment time is not particularly limited, but is preferably in the range of 1 to 30 minutes, and particularly preferably 2 to 10 minutes. This is because, within this range, the side chains can be sufficiently aligned and molecular degradation due to heat can be prevented.

  Next, the mesostructured body is formed by immersing the film after the heat treatment step in a mixed solution containing the surfactant and the silane compound to form a mesostructured body containing the surfactant and silica on the film after the heat treatment step. The process will be described.

  Here, the surfactant is not particularly limited, and a wide variety of well-known surfactants used as ultra-polymer templates can be used. For example, use of nonionic surfactants such as ammonium surfactants such as hexadecyltrimethylammonium chloride and trimethylammonium halides having 12 to 20 carbon atoms, alkylethylene oxides, and block copolymers of ethylene oxide and propylene oxide Can do.

Specifically, Alkyltrimethylammonium CnTMA C _n H _{2n + 1} N (CH ₃ ) ₃ (where n = 10, 12-16, 18, 20, 22), Gemini ammonium C _m H _{2m + 1} N (CH ₃ ) ₂ (CH ₂ ) _S N (CH ₃ ) ₂ C _m H _{2m + 1} (where m = 12, 14, 16, 18, 20, 22; s = 2-12), Divalent surfactant C _n H _{2n + 1} N (CH ₃ ) ₂ (CH ₂ ) _S N (CH ₃ ) ₃ (where n = 12, 14, 16, 18, 20, 22; s = 2, 3, 6), C _n H _{2n + 1} N (R ₁ ) (R ₂ ) (R ₃ ) (where n = 16; R ₁ , R ₂ , R ₃ = H, CH ₃ , C ₂ H ₅ , C ₃ H ₇ ), Hydroxy-functional ammonium C _n H _{2n + 1} N (CH ₃ ) ₂ (CH ₂ ) _m CH (where n = 16; m = 0, 1, 2, 3), Benzalkonium C _n H _{2n + 1} N (CH ₃ ) ₂ (CH ₂ ) _m C ₆ H ₅ (where n = 14, 16, 18, 20; m = 1, 2, 3), Bichain ammonium C _n H _{2n + 1} N (CH ₃ ) ₂ C _m H _{2m + 1} (where n = 12, 16, 18; m = 2-6, 12, 16, 18), Organosilane C _n H _{2n + 1} N (CH ₃ ) ₂ (CH ₂ ) ₃ Si (OCH ₃ ) ₃ (where n = 14).

  It does not specifically limit as a silane compound, A well-known silane compound can be used. For example, a condensation precursor of silica glass such as tetraalkoxysilane having 1 to 4 carbon atoms can be used. Specifically, for example, tetraethoxysilane can be used.

  Further, the solvent of the mixed solution is not particularly limited, but water is preferable, and other solvent (alcohol or the like) may be dissolved in water. Moreover, it is preferable to add acids, such as hydrochloric acid, to a mixed solution as a catalyst for promoting a sol-gel reaction.

  A film is immersed in the mixed solution to form a mesostructured body on the film. In this case, the mixed solution temperature is preferably in the range of 10 to 90 ° C. This is because if the temperature is within this range, the sol-gel condensation reaction proceeds well.

  The time for immersion in the mixed solution is not particularly limited, but is preferably in the range of 2 to 7 days. This is because the film thickness of the deposit (meso-organized body) can be controlled appropriately within this range.

As described above, a mesostructure containing a surfactant and silica is deposited on the polymer liquid crystal film. Thereafter, the surfactant used as a template is removed from the mesostructured body by the following method to prepare a mesoporous body.
The method for removing the surfactant is not particularly limited, but it is desirable to subject the mesostructured body to a combustion treatment (for example, 400 ° C. or higher), to elute using a solvent such as ethanol, or to a photo-ozone treatment. In particular, the photo-ozone treatment is preferable because the treatment is simple. The wavelength of ultraviolet light in the photo-ozone treatment is preferably in the range of 180 to 260 nm from the viewpoint that the surfactant is easily decomposed by the ozone treatment. The irradiation time of ultraviolet light is not particularly limited, and is preferably in the range of 0.5 to 20 hours. This is because when the irradiation time is within this range, the surfactant used as a template can be almost completely removed.

  Next, a first ultraviolet light irradiation step of irradiating the polymer liquid crystal film having a photocrosslinkable portion with linearly polarized ultraviolet light, a heat treatment step of heat-treating the film after the irradiation step, and a film after the heat treatment step A film after the second ultraviolet light irradiation step is immersed in a second ultraviolet light irradiation step of irradiating the ultraviolet light and a mixed solution containing a surfactant and a silane compound, and the film after the second ultraviolet light irradiation step is immersed on the film. A second production method including a mesostructured body forming step for forming a mesostructured body containing a surfactant and silica will be described.

  In this manufacturing method, the first ultraviolet light irradiation step is performed in the same manner as the linearly polarized ultraviolet light irradiation step of the first manufacturing method. Thereafter, a heat treatment step similar to the first manufacturing method is performed. Further, the film after the heat treatment step is irradiated with ultraviolet light (second ultraviolet light irradiation step). This further improves the stability (acid resistance and solvent resistance) in the mixed solution containing the surfactant and the silane compound.

Although the wavelength of the ultraviolet light in a 2nd ultraviolet light irradiation process is not specifically limited, Preferably, it is the range of 200-400 nm. More preferably, it is the light absorption wavelength region of each crosslinking group, and is preferably within the range of ± 10 nm of the maximum light absorption wavelength (λmax). This is because, in this wavelength range, the photocrosslinking reaction efficiency of the crosslinkable group is good, and the exposure amount of ultraviolet light is small.
The ultraviolet light may be either polarized ultraviolet light or non-polarized ultraviolet light. This is because the purpose of the ultraviolet irradiation in this step is to improve the stability (acid resistance and solvent resistance) of the film and not to achieve uniaxial orientation.

In addition, it is preferable that the exposure amount of the ultraviolet light in this process exists in the range of 0.05-10 Jcm ^<-2 >. This is because when the exposure amount is within this range, the polymer liquid crystal can be almost completely cross-linked and the stability of the film can be improved.

  Next, the film after the second ultraviolet light irradiation step is immersed in a mixed solution containing a surfactant and a silane compound, and the meso containing the surfactant and silica on the film after the second ultraviolet light irradiation step. An organization is formed (meso-organization formation step), and this step is performed in the same manner as in the first manufacturing method described above.

  Note that a mesoporous body can be prepared by removing the surfactant from the mesostructured body in the same manner as in the first production method.

<Example>
Examples of the present invention will be described below, but the present invention is not limited thereto.
<Example 1 (second manufacturing method)>
(1) Preparation of photo-aligned polymer liquid crystal film Among the side-chain photocrosslinkable polymer liquid crystals, poly {6- [4 '-(4-cyanocinnamoyloxy) biphenyl-4-yloxy] hexyl methacrylate} ( The chemical formula below was synthesized and used. The molecular weight of the polymer was determined by GPC measurement (Shodex, R1-101, UV-41). For the measurement, chloroform was used as a solvent, PS standard was used as a reference, the flow rate was 1 ml / min, and the column temperature was 40 ° C. From the GPC measurement, the number average molecular weight Mn was 51.8 × 10 ⁴ , and the weight average molecular weight Mw was 27.7 × 10 ⁴ .

また、示差走査熱量測定（Seiko Instruments Inc., SSC5200H)より、相転移温度はＴｇ：171℃、Ｔi: 326℃であった。測定には、窒素雰囲気下で昇温速度、降温速度10℃/minで行なった。偏光顕微鏡（OLYMPUS, BHA-P）により、中間相ではクロスニコル下でネマチック液晶相が観察できた。

From the differential scanning calorimetry (Seiko Instruments Inc., SSC5200H), the phase transition temperature was Tg: 171 ° C. and Ti: 326 ° C. The measurement was performed in a nitrogen atmosphere at a temperature rising rate and a temperature falling rate of 10 ° C./min. With a polarizing microscope (OLYMPUS, BHA-P), a nematic liquid crystal phase could be observed in the intermediate phase under crossed Nicols.

  A 0.75 wt% chloroform solution of poly {6- [4 ′-(4-cyanocinnamoyloxy) biphenyl-4-yloxy] hexyl methacrylate} is prepared, and a predetermined condition (specifically, two-stage condition 1st ( A spin cast film (film thickness: about 70 nm) was prepared at 1000 rpm (5 seconds) and 2nd (2000 rpm, 30 s)) and dried overnight at room temperature.

(2) Irradiation process of 1st ultraviolet light By irradiating linearly polarized ultraviolet light to this spin cast film, photocrosslinking reaction is selected only for the side chain group located parallel (//) to the electric field vibration direction of polarized light. It was awakened.
This selective photocrosslinking reaction was performed by irradiating the film with linearly polarized ultraviolet light having a light intensity of 30 mW / cm ² (325 nm) at room temperature for 350 seconds. The light source used was a high-pressure mercury lamp (SAN-EI ELECTRIC, SUPERCURE-203S) with a glass filter that cuts wavelengths below 290 nm and a Grand Taylor prism.

  Changes in polarized UV absorption spectrum before and after irradiation with linearly polarized ultraviolet light were evaluated using a spectroscope (Hewllet Packard, diode array spectrophotometer (8452A)) (see FIG. 3). In this polarized UV absorption spectrum, absorption due to the double bond of the biphenyl group (near 275 nm) and the uncrosslinked cinnamoyl group (near 312 nm) is observed, and when the side chain is crosslinked, the double bond of the cinnamoyl group decreases, A decrease in absorbance is observed.

The polarized UV absorption spectrum was observed with polarized light in two directions, that is, polarized light parallel (//) to linearly polarized ultraviolet light irradiated on the film and polarized light in the vertical (⊥) direction.
As shown in FIG. 3, before the polymer liquid crystal film is irradiated with linearly polarized ultraviolet light (before the first irradiation step), the absorbance in the parallel (//) direction is perpendicular to the electric field vibration of the linearly polarized ultraviolet light ( The absorbance in the ⊥ direction was almost the same (in the graph of FIG. 1, the two spectral data overlap). This is because the side chains of the polymer liquid crystal have a random orientation, so the side chains parallel (//) to the linearly polarized ultraviolet light and the side chains perpendicular (⊥) to the linearly polarized ultraviolet light are present in the same proportion. It is presumed to be.
On the other hand, after the polymer liquid crystal film is irradiated with linearly polarized ultraviolet light (after the first irradiation step), the absorbance in the parallel (//) direction is perpendicular to the electric field vibration of the linearly polarized ultraviolet light. It was smaller than the absorbance in the (⊥) direction. This is because the side chain groups in the parallel (//) direction are selectively sensitive to cross-linking to linearly polarized ultraviolet light, and as a result, the double bonds in the side chain in the parallel (//) direction are selectively reduced. Presumed to be.

(3) Heat treatment step Next, the exposed film was subjected to heat treatment (annealing treatment) at a liquid crystal temperature of 220 ° C. for 10 minutes using a hot plate (Thermolyne, Type 1900) to induce the orientation of the side chain groups. The heated film was immediately cooled to room temperature to fix the induced orientation. Changes in the polarized UV absorption spectrum before and after the heat treatment were evaluated using a spectroscope (same as above) (see FIG. 4). From FIG. 4, it can be seen that when heat treatment is performed, the absorbance in the parallel (//) direction increases and the absorbance in the vertical (⊥) direction decreases with respect to the electric field vibration of the linearly polarized ultraviolet light. It is estimated that such a result was obtained for the following reason. That is, due to the heat treatment, the uncrosslinked side chain group is affected by the already cross-linked parallel (//) side chain group, and the orientation in the parallel (//) direction is the same as that of the cross-linked side chain group. While increasing the number of uncrosslinked side groups in the parallel (//) direction, resulting in increased absorbance due to double bonds in the uncrosslinked side groups in the parallel (//) direction. This is probably because the absorbance due to the double bond of the uncrosslinked side chain group in the vertical (⊥) direction decreased.

  Moreover, the order parameter (s, 0 <= s <= 1) as an in-plane orientation degree was computed about the film | membrane after heat processing. In this order parameter (s), the absorbance in the parallel (//) direction to the electric field vibration of polarized light is A //, the absorbance in the vertical (⊥) direction is A⊥, and the dichroism is ΔA = A //-A It was determined as ⊥ and calculated by the following formula. As a result, the order parameter was about 0.4.

(formula)
S = (A //-A⊥) / (Alarge + 2Asmall)
However,
If A //> A⊥, then Alarge = A //, Asmall = A⊥,
If A // <A⊥, Alarge = A⊥ and Asmall = A //.

(4) Second ultraviolet light irradiation step In order to further improve the acid resistance and solvent resistance of the film, the film after the heat treatment is again subjected to a light intensity of 30 mW / cm ² (325 nm) as in the first ultraviolet light irradiation step. Were irradiated for 400 seconds at room temperature. Although linearly polarized ultraviolet light is used here, the ultraviolet light used in this step may be non-polarized ultraviolet light. Changes in the polarized UV absorption spectrum before and after the second ultraviolet light irradiation step were evaluated using a spectroscope (same as above) (see FIG. 5).

As shown in FIG. 5, the absorbance in the parallel (//) direction and the absorbance in the vertical (⊥) direction both decreased before and after this step, indicating that the cross-linking of the side chain groups had progressed.
By the way, ΔA = A // − A⊥ is hardly changed before and after this process. Therefore, it is considered that the alignment of the aligned side chain groups is maintained in this step.

(5) Mesostructured body formation step (5-1) Preparation of mixed solution Hydrochloric acid (UGR, UGT) in an aqueous solution of hexadecyltrimethylammonium chloride (abbreviation: CTACl, Kanto Chemical) as a template surfactant. Kanto Chemical) was added and stirred at about 30 ° C. for 2 to 3 hours. Subsequently, tetraethoxysilane (abbreviation: TEOS, Kanto Chemical), a silane compound, was added and stirred for several minutes at about 30 ° C. to prepare a mixed solution (sol-gel solution). The composition ratio of the raw materials in the mixed solution was TEOS: CTACl: water: hydrochloric acid = 0.11: 0.1: 100: 7.

(5-2) Formation of Mesostructured Body and Mesoporous Body As shown in FIG. 6, a Teflon (registered trademark) sheet 23 is laid on the bottom of a container 20 made of polypropylene, and a pair of Teflon (registered trademark) made thereon. Spacers 25 (Thickness: 0.2 mm) were set at predetermined intervals. Then, the mixed solution 27 was poured into the container 20. Subsequently, a quartz substrate 31 having a polymer liquid crystal film 29 formed on one side was disposed on the spacer 25. At this time, the surface of the polymer liquid crystal film 29 on the quartz substrate 31 was set so as to be immersed in the mixed solution 27 (see FIG. 6). This container 20 was sealed and allowed to stand at room temperature for 3 days to obtain a mesostructured body 33 (surfactant / silane compound hybrid thin film) as a precursor of mesoporous silica (mesoporous body) on the polymer liquid crystal film 29. .

  Then, the quartz substrate 31 was taken out and the surface of the polymer liquid crystal film 29 was washed. This was dried overnight at room temperature and then heat-treated at 100 ° C. under TEOS vapor for 2 hours. This is set in a UV-ozone cleaner (Nippon Laser & Electronics Lab, NL-UV253) and irradiated with ultraviolet light for 1.5 hours in an oxygen atmosphere to form a surfactant and polymer liquid crystal. The film 29 was photodecomposed to obtain a mesoporous body (mesoporous silica thin film).

(6) Evaluation of mesostructured body and mesoporous body (6-1) Determination of pore structure Small angle of mesostructured body before photolysis and mesoporous body after photolysis using X-ray diffractometer (Rigaku, RINT2000) Each X-ray diffraction measurement was performed (see FIG. 7). A Cu Kα ray was used as the X-ray, and this was scanned under the conditions of a tube current of 40 mA, a tube voltage of 40 mV, a scan range of 2θ = 1.5 to 10 °, a scan step of 0.01 °, and a scan speed of 1 ° / min.

  As a result of detailed analysis of the diffraction profile in FIG. 7, a diffraction peak due to the (1 0 0) plane at 2.35 ° and a peak due to the (2 0 0) plane at 4.77 ° were confirmed before photolysis. The pore structure of the tissue was found to be a hexagonal structure. It was also found that the diffraction peaks were almost maintained before and after photolysis, and that the hexagonal structure was maintained even in the mesoporous body after removal of the surfactant and the like. The slight shift of the diffraction peak to the wide-angle side after photolysis is presumed to be due to shrinkage of the pore diameter (a 2.53 ° diffraction peak is observed after photolysis). As a result of analysis by Bragg's equation based on the diffraction angle of 2.35 ° of the mesostructure, the pore size (channel period) was about 3 nm.

(6-2) Evaluation of pore arrangement regularity of mesostructures The surface morphology of the mesostructures deposited on the polymer liquid crystal film was observed using an optical microscope (OLYMPUS, BX51). FIG. 8 shows a photograph of the surface of the mesostructured body (in FIG. 8, the arrow indicates the electric field oscillation direction (the same direction as the orientation direction of the side chain group) of the linearly polarized ultraviolet light irradiated in the first ultraviolet light irradiation step. Show).
As shown in FIG. 8, a regular form in the uniaxial direction was observed, and it was found that this form occurred perpendicularly to the orientation direction of the side chain group induced by polarized ultraviolet light.

  FIG. 9 is a photograph of a structure in which a surfactant and a silane compound structure are deposited on a polymer liquid crystal film partially photomasked in the first ultraviolet light irradiation step. As shown in FIG. 9, in the unexposed area, the surface morphology of the deposited mesostructure was completely random, and a regular form was observed only in the exposed area.

  The regular surface morphology in the uniaxial direction was also observed unchanged in the mesoporous body (mesoporous silica thin film) after removing the surfactant by photolysis.

(6-3) Photopatterning Next, photopatterning of the mesoporous body was performed by irradiation (exposure) and non-irradiation (unexposed) of polarized ultraviolet light onto the substrate on which the photocrosslinkable polymer liquid crystal film was formed. In the experiment, the exposed portion and the unexposed portion were patterned on the polymer liquid crystal film using a photomask (first ultraviolet light irradiation step). Then, the heat treatment process, the 2nd ultraviolet light irradiation process, and the mesostructure formation process were performed by the above-mentioned method, and the mesostructure was formed.

  When the mesostructure was observed with an optical microscope (same as above), the deposited mesostructure was patterned depending on the difference between the exposed part (uniaxial regular form) and the unexposed part (random form) as shown in FIG. Was possible.

<Example 2 (first manufacturing method)>
A mesostructured body and a mesoporous body were produced in the same manner as in Example 1 except that the second ultraviolet light irradiation step was not performed.
Also in this case, as in the case of Example 1, when the surface morphology of the mesostructure was observed, a regular form in the uniaxial direction was observed as shown in FIG. This form was found to occur perpendicularly to the orientation direction of the side chain group of the polymer liquid crystal film induced by polarized ultraviolet light exposure.

  Also, the optical patterning was performed in the same manner as in Example 1. In this case as well, the deposited mesostructured body, as shown in FIG. 10, is exposed (uniaxial regular form), unexposed (random) Patterning was possible due to the difference in form) (not shown).

<Stability evaluation of polymer liquid crystal film in mixed solution>
By the way, the nano-array structure of the mesostructured body is controlled by the side chain group orientation of the polymer liquid crystal film immersed in the mixed solution.
Therefore, in order to control the nano-array structure highly, it is necessary to maintain the side chain group orientation of the polymer liquid crystal film in the mixed solution.

Therefore, the following experiment was performed in order to confirm how much the side chain group orientation is maintained in the mixed solution.
In this experiment, the polymer liquid crystal films of Example 1 and Example 2 were immersed in a test solution (hydrochloric acid: water: ethanol = 7: 100: 20) as a model of a mixed solution at 60 ° C. for 12 hours, Changes in polarized UV absorption spectrum before and after immersion were measured with a spectroscope (same as above). The hydrochloric acid solution was used because acid is used to promote the sol-gel reaction, and thus the stability of the film in an acidic aqueous solution is very important.
The results are shown in FIG. Even in the polymer liquid crystal films of Examples 1 and 2, ΔA = A // − A⊥ hardly changed before and after immersion. Therefore, it is considered that the orientation of the side chain group is maintained.

  Furthermore, in the case of the polymer liquid crystal film of Example 1, ΔA = A // − A⊥ is almost the same before and after the immersion, and the orientation of the side chain groups is considered to be maintained almost completely. It is done.

<Example 3 (first manufacturing method)>
Instead of poly {6- [4 '-(4-cyanocinnamoyloxy) biphenyl-4-yloxy] hexyl methacrylate} in Example 1, poly {6- [4'-(4-methylcinnamoyloxy) biphenyl-4-iroxy Hexyl methacrylate} (see chemical formula below) was synthesized and used. The molecular weight of the polymer was determined by GPC measurement (Shodex, R1-101, UV-41). For the measurement, chloroform was used as a solvent, PS standard was used as a reference, the flow rate was 1 ml / min, and the column temperature was 40 ° C. From the GPC measurement, the number average molecular weight Mn was 4.5 × 10 ⁴ , and the weight average molecular weight Mw was 11.0 × 10 ⁴ .

Then, using this polymer liquid crystal, a spin cast film (film thickness: about 70 nm) was produced in the same manner as in Example 1, and dried overnight at room temperature.
The film was irradiated with linearly polarized ultraviolet light in the same manner as in Example 1 except that the irradiation time was 280 seconds (first ultraviolet light irradiation step).
As shown in FIG. 12, as in Example 1, before the polymer liquid crystal film was irradiated with linearly polarized ultraviolet light (before the first irradiation step), it was parallel (//) to the electric field vibration of the linearly polarized ultraviolet light. The absorbance in the direction and the absorbance in the vertical (⊥) direction were almost the same (in the graph of FIG. 12, the two spectral data overlap).
On the other hand, after irradiating the linearly polarized ultraviolet light to the polymer liquid crystal film (after the first irradiation step), in the same manner as in Example 1, it is parallel (//) to the electric field vibration of the linearly polarized ultraviolet light. The absorbance was smaller than the absorbance in the vertical (⊥) direction.

Next, the spin cast film was heat-treated in the same manner as in Example 1 except that the heating temperature was 180 ° C.
Changes in polarized UV absorption spectrum before and after heat treatment were evaluated in the same manner as in Example 1. The results are shown in FIG. The same result as in Example 1 was obtained. That is, the heat treatment increased the absorbance in the parallel (//) direction to the electric field vibration of the linearly polarized ultraviolet light, and decreased the absorbance in the vertical (⊥) direction.
For the film after the heat treatment, the order parameter as the in-plane orientation degree was calculated in the same manner as described above, and was about 0.5.

  Further, a mesostructured body was formed in the same manner as in Example 1 by using the spin cast film after the heat treatment. When the surface morphology of the mesostructures deposited on the polymer liquid crystal film was observed using an optical microscope (OLYMPUS, BX51), a regular morphology in the uniaxial direction was observed as in Example 1. The morphology was found to occur perpendicular to the orientation direction of the side chain groups of the polymer liquid crystal film induced by polarized ultraviolet light exposure (not shown). Thus, even when a polymer liquid crystal other than poly {6- [4 '-(4-cyanocinnamoyloxy) biphenyl-4-yloxy] hexyl methacrylate} is used, a regular form in the uniaxial direction of the mesostructure is obtained. Observed.

<Example 4 (first manufacturing method)>
Instead of poly {6- [4 '-(4-cyanocinnamoyloxy) biphenyl-4-yloxy] hexyl methacrylate} in Example 1, poly {6- [4'-(4-methoxycinnamoyloxy) biphenyl-4-iroxy] ] Hexyl methacrylate (see chemical formula below) was synthesized and used. The molecular weight of the polymer was determined by GPC measurement (Shodex, R1-101, UV-41). For the measurement, chloroform was used as a solvent, PS standard was used as a reference, the flow rate was 1 ml / min, and the column temperature was 40 ° C. From the GPC measurement, the number average molecular weight Mn was 3.7 × 10 ⁴ , and the weight average molecular weight Mw was 9.0 × 10 ⁴ .
From the differential scanning calorimetry (Seiko Instruments Inc., SSC5200H), the phase transition temperatures were Tg: 120 ° C. and Ti: 323 ° C.

Then, using this polymer liquid crystal, a spin cast film (film thickness: about 50 nm) was prepared in the same manner as in Example 1 except that a 0.50 wt% chloroform solution was used, and was dried overnight at room temperature. .
The film was irradiated with linearly polarized ultraviolet light in the same manner as in Example 1 except that the irradiation time was 120 seconds (first ultraviolet light irradiation step).
As shown in FIG. 14, as in Example 1, before the polymer liquid crystal film was irradiated with linearly polarized ultraviolet light (before the first irradiation step), it was parallel (//) to the electric field vibration of the linearly polarized ultraviolet light. The absorbance in the direction and the absorbance in the vertical (⊥) direction were almost the same (in the graph of FIG. 14, the two spectral data overlap).
On the other hand, after irradiating the linearly polarized ultraviolet light to the polymer liquid crystal film (after the first irradiation step), in the same manner as in Example 1, it is parallel (//) to the electric field vibration of the linearly polarized ultraviolet light. The absorbance was smaller than the absorbance in the vertical (⊥) direction.

Next, the spin cast film was heat-treated in the same manner as in Example 1 except that the heating temperature was 150 ° C.
Changes in polarized UV absorption spectrum before and after heat treatment were evaluated in the same manner as in Example 1. The results are shown in FIG. The same result as in Example 1 was obtained. That is, the heat treatment increased the absorbance in the parallel (//) direction to the electric field vibration of the linearly polarized ultraviolet light, and decreased the absorbance in the vertical (⊥) direction.
In addition, about the film after heat processing, when the order parameter as an in-plane orientation degree was computed similarly to the above-mentioned, it was about 0.7.

  Further, a mesostructured body was formed in the same manner as in Example 1 by using the spin cast film after the heat treatment. When the surface morphology of the mesostructures deposited on the polymer liquid crystal film was observed using an optical microscope (OLYMPUS, BX51), a regular morphology in the uniaxial direction was observed as in Example 1. The morphology was found to occur perpendicular to the orientation direction of the side chain groups of the polymer liquid crystal film induced by polarized ultraviolet light exposure (not shown). Thus, even when a polymer liquid crystal other than poly {6- [4 '-(4-cyanocinnamoyloxy) biphenyl-4-yloxy] hexyl methacrylate} is used, a regular form in the uniaxial direction of the mesostructure is obtained. Observed.

  As described above, according to the present invention, since the pore arrangement of the mesostructured body and mesoporous body can be arbitrarily controlled, not only the application to the catalyst and the separation membrane, but also the nano-sized laser oscillation element, the solid for battery Advanced application development can be expected as various nano-level optical / electrical next-generation devices such as electrolyte materials and light-emitting thin films exhibiting photoluminescence. It can also be used as a reaction field for polymerizing special polymer fibers having new functionality.

It is a conceptual diagram of the manufacturing method of a mesostructure. It is a conceptual diagram of the manufacturing method of a mesostructure. It is a polarized UV absorption spectrum before and after the first ultraviolet irradiation process. It is a polarized UV absorption spectrum before and after heat treatment. It is a polarized UV absorption spectrum before and after the second ultraviolet irradiation process. It is a schematic diagram which shows the preparation methods of a mesostructure. It is a figure which shows a small angle X-ray-diffraction measurement result. It is a surface photograph of a mesostructure. It is a surface photograph of a mesostructure. It is a surface photograph of a mesostructure. It is a polarized UV absorption spectrum before and after immersion in a test solution. It is a polarized UV absorption spectrum before and after the first ultraviolet irradiation process. It is a polarized UV absorption spectrum before and after heat treatment. It is a polarized UV absorption spectrum before and after the first ultraviolet irradiation process. It is a polarized UV absorption spectrum before and after heat treatment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Side chain group 3 ... Polymer liquid crystal film 5 ... Ultraviolet light 7 ... Mesostructured body

Claims (5)

Irradiation step of linearly polarized ultraviolet light that irradiates a linearly polarized ultraviolet light onto a polymer liquid crystal film having a liquid-crosslinkable site on the side chain and a liquid crystal group
A heat treatment step of heat treating the film after the irradiation step;
A mesostructure formation step of forming a mesostructured body containing a surfactant and silica on the film after the heat treatment step by immersing the film after the heat treatment step in a mixed solution containing a surfactant and a silane compound A method for producing a mesostructured body comprising: A first ultraviolet light irradiation step of irradiating a polymer liquid crystal film having a liquid-crosslinkable portion and a liquid crystal group on a side chain with linearly polarized ultraviolet light;
A heat treatment step of heat treating the film after the first irradiation step;
A second ultraviolet light irradiation step of irradiating the film after the heat treatment step with ultraviolet light;
A mesostructured body containing a surfactant and silica on the film after the second ultraviolet light irradiation step by immersing the film after the second ultraviolet light irradiation step in a mixed solution containing a surfactant and a silane compound. A mesostructured body forming step of forming a mesostructured body. The method for producing a mesostructured body according to claim 1 or 2, wherein the heat treatment temperature is a temperature at which the polymer liquid crystal develops a liquid crystal phase. A polymer liquid crystal film having side-chain photocrosslinkable sites and liquid crystal groups was crosslinked by linearly polarized ultraviolet light, and silica was deposited on the film by a sol-gel method using a surfactant organic structure as a template. Organization. A polymer liquid crystal film having a photocrosslinkable site in the side chain and a liquid crystal group is cross-linked by linearly polarized ultraviolet light, and silica is deposited on the film by a sol-gel method using a surfactant organic structure as a template. A mesoporous body obtained by removing the surfactant.

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