JP2008254165A - Nano-structure of hydrophobic polymer obtained by using boron compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To develop techniques to organize a sheet type nano-structure by linking a composite material of a hydrophobic polymer such as a monolayer carbon nanotube wrapped with unmodified polysaccharide. <P>SOLUTION: A sheet type structure is obtained by preliminarily wrapping a hydrophobic polymer with β-1,3-glucan and then crosslinking and connecting the polysaccharides with a boron compound (having two or more reactive moieties composed of B(OH)<SB>2</SB>that can react with a hydroxy group). Schizophyllan is effectively used as the β-1,3-glucan. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for organizing a hydrophobic polymer such as a carbon nanotube or a conductive polymer into a regular nanostructure (a nanometer-sized structure) such as a sheet.

  Hydrophobic polymers such as carbon nanotubes and conductive polymers are expected to be used for new purposes by organizing into regular structures. For example, the carbon nanotube is a one-dimensional nanowire having a high carrier transport ability and a rigid structure. Therefore, carbon nanotubes are one of the most suitable nanomaterials for use as basic parts of molecular machines. However, carbon nanotubes exhibit very strong cohesiveness, and it is actually difficult to regularly arrange each carbon nanotube as a molecular machine. There are many other high-value-added hydrophobic polymers such as various conductive polymers, but in order to exert their functions, depending on the respective characteristics such as dispersion, thinning, sheet form, layering, etc. It is important to realize a regular shape.

To date, the present inventors have succeeded in complexing carbon nanotubes with natural polysaccharide schizophyllan (SPG). This research has succeeded in stabilizing the carbon nanotube as a single fiber while preventing the aggregation of the carbon nanotubes which are very easily aggregated.
M. Numata, M. Asai, K. Kaneko, T. Hasegawa, K. Sakurai, and S. Shinkai, J. Am. Chem. Soc., 127, 5875 (2005). Development of a novel structure made of a conductive polymer, for example, a sheet-like regular nanostructure, is desired.

  An object of the present invention is to provide a simple new technique for organizing a nanostructure by linking a polysaccharide-hydrophobic polymer complex obtained in nature.

It is well known that a site composed of B (OH) ₂ (B represents a boron atom) binds to an OH group (hydroxyl group) (Non-patent Documents 2-5). For example, in FIG. 1a, a boronic acid compound having a B (OH) ₂ group (boronic acid group) is mixed with a sugar to form a B (OH) ₂ group and two OH groups (diol groups) at the cis position. A dehydration reaction is caused in the middle, and a state in which a covalent bond is formed between the sugar and the boronic acid is schematically shown. FIG. 1b schematically shows a state in which a boric acid ion forms a covalent bond by causing a dehydration reaction at a site composed of B (OH) _{2 with} respect to a diol such as glucose in a sugar chain. (Non-Patent Document 6).
Y. Kanekiyo, Y. Ono, K. Inoue, M. Sano, S. Shinkai, J. Chem. Soc., Perkin Trans. 2, 557 (1999). Y. Kanekiyo, K. Inoue, Y. Ono, M. Sano, S. Shinkai, DN. Reinhoubt, J. Chem. Soc., PerkinTrans. 2, 2719 (1999). LK Mohler, AW Czarnik, J. Am. Chem. Soc., 115, 2998 (1993). T- D. James, KRAS Sandanayake, S. Shinkai, Angew. Chem. Int. Ed, 35, 1910 (1996). T. Ishii, H. Ono, carbohydrate research, 2004, volume 321, pp257-260

According to the present invention, a polysaccharide is helically wrapped around a hydrophobic polymer using a boron compound having two or more reactive sites consisting of _two B (OH) groups capable of reacting with a hydroxyl group as a molecular structure. In this state, the polysaccharide / hydrophobic polymer complex is cross-linked and linked to each other. That is, one B (OH) ₂ site of the boron compound reacts with two OH groups (diols) of the polysaccharide present on the complex surface, and the remaining B (OH) ₂ site is another polysaccharide / hydrophobic high By reacting with the sugar diol of the molecular complex, the complex is cross-linked and linked to obtain a sheet-like nanostructure in which the polysaccharide / hydrophobic polymer complex is two-dimensionally arranged ( (See schematic diagram in FIG. 2).

The advantage of arranging the polysaccharide / hydrophobic polymer complex in two dimensions according to the present invention is that the polysaccharide can be arranged by a simple method without modifying the side chain. In addition, polysaccharides represented by schizophyllan have been reported to work on various compounds such as conductive polymers inside, but it is possible to develop new functional materials by arranging these complexes two-dimensionally. Has the potential to be applied. In addition, the distance between hydrophobic polymers can be controlled according to the molecular length of the crosslinking agent used by changing the crosslinking agent (boron compound).

A preferred example of the boron compound used as a crosslinking agent in the present invention is a boronic acid compound having a plurality of B (OH) ₂ groups, particularly represented by the general formula: (HO) ₂ BLB (OH) _2. It is a diboronic acid compound. Here, L corresponding to the linker in the formula represents an atomic group containing various groups such as an aromatic hydrocarbon group. Particularly suitable diboronic acid compounds for use in the present invention include 1,4-phenylene-bis-boronic acid shown in FIG. 8 and 4,4′-biphenyl-diboronic acid shown in FIG. It is not limited to.

  Furthermore, by introducing a skeleton of a high-functional molecule such as various heterocyclic compounds and polymerizable monomers / oligomers at the site corresponding to L, the boronic acid compound can be used not only as a cross-linking material for hydrophobic polymers but also as an encapsulating material. It is also possible to impart the function of the diboronic acid compound to the hydrophobic polymer via the polysaccharide. For example, the boronic acid compound (P-1) [5, 10, 15, 20-tetrakis (4-boronylphenyl) porphyrin] having a chemical structure having a porphyrin skeleton shown in FIG. The diboronic acid compound (C-1) having the oligothiophene structure shown in FIG. 18 [pyridinium, 4,4 ′-{2,5-bis (2,2′-bithiophen-5-yl) -1 , 4-phenylene} bis [1- (benzyl-4-boronic acid) methyl] bromide (1: 2)] can be polymerized at the thiophene site after crosslinking.

The boron compound used as a crosslinking agent in the present invention is boric acid such as tetraboric acid, orthoboric acid, metaboric acid, and salts thereof, and has two or more reactive sites composed of B (OH) _2. Also included. Here, the reactive sites consisting of B (OH) _2, respectively as in the boronic acid compound as described above not only when there exist a plurality as B (OH) ₂ group, via a common boron atom A plurality of B (OH) ₂ sites may be formed. For example, as already described with respect to FIG. 1b, tetraborate salts, represented by sodium tetraborate (borax), can form tetraborate ions in water, ie, two B ( OH) ₂ sites are formed, each functioning to dehydrate and condense with the cis-diol of the sugar chain to crosslink and link the sugar chains. Thus, tetraborate is an example of a boron compound suitable for use in the present invention.

  A preferred polysaccharide for use in the present invention is β-1,3-glucan, and various β-1,3 known by common names such as schizophyllan, scleroglucan, lentinan, perchiman, glyphoran, curdlan and the like. -Glucans can be used. These are natural polysaccharides whose main chains are linked by β-linkages (β-D-linkages) and have different side chain frequencies. Of these, schizophyllan, scleroglucan and lentinan are preferable because they have a side chain frequency of 33 to 40% and are suitable because they are water-soluble and easy to use. It is suitable because it has been used and its safety has been confirmed.

  The principle of the present invention is applied to obtain nanostructures using various hydrophobic polymers. Preferred hydrophobic polymers for use in the present invention include carbon nanotubes, particularly single-walled carbon nanotubes (SWNT), or conductive polymers such as polyphenylene ethynylene (PPE), polyacetylene, polypyrrole, polythiophene or their derivatives. However, it is not limited to these.

The structure of the present invention can be prepared by a relatively simple method. That is, a solution of β-1,3-glucan such as schizophyllan (a polar solvent such as DMSO is used as a solvent) under the above-mentioned hydrophobic polymer solution (aqueous solution) under strong mixing conditions such as ultrasonic irradiation. Is added to the hydrophobic space inside the β-1,3-glucan molecule by allowing it to stand at room temperature for an appropriate time (for example, 1 day) and then purifying it by centrifugation or the like. As a result, a complex wrapped in a helical β-1,3-glucan is obtained. In this way, the present inventors have already reported that a β-1,3-glucan / hydrophobic polymer complex is formed (Non-patent Documents 1 and 7-9). By adding the above boron compound (aqueous solution) to the complex thus obtained and allowing it to stand at room temperature for an appropriate time (for example, 7 days), the polysaccharide (β -1,3-glucan) sugar chains are cross-linked and linked to obtain a nanostructure in which β-1,3-glucan / hydrophobic polymer composites are two-dimensionally arranged (described later). See example).
C. Li, M. Numata, M. Takeuti, S. Shinkai, Angew. Chem., 117, 2 (2005) C. Li, M. Numata, T. Hasegawa, K. Sakurai, S. Shinkai, Chem. Lett., 34, 1354 (2005). C. Li, M. Numata, A.-H. Bae, K. Sakurai, S. Shinkai, J. Am. Chem. Soc., 127, 4548 (2005).

The complex of SWNT and SPG was purified by centrifugation (1500 rpm, 60 min.). SPG / DMSO (100 μL, 5 mg / mL) was added to SWNT / H ₂ O (500 μL) all at once while performing ultrasonic irradiation. This was left still for one day under room temperature conditions. The supernatant solution was taken out, and the complex was precipitated by centrifugation (60 min., 8 × 10 ³ rpm), and the supernatant solution was removed and redispersed again in water three times, and only the complex was taken out. The pH of the complex aqueous solution at this time was 7.77. An aqueous sodium tetraborate solution (0.5 mg / mL, pH = 9.31) was added, and the mixture was allowed to stand at room temperature for 7 days, and crosslinking between sugar chains with sodium tetraborate was attempted. Three types of samples with different molar ratios of SPG / SWNT complex and sodium tetraborate were prepared. A sample solution containing no sodium tetraborate was also prepared as a reference (R-1). In addition, in order to perform TEM observation of CUR (curdlan) and SWNT composites, CUR / SWNT composites were prepared as follows. 100 μL of CUR / DMSO (5 mg / mL) was mixed with a purified cut-SWNT aqueous solution (500 μL) with ultrasonic irradiation. Only the complex was removed by centrifugation. An aqueous sodium borate solution (pH = 9.81) was added to the complex solution, and the mixture was allowed to stand for 1 day (R-2 to 3). A solution in which SPG and an aqueous sodium tetraborate solution were mixed and allowed to stand at room temperature was also prepared as a reference (R-4 to 5). Moreover, the sample which mixed the paramethyl boronic acid which is monoboronic acid, and SPG / SWNT was also prepared (R-6-8). Table 1 shows the amount of each component in the prepared solution.

The TEM observation sample solution was cast on a TEM grid (without a supporting film), dried under reduced pressure, and then subjected to TEM observation. As a result of the observation in FIG. 4, many sheet-like images were confirmed from samples other than the reference solution R. Among the samples forming the sheet, there were many sheets that were particularly well-ordered in 3 where the amount of sodium borate in the solution was small (Fig. 4f, 4g). Moreover, only the image that SWNT aggregated randomly was seen in R-1. From this result, it is considered that SWNT-SPG may be crosslinked in a sheet form with boric acid. This result is considered to be because the amount of boric acid in 3 was less than the amount of binding sites on the SPG side chain, and thus boric acid was easily bound uniformly to the binding sites. From the sample mixed with sodium tetraborate in the CUR / SWNT composite, there was a morphology in which SWNT that was hardly seen in the sample mixed with sodium tetraborate in the SPG / SWNT composite existed without forming a sheet. Mainly confirmed (Figure 4i). Moreover, the morphology which forms the sheet | seat very rarely was also confirmed. From these results, it is considered that although it is difficult to interact with the hydroxyl groups at the 4th and 5th positions of CUR, it is somewhat interacting. Although it may be converted into diols at the 4th and 5th positions of CUR, the hydroxyl group is attached to trans at the 4th and 5th positions of CUR. As a result of observation from the reference sample (R-4 ~ 5), which is a mixture of SPG and sodium borate, a sheet-like morphology was confirmed. The image which is hard to say with the morphology is obtained. It is possible that the last name obtained by the presence of SWNT in the SPG is necessary to form a regular sheet. From the reference solution in which the monoboronic acid compound and SPG / SWNT were mixed, a black lump or a morphology in which SWNTs were bundled was observed in each sample. That is, since a sheet was not confirmed with monoboronic acid and a sheet was confirmed with diboronic acid compound, it was found that the formation of a sheet requires two or more binding sites with sugar.

HR-TEM observation From the results of Fig. 5, a large number of sheets with a size of 2μm square or more were confirmed, and the diffraction pattern of the image in which the fibers observed in TEM observation were cross-linked was observed over a wide range. A regular diffraction pattern was observed. From this result, it was found that a structure close to a crystal was formed. Further, from the EDX-TEM observation, the presence of sodium which is a tetraborate counter was confirmed in the sheet.

SEM Observation Next, SEM observation was performed on each solution in which the most regular sheet-like image was confirmed by TEM observation, and macroscopic morphology was observed compared to TEM (FIG. 6). Each solution was cast on a TEM substrate (no support film) and dried under reduced pressure. From the SEM observation of this sample, an image as if the sheets overlapped was confirmed. This sheet also matched in size to the point where the length of the cut SWNT was several hundred nanometers. Therefore, SEM observation also showed the formation of sheets in each solution. As a result of SEM observation, a sheet-like image was confirmed from any sample containing SWNT. Many sheets with a size of 2μm or more were observed by SEM observation. A large number of sheet-like images were confirmed from each solution. In many cases, several sheets overlapped, but there were also images in which the sheets did not overlap and existed alone.

Micro Raman spectrum measurement was performed to confirm the presence of SWNTs in a sheet having a size of about 500 nm observed from micro Raman spectrum TEM and SEM observation. If SWNT is present, the G band derived from SWNT should be confirmed. The measurement sample was cast 3 on a glass substrate. After sufficiently drying, a micro Raman spectrum was measured. As a result of the measurement in FIG. 7, a peak near 1600 cm ⁻¹ that seems to be derived from the G band was confirmed. In addition, a peak considered to be derived from RBM was also observed in the vicinity of 200 cm- ¹ . From this result, it was shown that SWNT exists in the sheet-like morphology obtained by TEM and SEM observation. In this study, cleaved SWNT and SPG complexes were sequenced by adding sodium tetraboronate to the cleaved SWNT and SPG complex. As a result, the sheet-like morphology was confirmed by TEM and AFM observation, and the SWNT-derived G band and RBM peak were confirmed by Raman spectrum measurement.

As a diboronic acid compound crosslinking agent, a crosslinking experiment was attempted using a diboronic acid compound having a molecular length longer than that of sodium tetraborate. The complex of SWNT and SPG was purified by centrifugation (1500 rpm, 60 min.). SPG / DMSO (50 μL, 5 mg / mL) was added to SWNT / H ₂ O (500 μL) all at once while performing ultrasonic irradiation. This was left still for one day under room temperature conditions. Remove the supernatant solution and centrifuge (60 min.,
The complex was precipitated at 8 × 10 ³ rpm), the supernatant solution was removed, and the dispersion was redispersed in water three times, and only the complex was taken out. The pH of the complex aqueous solution at this time was 7.07. 1,4-Phenylene-bis-boronic acid aqueous solution (Figure 8, acetic acid / sodium acetate buffer) (0.5mg / mL, pH = 9.84) was added, and the mixture was allowed to stand at room temperature for 1 day. Sodium tetraborate Attempts were made to crosslink between sugar chains. Three types of samples with different molar ratios of SPG / SWNT complex and sodium tetraborate were prepared. A sample solution containing no sodium tetraborate was also prepared as a reference. Table 2 shows the amount of each component in the prepared solution.

  The supernatant of the sample solution was cast on a TEM grid (without a supporting film), dried under reduced pressure, and then observed with TEM. As a result of the observation in FIG. 8, a sheet-like image having a size of 2 μm square or more was confirmed from all the samples. In addition, an image as if fibers were arranged in the sheet and moire fringes were confirmed. However, although the sample 3 may be because the cast amount is small, the sheet was not so much seen. From this result, it is considered that SPG / SWNT is crosslinked in a sheet form by a boric acid compound.

Solution Preparation The complex of SWNT and SPG was purified by centrifugation (1500 rpm, 60 min.). To SWNT / H ₂ O (500 μL), SPG / DMSO (50 μL, 5 mg / mL) was added all at once while performing ultrasonic irradiation. This was left still for one day under room temperature conditions. The supernatant solution was taken out, and the complex was precipitated by centrifugation (60 min., 8 × 10 ³ rpm), and the supernatant solution was removed and redispersed again in water three times, and only the complex was taken out. The pH of the complex aqueous solution at this time was 7.07. Add 4,4'-biphenyl-di-boronic acid aqueous solution (Fig. 10, acetic acid / sodium acetate buffer) (0.5mg / mL, pH = 10.3) and let stand at room temperature for 1 day. Attempts were made to crosslink between sugar chains. Three types of samples with different molar ratios of SPG / SWNT complex and boric acid compound were prepared. A sample solution containing no diboronic acid compound was also prepared as a reference. Table 3 shows the amount of each component in the prepared solution.

  The supernatant of the generated sample solution was cast on a TEM grid (without a supporting film), dried under reduced pressure, and then subjected to TEM observation. As a result of the observation in FIG. 10, a sheet-like image having a size of 2 μm square or more was confirmed from all the samples. In addition, an image as if fibers were arranged in the sheet and moire fringes were confirmed. From this result, it is considered that SPG / SWNT is crosslinked in a sheet form by a boric acid compound.

Arrangement of SPG / PPE with diboronic acid compound It is necessary for the advancement of next-generation electronic devices such as organic displays to arrange SPG conductive polymer composites in sheet form. As an evolution of the SPG / SWNT arrangement with sodium tetraborate, SPG / PPE complexes complexed with SPG were regularly arranged with sodium tetraborate (FIG. 12).

Preparation of solution Complexing of PPE and SPG and purification of the complex were carried out as follows. 1M (to monomer unit) SPG aqueous solution and 1M PPE / DMSO solution were mixed, and 2200 μL of water was added to unwind SPG. This was left still for one day under room temperature conditions. Sodium tetraborate aqueous solution (acetic
acid / sodium acetate buffer) (0.5mg / mL, pH =
9.46) was added and the mixture was allowed to stand at room temperature for 1 day, and crosslinking between sugar chains with sodium tetraborate was attempted. Three types of samples with different molar ratios of SPG / SWNT complex and sodium tetraborate were prepared. A sample solution containing no sodium tetraborate was also prepared as a reference. Table 4 shows the amount of each component in the prepared solution.

  The supernatant of the sample solution was cast on a TEM grid (without a supporting film), dried under reduced pressure, and then observed with TEM. As a result of the observation in FIG. 13, sheet-like images were confirmed from all the samples. From this result, it is considered that SPG / SWNT- may be crosslinked in a sheet form with boric acid. Since the length of the cut SWNT is several hundreds of nanometers, it seems that the length of one sheet is almost the same as the theoretical value.

Preparation of solution Crosslinker with porphyrin as molecular skeleton 5,10,15,20-tetrakis (4-boronylphenyl)
In order to examine the cross-linking between SPG / SWNT complexes by porphine (abbreviated as P-1: FIG. 14, synthesis method: Non-Patent Document 10-12), a DMSO solution (1 mgmL ⁻¹ ) of P-1 was prepared, To this was added carbonate-bicarbonate buffer (100 mM, pH = 10.0). Further, an aqueous SWNT-SPG complex solution (pH = 7.8) prepared in Example 1 was added to bond between SPG side chain glucoses. Table 5 shows the component amounts of the solution. Incidentally, porphyrins TPPS containing no acid to examine the differences in interaction with the SPG with or without acid (5,10,15,20-tetraphenyl-21H, 23H -porphine-p, p., P .. , p ^...-
A sample to which tetrasulfonic acidtetrasodium salt hydrate) was added was also prepared.
Arimori, S .; Takeuchi, M .; Shinkai, S. Chem. Lett., 1996, 1, 77, Imada, T .; Murakami, H .; Shinkai, S. Chem. Commun., 1994, 13, 1557, Toi, H .; Nagai, Y .; Aoyama, Y .; Kawabe, H .; Aizawa, K .; Ogoshi, H. Chem. Lett., 1993, 6, 1043.

UV-vis and CD spectrum measurement In order to confirm the interaction between SPG and crosslinker P-1, crosslinking between SPGs was performed under the same conditions as in Example 1, and then UV-vis spectrum and CD spectrum were measured for optical path length. : 1 cm, temperature: room temperature, [P-1] = 16.2 μM, solvent: H ₂ O / DMSO
(8914: 1 (v / v)) and pH: 9.9. From the measurement result of FIG. 15, induced CD depending on the amount of SPG-SWNT was confirmed around 428 nm, which is the maximum absorption wavelength of P-1 in the Soret band. From this result, it became clear that SPG and P-1 interacted.

TEM observation and EDX-TEM observation In order to confirm the regular arrangement of SPG / SWNT fibers after crosslinking from the aspect of morphology, TEM observation of the prepared solution was performed.
As a result of TEM observation in FIG. 16, a sheet-like image was confirmed in the same manner as the sample using sodium tetraborate as a crosslinking agent, and moire fringes suggesting a regular structure were observed in the sheet-like morphology. In addition, regular arrangement of fibers was confirmed by HR-TEM observation, suggesting that SWNTs were indeed arranged. Further, when EDX-TEM observation was performed on the sheet morphology observed by TEM observation, the presence of nitrogen element contained only in the crosslinking agent P-1 was confirmed among the compounds present in the solution. This clearly showed that the cross-linking agent P-1 was present in the sheet-like morphology.

A sample solution cross-linked by polarizing microscope observation P-1 of a sheet-like aggregate formed of a cross-linking agent was dropped on a glass plate and dried under reduced pressure conditions, and then observed under a polarizing microscope. As a result of the polarization microscope observation shown in FIG. 17, many aggregates having optical anisotropy were observed even when a polarizer was inserted.

Preparation of solution Pyridinium, 4,4 '-{2,5-bis (2,2'-bithiophen-5-yl) -1,4-phenylene} bis [1- (benzyl-4-boronic acid) ) methyl] -bromide (1: 2) (abbreviated as C-1, chemical structure: FIG. 18, synthesis reference: non-patent reference 13-15, identification by ¹ H-NMR: Table 6) To examine cross-body cross-linking, a C-1 / DMSO solution (0.1 mg / mL) was prepared and carbonate-bicarbonate buffer (100 mM, pH = 9.95) was added. The SWNT-SPG complex aqueous solution prepared in Example 1 was added to this, and the coupling | bonding between SPG side chains was tried. Table 7 shows the component amounts of the solution.
K. Takahashi, T. Nihira, Bull. Chem. Soc. Jpn, 1992, 65, 1855 RM.Chen, TY.Lue, Tetrahedron, 1998, 54, 119 JNCamara, JTSuri, FECappuccio, RAWessling, B. Singaram, Tetrahedron Lett., 2002, 43, 1139

The interaction between SPG and boronic acid was confirmed by UV-vis and CD spectroscopy . From the results of FIG. 19, induced CD depending on the amount of SPG-SWNT was confirmed. In addition, the confirmed induced CD had a shape in which a plurality of induced CDs overlapped. At present, it is considered that a CD spectrum pattern having such a shape was obtained by the interaction between CPG and C-1 associated species in a single molecule dispersed state and SPG.

TEM observation The prepared solution was cast on a TEM grid (without a carbon support film) and subjected to TEM observation. As a result of FIG. 20, sheet-like morphology showing moire fringes was mainly observed from all the samples containing C-1. Moreover, only an image that C-1 aggregated was obtained from the sample not containing the SWNT-SPG complex.

  For example, by arranging conductive polymer composites in a sheet form, it is expected as a material for next-generation electronic devices such as organic displays.

The reaction characteristic of the boronic acid compound used as the principle of this invention is shown. The reaction characteristic of the tetraborate ion used as the principle of this invention is shown. The conceptual diagram of this invention is shown. The conceptual diagram of the bridge | crosslinking of the polysaccharide / SWNTs complex by a diboronic acid compound is shown. An example of a TEM image of a diboronic acid compound crosslinked sample is shown. Examples of HR-TEM images and EDX-TEM observations of diboronic acid compound crosslinked samples are shown. The example of a SEM image of the diboronic acid compound crosslinked sample is shown. The example of a micro Raman spectrum of the diboronic acid compound crosslinked sample is shown. Shows the structure of 1,4-phenylene-bis-boronic acid. An example of a TEM image of a 1,4-phenylene-bis-boronic acid crosslinked sample is shown. Shows the structure of 4,4'-biphenyl-di-boronic acid. An example of a TEM image of a 4,4'-biphenyl-di-boronic acid crosslinked sample is shown. The cross-linking conceptual diagram of a polysaccharide / conductive polymer composite is shown. The example of a TEM image of the bridge | crosslinking sample by sodium tetraborate of a polysaccharide / conductive polymer composite is shown. The chemical structure of boronic acid compound P-1 is shown. An a.UV-vis diagram example, b.CD and c.fluorescence spectrum diagram example (λ _ex = 390 nm) of the P-1 cross-linked SPG / SWNT complex are shown. Examples of a.TEM image and b.EDX spectrum of P-1 cross-linked SPG / SWNT composite are shown. An example of a polarizing microscope image of a P-1 crosslinked SPG / SWNT composite (a. No polarizer, b. With polarizer) is shown. 1 shows the chemical structure of diboronic acid compound C-1. Examples of a.CD spectrum and b.UV-vis, spectrum diagram of C-1 crosslinked SPG / SWNT composite are shown. An example of a TEM image of a C-1 crosslinked SPG / SWNT composite is shown.

Claims (9)

A nanostructure comprising a β-1,3-glucan / hydrophobic polymer complex crosslinked with a boron compound having two or more reactive sites composed of B (OH) ₂ capable of reacting with a hydroxyl group .   The nanostructure according to claim 1, wherein the hydrophobic polymer is a single-walled carbon nanotube.   The nanostructure according to claim 1, wherein the hydrophobic polymer is a conductive polymer.   The nanostructure according to claim 1, wherein β-1,3-glucan is schizophyllan.   The nanostructure of claim 1, wherein the boron compound is tetraborate.   The nanostructure of claim 1, wherein the boron compound is 1,4-phenylene-bis-boronate.   The nanostructure of claim 1, wherein the boron compound is 4,4'-biphenyl-di-boronate.   The nanostructure according to claim 1, wherein the boron compound is 5,10,15,20-tetrakis (4-boronylphenyl) porphyrin. The boron compound is pyridinium, 4,4 '-{2,5-bis (2,2'-bithiophen-5-yl) -1,4-phenylene} bis [1- (benzyl-4-boronic acid) methyl]- The nanostructure of claim 1, wherein the nanostructure is bromide (1: 2).