Method for producing a polymer nanofiber assembly, polymer nanofiber assembly, uniaxially oriented polymer nanofiber assembly substrate, and laser desorption / ionization mass spectrometry substrate

Abstract

To provide a method for manufacturing a polymer nanofiber assembly, which can efficiently manufacture longitudinally uniaxially oriented polymer nanofiber assembly.SOLUTION: A method for manufacturing a polymer nanofiber assembly includes: a step to obtain a gel-like composition by dispersing a specific water-insoluble self assembly compound in either one of a specific organic solvent or a mixed solvent of the organic solvent and water; a step to obtain water replaced gel-like composition by replacing the organic solvent in the gel-like composition with the water; a step to obtain a self assembly fiber bundle by compressing the water replaced gel-like composition by compressing from a plurality of directions that are open in a longitudinal direction and substantially orthogonal to the longitudinal direction; and a step to obtain an assembly consisting of polymer nanofibers oriented in the longitudinal direction by polymerizing the self assembly compound in the self assembly fiber bundle.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a polymer nanofiber assembly, a polymer nanofiber assembly, a uniaxially oriented polymer nanofiber assembly substrate, and a laser desorption / ionization mass spectrometry substrate.

Background Art

[0002] A porous substrate having a vertically oriented structure is expected to be applied to various fields from the viewpoints of optical and electronic devices and their performance improvement (improvement of light absorption performance, expansion of surface area, securing of conductive buses, securing of smooth substance diffusion, etc.). And as an application of such a porous substrate, for example, a laser desorption / ionization mass spectrometry substrate can be mentioned. As a technique used for a laser desorption / ionization mass spectrometry substrate using such a porous substrate having a vertically oriented structure, for example, Non-Patent Document 1 (Nicholas J. Morris et al., “Laser desorption ionization (LDI) silicon nanopost array chips fabricated using deep UV projection lithography and deep reactive ion etching”, Rsc Advances, vol. 5, 2015, P. 72051-P. 72057) discloses that a silicon substrate having a nanopost (nanopillar) array structure formed by a photolithography technique is used as a substrate for laser desorption / ionization mass spectrometry.

[0003] Although it is not a porous substrate having a vertical alignment structure, as a technique of using a substrate having a randomly oriented structure as a laser desorption / ionization mass spectrometry substrate, for example, in Non-Patent Document 2 (Tian Lu et al., “Electrospun nanofibers as substrates for surface-assisted laser desorption / ionization and matrix-enhanced surface-assisted laser desorption / ionization mass spectrometry”, Analytical chemistry, vol. 85, issue 9, 2013, P. 4384-p. 4391), it is disclosed that an aggregate of resin nanofibers produced by electrospinning or a fibrous carbon substrate obtained by firing the same is used as a substrate for laser desorption / ionization mass spectrometry.

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the technology described in Non-Patent Document 1, at least eight steps such as surface treatment, installation and patterning of photoresist are required for the production of a single substrate, and the process is complicated and not sufficient in terms of production efficiency (such as speeding up and cost reduction of substrate production).

[0006] On the other hand, the technology described in Non-Patent Document 2 is a technology that applies an aggregate of resin nanofibers to a substrate for laser desorption / ionization mass spectrometry. However, since electrospinning is used in the substrate manufacturing method, only randomly oriented fibrous structures can be obtained as the formed fibrous structures. On the other hand, Non-Patent Document 2 does not disclose anything such as forming a uniaxially oriented fibrous structure at all.

[0007] The present invention has been made in view of the problems of the prior art, and a method for producing a polymer nanofiber aggregate capable of efficiently producing a polymer nanofiber aggregate uniaxially oriented in the longitudinal direction; a polymer nanofiber aggregate obtained by using the production method; a uniaxially oriented polymer nanofiber aggregate substrate capable of efficiently producing a cut product of the polymer nanofiber aggregate; and a laser desorption / ionization mass spectrometry substrate using the uniaxially oriented polymer nanofiber aggregate substrate. The purpose is to provide. [Means for Solving the Problems]

[0008] As a result of intensive studies to achieve the above object, the present inventors first dispersed a water-insoluble self-assembling compound having a polymerizable functional group and capable of forming a fibrous molecular aggregate by self-assembly in either an organic solvent miscible with water or a mixed solvent of the organic solvent and water to form a gel-like composition. Then, after replacing the organic solvent in the gel-like composition with water to form a water-replaced gel-like composition, the water-replaced gel-like composition was squeezed by compressing it from a plurality of directions substantially orthogonal to the longitudinal direction while opening the longitudinal direction to form a self-assembled fiber bundle. Thereafter, the present inventors found that a longitudinally uniaxially oriented polymer nanofiber aggregate can be efficiently produced by polymerizing the self-assembling compound in the self-assembled fiber bundle, and thus completed the present invention.

[0009] That is, the present invention provides the following aspects.

[0010] [1] A step of obtaining a gel-like composition by dispersing a water-insoluble self-assembling compound having a polymerizable functional group and capable of forming a fibrous molecular aggregate by self-assembly in either an organic solvent miscible with water or a mixed solvent of the organic solvent and water; A step of obtaining a water-replaced gel-like composition by replacing the organic solvent in the gel-like composition with water; A step of squeezing the water-replaced gel-like composition by compressing it from a plurality of directions substantially orthogonal to the longitudinal direction while opening the longitudinal direction to obtain a self-assembled fiber bundle; A step of obtaining an aggregate composed of longitudinally oriented polymer nanofibers by polymerizing the self-assembling compound in the self-assembled fiber bundle; A method for producing a polymer nanofiber aggregate, comprising:

[0011] [2] The method for producing a polymer nanofiber aggregate according to [1], wherein the polymerizable functional group is at least one group selected from the group consisting of a trialkoxysilyl group, a vinyl group, an acryloyl group, a methacryloyl group, a dienyl group, and a diacetylene group.

[0012] [3] The water-insoluble self-assembling compound is an organic compound having two or more amide bonds and two or more aromatic groups in the molecular skeleton, each of the two or more aromatic groups is a group having one aromatic ring selected from the group consisting of a naphthalimide ring, a triphenylamine ring, a pyrene ring, a perylene ring, and an acridone ring, and an organosilane compound in which two or more trialkoxysilyl groups as the polymerizable functional group are bonded to each of the two or more aromatic groups, the method for producing a polymer nanofiber aggregate according to [1] or [2].

[0013] [4] A polymer nanofiber aggregate in which nanofibers composed of a polymer of a water-insoluble self-assembling compound having a polymerizable functional group and capable of forming a fibrous molecular aggregate by self-assembly are aligned and aggregated in the longitudinal direction It is a polymer nanofiber aggregate, and the polymer nanofiber aggregate has a surface with a porous structure composed of nanofibers whose cross-sectional plane when cut from a direction substantially perpendicular to the longitudinal direction is oriented substantially perpendicular to the cross-sectional plane. .

[0014] [5] A uniaxially oriented polymer nanofiber aggregate substrate comprising a thin film composed of a cut product of a polymer nanofiber aggregate in which nanofibers composed of a polymer of a water-insoluble self-assembling compound having a polymerizable functional group and capable of forming a fibrous molecular aggregate by self-assembly are aligned and aggregated in the longitudinal direction, and the cutting direction of the cut product is substantially perpendicular to the longitudinal direction of the polymer nanofiber aggregate.

[0015] [6] A laser desorption / ionization mass spectrometry substrate comprising the uniaxially oriented polymer nanofiber aggregate substrate according to [5] or a hydrophobized product thereof.

[0016] Although the reason why the above object can be achieved by the present invention is not necessarily clear, the inventors presume as follows. That is, first, the fibrous molecular aggregates formed by the molecules of the self-organizable compound usually have a random orientation. Since such randomly oriented fibrous molecular aggregates are aggregates of low molecular compounds, they are very fragile mechanically, and it has been considered impossible to mechanically process the molecular aggregates.

[0017] Under such circumstances, the present inventors have found that, by using a water-insoluble compound (raw material molecule) that has a polymerizable functional group and can form a fibrous molecular aggregate as a self-organizing compound, dispersing the compound in either one of an organic solvent (e.g., alcohol) miscible with water or a mixed solvent of the organic solvent and water, and allowing the molecules of the compound to self-organize in the solvent to obtain a gel composition (a gel composition containing a molecular aggregate in which the molecules self-organize into a fibrous shape), and then replacing the organic solvent contained in the obtained gel composition with water, the fibrous molecular aggregate in the composition can be mechanically processed. Note that, in the water-substituted gel composition thus obtained, a state in which the water-insoluble fibrous molecular aggregate is forcibly dispersed in an aqueous medium is formed, and the present inventors presume that this will result in strong hydrophobic interactions between the molecules, thereby reinforcing the mechanical properties of the fibrous molecular aggregate and making it possible to mechanically process it. In the present invention, the water-displaced gel composition having the reinforced mechanical properties is subjected to a process of compressing and squeezing the composition from multiple directions substantially perpendicular to the longitudinal direction while releasing the composition in the longitudinal direction. This process causes the fibrous molecular aggregates in the composition to be oriented in the longitudinal direction. The fibrous molecular aggregates are oriented in the longitudinal direction to form a bundle-shaped aggregate (self-assembled fiber bundle) in this manner, and then the fibrous molecular aggregates in the self-assembled fiber bundle obtained are polymerized, thereby efficiently producing a polymer nanofiber assembly uniaxially oriented in the longitudinal direction. In this way, in the present invention, the water-insoluble self-assembling compound is dispersed in the solvent, and then the organic solvent contained in the solvent is forcibly changed to water, thereby improving the mechanical properties of the fibrous molecular aggregate and enabling mechanical processing that was previously impossible, thereby enabling the production of a uniaxially oriented polymer nanofiber assembly.Thus, by using a specific compound and adopting a simple process such as replacing the medium, in the present invention, it is possible to process the fibrous molecular assembly formed by molecular self-assembly into a bundled state with one-way orientation, and by polymerizing and immobilizing it, it is possible to produce an axially oriented polymer nanofiber assembly. Therefore, the present invention provides a method capable of efficiently producing a polymer nanofiber assembly without adopting a complicated process.

[0018] Further, by using the polymer nanofiber assembly obtained by the method for producing a polymer nanofiber assembly of the present invention and performing a simple process of cutting it in a direction substantially perpendicular to the longitudinal direction (preferably the short-side direction) to form a thin film, it is also possible to continuously, rapidly, and stably produce a substrate provided with a thin film in which the polymer of the fibrous compound is axially oriented in the vertical direction (uniaxially oriented polymer nanofiber integrated substrate: note that due to its structure, it becomes a substrate having a porous structure (pillar array structure)). Therefore, according to the present invention, it is also possible to efficiently produce a uniaxially oriented polymer nanofiber integrated substrate.

Advantages of the Invention

[0019] According to the present invention, it is possible to provide a method for producing a polymer nanofiber assembly capable of efficiently producing an axially oriented polymer nanofiber assembly in the longitudinal direction; a polymer nanofiber assembly obtained by using the production method; a uniaxially oriented polymer nanofiber integrated substrate that can be efficiently produced as a cut product of the polymer nanofiber assembly; and a laser desorption / ionization mass spectrometry substrate applying the uniaxially oriented polymer nanofiber integrated substrate.

Brief Description of the Drawings

[0020]

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Mode for Carrying Out the Invention

[0021] Hereinafter, the present invention will be described in detail with reference to its preferred embodiments. In the following description, for convenience, the preferred embodiments of the present invention will be described with reference to the drawings as appropriate. Also, in the following description and drawings, the same or corresponding elements are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0022] [Method for producing a polymer nanofiber aggregate] The method for producing a polymer nanofiber aggregate of the present invention comprises a step of dispersing a water-insoluble self-assembling compound having a polymerizable functional group and capable of forming a fibrous molecular aggregate by self-assembly in either an organic solvent miscible with water or a mixed solvent of the organic solvent and water to obtain a gel-like composition (hereinafter, sometimes simply referred to as the "first step"); a step of replacing the organic solvent in the gel-like composition with water to obtain a water-replaced gel-like composition (hereinafter, sometimes simply referred to as the "second step"); a step of squeezing the water-replaced gel-like composition by compressing it from a plurality of directions substantially orthogonal to the longitudinal direction while opening the longitudinal direction to obtain a self-assembled fiber bundle (hereinafter, sometimes simply referred to as the "third step"); a step of polymerizing the self-assembling compound in the self-assembled fiber bundle to obtain an aggregate composed of polymer nanofibers oriented in the longitudinal direction (hereinafter, sometimes simply referred to as the "fourth step"); and is characterized by including the above. Hereinafter, each step will be described separately.

[0023] <First step> The first step is a step of dispersing a water-insoluble self-assembling compound (hereinafter, for convenience, sometimes simply referred to as the "self-assembling compound") having a polymerizable functional group and capable of forming a fibrous molecular aggregate by self-assembly in either an organic solvent miscible with water or a mixed solvent of the organic solvent and water to obtain a gel-like composition.

[0024] The self-assembling compound used in such a process needs to have a polymerizable functional group. Such a polymerizable functional group enables the orientation state to be polymerized and fixed in the fourth step. Also, the number of polymerizable functional groups contained in one molecule of the self-assembling compound is not particularly limited, but is preferably 2 to 8, and more preferably 2 to 4. When the number of such polymerizable functional groups is equal to or greater than the lower limit, it is possible to obtain a higher effect in terms of structural stabilization by forming an efficient crosslinked structure as compared with the case where it is less than the lower limit. On the other hand, when it is equal to or less than the upper limit, it is possible to obtain a higher effect in terms of reducing deformation and volume shrinkage due to polymerization as compared with the case where it exceeds the upper limit.

[0025] Also, the polymerizable functional group is not particularly limited, but from the viewpoint of ensuring high reactivity in the solid state, it is preferably a trialkoxysilyl group, vinyl group, acryloyl group, methacryloyl group, dienyl group, or diacetylene group, more preferably a trialkoxysilyl group or dienyl group, and particularly preferably a trialkoxysilyl group. Examples of such a trialkoxysilyl group include a trimethoxysilyl group, triethoxysilyl group, tripropoxysilyl group, triisopropoxysilyl group, etc. When a plurality of polymerizable functional groups are contained in one molecule of the self-assembling compound, the plurality of polymerizable functional groups may each be the same, or may each be of different types. Thus, as the polymerizable functional group in the self-assembling compound, one type of group may be used alone, or two or more types may be used in combination.

[0026] Further, the self-assembling compound is a compound capable of forming a fibrous molecular aggregate by self-assembly and is water-insoluble. Here, "fibrous" means a shape in which the length is sufficiently long with respect to the diameter (preferably, the ratio of the length to the diameter is 10 times or more), and is a concept including so-called fibrous, linear, thread-like, needle-like, columnar, and other slender extended shapes (note that the fiber referred to here may be linear or may have branches).

[0027] As such a compound (molecule) capable of forming a fibrous molecular aggregate by self-assembly, known compounds (for example, compounds described in Non-Patent Document 3 (Sukumaran Santhosh Babu et al., “Functional π-Gelators and Their Applications”, Chem. Rev., 2014, vol. 114, No. 4, P. 1973 - P. 2129) and compounds described in Non-Patent Document 4 (Neralagatta M. Sangeetha et al., “Supramolecular gels: Functions and uses”, Chem. Soc. Rev., 2005, vol. 34, P. 821 - P. 836), etc.) can be appropriately used. Since the self-assembling compound has a polymerizable functional group, for example, a compound obtained by introducing a polymerizable functional group into the compounds (molecules) described in Non-Patent Documents 3 to 4 may be prepared and appropriately used. Thus, as the self-assembling compound, for example, a known compound (such as the compounds described in Non-Patent Documents 3 to 4) capable of forming a fibrous molecular aggregate by self-assembly can be used as a molecular skeleton, and a compound in which a polymerizable functional group is bonded directly or via a linking group (such as an alkylene group, etc.) to the molecular skeleton can be appropriately used. Note that the method for introducing a polymerizable functional group into a compound capable of forming a fibrous molecular aggregate by self-assembly is not particularly limited, and a known method that enables the introduction of a polymerizable functional group can be appropriately adopted.

[0028] Examples of the molecular skeleton of the self-organizing compound include amino acid-derived alkylamide compounds, oligoamino acid-derived alkylamide compounds, cyclic oligoamino acid derivatives, N,N’,N’’-trialkyl-substituted benzene tricarboxamide, N,N’,N’’-trialkyl-substituted cyclohexane tricarboxamide, N,N’-dialkyl-substituted cyclohexane dicarboxamide, N,N’,N’’-trialkyl-substituted triureido cyclohexane, N,N’-dialkyl-substituted diureido cyclohexane, alkylene diamide derivatives, alkylene diureido derivatives, dialkoxyxanthracene derivatives, dialkoxy anthraquinone derivatives, steroid derivatives, porphyrin derivatives, phthalocyanine derivatives, naphthalimide derivatives, naphthalene bisimide derivatives, perylene bisimide derivatives, alkoxy-substituted oligo-phenylene vinylene compounds, dibenzylidene sorbitol derivatives, gluconamide derivatives, triphenylamine derivatives, pyrene derivatives, perylene derivatives, and acridone derivatives, diphenylpyrene derivatives, tetraphenylpyrene derivatives, acridone derivatives, methylacridone derivatives, styrylbenzene derivatives, divinylbenzene derivatives, fluorene derivatives, quarterphenyl derivatives, anthracene derivatives, acridine derivatives, phenylpyridine derivatives, divinylpyridine derivatives, porphin derivatives, phthalocyanine derivatives, diketopyrrolopyrrole derivatives, dithienylbenzothiazole derivatives, or those obtained by linking two or more of these. Note that the molecular skeleton of the self-organizing compound is not limited to the above-exemplified substances, and for example, the molecular skeleton in the organic silyl compounds described later can also be used.

[0029] The molecular skeleton of the self-assembling compound is not particularly limited. For example, N-benzyloxycarbonyl-L-isoleucine octadecylamide, N-benzyloxycarbonyl-L-valine octadecylamide, N-benzyloxycarbonyl-L-valyl-L-valine octadecylamide, N-benzyloxycarbonyl-L-isoleucyl-L-isoleucyl-L-isoleucine dodecylamide, cyclo(L-β-3,7-dimethyloctylasparaginyl-L-phenylalanyl), cyclo(L-β-2-ethylhexylasparaginyl-L-phenylalanyl), N,N’,N’’-tristearyltrimethasamide, cis,cis-1,3,5-tris(stearylaminocarbonyl)cyclohexane, trans-1,2-bis(undecylcarbonylamino)cyclohexane, trans-1,2-bis(N-octadecylureido)cyclohexane, 1,12-bis(N-benzyloxycarbonyl-L-valyl)aminododecane, 1,12-bis(N-dodecylureido)dodecane, 2,3-bis(decylthio)anthracene, 2,3-bis(decylthio)-9,10-anthraquinone, cholesteryl-4-(2-anthryloxy)butanoate, cholesteryl anthraquinone-2-carboxylate, meso-tetrakis(p-carboxyphenyl)porphyrin trihexadecyl ester, (2-cholesteryloxycarbonylaminoethyl)aminocarbonyltris(tert-butyl)-Zn(II)-phthalocyanine, N-(N’-benzyloxycarbonyl-L-phenylalanylamino)-1,8-naphthalimide, N,N’-bis[2-(3,4,5-trioctyloxyphenylcarbonylamino)ethyl]-1,4,5,8-naphthalene bisimide, N,N’-bis[2-(3,4,5-trioctyloxyphenylcarbonylamino)ethyl]-3,4,9,10-perylene bisimide, 1,4-bis(4-hydroxymethyl-2,5-dioctyloxystyryl)-2,5-dioctyloxybenzene, dibenzylidene sorbitol, and N-octyl-D-gluconamide-6-benzoate, etc. In addition, the following formula (I A ): R 1 -R 2 ‐NH-CO-R2 -CO-NH-R 2 -R 1 (I A ) (In the formula, two Rs 1 each independently represent an aromatic group having a cyclic structure selected from the group consisting of a naphthalimide ring, a triphenylamine ring, a pyrene ring, a perylene ring, and an acridone ring, and a plurality of Rs 2 each independently represent an alkylene group having 2 to 16 carbon atoms.) A molecular skeleton represented by the following formula may be used.

[0030] Among such molecular skeletons, from the viewpoint that it contains an "organic group having a maximum absorption wavelength in the range of 200 to 600 nm (for example, naphthalimide, triphenylamine, pyrene, perylene, acridone, etc.)" in the skeleton and enables more sensitive analysis when used for a laser desorption / ionization mass spectrometry substrate, the molecular skeleton represented by the formula (I A ) is more preferable.

[0031] In addition, such a self-assembled compound needs to be water-insoluble. Here, "water-insoluble" means that when the compound is mixed with water (preferably so-called pure water) under a temperature condition of 20°C, recovered, and dried, the difference between the mass of the compound before mixing with water and the mass of the compound after mixing with water is 0.1% by mass or less of the mass of the compound before mixing with water (a property that can be regarded as having almost zero solubility in water under a temperature condition of 20°C). Therefore, as the self-assembled compound, those satisfying the above water-insoluble conditions may be appropriately selected from the above-mentioned compounds and used.

[0032] In addition, as the self-assembling compound, an organic silane compound having a site capable of forming a hydrogen bond, an aromatic group which is an organic group having a maximum absorption wavelength in the range of 200 to 600 nm (a group having an aromatic ring having a maximum absorption wavelength in the range of 200 to 600 nm), and a trialkoxysilyl group as a polymerizable functional group (hereinafter, for convenience, referred to as "organic silane compound (A-1)") is more preferable. Among them, having two or more (more preferably 2 to 8) amide bonds and two or more (more preferably 2 to 4) aromatic groups in the molecular skeleton, each of the two or more aromatic groups is a group having one aromatic ring selected from the group consisting of a naphthalimide ring, a triphenylamine ring, a pyrene ring, a perylene ring, and an acridone ring, and an organic silane compound in which two or more trialkoxysilyl groups as the polymerizable functional group are bonded to each of the two or more aromatic groups (may be directly bonded or bonded via a linking group) (hereinafter, for convenience, referred to as "organic silane compound (A-2)") is more preferable. It has a molecular skeleton represented by the formula (I A ), and an organic silane compound in which two or more trialkoxysilyl groups as the polymerizable functional group are bonded to each of the aromatic groups represented by R 1 constituting the molecular skeleton (hereinafter, for convenience, referred to as "organic silane compound (A-3)") is particularly preferable. When such an organic silane compound (A-1) (more preferably compound (A-2), still more preferably compound (A-3)) is used as the self-assembling compound, the polymer nanofiber (fibrous organosilica) obtained after polymerizing the compound can be made of an organosilica compound, and a polymer nanofiber aggregate having fibrous organosilica as a structural unit can be obtained.

[0033] The hydrogen-bondable site (hydrogen-bonding site) of such an organosilane compound (A-1) is not particularly limited. For example, an amide bond (a bond represented by -NH-CO-), a urethane bond (a bond represented by -NH-COO-), a urea bond (a bond represented by -NH-CO-NH-), a hydroxyl group (-OH), an imidazole group, an aminopyridyl group, etc. can be mentioned. Such a hydrogen-bonding site enables the formation of a fibrous molecular aggregate by the formation of a chain-like hydrogen bond, and furthermore, when a substrate formed using the compound is used as a substrate for laser desorption / ionization mass spectrometry, it is possible to adsorb a measurement target molecule, particularly a highly hydrophilic compound such as a bio-related molecule, and uniformly support the measurement target molecule on the substrate. Among such hydrogen-bonding sites, an amide bond (amide group) is particularly preferable because it can further improve the adsorptivity of the measurement target molecule. Further, the hydrogen-bonding site (preferably an amide bond) is preferably directly or indirectly (via another element) bonded to the aromatic group. Thereby, since the hydrogen-bonding sites are regularly arranged within the skeleton of the substrate, in laser desorption / ionization mass spectrometry, the adsorption sites of the measurement target molecules become homogeneous, and the uniformity of the detection intensity of the signals corresponding to the measurement target molecules is improved. Specific examples of the organosilane compound (A-1) having an amide bond as the hydrogen-bonding site include the above-mentioned organosilane compounds (A-2) and (A-3).

[0034] The aromatic group in the organic silane compound (A-1) is an organic group having a maximum absorption wavelength within the range of 200 to 600 nm (a group having an aromatic ring having a maximum absorption wavelength within the range of 200 to 600 nm). The aromatic ring having a maximum absorption wavelength within the range of 200 to 600 nm is not particularly limited, and known aromatic rings (naphthalimide ring, triphenylamine ring, pyrene ring, diphenylpyrene ring, tetraphenylpyrene ring, perylene ring, perylenebisimide ring, acridone ring, methylacridone ring, styrylbenzene ring, divinylbenzene ring, fluorene ring, quarterphenyl ring, anthracene ring, acridine ring, phenylpyridine ring, divinylpyridine ring, porphyrin ring, phthalocyanine ring, diketopyrrolopyrrole ring, dithienylbenzothiazole ring, etc.) can be appropriately used. Among them, from the viewpoint of chemical stability against laser light irradiation, the naphthalimide ring, triphenylamine ring, pyrene ring, perylene ring, and acridone ring are more preferable. Further, the organic silane compound (A-1) may contain one kind of aromatic group alone or two or more kinds. Further, as the organic silane compound (A-1) containing a group having one aromatic ring selected from the group consisting of a naphthalimide ring, triphenylamine ring, pyrene ring, perylene ring, and acridone ring, which is suitable as such an aromatic group, specifically, the organic silane compounds (A-2) and (A-3) can be mentioned as suitable ones. Further, in the organic silane compounds (A-1) to (A-3), from the viewpoint of ensuring the absorption performance of near-ultraviolet light and high chemical stability against light irradiation, it is particularly preferable that the aromatic group is a group having a naphthalimide ring. The aromatic group may have any of the above-mentioned various rings, and may be the ring itself or a ring having a substituent bonded thereto. Such substituents are not particularly limited, and examples thereof include an alkyl group, an alkoxy group, a phenyl group, a phenoxy group, a nitro group, a cyano group, an amino group, a hydroxyl group, a thiol group, a thioalkyl group, and a halogen group.

[0035] In addition, in the organic silane compounds (A-1) to (A-3), the trialkoxysilyl group is preferably bonded to the aromatic group directly or via a linking group. In the organic silane compounds (A-1) to (A-3), the upper limit of the number of trialkoxysilyl groups bonded to the aromatic group is not particularly limited, but is preferably 6 or less, more preferably 4 or less, and particularly preferably 3 or less. When the number of silyl groups bonded to one aromatic group exceeds the above upper limit, the proportion of the laser light-absorbing organic group decreases, and the absorption efficiency of the laser light tends to decrease. When a trialkoxysilyl group is bonded to the molecular skeleton directly or via a linking group, such a linking group is not particularly limited, but is preferably an alkylene group. Among them, from the viewpoint of easier preparation of the compound, an ethylene group, a propylene group, or a butylene group is preferable, and an ethylene group is particularly preferable.

[0036] In addition, the organic silane compounds (A-2) and (A-3) are compounds having two or more amide bonds (two in the case of compound (A-3)). The upper limit of the number of such amide bonds is not particularly limited, but is preferably 6 or less, more preferably 4 or less, and still more preferably 3 or less. When the number of such amide bonds exceeds the above upper limit, in laser desorption / ionization mass spectrometry, the measured target molecule supported on the substrate tends to be difficult to desorb. From the viewpoint of being able to exhibit appropriate adsorptivity and enabling efficient laser desorption / ionization mass spectrometry, the number of the amide bonds is more preferably two.

[0037] In addition, among the organic silane compounds (A-3), in particular, the following general formula (i):

[0038] [Chemical formula]

[0039] [In the formula, two cyclic organic groups R 1represents, independently of each other, an aromatic group having one cyclic structure selected from the group consisting of a naphthalimide ring, a triphenylamine ring, a pyrene ring, a perylene ring, and an acridone ring (particularly preferably a group derived from naphthalimide), and a plurality of R 2 each independently represents an alkylene group having 1 to 5 carbon atoms (more preferably 2 to 3 carbon atoms) (particularly preferably an ethylene group), Z represents an organic group containing a trialkoxysilyl group (an organic group that binds to the cyclic organic group R 1 and may be the trialkoxysilyl group itself or an organic group containing a trialkoxysilyl group and a linking group (a group that links between the cyclic organic group R 1 and the trialkoxysilyl group)), n represents the number of organic groups Z that bind to the cyclic organic group R 1 and represents an integer of 2 to 3 (more preferably 2).] The organosilane compound represented by is particularly preferred (note that as the trialkoxysilyl group in such a compound, a trimethoxysilyl group, a triethoxysilyl group, and a tripropoxysilyl group are preferred, and as the linking group that links the trialkoxysilyl group to the cyclic organic group R 1 ethylene group, propylene group, and butylene group are preferred). Note that the production method of such an organosilane compound is not particularly limited, and a known method can be appropriately adopted.

[0040] Also, in the first step, the self-assembling compound is dispersed in either one of a water-miscible organic solvent; and a mixed solvent of the organic solvent and water. As the water-miscible organic solvent used as such a solvent, any water-soluble solvent generally known as being miscible with water may be used, and there is no particular limitation. For example, alcohols (ethanol, methanol, propanol, etc.), acetone, acetonitrile, tetrahydrofuran, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, pyridine, triethylamine, etc. can be used. Note that when the organic solvent is used as the solvent for dispersing such a self-assembling compound, the organic solvent may be used alone or in combination of two or more.

[0041] Further, when using a mixed solvent of the organic solvent (an organic solvent miscible with water) and water as the solvent for dispersing the self-organizing compound, the content of the organic solvent in such a solvent is preferably 50% by mass or more (more preferably 60 to 95% by mass, still more preferably 65 to 90% by mass). When the content of such an organic solvent is at least the above lower limit, a higher effect can be obtained in terms of the solubility of the self-organizing compound during heating as compared with the case where it is less than the lower limit. On the other hand, when it is at most the above upper limit, a higher effect can be obtained in terms of efficient fiber formation near room temperature and reduction of the dissolved ratio of the self-organizing compound as compared with the case where it exceeds the upper limit. Note that as such an organic solvent in the mixed solvent, one kind may be used alone or two or more kinds may be used in combination.

[0042] In the present invention, since the organic solvent itself or the mixed solvent containing the organic solvent is used as the solvent, in any case of using either solvent, at least an "organic solvent miscible with water" is used. By using such an "organic solvent miscible with water", in the present invention, when a heating / cooling step as described below is employed in the first step, it becomes possible to efficiently generate a fibrous molecular assembly, and the gel-like composition obtained in the first step necessarily contains an organic solvent. In the subsequent second step, when a simple step such as immersing the gel-like composition containing the organic solvent in, for example, a large amount of water is performed, since the organic solvent is miscible with water (since the organic solvent and water form a uniform mixture), the substitution between the organic solvent and water contained in the gel-like composition easily proceeds so that the concentration of the organic solvent in water becomes uniform, and it becomes possible to efficiently produce a desired water-substituted gel-like composition.

[0043] In the first step, the self-assembling compound is dispersed in the organic solvent or the mixed solvent. However, from the perspective that more efficient formation of fibrous molecular aggregates becomes possible when the subsequent heating and cooling steps are employed, it is preferable to disperse the self-assembling compound in the mixed solvent.

[0044] Also, when dispersing the self-assembling compound in the solvent (the organic solvent or the mixed solvent), the amount of the self-assembling compound added to the solvent is preferably 0.5 to 10% by mass, more preferably 1 to 3% by mass, based on the total amount of the solvent and the self-assembling compound. When the amount (ratio) of the self-assembling compound added to the solvent is less than 0.5% by mass, the mixture of the organic solvent and the fibrous molecular aggregate formed by the self-assembling compound tends to lose its macroscopic shape as a gel, making it difficult to obtain a gel composition. Further, when the amount (ratio) of the self-assembling compound added to the solvent exceeds 10% by mass, the ratio of the organic solvent decreases, and the compression ratio during compression after replacing the organic solvent with water becomes low. Therefore, the orientation tends to deteriorate when orienting the fibrous molecular aggregate.

[0045] Also, when dispersing the self-assembling compound in the solvent (the organic solvent or the mixed solvent), after uniformly dissolving it by heating and then cooling, more homogeneous nanofibers can be formed more efficiently. Therefore, after adding the self-assembling compound to the solvent, it is preferable to adopt a step (heating and cooling step) of heating to 70 to 100°C (more preferably 75 to 85°C) to dissolve the self-assembling compound in the solvent and then cooling to room temperature (25°C).

[0046] In this way, the self-organizing compound is dispersed in the solvent (the organic solvent or the mixed solvent), thereby making it possible to obtain a gel composition. Such a gel composition is formed by a mixture of the fibrous molecular aggregate (nanofibers generated by molecular self-organization) formed by the self-organizing compound and the solvent. Since the solvent constituting the gel composition necessarily contains the organic solvent, the gel composition contains at least the organic solvent together with the fibrous molecular aggregate. Since the fibrous molecular aggregate is basically randomly oriented in the composition and becomes a mesh-like nanostructure (nanofiber), it is considered that the solvent is taken into the mesh-like hollow portion in the obtained composition, and the composition becomes gel-like.

[0047] <Second process> The second step is a step of replacing the organic solvent in the gel composition with water to obtain a water-substituted gel composition.

[0048] The method of replacing the organic solvent in the gel composition with water is not particularly limited, and a known method can be appropriately adopted. For example, a method of replacing the organic solvent with water by immersing the gel composition in water can be suitably adopted. When a method of immersing the gel composition in water is adopted as a method of replacing the organic solvent in the gel composition with water, it is preferable to immerse the gel composition in water and leave it for 1 to 3 days from the viewpoint of sufficiently progressing the replacement. In this way, a water-replaced gel composition can be obtained by replacing the organic solvent with water.

[0049] Furthermore, the inventors presume that in the water-substituted gel composition obtained in this manner, it is possible to more strongly express hydrophobic interactions between the molecules of the water-insoluble self-organizing compound, thereby reinforcing the mechanical properties of the fibrous molecular aggregates in the composition and enabling mechanical processing such as that employed in the third step described below to be carried out.

[0050] <Third Step> The third step is a step of squeezing the water-displaced gel composition by compressing it from a plurality of directions substantially orthogonal to the longitudinal direction while opening the longitudinal direction to obtain a self-assembled fiber bundle.

[0051] Here, as the "longitudinal direction" when compressing the water-displaced gel composition, for example, when the shape of the gel composition itself is a shape with different lengths in the vertical, horizontal, and height directions (for example, when it is a substantially rectangular parallelepiped), the longer direction among them may be adopted. On the other hand, when the gel composition is a substantially cube and the lengths in the vertical, horizontal, and height directions are approximately the same, a direction perpendicular to one surface may be adopted as the longitudinal direction.

[0052] Also, in the third step, the water-displaced gel composition is compressed from a plurality of directions substantially orthogonal to the longitudinal direction while opening the longitudinal direction. Such a compression step will be described with reference to FIG. 1. FIG. 1 is a schematic diagram schematically showing a preferred embodiment of a substantially rectangular parallelepiped-shaped water-displaced gel composition 10 before compression in which the z-axis direction is the longitudinal direction and a self-assembled fiber bundle 11 obtained after compression. Note that F in the composition 10 and the self-assembled fiber bundle 11 shown in FIG. 1 schematically represents a fibrous molecular aggregate of the self-assembled compound (hereinafter, sometimes simply referred to as "fiber F").

[0053] In the water-replacing gel composition 10, as in the embodiment shown in FIG. 1, the fibers F have no orientation, and each fiber F is oriented in a random direction to form a network-like shape. Such a water-replacing gel composition 10 is a structure (a gel containing water as a solvent) like a random dispersion of nanofibers (fibers F) of a self-organizing compound. Note that such a water-replacing gel composition 10 is in a state where mechanical processing is possible without collapsing the gel structure due to the solvent being water. And in the embodiment shown in FIG. 1, the water-replacing gel composition 11 is squeezed by compressing it from two directions (x direction and y direction) orthogonal to the longitudinal direction (z-axis direction), and the fibers F in the composition are oriented in the longitudinal direction.

[0054] Thus, in the embodiment shown in FIG. 1, while the longitudinal direction (z-axis direction) is open, the water-displacing gel-like composition 10 is compressed from a plurality of directions (two directions in the x-direction and the y-direction) that are substantially orthogonal to the longitudinal direction. Here, as the direction substantially orthogonal to the longitudinal direction, for example, the same direction or substantially the same direction as the radial direction when a circle is drawn on the xy-plane centered on the z-axis can be adopted. In this case, by compressing from two or more directions selected from the same direction as the radial direction and substantially the same direction as the radial direction, it becomes possible to compress from a plurality of directions substantially orthogonal to the longitudinal direction (in the embodiment shown in FIG. 1, both the x-direction and the y-direction are the radial directions when a circle is drawn on the xy-plane centered on the z-axis). Note that the "direction substantially orthogonal to the longitudinal direction" here may be a direction that intersects the longitudinal direction substantially perpendicularly (preferably at an angle in the range of 90° ± 20°, more preferably at an angle in the range of 90° ± 15°). Further, in the embodiment shown in FIG. 1, while the longitudinal direction is open (no pressure is applied from the longitudinal direction), since compression is performed from the two directions of the x-direction and the y-direction that are orthogonal to the longitudinal direction, a force is applied to the fibers F in the composition 10 during compression so as to be oriented in the longitudinal direction, and thereby it becomes possible to orient the fibers F sufficiently uniformly. Thus, in the present invention, while the longitudinal direction is open, the composition 10 is compressed from a plurality of directions substantially orthogonal to the longitudinal direction to squeeze the composition 10, so that the fibers F are in a state of being sufficiently uniformly oriented in the longitudinal direction, and it becomes possible to obtain a self-organized fiber bundle 11 in a form in which the fibers F are bundled together.

[0055] As in the preferred embodiment shown in FIG. 1 as described above, by compressing the water-substituted gel-like composition from a plurality of directions substantially orthogonal to the longitudinal direction while opening the longitudinal direction, it is possible to compress the composition while sufficiently uniformly orienting the fibrous molecular aggregates in the composition. As a result, it becomes possible to obtain a self-assembled fiber bundle in a form in which the fibrous molecular aggregates of the self-assembling compound are bundled and accumulated in an oriented state in the longitudinal direction. Note that conditions such as the compression ratio during such compression are not particularly limited and can be appropriately set according to the type of the self-assembling compound, the content ratio (concentration) of the self-assembling compound in the water-substituted gel-like composition, the intended design, and the like. For example, when the self-assembling compound is the organosilane compounds (A-1) to (A-3), and the gel-like composition before water substitution is a gel-like composition having a content ratio of the self-assembling compound of about 2% by mass (when the concentration of the fiber F is about 2% by mass), and the form of the water-substituted gel-like composition obtained by substituting water for the gel-like composition is a substantially rectangular parallelepiped, it is preferable to compress the gel-like composition in two directions that are substantially orthogonal to the longitudinal direction and perpendicular to each other (the x direction and the y direction in the embodiment shown in FIG. 1) until the length in each direction becomes 1 / 5 to 1 / 7 (particularly preferably 1 / 7) times the original length.

[0056] Further, it is preferable to perform a drying process on the self-assembled fiber bundle obtained by such a compression process to remove the solvent (water) inside the self-assembled fiber bundle before performing the fourth process described below. Such a drying process is not particularly limited, but for example, a process of removing water in the self-assembled fiber bundle by heating at a temperature condition of 90 to 120 ° C (more preferably 95 to 120 ° C) for 1 to 12 hours (more preferably 3 to 6 hours) can be employed.

[0057] <Fourth Step> The fourth step is a step of obtaining an aggregate composed of polymer nanofibers oriented in the longitudinal direction by polymerizing the self-assembling compound in the self-assembled fiber bundle.

[0058] When polymerizing such self-organizing compounds, the polymerization method is not particularly limited, and known polymerization methods such as hydrolysis polycondensation, photopolymerization, thermal polymerization, and polyaddition can be appropriately adopted according to the type of polymerizable functional group in such compounds.

[0059] In addition, as such a polymerization method, when the drying process is performed on the self-organizing fiber bundle as described above, the dried self-organizing fiber bundle is exposed to acidic vapor (vapor containing an acidic catalyst) or basic vapor (vapor containing a basic catalyst) under heating conditions to polymerize the self-organizing compound (hereinafter, such a method is, for convenience, sometimes simply referred to as "polymerization method (i)"). It is preferable to adopt. Examples of such acidic vapor include hydrochloric acid vapor, nitric acid vapor, and sulfuric acid vapor. Examples of the basic catalyst include vapor of aqueous ammonia and vapor of an aqueous solution of alkylamines. In addition, the heating conditions in the case of adopting the polymerization method (i) may be appropriately set according to the type of polymerizable functional group in the self-organizing compound and the like, and are not particularly limited, but it is preferable to heat at a heating temperature of about 80 to 120 ° C for about 1 to 48 hours. Exposure to the vapor under such heating conditions enables the promotion of reactions on the surface and inside of the self-organizing fiber bundle, and enables the polymerization to proceed more efficiently. Further, when the polymerization method (i) is adopted, when the type of the polymerizable functional group in the self-organizing compound is a trialkoxysilyl group, since no residue remains after drying the aggregate obtained after polymerization, it is preferable to use hydrochloric acid vapor or aqueous ammonia vapor as the vapor to be exposed.

[0060] By polymerizing the self-assembling compound in the self-assembling fiber bundle, it becomes possible to polymerize and immobilize the fiber-like aggregate (nanofiber), which is an oriented material in the self-assembling fiber bundle, while maintaining the oriented state, and it becomes possible to obtain an aggregate composed of nanofibers of a polymer oriented in the longitudinal direction. That is, according to such a method, it becomes possible to obtain a polymer nanofiber aggregate in which nanofibers (polymer nanofibers) composed of a polymer of a water-insoluble self-assembling compound are oriented and aggregated in the longitudinal direction.

[0061] As the polymer nanofibers constituting such an aggregate, those having an average diameter in the range of 10 to 1000 nm (more preferably 20 to 800 nm) are preferable. When the diameter of such nanofibers is less than the lower limit value, the structure of the nanofibers becomes unstable, and it becomes difficult to handle a single nanofiber as an independent fiber-like structure. On the other hand, when the diameter of the nanofibers exceeds the upper limit, the aggregate becomes larger than the nano size, and even if the aggregate is made porous, it becomes difficult to obtain optical, electronic, or physical effects. Such an average diameter can be measured by obtaining the diameters of 50 or more polymer nanofibers randomly selected by observation with a scanning electron microscope (SEM observation) and averaging them.

[0062] Also, as the polymer nanofibers constituting such an aggregate, those having an average length in the range of 1 to 500 μm (more preferably 10 to 100 μm) are preferable. When the length of such nanofibers is less than the lower limit value, the fiber bundle tends to have a reduced orientation with respect to the compression treatment. On the other hand, when it exceeds the upper limit value, the fibers tend to break or be cut during the compression treatment, resulting in a fiber bundle containing a refined molecular aggregate. Such an average length can be measured by obtaining the lengths of 50 or more polymer nanofibers randomly selected by SEM observation and averaging them.

[0063] In addition, as the polymer nanofibers constituting such an aggregate, those having a ratio of average length to average diameter ([average length] / [average diameter]) of 10 to 1000 (more preferably 20 to 500) are preferred. When such a ratio is less than the lower limit value, it tends to form a fiber bundle with reduced orientation with respect to the compression treatment. On the other hand, when it exceeds the upper limit value, fiber breakage and cutting occur during the compression treatment, and it tends to form a fiber bundle containing a refined molecular aggregate.

[0064] After obtaining the aggregate composed of the polymer nanofibers, in order to maintain the structure (orientation state, etc.) of the aggregate, the periphery of the aggregate may be covered (solidified with resin) and reinforced with resin. The resin that can be used for reinforcing such an aggregate is not particularly limited, and for example, epoxy resin, acrylic resin, silicone resin, etc. can be used. By reinforcing the periphery of the aggregate with resin in this way, the processability of the aggregate is improved. For example, when manufacturing a thin film by cutting the aggregate, the orientation state of the nanofibers can be more sufficiently maintained, and it becomes possible to more easily manufacture a porous thin film.

[0065] [Polymer Nanofiber Aggregate] The polymer nanofiber assembly of the present invention is characterized in that nanofibers composed of a polymer of a water-insoluble self-assembling compound having a polymerizable functional group and capable of forming a fibrous molecular assembly by self-assembly are aligned and integrated in the longitudinal direction. Such a "water-insoluble self-assembling compound having a polymerizable functional group and capable of forming a fibrous molecular assembly by self-assembly" is the same as that described in the method for producing the polymer nanofiber assembly of the present invention. Further, such "nanofibers" composed of a polymer of a self-assembling compound are the same as the "polymer nanofibers" described in the method for producing the polymer nanofiber assembly of the present invention (the suitable conditions thereof, such as the average diameter, are also the same). Therefore, the "nanofibers" in the polymer nanofiber assembly of the present invention are composed of a polymer of an assembly of self-assembling compounds assembled in a fibrous shape by self-assembly. Such a polymer nanofiber assembly can be efficiently produced by the method for producing the polymer nanofiber assembly of the present invention.

[0066] [Uniaxially Oriented Polymer Nanofiber Integrated Substrate] The uniaxially oriented polymer nanofiber integrated substrate of the present invention comprises a thin film made of a cut piece of a polymer nanofiber assembly in which nanofibers composed of a polymer of a water-insoluble self-assembling compound having a polymerizable functional group and capable of forming a fibrous molecular assembly by self-assembly are aligned and integrated in the longitudinal direction, and is characterized in that the cutting direction of the cut piece is substantially perpendicular to the longitudinal direction of the polymer nanofiber assembly. Such "self-assembling compound", "nanofibers" and "polymer nanofiber assembly" are the same as those described in the polymer nanofiber assembly of the present invention.

[0067] Such a uniaxially oriented polymer nanofiber integrated substrate of the present invention can be said to comprise, in other words, a thin film composed of a cut piece obtained by cutting the polymer nanofiber integrated body in a direction substantially perpendicular to the longitudinal direction of the integrated body. Here, with reference to FIG. 2, a preferred embodiment of the thin film composed of the cut piece will be briefly described.

[0068] FIG. 2 shows a polymer nanofiber integrated body 12 in a form in which nanofibers Fp made of a polymer are oriented and integrated in the longitudinal direction and fixed (reinforced) with a resin R around the integrated body, and the integrated body 12 is cut at the positions indicated by dotted lines L A and dotted line L B (note that the directions of dotted lines L A and dotted line L B are perpendicular to the longitudinal direction of the integrated body 12), and is a schematic diagram schematically showing a preferred embodiment of a thin film 13 composed of the cut pieces obtained.

[0069] As shown in FIG. 2, by forming a thin film by cutting the polymer nanofiber integrated body 12 in a direction substantially perpendicular to its longitudinal direction, when the cut piece is viewed from above the cut surface (the surface of the thin film), due to the orientation state of the polymer nanofiber integrated body, a thin film in a state where cut pieces of fine polymer nanofibers Fp (nanosize columnar objects) are oriented substantially perpendicular to the cut surface can be easily formed. Thus, since the cut pieces of a plurality of polymer nanofibers Fp (nanosize columnar objects) are in a state of being oriented substantially perpendicular to the surface of the thin film, such a thin film can be used as one having a porous surface (a surface having a pillar array structure) composed of nanofibers oriented substantially perpendicularly. And when the polymer nanofiber integrated body 12 is cut at a plurality of locations to produce a plurality of thin films 13, it becomes possible to continuously produce the thin films 13 at high speed and at low cost. Therefore, according to the present invention, it becomes possible to efficiently manufacture a uniaxially oriented polymer nanofiber integrated substrate in which polymer nanofibers (cut pieces) are oriented in a direction substantially perpendicular to the surface of the thin film. Note that "substantially perpendicular to the longitudinal direction" means being generally perpendicular to the longitudinal direction (preferably 90° ± 20°, more preferably 90° ± 15°).

[0070] In the embodiment shown in FIG. 2, a polymer nanofiber aggregate 12 in a form fixed (reinforced) around with a resin R is cut to form a thin film. Such a resin R is the same as that described in the above-mentioned "resin that can be used for reinforcing the aggregate". In the embodiment shown in FIG. 2, a polymer nanofiber aggregate 12 in a form fixed (reinforced) around with a resin R is used. However, when the aggregated shape of the polymer nanofiber aggregate can be maintained after cutting, a polymer nanofiber aggregate not reinforced around with a resin R may be directly used and cut, whereby a thin film (one without the resin R) composed of a cut product of the polymer nanofiber aggregate may be manufactured. Thus, the form of the thin film is not particularly limited, and it may be in a form fixed (reinforced) around with the resin R or in a form composed of a cut product of a polymer nanofiber aggregate not reinforced with the resin R.

[0071] Further, in a thin film composed of a cut product of the polymer nanofiber aggregate and having polymer nanofibers (cut products) oriented in a direction substantially perpendicular to the surface, the average distance (average interval between polymer nanofibers) between the polymer nanofibers oriented in the substantially perpendicular direction is preferably 1.0 to 2.0 times (more preferably 1.1 to 1.8 times) the average diameter of the polymer nanofibers. When the average distance is shorter than the lower limit, lateral fusion between the polymer nanofibers tends to progress, making it difficult to form a porous structure (pillar array structure, nano uneven structure). On the other hand, when the average distance is longer than the upper limit, physical cross-linking due to contact between the polymer nanofibers is not formed, so the fiber orientation structure in the structure (thin film) after cutting (slicing) tends to become unstable. Such an average interval between polymer nanofibers can be measured by observing the thin film surface by SEM, measuring the distance between the closest polymer nanofibers for 50 or more randomly selected polymer nanofibers, and averaging the distances.

[0072] Further, the thickness of the thin film composed of the cut pieces of the polymer nanofiber aggregate is preferably 0.2 to 300 μm (more preferably 0.3 to 50 μm). When the thickness of the thin film is less than the lower limit, it tends to be difficult to obtain a uniform cross section during cutting (machining). When the thickness of the thin film exceeds the upper limit, it tends to be difficult for light to penetrate into the thin film and for substances to diffuse, and the applicability as an optical functional material or the like tends to decrease.

[0073] Furthermore, the uniaxially oriented polymer nanofiber integrated substrate of the present invention only needs to include the thin film, and its form is not particularly limited. For example, it may be the thin film itself composed of a cut piece of the polymer nanofiber integrated body (it may be composed of the self-supporting thin film), or it may be formed by fixing the thin film to a solid substrate (support). As such an uniaxially oriented polymer nanofiber integrated substrate of the present invention, from the viewpoint of structural stability, it is preferably in a form in which the cut surface is fixed to the support. Such a support is not particularly limited, and depending on the use of the uniaxially oriented polymer nanofiber integrated substrate, known supports such as silicon substrates (Si substrates), ITO substrates, FTO substrates, quartz substrates, glass substrates, various metal substrates, and various thin film substrates can be appropriately used. When the use of the uniaxially oriented polymer nanofiber integrated substrate is a substrate for laser desorption / ionization mass spectrometry, as such a support, it is preferable to use a conductive substrate such as a silicon substrate, stainless steel, ITO substrate, ZnO substrate, SnO substrate, or FTO group. In addition, the shape of such a support is not particularly limited, but it is preferably flat. The method of laminating the thin film on the support is not particularly limited, and known methods can be appropriately adopted. For example, a section of the thin film can be attached to one surface of a carbon seal (both sides), and the other surface can be attached to the support side to laminate the thin film on the support. Also, a form in which one of the cut surfaces of the thin film is attached to a carbon seal to protect the section may be directly used as the uniaxially oriented polymer nanofiber integrated substrate. Thus, the uniaxially oriented polymer nanofiber integrated substrate of the present invention only needs to include the thin film, and its form is not particularly limited.

[0074] The method for manufacturing such a uniaxially oriented polymer nanofiber integrated substrate is not particularly limited. For example, after preparing the polymer nanofiber integrated body by using the method for manufacturing the polymer nanofiber integrated body of the present invention, such an integrated body can be easily manufactured by performing a step of cutting it from a direction substantially perpendicular to the longitudinal direction (see Fig. 2). Here, the method for cutting the polymer nanofiber integrated body is not particularly limited, and known methods can be appropriately adopted. For example, a known cutting device (such as a rotary microtome, etc.) capable of cutting a bulk material into a thin film shape can be used to adopt a method of cutting the polymer nanofiber integrated body to a desired thickness. Further, after cutting in this way to form a thin film, if necessary, a step of fixing it to a support may be performed. Note that the method for such fixation is not particularly limited, and for example, a method of attaching it to the surface of an adhesive substrate may be adopted.

[0075] Thus, the uniaxially oriented polymer nanofiber integrated substrate of the present invention can be easily manufactured by cutting the polymer nanofiber aggregate. In this way, a substrate provided with a thin film in which nanofibers are uniformly oriented can be manufactured by a simple method such as cutting the polymer nanofiber aggregate. The uniaxially oriented polymer nanofiber integrated substrate of the present invention can be produced at low cost, at high speed, and continuously and stably. Therefore, it is also possible to very efficiently manufacture substrates applicable to various uses according to the surface structure of the substrate, the type of the polymer of the fiber, and the like. Further explaining such a point, conventionally, in order to manufacture a uniaxially oriented substrate having a vertically oriented nano-concavo-convex structure, generally, it has been necessary to perform particle growth, thin film formation, or surface processing treatment (see, for example, Patent Document 1) on each substrate under special conditions. Further, since the fibrous molecular aggregate was mechanically brittle and could not be subjected to molding processing, it has not been possible to orient nanofibers in one direction by a simple processing method such as compression. On the other hand, according to the present invention, it becomes possible to process the fibrous molecular aggregate formed by molecular self-assembly so as to be oriented in one direction, and by bundling and polycondensing (immobilizing) this, the polymer nanofiber aggregate can be easily manufactured. And, since a uniaxially oriented substrate (uniaxially oriented polymer nanofiber integrated substrate) can be easily manufactured by a method such as simply cutting such a polymer nanofiber aggregate, according to the present invention, it becomes possible to efficiently and continuously manufacture a uniaxially oriented substrate. Further, if an organic group (functional site) capable of expressing a desired functionality is introduced into the self-assembling compound serving as a raw material of the fibrous molecular aggregate, it is also possible to express a desired function (such as a light absorption function) in the formed fiber skeleton structure itself. Thus, according to the present invention, a uniaxially oriented polymer nanofiber integrated substrate having desired characteristics can be continuously manufactured at low cost. For example, by introducing an organic group having a laser light absorption function or the like into the self-assembling compound to form nanofibers, it is also possible to continuously and stably manufacture at low cost a substrate suitably used for a laser desorption / ionization mass spectrometry substrate.Therefore, the uniaxially oriented polymer nanofiber integrated substrate of the present invention and the method for manufacturing the substrate are particularly preferably applicable to, for example, a laser desorption / ionization mass spectrometry substrate assumed to be used as a disposable substrate and the method for manufacturing the same.

[0076] [Laser desorption / ionization mass spectrometry substrate] The laser desorption / ionization mass spectrometry substrate of the present invention is characterized by including the uniaxially oriented polymer nanofiber integrated substrate of the present invention or a hydrophobized product thereof.

[0077] The laser desorption / ionization mass spectrometry substrate of the present invention can be used in known laser desorption / ionization mass spectrometry methods (for example, the so-called matrix-assisted laser desorption ionization mass spectrometry (MALDI method), laser desorption / ionization mass spectrometry methods without using a matrix, etc.), and a suitable analysis method can be appropriately adopted according to the type of polymer nanofibers constituting the substrate. Using such a laser desorption / ionization mass spectrometry substrate of the present invention, for example, a measurement target molecule is supported on the substrate surface (for example, by dropping a sample solution containing the measurement target molecule (which may be a solution of the matrix (usually a low molecular weight organic substance that absorbs laser light) and the measurement target molecule according to the type of analysis method)), and a measurement sample (which may be supported in the form of a mixture of the measurement target molecule and the matrix) with the measurement target molecule supported on the substrate surface is formed. Then, mass spectrometry can be performed by irradiating the measurement sample with laser light.

[0078] Here, the laser desorption / ionization mass spectrometry substrate of the present invention uses the same substrate as the uniaxially oriented polymer nanofiber integrated substrate of the present invention described above, or a hydrophobized product thereof. The uniaxially oriented polymer nanofiber integrated substrate of the present invention has, as described above, a porous structure (pillar array structure (nano uneven structure)) in which polymer nanofibers (cut products) are oriented in a direction substantially perpendicular to the surface of the substrate on the surface of the substrate. Therefore, when such a uniaxially oriented polymer nanofiber integrated substrate or a hydrophobized product thereof is used for laser desorption / ionization mass spectrometry, by dropping a solution of the molecule to be measured onto the surface of the thin film portion of the substrate (the portion having the porous structure), it is possible to easily support the molecule to be measured on the substrate due to the porous structure on the surface of the thin film.

[0079] As the uniaxially oriented polymer nanofiber integrated substrate (or its hydrophobized product) of the present invention used for the laser desorption / ionization mass spectrometry substrate of the present invention, in the thin film of the substrate, "nanofibers composed of polymers of self-organizing compounds" that are oriented and integrated in the longitudinal direction are used as the self-organizing compounds, and are formed by using the organosilane compound (A-1) (more preferably the organosilane compound (A-2), still more preferably the organosilane compound (A-3)), that is, it is preferably composed of fibrous organosilica composed of polymers of the organosilane compound (A-1) (more preferably the organosilane compound (A-2), still more preferably the organosilane compound (A-3)). When the "nanofibers composed of polymers of self-organizing compounds" are composed of the fibrous organosilica, the thin film in which the nanofibers are oriented and integrated in the longitudinal direction is composed of an organosilica thin film (hereinafter, sometimes simply referred to as "organosilica thin film") which is a cut of a polymer nanofiber integrated body having such fibrous organosilica as a structural unit (polymer nanofiber). Such fibrous organosilica composed of polymers of the organosilane compound (A-1) contains, in its skeleton, an organic group having a maximum absorption wavelength in the range of 200 to 600 nm (hereinafter, sometimes also referred to as "laser light-absorbing organic group") derived from the structure of the organosilane compound (A-1), and a site capable of forming a hydrogen bond (more preferably an amide bond). Therefore, when the thin film provided in the uniaxially oriented polymer nanofiber integrated substrate is the organosilica thin film, when the substrate is used as a laser desorption / ionization mass spectrometry substrate, for example, when a sample solution containing a molecule to be measured (such as a highly hydrophilic compound such as a biomolecule-related molecule) is dropped onto the thin film portion of the substrate to prepare a measurement sample, the molecule to be measured such as a biomolecule-related molecule is easily adsorbed and supported at the hydrogen bond site (preferably the site of the amide bond). Here, due to the structure of the organosilane compound (A-1), in the fibrous organosilica, the hydrogen bond sites (sites functioning as adsorption sites for molecules to be measured) are uniformly dispersed, so that the molecules to be measured are supported in a uniformly and highly dispersed state in the thin film.In addition, in the thin film, the laser light-absorbing organic groups are also uniformly dispersed in the same manner as the hydrogen bonding sites due to the structure of the organosilane compound (A-1). Therefore, when the measurement sample is irradiated with laser light, the laser light can be efficiently absorbed by the organic group portion, and the energy of the laser light can be efficiently utilized without using a matrix. Thus, when the thin film is the organosilica thin film, it is possible to uniformly support the measurement target molecules in a state where they are highly dispersed, and since the thin film itself can absorb the laser light and efficiently utilize the energy of the laser light, even when a measurement sample with a low concentration of the measurement target molecules is used, it is possible to efficiently perform laser desorption / ionization mass spectrometry of the measurement target molecules without using a matrix.

[0080] On the other hand, focusing on the prior art as described in the aforementioned Non-Patent Document 2, in such a technique, it was necessary to add a matrix (the same as the general MALDI method) to detect angiotensin I with a molecular weight of about 1300 at a low concentration. Thus, when using the conventional substrate as described in the aforementioned Non-Patent Document 2, it was difficult to perform highly sensitive analysis using a low-concentration measurement target molecule without using a matrix. In addition, when using a matrix, signals derived from the matrix may be observed as interfering peaks in the low molecular weight region. In contrast, as described above, when the thin film provided in the uniaxially oriented polymer nanofiber integrated substrate is the organosilica thin film, even when a measurement sample with a low concentration of the measurement target molecules is used, it is possible to perform laser desorption / ionization mass spectrometry of the measurement target molecules without using a matrix. Therefore, it is possible to perform more accurate analysis for mass spectrometry in the low molecular weight region. From such a viewpoint, the thin film provided in the uniaxially oriented polymer nanofiber integrated substrate used for the laser desorption / ionization mass spectrometry substrate is preferably the organosilica thin film (a thin film comprising fibrous organosilica made of a polymer of the organosilane compound (A-1) as the polymer nanofiber).

[0081] In general, in order to exhibit excellent optical or electronic functions in a thin film substrate, in addition to the material itself, the formation of a nano-structure on the surface is important. Particularly, in the field of substrates used for laser desorption / ionization mass spectrometry, since it is considered possible to perform highly sensitive analysis, (i) it should be possible to efficiently absorb light, (ii) it should be possible to efficiently transfer the absorbed energy to the analyte molecules adsorbed on the substrate surface, and (iii) it should be possible to quickly vaporize and ionize the molecules that have received the energy and release them outside the substrate. It is preferable that such conditions are met. From such a perspective, when the uniaxially oriented polymer nanofiber integrated substrate having a pillar array structure (nano-concavo-convex structure) in which polymer nanofibers are vertically aligned with respect to the surface of the substrate is provided with the organic silica thin film, it is considered that more sensitive mass spectrometry becomes possible. Furthermore, since it is not very realistic to clean and reuse a substrate having a nano-scale surface concavo-convex structure after use, a substrate for laser desorption / ionization mass spectrometry having such a structure is usually assumed to be a disposable substrate. However, as described above, the uniaxially oriented polymer nanofiber integrated substrate is a substrate having a nanoporous structure in which polymer nanofibers are uniformly oriented, and can be produced at high speed and continuously at low cost. Therefore, as in the present invention, by using the uniaxially oriented polymer nanofiber integrated substrate or a hydrophobized product thereof as a substrate for laser desorption / ionization mass spectrometry, there are advantages in that mass production of the substrate, acceleration of substrate production, cost reduction, etc. can be achieved.

[0082] In addition, the hydrophobized product that can be used for the laser desorption / ionization mass spectrometry substrate of the present invention is obtained by subjecting the uniaxially oriented polymer nanofiber integrated substrate of the present invention to a hydrophobization treatment. The method of such a hydrophobization treatment is not particularly limited, and a known method capable of introducing a hydrophobic group into the thin film provided in the uniaxially oriented polymer nanofiber integrated substrate can be appropriately employed.

[0083] The hydrophobic group is not particularly limited as long as it can impart hydrophobicity, and there is no particular limitation as long as it is a group capable of imparting hydrophobicity. Examples thereof include an alkyl group, an alkynyl group, an alkenyl group, a fluorine atom-containing group, a halogen atom-containing group other than a fluorine atom, an alkoxy group, an aromatic ring, etc. Among them, from the viewpoint of being able to promote the desorption of the measurement target molecule while enabling the measurement target molecule to be supported at a high density on the surface of the thin film, an alkyl group, a fluoroalkyl group, and a phenyl group are preferable, and an alkyl group and a fluoroalkyl group are particularly preferable.

[0084] Particularly preferable examples of the alkyl group as such a hydrophobic group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a cyclohexyl group, etc. Further, particularly preferable examples of the fluoroalkyl group as the hydrophobic group include a perfluoroalkyl group in which all hydrogen atoms such as a trifluoromethyl group (CF3-), a pentafluoroethyl group (CF3-CF2-), and a heptafluoropropyl group (CF3-CF2-CF2-) are substituted with fluorine atoms; a fluoroalkyl group in which at least a part of hydrogen atoms such as a 2,2,2-trifluoroethyl group (CF3-CH2-), a 3,3,3-trifluoropropyl group (CF3-CH2-CH2-), a 2,2,3,3,3-pentafluoropropyl group (CF3-CF2-CH2-), a 3,3,4,4,4-pentafluorobutyl group (CF3-CF2-CH2-CH2-), a 3,3,4-trifluorobutyl group (F-CH2-CF2-CH2-CH2-), and a 1H,1H,2H,2H-nonafluorohexyl group (CF3-CF2-CF2-CF2-CH2-CH2-) are substituted with fluorine atoms; etc.

[0085] Further, as such a hydrophobization method, when the thin film provided on the uniaxially oriented polymer nanofiber integrated substrate is the organic silica thin film, a method of introducing a hydrophobic group by bringing an organic silane compound containing a hydrophobic group into contact with the organic silica thin film (hereinafter, such a method may be simply referred to as "method (a)") can be adopted. Hereinafter, such method (a) will be briefly described.

[0086] In such a method (a), an organosilane compound (B-1) containing a hydrophobic group is used. As the hydrophobic group of such an organosilane compound, the same ones as the aforementioned hydrophobic groups can be preferably used. When the organosilica thin film is brought into contact with the organosilane compound (B-1) containing the hydrophobic group, the silicon atom of the siloxane bond constituting the organosilica thin film reacts with the silyl group of the organosilane compound containing the hydrophobic group, and an organosilica thin film further containing the hydrophobic group is obtained. The method of bringing the organosilane compound (B-1) containing the hydrophobic group into contact with the organosilica thin film is not particularly limited. For example, a method of applying a solution containing the organosilane compound (B-1) to the organosilica thin film, a method of immersing the organosilica film in a solution containing the organosilane compound (B-1), a method of exposing the organosilica film to the vapor of the organosilane compound (B-1), etc., are mentioned as conventionally known methods. Examples of such an organosilane compound (B-1) containing a hydrophobic group include an alkylsilane compound, an alkynylsilane compound, an alkenylsilane compound, a fluorine atom-containing silane compound, a halogen atom-containing silane compound other than a fluorine atom, an alkoxysilane compound, an aromatic ring-containing silane compound, and the like.

[0087] In addition, the organosilica thin film obtained by such a method (a) has a laser light-absorbing organic group and a hydrogen bonding site (preferably an amide bond site) within the skeleton of the organosilica thin film, and a hydrophobic group is further bonded to the silicon atom of the siloxane bond in the skeleton, resulting in an organosilica thin film. Here, the hydrogen bonding site and the laser light-absorbing organic group are sites introduced into the skeleton of the thin film derived from the structure in the self-assembled compound, and since the skeleton of the thin film is formed by the polymerization of the self-assembled compound, the laser light-absorbing organic group and the hydrogen bonding site are sufficiently uniformly dispersed and arranged in the organosilica thin film. When a hydrophobic group is introduced into such an organosilica thin film by method (a), the amide group and the hydrophobic group are uniformly and balancedly arranged on the surface of the organosilica film. Further, when a sample solution containing a measurement target molecule composed of a highly hydrophilic compound such as a bio-related molecule is dropped onto the surface of the organosilica thin film into which such a hydrophobic group has been introduced to prepare a measurement sample, the sample solution is concentrated by the action of the hydrophobic group, and at the same time, the highly hydrophilic compound can be adsorbed and supported on the hydrogen bonding site (such as a site having an amide bond), so that the highly hydrophilic compound (measurement target molecule) is uniformly and highly dispersed and supported on the surface of the organosilica thin film. Then, when laser desorption / ionization mass spectrometry is performed using a measurement sample composed of an organosilica thin film on which the highly hydrophilic compound (measurement target molecule) is highly dispersed in this way, the laser light-absorbing organic group in the organosilica thin film (it is clear that it is dispersed and arranged together with the hydrogen bonding site in the vicinity of the hydrogen bonding site) absorbs the laser light and can efficiently transfer the absorbed energy to the highly hydrophilic compound (measurement target molecule) adsorbed and supported on the hydrogen bonding site on the thin film surface. At the same time, the hydrophobic group reduces the interaction between the surface of the organosilica thin film and the highly hydrophilic compound, thereby promoting the desorption of the highly hydrophilic compound. Therefore, the desorption and ionization of the highly hydrophilic compound can proceed more efficiently, and moreover, since a signal corresponding to the highly hydrophilic compound can be detected from the entire surface of the organosilica thin film, it is considered possible to detect the highly hydrophilic compound with higher sensitivity and more uniformly.

[0088] Thus, from the perspective that the promoting effect of the desorption of the highly hydrophilic compound by the hydrophobic group can be received and more sensitive mass spectrometry can be performed, as the laser desorption / ionization mass spectrometry substrate of the present invention, it is preferable to use a hydrophobized product of a uniaxially oriented polymer nanofiber integrated substrate. Among them, it is particularly preferable to use a hydrophobized product of a uniaxially oriented polymer nanofiber integrated substrate provided with the organic silica thin film as a thin film.

[0089] Here, a preferred method of the laser desorption / ionization mass spectrometry method using the laser desorption / ionization mass spectrometry substrate of the present invention will be described. Such a laser desorption / ionization mass spectrometry method is a method in which a measurement target molecule is supported on the laser desorption / ionization mass spectrometry substrate of the present invention to prepare a measurement sample, and the measurement sample is irradiated with laser light to desorb the measurement target molecule from the organic silica substrate, ionize it, and perform mass spectrometry.

[0090] In such a laser desorption / ionization mass spectrometry method, first, a sample to be measured (a sample containing a measurement target molecule) in laser desorption / ionization mass spectrometry is supported on the laser desorption / ionization mass spectrometry substrate of the present invention. Next, the substrate (measurement sample) supporting the sample containing the measurement target molecule is irradiated with laser light. Thereby, the measurement target molecule can be desorbed from the substrate, ionized, and mass spectrometry can be performed.

[0091] In addition, the sample containing the measurement target molecule to which such a laser desorption / ionization mass spectrometry method can be applied is not particularly limited, but from the perspective that more sensitive analysis can be performed, biomolecule-related molecules such as amino acids, proteins, sugars, phospholipids, hormones, nucleic acids, and their metabolites are suitable.

[0092] In addition, the laser light used in such a laser desorption / ionization mass spectrometry method is not particularly limited. For example, a nitrogen laser (wavelength: 337 nm), a third harmonic of a YAG laser (wavelength: 355 nm), a NdYAG laser (wavelength: 256 nm), a carbon dioxide laser (wavelengths: 9400 nm and 10600 nm), etc. can be mentioned. The irradiation conditions of the laser light (irradiation intensity, irradiation time, etc.) are not particularly limited, and the optimal conditions can be appropriately selected and set from known mass spectrometry conditions according to the molecule to be measured.

[0093] Furthermore, the method for separating and detecting ions for mass spectrometry in the laser desorption / ionization mass spectrometry method is not particularly limited, and a double focusing method, a quadrupole focusing method (quadrupole (Q) filter method), a tandem quadrupole (QQ) method, an ion trap method, a time-of-flight (TOF) method, etc. can be adopted.

[0094] By adopting such a laser desorption / ionization mass spectrometry method, it becomes possible to efficiently perform laser desorption / ionization mass spectrometry using the laser desorption / ionization mass spectrometry substrate of the present invention.

Examples

[0095] Hereinafter, the present invention will be described more specifically based on examples and comparative examples, but the present invention is not limited to the following examples.

[0096] <Synthesis of self-assembled compound> (Synthesis Example 1) First, under a nitrogen atmosphere, 1,8-naphthalic anhydride (5.95 g, 30.0 mmol, the compound represented by the following formula (1)), pyridine (60 ml), and ethylenediamine (60 ml) were mixed, and the resulting mixture was stirred while heating at 110 °C for 72 hours to obtain the following reaction formula (I):

[0097]

Chemical formula

[0098] The reaction represented by [the given formula] was carried out. After removing most of the pyridine and ethylenediamine from the resulting solution using a rotary evaporator, the residue was recrystallized using cold acetonitrile. The obtained crystals were collected by suction filtration and dried under vacuum to obtain a solid component (yield: 5.10 g, yield rate: 71%).

[0099] The obtained solid component was dissolved in deuterated chloroform (CDCl3), and an 1H-NMR spectrum was measured and identified using an NMR measuring device (“JNM-ECX400P” manufactured by JEOL Ltd.). It was confirmed that it was N-(2-aminoethyl)-1,8-naphthalimide (the compound represented by the above formula (2)). The results are shown below. 1 1H-NMR (CDCl3, δ in ppm): 3.08 (t, J = 6.6 Hz, 2H), 4.29 (t, J = 6.6 Hz, 2H), 7.76 (m, 2H), 8.22 (m, 2H), 8.61 (m, 2H). 1 1H-NMR(CDCl3,δ in ppm):3.08(t,J = 6.6Hz,2H),4.29(t,J = 6.6Hz,2H),7.76(m,2H),8.22(m,2H),8.61(m,2H).

[0100] Next, under a nitrogen atmosphere, N-(2-aminoethyl)-1,8-naphthalimide (2.40 g, 10.0 mmol), succinic acid (0.53 g, 4.50 mmol), 4-dimethylaminopyridine (DMAP, 48.9 mg, 0.40 mmol) and dichloromethane (40 ml) were mixed, and further 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC, 3.50 g, 18.3 mmol) was added. The resulting mixture was stirred at room temperature for 3 days to obtain the following reaction formula (II):

[0101]

Chemical formula

[0102] The reaction represented by [formula] was carried out. Ethanol (150 ml) was added to the obtained suspension, and the mixture was stirred for 1 hour. Then, the insoluble solid component was collected by suction filtration. This solid component was redispersed in acetonitrile and stirred while heating at 70 °C for 5 minutes. After the obtained suspension was cooled to room temperature, the insoluble solid component was collected by suction filtration and dried under vacuum (yield: 1.81 g, yield rate: 71%).

[0103] The obtained solid component was dissolved in deuterated dimethyl sulfoxide (DMSO-d6), and 1 the 1H-NMR spectrum was measured and identified using an NMR measuring device (JNM-ECX400P manufactured by JEOL Ltd.). It was confirmed that the compound was the one represented by the above formula (3) (a dimer of naphthalimide with an amide group bonded: hereinafter, sometimes simply referred to as "NI(amide)-d"). The results are shown below. It is considered that one of the peaks of methylene overlaps with the peak of DMSO (δ ~ 3.3 ppm). 1 1H-NMR (DMSO-d6, δ in ppm): 2.06 (s, 4H), 4.10 (m, 4H), 7.85 (m, 4H), 7.91 (m, 2H), 8.45 (m, 8H).

[0104] Next, under a nitrogen atmosphere, NI(amide)-d (the compound represented by the above formula (3), 0.62 g, 1.10 mmol), carbonyl dihydridotris(triphenylphosphine)ruthenium [RuH2(CO)(PPh3)3] (55.1 mg, 0.06 mmol) and dimethylacetamide (DMAc, 20 ml) were mixed, and further triisopropoxyvinylsilane (2.35 ml, 2.05 g, 8.80 mmol) was added. The obtained mixture was stirred while heating at 160 °C for 3 hours to obtain the following reaction formula (III):

[0105]

Chemical formula

[0106] The reaction represented by was carried out. After removing most of the DMAc from the resulting solution using a rotary evaporator, the residue was mixed with ethyl acetate (10 ml), and further hexane (150 ml) was added. The resulting mixture was cooled in a refrigerator for 12 hours. The obtained crystals were collected by suction filtration, washed with cold hexane, and then dried under vacuum to obtain a solid component (yield: 1.22 g, yield rate: 74%). When a part of the obtained solid component was used and mixed with water and then recovered and dried under vacuum again, the change in the mass of the solid component before and after mixing with water was 0.1% by mass or less of the mass before mixing with water (an amount that can be regarded as almost zero). Therefore, it was confirmed that the obtained solid component is a water-insoluble component.

[0107] Also, the obtained solid component was dissolved in deuterated chloroform (CDCl3), and using an NMR measuring device ("JNM-ECX400P" manufactured by JEOL Ltd.) 1 an 1H-NMR spectrum was measured and identified. It was confirmed that it is the compound represented by the above formula (4), which is a reaction product of a dimer of naphthalimide bonded with an amide group and triisopropoxybvinylsilane (hereinafter, sometimes referred to as "NI(amide)-d-Si"). The results are shown below. 1 1H-NMR (CDCl3, δ in ppm): 1.03 (m, 8H), 1.23 (d, J = 6.0 Hz, 72H), 2.40 (s, 4H), 3.50 (m, 12H), 4.28 (m, 12H), 4.34 (m, 4H), 6.69 (bs, 2H), 7.53 (d, J = 8.4 Hz, 4H), 7.99 (d, J = 8.4 Hz, 4H).

[0108] <Production of Polymer Nanofiber Aggregate and Uniaxially Oriented Polymer Nanofiber Integrated Substrate> The structures and the like of the polymer nanofiber aggregate and the uniaxially oriented polymer nanofiber integrated substrate obtained in the following examples and the like were measured as follows.

[0109] 〈Evaluation of the State of the Aggregate (SEM Observation)〉 The orientation state and the like of nanofibers in the polymer nanofiber aggregate and the uniaxially oriented polymer nanofiber integrated substrate were observed and evaluated by a scanning electron microscope (SEM: "SU3500" manufactured by HITACHI).

[0110] 〈Confirmation of Polycondensation of Self-Assembling Compound〉 The progress of polycondensation (analysis of cross-linked state) of the self-assembling compound was carried out in the solid state 29 by measuring the Si MAS NMR spectrum. For the measurement, "AVANCE 400" manufactured by Bruker was used as the measuring device.

[0111] (Example 1) 〈Manufacturing Process of Polymer Nanofiber Aggregate〉 NI(amide)-d-Si (0.5 g, the compound represented by the above formula (4)) obtained in Synthesis Example 1 was added to a mixed solvent (24.5 g) containing ethanol and water at a mass ratio ([ethanol]:[water]) of 4:1 to obtain a mixed solution with a concentration of NI(amide)-d-Si of 2 wt%. Next, the obtained mixed solution was heated to 80 °C to dissolve NI(amide)-d-Si in the mixed solvent, and then transferred to a square glass pipe (30×30×100 mm) with one end sealed, and cooled to room temperature (about 25 °C) to form a gel-like composition in the square glass pipe. Then, by removing the seal of the square glass pipe and slowly taking it out, the composition was taken out of the glass pipe while maintaining the gel state, and a rectangular parallelepiped-shaped gel composition with a length of 30 mm, a width of 30 mm, and a height of 35 mm was obtained.

[0112] In order to confirm the state of NI(amide)-d-Si in the gel-like composition thus obtained, SEM observation was carried out. The results obtained are shown in Fig. 3. As is also clear from the results shown in Fig. 3, as a result of the observation by SEM, it was confirmed that in the gel-like composition, nanofiber-like molecular aggregates with a width of about 300 to 800 nm were randomly aggregated to form a network-like structure. Further, from the results shown in Fig. 3, it was confirmed that NI(amide)-d-Si forms a fiber-like molecular aggregate by self-organization, and it was confirmed that the gel-like composition is a composite of a mixed solvent and a nanofiber-like molecular aggregate.

[0113] Next, the rectangular parallelepiped-shaped gel composition (a composite of a mixed solvent and a nanofiber-like molecular aggregate) produced as described above was immersed in 1 L of water for 3 days to replace the ethanol contained in the gel with water, and a water-replaced gel-like composition (a composite (gel) composed of water and a nanofiber-like molecular aggregate) was formed.

[0114] Then, the water-replaced gel-like composition (rectangular parallelepiped shape with a length of 30 mm, a width of 30 mm, and a height of 35 mm) thus obtained was taken out of the water. Then, while releasing the height direction of the rectangular parallelepiped-shaped water-replaced gel-like composition, it was squeezed by compressing from two directions in the longitudinal and transverse directions to make the shape of the water-replaced gel-like composition substantially prismatic. Next, such a substantially prismatic water-replaced gel-like composition (after squeezing) was dried under the conditions of 120 °C for 3 hours to obtain a substantially prismatic solid having a cross-section of about 5 mm in length and about 5 mm in width. An external appearance photograph of the obtained substantially prismatic solid (the state of an aggregate in which nanofibers are aggregated) is shown in Fig. 4 while conceptually indicating the compression direction.

[0115] In order to confirm the state of the obtained substantially prismatic solid, SEM observation was performed. The electron micrograph (SEM image) obtained by such measurement is shown in Fig. 5. As is clear from the results shown in Fig. 5, in the obtained substantially prismatic solid, nanofiber-like molecular aggregates are oriented in a direction (longitudinal direction) perpendicular to the compression direction, and it was confirmed that it has a structure like a bundle of fibers, and it was found that it is an aggregate of bundle-like nanofibers (hereinafter referred to as "nanofiber bundle").

[0116] Next, the nanofiber bundle (substantially prismatic solid) obtained as described above was exposed to the vapor of 2M hydrochloric acid at a temperature of 100 °C for 3 hours to polycondense NI(amide)-d-Si in the bundle, and a polymer nanofiber aggregate containing nanofibers made of organic silica (polymer of NI(amide)-d-Si) was obtained. The progress of the polycondensation of NI(amide)-d-Si was 29 confirmed by detecting the signal of T n species (T n :-Si(OSi) n (OH) 3-n ) in the Si MAS NMR spectrum. The graph of the Si MAS NMR spectrum of the polymer nanofiber aggregate obtained by such measurement is shown in Fig. 6. From the results shown in Fig. 6, it was found that in the polymer nanofiber aggregate, the polycondensation reaction of NI(amide)-d-Si is proceeding and the nanofibers are formed by organic silica (polymer of NI(amide)-d-Si). 29

[0117] ​In addition, the appearance photograph of the obtained polymer nanofiber assembly (organic silica nanofiber bundle) (state of the fiber) is shown in Fig. 7 while conceptually indicating the compression direction. Further, SEM observation was carried out to confirm the state of the obtained assembly of polymer nanofibers. The electron micrograph (SEM image) obtained by such measurement is shown in Fig. 8. From the results shown in Fig. 8, it was confirmed that the nanofibers made of organic silica are oriented in the direction perpendicular (longitudinal direction) to the compression direction, and no significant morphological change has occurred due to polycondensation, and it was confirmed that polymerization and immobilization can be achieved while sufficiently maintaining the orientation structure of the self-assembled nanofiber bundle. The nanofibers constituting such a polymer nanofiber assembly had an average diameter and an average length of 550 nm (average diameter) and 70 μm (average length), respectively, which were obtained as the average values of 50 randomly selected nanofibers by SEM observation.

[0118] <Manufacturing Process of Uniaxially Oriented Polymer Nanofiber Integrated Substrate> After reinforcing by covering the periphery of the polymer nanofiber assembly (organic silica nanofiber bundle) obtained as described above with an epoxy resin ("Crystal Resin NEO" manufactured by Nisshin Resin Co., Ltd.) and solidifying it, the polymer nanofiber assembly was cut with a thickness of 20 μm in a direction substantially perpendicular to the orientation direction (longitudinal direction) of the nanofibers using a rotary microtome HM360 (Micro Edge) to obtain a section, and then the section was fixed on a carbon seal (support) to obtain a substrate (uniaxially oriented polymer nanofiber integrated substrate: thin film substrate) provided with an organic silica thin film formed of nanofibers made of organic silica (polymer of NI(amide)-d-Si). A photograph showing the state (appearance) of the obtained organic silica thin film is shown in Fig. 9.

[0119] In addition, in order to confirm the structure of the obtained thin film, SEM observation was performed on the surface and cross-section of the thin film. The electron micrograph (SEM image) of the surface of the thin film is shown in FIG. 10, and the electron micrograph (SEM image) of the cross-section of the thin film is shown in FIG. 11. As is clear from the results shown in FIGS. 10 to 11, by SEM observation, the obtained thin film (organic silica thin film) is a porous thin film (vertically oriented porous thin film of organic silica nanofibers) having a structure in which cut pieces (columnar bodies) of organic silica nanofibers are vertically oriented (oriented in one direction) (pillar array structure of nanofibers: nano-concavo-convex structure). It was confirmed that a uniaxially oriented polymer nanofiber integrated substrate provided with a thin film in which organic silica nanofibers are oriented and integrated in one direction with respect to the substrate surface was obtained by the above process. In the obtained porous thin film, the average distance between polymer nanofibers (the average distance obtained by obtaining the distance to the nearest nanofiber for each of 50 randomly selected nanofibers by SEM observation) was 1.8 times the average diameter of the polymer nanofibers.

[0120] In addition, the step of cutting the polymer nanofiber integrated body (organic silica nanofiber bundle) to a thickness of 20 μm was repeatedly performed to continuously manufacture a plurality of substrates having the same structure. Photographs of the obtained plurality of thin films are shown in FIG. 12.

[0121] (Example 2) In the manufacturing process of the uniaxially oriented polymer nanofiber integrated substrate, except that the thickness to be cut was changed from 20 μm to 10 μm, in the same manner as in Example 1, a substrate (uniaxially oriented polymer nanofiber integrated substrate) provided with an organosilica thin film formed of nanofibers made of organosilica (polymer of NI(amide)-d-Si) was obtained. To confirm the structure of the obtained thin film, SEM observation was performed on the surface and cross-section of the thin film. An electron micrograph (SEM image) of the surface of the thin film is shown in Fig. 13, and an electron micrograph (SEM image) of the cross-section of the thin film is shown in Fig. 14. As is clear from the results shown in Figs. 13 to 14, by SEM observation, it was confirmed that the obtained thin film (organosilica thin film) is a porous thin film (vertically oriented porous thin film of organosilica nanofibers) having a structure in which cut products (columnar bodies) of organosilica nanofibers are vertically oriented (oriented in one direction), and it was confirmed that by the above process, a uniaxially oriented polymer nanofiber integrated substrate provided with a thin film in which organosilica nanofibers are oriented and integrated in one direction with respect to the substrate surface was obtained.

[0122] (Example 3) In the manufacturing process of the uniaxially oriented polymer nanofiber integrated substrate, except that the thickness to be cut was changed from 20 μm to 30 μm, in the same manner as in Example 1, a substrate (uniaxially oriented polymer nanofiber integrated substrate) provided with an organosilica thin film formed of nanofibers made of organosilica (polymer of NI(amide)-d-Si) was obtained. To confirm the structure of the obtained thin film, SEM observation was performed on the surface and cross-section of the thin film. An electron micrograph (SEM image) of the surface of the thin film is shown in Fig. 15, and an electron micrograph (SEM image) of the cross-section of the thin film is shown in Fig. 16. As is clear from the results shown in Figs. 15 to 16, by SEM observation, it was confirmed that the obtained thin film (organosilica thin film) is a porous thin film (vertically oriented porous thin film of organosilica nanofibers) having a structure in which cut products (columnar bodies) of organosilica nanofibers are vertically oriented (oriented in one direction), and it was confirmed that by the above process, a uniaxially oriented polymer nanofiber integrated substrate provided with a thin film in which organosilica nanofibers are oriented and integrated in one direction with respect to the substrate surface was obtained.

[0123] From the results shown in Examples 1 to 3 as described above, after forming a nanofiber structure by self-assembly in a mixed solvent containing an organic solvent to obtain a gel-like composition, by replacing the organic solvent with water, it becomes possible to process the orientation direction of the nanofibers to be unidirectional. Furthermore, after fixing a bundle composed of the nanofibers oriented in that unidirectional direction by polycondensation and then cutting (slicing), it was confirmed that it is possible to continuously and efficiently produce a porous substrate (uniaxially oriented polymer nanofiber integrated substrate) in which the nanofibers are vertically oriented.

[0124] (Comparative Example 1) NI(amide)-d-Si (40 mg, the compound represented by the above formula (4)) obtained in Synthesis Example 1 was added to a mixed solvent (1.96 g) containing ethanol and water in a mass ratio ([ethanol]:[water]) of 4:1 to obtain a mixed solution with a concentration of NI(amide)-d-Si of 2 wt%. Next, the obtained mixed solution was heated to 80 °C to dissolve NI(amide)-d-Si in the mixed solvent, and then cooled to room temperature (about 25 °C) to obtain a gel-like composition. Such a gel-like composition is, from its production method, clearly a composite of a mixed solvent and a nanofiber-like molecular aggregate composed of NI(amide)-d-Si, referring to Example 1.

[0125] Next, ultrasonic treatment was performed on the gel-like composition by irradiating it with ultrasonic waves (42 kHz) for 10 minutes to prepare a dispersion containing self-assembled nanofibers (nanofiber-like molecular aggregates). Next, the obtained dispersion was applied onto a silicon substrate so that the coating amount was 40 μL / cm 2 and the solvent was removed by drying at room temperature for 24 hours. Thereafter, the obtained dry coating film was exposed to the vapor of 2M hydrochloric acid at a temperature of 100 °C for 3 hours to polycondense NI(amide)-d-Si in the dry coating film, and a thin film (substrate) for comparison containing nanofibers composed of organic silica (polymer of NI(amide)-d-Si) was obtained.

[0126] To confirm the structure of the obtained thin film, SEM observations were performed on the surface and cross-section of the thin film. The electron micrograph (SEM image) of the surface of the thin film is shown in Fig. 17, and the electron micrograph (SEM image) of the cross-section of the thin film is shown in Fig. 18. As is clear from the results shown in Figs. 17 to 18, it was confirmed that the obtained thin film was formed by randomly oriented nanofibers made of organic silica (polymer of NI(amide)-d-Si) aggregated to a thickness of 15 to 20 μm. Thus, in Comparative Example 1, a thin film oriented in a uniaxial direction could not be produced, and the obtained thin film (substrate) was composed of randomly oriented organic silica nanofibers.

[0127] (Comparative Example 2) After producing a gel-like composition in the same procedure as in Example 1, using the gel-like composition as it was, after processing a part of the gel-like composition into a cylindrical shape with a diameter of about 1 cm, without performing the step of replacing ethanol with water, when the cylindrical gel-like composition was compressed with a glass plate, the gel structure of the composition collapsed. Photographs showing the state of the gel-like composition before and after compression are shown in Fig. 19. From the results shown in Fig. 19, it was confirmed that when the organic solvent (ethanol) in the gel-like composition was not replaced with water, the gel-like composition could not be squeezed by compression, and it was impossible to compress and process while maintaining the gel structure.

[0128] In order to confirm the collapse of the gel structure in Comparative Example 2 from the mechanical data, the load-displacement characteristics during compression of the gel composition (type of solvent: mixed solvent) and the water-substituted gel composition (type of solvent: water) were measured. For such measurements, after producing the gel composition by the same procedure as in Example 1, using the gel composition as it was, a part of it was processed into a cylindrical shape with a diameter of 1 cm and a height of 1.5 cm (type of solvent: mixed solvent), and a water-substituted gel composition obtained in the same manner as the method employed in Example 1 was used to prepare a water-substituted gel composition (type of solvent: water) with a part processed into a cylindrical shape with a diameter of 1 cm and a height of 1.5 cm, respectively, and each was used as a cylindrical measurement sample. Then, for each measurement sample (cylinder), while applying a load at a speed of 1 mm / min in the height direction of the cylinder, compression was carried out to measure the load-displacement characteristics of the sample. The results obtained are shown in Fig. 20.

[0129] As is also clear from the results shown in Fig. 20, when the ethanol in the mixed solvent contained in the gel composition was not replaced with water, even when the displacement increased, the load hardly increased, and it was confirmed that the load clearly turned to a decrease at a position where the displacement was around 9 mm. From the mechanical data as well, it was shown that in Comparative Example 2, the gel structure collapsed due to compression. In contrast, for the water-substituted gel composition with the solvent replaced with water, the load increased monotonically with the increase in displacement, and the load increased to about 1.2 N at a displacement of 14 mm. From such mechanical data, it was also shown that by replacing the organic solvent (ethanol) in the gel composition with water, the strength of the self-assembled nanofibers constituting the gel was significantly improved. From such results as well, it was found that after obtaining the gel composition as described above, by replacing the organic solvent in the gel with water, it becomes possible to process the self-assembled nanofibers to be oriented in one direction.

[0130] <Laser desorption / ionization mass spectrometry> (Example 4) First, a substrate (uniaxially oriented polymer nanofiber integrated substrate: thin film substrate) provided with an organosilica thin film (thickness: 20 μm) formed of nanofibers made of the organosilica (polymer of NI(amide)-d-Si) obtained in Example 1 was attached to a silicon substrate (support) (the back surface of the carbon seal of the thin film substrate was attached to the support), and a silicon substrate provided with an organosilica thin film (for convenience, hereinafter sometimes referred to as a "laminated substrate") was obtained.

[0131] Next, the obtained laminated substrate was sealed in a Teflon (registered trademark) container together with a glass bottle containing 25 μL of trimethoxy(1H,1H,2H,2H-nonafluorohexyl)silane and heated at a temperature of 150 °C for 1 hour under an argon atmosphere to perform a hydrophobization treatment on the laminated substrate. The progress of the hydrophobization treatment was confirmed from the fact that the surface of the laminated substrate after the treatment exhibited superhydrophobicity with a contact angle of water droplets of 150 degrees or more.

[0132] Next, a plurality of such laminated substrates (hydrophobized products of uniaxially oriented polymer nanofiber integrated substrates supported by a support) were prepared and used as substrates for laser desorption / ionization mass spectrometry, respectively, to perform laser desorption / ionization mass spectrometry.

[0133] In such laser desorption / ionization mass spectrometry, verapamil, angiotensin I, and amyloid β (human, 1-40) were used as the target molecules for analysis, respectively. As the sample solution, a mixed solvent containing acetonitrile and an aqueous solution of 0.1% by mass trifluoroacetic acid with a volume ratio ([acetonitrile]:[aqueous solution]) of 1:4 was prepared, and solutions in which the target molecules for analysis were dissolved at predetermined concentrations (verapamil: 1.0 pmol / μL, angiotensin I: 0.5 pmol / μL, amyloid β: 0.5 pmol / μL) were prepared and used respectively. Then, 1.0 μL of each sample solution was dropped onto the site of the organic silica thin film provided on each substrate for laser desorption / ionization mass spectrometry, and dried rapidly under vacuum, so that the target molecules for analysis were supported on the substrate surface, and measurement samples were formed for each target molecule for analysis. Next, laser light (laser wavelength: 355 nm) was irradiated onto the site where the target molecules for analysis of each measurement sample were supported (the site of the organic silica thin film), and laser desorption / ionization mass spectrometry was performed. For such laser desorption / ionization mass spectrometry, "autoflex maX" manufactured by Bruker Daltonics was used as the measuring device.

[0134] As a result of such measurement, the result of mass spectrometry (mass spectrum of verapamil) performed on the measurement sample to which 1.0 pmol / μL of verapamil (molecular weight: 454.6) was dropped is shown in FIG. 21. As is clear from the results shown in FIG. 21, in the obtained mass spectrum, a signal corresponding to the proton adduct of verapamil was clearly observed at the position of mass-to-charge ratio (m / z) = 455.1, and it was confirmed that the signal / noise (S / N) ratio was 28.

[0135] Also, the result of mass spectrometry (mass spectrum of angiotensin I) performed on the measurement sample to which 0.5 pmol / μL of angiotensin I (molecular weight: 1296.5) was dropped is shown in FIG. 22. As is clear from the results shown in FIG. 22, in the obtained mass spectrum, a signal corresponding to the proton adduct of angiotensin I was clearly observed at the position of m / z = 1296.6, and it was confirmed that the S / N ratio was 38.

[0136] Furthermore, the results of mass spectrometry (the mass spectrum of amyloid-β) performed on the measurement sample to which 0.5 pmol / μL of amyloid-β (molecular weight: 4329.8) was dropped are shown in FIG. 23. As is also clear from the results shown in FIG. 23, a signal corresponding to the proton adduct of amyloid-β was clearly observed at the position of m / z = 4330, and it was confirmed that the S / N ratio thereof was 24.

[0137] (Comparative Example 3) Except for using the thin film (substrate) for comparison obtained in Comparative Example 1 instead of the uniaxially oriented polymer nanofiber integrated substrate obtained in Example 1, in the same manner as in Example 4, a plurality of hydrophobized substrates were prepared, and verapamil, angiotensin I, and amyloid-β (human, 1-40) were used as analysis target molecules, and laser desorption / ionization mass spectrometry was performed.

[0138] As a result of such measurement, the results of mass spectrometry (the mass spectrum of verapamil) performed on the measurement sample to which 1.0 pmol / μL of verapamil (molecular weight: 454.6) was dropped are shown in FIG. 24. As is also clear from the results shown in FIG. 24, a signal corresponding to the proton adduct of verapamil was observed at the position of the mass-to-charge ratio (m / z) = 455.1, but the signal intensity was low and the S / N ratio thereof was 4.

[0139] Also, the results of mass spectrometry (the mass spectrum of angiotensin I) performed on the measurement sample to which 0.5 pmol / μL of angiotensin I (molecular weight: 1296.5) was dropped are shown in FIG. 25. As is also clear from the results shown in FIG. 25, a signal corresponding to the proton adduct of angiotensin I was observed near the position of m / z = 1297, but the S / N ratio thereof was less than 3 (about 2), and sufficient intensity was not obtained as a mass spectrometry signal.

[0140] Furthermore, the results of mass spectrometry (mass spectrum of amyloid β) performed on the measurement sample to which 0.5 pmol / μL of amyloid β (molecular weight: 4329.8) was dropped are shown in FIG. 26. As is clear from the results shown in FIG. 26, a signal corresponding to the proton adduct of amyloid β was observed at the position of m / z = 4330, but the signal intensity was low and the S / N ratio was 6.

[0141] Here, FIG. 27 shows a graph comparing the signal intensities of the mass spectra of each molecule to be analyzed obtained by laser desorption / ionization mass spectrometry performed in Example 4 and Comparative Example 3. As is clear from the results shown in FIG. 27, when a substrate formed by integrating vertically aligned polymer nanofibers of organosilica was used (Example 4), compared with the case where a substrate formed by integrating randomly oriented polymer nanofibers of organosilica was used (Comparative Example 3), it was found that the performance of mass spectrometry was significantly improved and more sensitive analysis became possible.

Industrial Applicability

[0142] As described above, according to the present invention, it is possible to provide a method for manufacturing a polymer nanofiber integrated body capable of efficiently manufacturing a polymer nanofiber integrated body having uniaxial orientation in the longitudinal direction; a polymer nanofiber integrated body obtained by using the manufacturing method; a uniaxially oriented polymer nanofiber integrated substrate capable of efficiently manufacturing as a cut product of the polymer nanofiber integrated body; and a laser desorption / ionization mass spectrometry substrate applying the uniaxially oriented polymer nanofiber integrated substrate.

[0143] Therefore, the method for manufacturing a polymer nanofiber integrated body of the present invention is useful as a method for efficiently manufacturing a polymer nanofiber integrated body that can be suitably used as a raw material for a laser desorption / ionization mass spectrometry substrate.

Explanation of Signs

[0144] 10…Water replacement gel composition, 11…Self-assembled fiber bundle, 12…Polymer nanofiber aggregate in a form fixed (reinforced) with resin, 13…Thin film composed of cut pieces of polymer nanofiber aggregate, F…Fibrous molecular assembly of self-assembled compound, Fp…Nanofiber made of polymer, R…Resin covering the periphery of polymer nanofiber aggregate.

Claims

1. A step of dispersing a water-insoluble self-assembling compound having a polymerizable functional group and capable of forming a fibrous molecular aggregate by self-assembly in either an organic solvent miscible with water or a mixed solvent of the organic solvent and water to obtain a gel-like composition; A step of replacing the organic solvent in the gel-like composition with water to obtain a water-replaced gel-like composition; A step of squeezing the water-replaced gel-like composition by compressing it from a plurality of directions substantially orthogonal to the longitudinal direction while opening the longitudinal direction to obtain a self-assembled fiber bundle; A step of polymerizing the self-assembling compound in the self-assembled fiber bundle to obtain an aggregate composed of polymer nanofibers oriented in the longitudinal direction; A method for producing a polymer nanofiber aggregate, comprising the above steps.

2. The method for producing a polymer nanofiber aggregate according to claim 1, wherein the polymerizable functional group is at least one group selected from the group consisting of a trialkoxysilyl group, a vinyl group, an acryloyl group, a methacryloyl group, a dienyl group, and a diacetylene group.

3. The water-insoluble self-assembling compound is It has two or more amide bonds and two or more aromatic groups in the molecular skeleton, Each of the two or more aromatic groups is a group having one aromatic ring selected from the group consisting of a naphthalimide ring, a triphenylamine ring, a pyrene ring, a perylene ring, and an acridone ring, and The method for producing a polymer nanofiber aggregate according to claim 1, which is an organosilane compound in which two or more trialkoxysilyl groups as the polymerizable functional group are bonded to each of the two or more aromatic groups.

4. A polymer nanofiber aggregate in which nanofibers composed of a polymer of a water-insoluble self-assembling compound having a polymerizable functional group and capable of forming a fibrous molecular aggregate by self-assembly are aligned and aggregated in the longitudinal direction. The polymer nanofiber aggregate is characterized in that, when cut from a direction substantially perpendicular to the longitudinal direction, the cut surface has a surface having a porous structure composed of nanofibers oriented substantially perpendicular to the cut surface.

5. A uniaxially oriented polymer nanofiber aggregate substrate comprising a thin film made of a cut product of a polymer nanofiber aggregate in which nanofibers composed of a polymer of a water-insoluble self-assembling compound having a polymerizable functional group and capable of forming a fibrous molecular aggregate by self-assembly are aligned and aggregated in the longitudinal direction, and the cutting direction of the cut product is substantially perpendicular to the longitudinal direction of the polymer nanofiber aggregate.

6. A laser desorption / ionization mass spectrometry substrate comprising the uniaxially oriented polymer nanofiber aggregate substrate according to Claim 5 or a hydrophobized product thereof.

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