Polymerization in Nanometer-Sized Fibers:  Molecular Packing Order and Polymerizability

Masuda, Mitsutoshi; Hanada, Takeshi; Okada, Tatsuhiro; Yase, Kiyoshi; Shimizu, Toshimi

doi:10.1021/ma001157e

Cited by 76 publications

(42 citation statements)

References 24 publications

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“…87 TEM observation showed that the obtained fibrous assemblies are fiber-or ribbon-shaped sheets with a minimum width of 50 nm, much larger than those obtained for fibers from 8 (6 nm). The UV polymerization for the fibrous assemblies from 10 resulted into the production of polydiacetylenic nanostructures with relatively higher molecular weights of 64-mer (Figure 12b) since the amide and sugar hydroxyl groups in 10 will allow the formation of stronger, multiple hydrogen bond networks within the gel nanofibers as compared to the case of 8.…”

Section: Self-assembly and Subsequent Polymerization Of Bola-form Monmentioning

confidence: 66%

“…86 Thus, we succeeded in obtaining covalently linked polydiacetylenic nanometer-sized fibers by the combination of the self-assembly into nanofiber morphologies and subsequent polymerization within the nanofibers. 87 The polymerization scheme using a nanofiber matrix is schematically shown in Figure 10. Polymerization of constituent polymerizable molecules in supramolecular assemblies resulted in stable covalent assemblies.…”

Section: Self-assembly and Subsequent Polymerization Of Bola-form Monmentioning

confidence: 99%

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Bottom-Up Synthesis and Morphological Control of High-Axial-Ratio Nanostructures through Molecular Self-Assembly

Shimizu

2003

Polym J

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ABSTRACT:Based on our recent results, the present paper overviews noncovalent formation of high-axial-ratio nanostructures (HARNs), such as fibers, rods, tubes and ropes, through molecular self-assembly of bola-form amphiphilic (bolaamphiphilic) monomers. A variety of bolaamphiphiles, in which sugars, peptides, or nucleobases as headgroups are connected to both ends of a hydrocarbon spacer, were newly designed and synthesized. Their self-assembling behavior was examined in aqueous solutions in terms of bottom-up fabrication of organic nanostructures. The morphologies proved to strongly depend on the headgroup structure, spacer chain lengths and even-odd carbon numbers of used oligo(methylene) spacers. Typical examples of self-assembled morphologies include nanofibers from 1-glucosamide-or thymidine-appended bolaamphiphiles, vesicle-encapsulated microtubes from glycylglycine-appended bolaamphiphiles, double-helical ropes from thymine-appended bolaamphiphiles. These self-assembled HARNs are constructed hierarchically in a manner similar to biological structures. On the basis of several solid-state analyses, molecular packing and orientation within the HARNs are discussed and compared with the single crystal structures in terms of hydrogen-bond networks. Furthermore, pH-dependent reversible polymer formation was achieved using the combination of glucuronamideand aromatic boronic acid-appended bola-form derivatives. Polymerization of bola-form 1-glucosamide derivatives with a 1,4-butadiyne group was performed in self-assembled nanometer-sized fibers, giving a single polydiacetylene chain of 64-mer that can be seen in TEM.KEY WORDS High-Axial-Ratio Nanostructure (HARN) / Bolaamphiphile / Self-Assembly / Noncovalent Synthesis / Hydrogen Bond / Nanofiber / Microtube / Nano-Rod / Rope / Hydrogel / Crystal Structure / Biomaterials possess highly organized non-covalent structures formed spontaneously in bottom-up fashion, 1 shaping natural body and functioning as energyconverting and information-converting materials. In contrast, conventional polymers are so-called linear macromolecules in which tens of thousands to millions of low-molecular-weight monomer units are connected to each other through covalent bonds. Very recently, a new family of polymers, including topologically complex polymers 2-13, 18-25 and self-assembled nanostructures, [14][15][16][17]26 has attracted much attention. 27,28 In particular, Kunitake and his co-worker built up the fundamental concept behind the polymolecular materials based on bilayer-containing molecular assemblies. 29,30 Stupp et al., 31, 32 Percec et al., 33 and Whitesides et al. 34,35 also succeeded in a molecule-up fabrication using polymer building blocks to realize nanometersized assemblies with well-defined shapes. The advantage of non-covalent self-assembly technique, unlike chemical reaction or polymerization, is in that it can directly produce ordered two-and three-dimensional structures like sheets, rods, fibers, tubes, disks, and spheres. It is more important that nanostruct...

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Section: Self-assembly and Subsequent Polymerization Of Bola-form Monmentioning

confidence: 66%

Section: Self-assembly and Subsequent Polymerization Of Bola-form Monmentioning

confidence: 99%

Bottom-Up Synthesis and Morphological Control of High-Axial-Ratio Nanostructures through Molecular Self-Assembly

Shimizu

2003

Polym J

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“…振动峰 [20] 以及聚合物中腺嘌呤上伯胺 N-H 变形振动峰 [21] . 谱线 c 中, 1724 和 1672 cm -1 分别为 5-氟尿嘧啶中 C(2)＝O 和 C(4)＝O 伸缩振动峰 [20] .…”

Section: 实验过程unclassified

Preparation and Properties of Amphiphilic Polymer Nanospheres Containing Aza-crown ether

Zhang¹,

Xie²,

Zhang³

et al. 2012

Acta Chim. Sinica

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An amphiphilic polymer containing adenine and aza-crown ethers, poly-{[N,N-bis(2-ethoxy)-1,10-diaza-18-crown-6][5-methylene-(1-adenine)]sophthaloyl ester} (PCASE), was synthesized. The SEM morphology observed indicates that the amphiphilic PCASE polymer self-organized into diameters of about 140～210 nm nanospheres in dilute aqueous solution after recognized with 5-fluorouracil spontaneously. The sizes of PCASE/5-flu nanospheres in dilute aqueous solution determined by dynamic light scattering (DLS) are mainly dispersed at 120～230 nm. The molecule recognition based on hydrogen bond between adenine of polymer and 5-fluorouracil substrate in PCASE/5-flu nanospheres was studied. After recognition the C(2)＝O stretching vibration at 1724 cm -1 of 5-fluorouracil subtract shifted to 1718 cm -1 , the NH 2 stretching vibration at 3324 cm -1 disappeared, and a new peak at 3432 cm -1 arised, indicating the formation of hydrogen bonds between 5-fluorouracil and adenine in polymer PCASE． The study on variable temperature FTIR show that the peak 1718 cm -1 gradually shifted back to the position at 1724 cm -1 , and the new peak 3432 cm -1 disappeared finally, indicating that the H-bond was broken.

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“…[10][11][12][13][14][15][16] We recently described a complementary strategy to obtain well-defined, hierarchically structured p-conjugated polymers that was based on the self-assembly and topochemical polymerization of the diacetylene macromonomers 1 (see below). [17][18][19][20] Related attempts to extend the scope of the UV-induced topochemical diacetylene polymerization from single crystals [21,22] or crystalline mono-and multilayers [23][24][25][26][27] toward less geometrically constrained systems such as vesicles and other types of colloidal structures [28][29][30][31][32][33] or fibrillar aggregates in organogels [34][35][36][37][38][39][40] have been spurred by the prospect of potential applications, for example, in biosensing.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Diacetylene‐Containing Peptide Building Blocks and Amphiphiles, Their Self‐Assembly and Topochemical Polymerization in Organic Solvents

Jahnke

Weiss

Neuhaus

et al. 2008

Chemistry A European J

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A series of functional iodoacetylenes was prepared and converted into the corresponding diacetylene-substituted amino acids and peptides via Pd/Cu-promoted sp-sp carbon cross-coupling reactions. The unsymmetrically substituted diacetylenes can be incorporated into oligopeptides without a change in the oligopeptide strand's directionality. Thus, a series of oligopeptide-based, amphiphilic diacetylene model compounds was synthesized, and their self-organization as well as their UV-induced topochemical polymerizability was investigated in comparison to related polymer-substituted macromonomers. Solution-phase IR spectroscopy, gelation experiments, and UV spectroscopy helped to confirm that a minimum of five N-H...O=C hydrogen-bonding sites was required in order to obtain reliable aggregation into stable beta-sheet-type secondary structures in organic solvents. Furthermore, the non-equidistant spacing of these hydrogen-bonding sites was proven to invariably lead to beta-sheets with a parallel beta-strand orientation, and the characteristic IR-spectroscopic signatures of the latter in organic solution was identified. Scanning force micrographs of the organogels revealed that compounds with six hydrogen-bonding sites gave rise to high aspect ratio nanoscopic fibrils with helical superstructures but, in contrast to the related macromonomers, did not lead to uniform supramolecular polymers. The UV-induced topochemical polymerization within the beta-sheet aggregates was successful, proving parallel beta-strand orientation and highlighting the effect of the number and pattern of N-H...O=C hydrogen-bonding sites as well as the hydrophobic residue in the molecular structure on the formation of higher structures and reactivity.

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Polymerization in Nanometer-Sized Fibers: Molecular Packing Order and Polymerizability

Cited by 76 publications

References 24 publications

Bottom-Up Synthesis and Morphological Control of High-Axial-Ratio Nanostructures through Molecular Self-Assembly

Bottom-Up Synthesis and Morphological Control of High-Axial-Ratio Nanostructures through Molecular Self-Assembly

Preparation and Properties of Amphiphilic Polymer Nanospheres Containing Aza-crown ether

Synthesis of Diacetylene‐Containing Peptide Building Blocks and Amphiphiles, Their Self‐Assembly and Topochemical Polymerization in Organic Solvents

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