共查询到20条相似文献,搜索用时 46 毫秒
1.
Emulsion‐Assisted Polymerization‐Induced Hierarchical Self‐Assembly of Giant Sea Urchin‐like Aggregates on a Large Scale 下载免费PDF全文
Dr. Qingsong Xu Tong Huang Shanlong Li Ke Li Chuanlong Li Yannan Liu Yuling Wang Chunyang Yu Prof. Dr. Yongfeng Zhou 《Angewandte Chemie (International ed. in English)》2018,57(27):8043-8047
Hierarchical solution self‐assembly has become an important biomimetic method to prepare highly complex and multifunctional supramolecular structures. However, despite great progress, it is still highly challenging to prepare hierarchical self‐assemblies on a large scale because the self‐assembly processes are generally performed at high dilution. Now, an emulsion‐assisted polymerization‐induced self‐assembly (EAPISA) method with the advantages of in situ self‐assembly, scalable preparation, and facile functionalization was used to prepare hierarchical multiscale sea urchin‐like aggregates (SUAs). The obtained SUAs from amphiphilic alternating copolymers have a micrometer‐sized rattan ball‐like capsule (RBC) acting as the hollow core body and radiating nanotubes tens of micrometers in length as the hollow spines. They can capture model proteins effectively at an ultra‐low concentration (ca. 10 nm ) after functionalization with amino groups through click copolymerization. 相似文献
2.
Optoelectronic and Self‐assembly Properties of Porphyrin Derivatives with Click Chemistry Modification 下载免费PDF全文
Liang Pengxia Zhengcai Du Dr. Dong Wang Prof. Dr. Zhou Yang Huiyun Sheng Shuqiong Liang Hui Cao Wanli He Prof. Dr. Huai Yang 《Chemphyschem》2014,15(16):3523-3529
A series of functionalized porphyrin molecules containing electron‐rich alkynes, synthesized by means of the Sonogashira coupling reaction were further modified by reacting the ethynyl groups with click reagent through a formal [2+2] click reaction. The photophysical and electrochemical properties of the porphyrin derivatives were studied by UV/Vis spectroscopy and cyclic voltammetry. We show that the optoelectronic properties are affected by the click reagent groups and central metal ions. The functionalized porphyrin molecules show strong charge‐transfer (CT) bands in the visible region (near‐IR region) and potent redox activities. Through a phase‐exchange self‐assembly method, the highly organized morphologies were observed by scanning electron microscopy (SEM). The functionalized porphyrin molecules represent an interesting set of candidates for optoelectronic device components. The effect of the metal ions or click reagent groups on the self‐assembly properties were also studied by the UV/Vis spectroscopic titration experiments. 相似文献
3.
Ferrocene was covalently bonded to a layer of adsorbed single‐walled carbon nanotubes on a glassy carbon electrode surface using electrochemical grafting and click chemistry. Grafting of the 4‐azidobenzenediazonium salt onto the surface was accomplished by electrochemical reduction. The surface‐bound azide groups, with the use of a copper(I) catalyst, were reacted with ethynylferrocene to form covalent 1,2,3‐triazole bonds by click chemistry. This layer by layer construction of the electrode surface results in stable electrodes by combining good electrical conductivity and increased surface area of the nanotubes with the versatility of the Sharpless click reaction. 相似文献
4.
Self‐Assembly of Achiral Shape Amphiphiles into Multi‐Walled Nanotubes via Helicity‐Selective Nucleation and Growth 下载免费PDF全文
Li‐Jun Ren Dr. Han Wu Dr. Min‐Biao Hu Dr. Yu‐Han Wei Dr. Yue Lin Prof. Wei Wang 《化学:亚洲杂志》2018,13(7):775-779
Soft nanotubes are normally constructed from chiral amphiphiles through helical self‐assembly. Yet, how to self‐assemble achiral molecules into nanotubes is still a challenge. Here, we report the nanotube construction with achiral shape amphiphiles through helical self‐assembly and also unravel the formation mechanisms. The amphiphiles have a dumbbell shape and are composed by covalently linking three achiral moieties together: two unlike clusters and an organic tether. The difference in polarity between the unlike clusters drives the amphiphiles to self‐assemble into single‐ and multi‐walled nanotubes as well as intermediates. Analysis of the key intermediates unravels the self‐assembly mechanism of helicity‐selective nucleation and growth. Meanwhile, direct visualization of the individual clusters in the ribbons displays a two‐dimensional deformed hexagonal lattice. Thus, we speculate that it is the lattice deformation that creates anisotropic tension along different directions of the ribbon which further results in the formation of helical ribbons towards nanotubes by amphiphiles. 相似文献
5.
Dr. Joanna M. Malicka Anjamkudy Sandeep Dr. Filippo Monti Dr. Elisa Bandini Dr. Massimo Gazzano Dr. Choorikkat Ranjith Dr. Vakayil K. Praveen Prof. Dr. Ayyappanpillai Ajayaghosh Dr. Nicola Armaroli 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(39):12991-13001
A squaraine dye functionalized with a bulky trialkoxy phenyl moiety through a flexible diamide linkage ( GA‐SQ ) capable of undergoing self‐assembly has been synthesized and fully characterized. Rapid cooling of a hot solution of GA‐SQ to 0 °C results in self‐assembled precipitates consisting of two types of nanostructures, rings and ill‐defined short fibers. The application of ultrasound modifies the conditions for the supersaturation‐mediated nucleation, generating only one kind of nuclei and prompting the formation of crystalline fibrous structures, inducing gelation of solvent molecules. The unique self‐assembling behavior of GA‐SQ under ultrasound stimulus has been investigated in detail by using absorption, emission, FT‐IR, XRD, SEM, AFM and TEM techniques. These studies reveal a nucleation growth mechanism of the self‐assembled material, an aspect rarely scrutinized in the area of sonication‐induced gelation. Furthermore, in order to probe the effects of nanoscale substrates on the sonication‐induced self‐assembly, a minuscule amount of single‐walled carbon nanotubes was added, which leads to acceleration of the self‐assembly through a heterogeneous nucleation process that ultimately affords a supramolecular gel with nanotape‐like morphology. This study demonstrates that self‐assembly of functional dyes can be judiciously manipulated by an external stimulus and can be further controlled by the addition of carbon nanotubes. 相似文献
6.
Herein, the relationship between the supramolecularly self‐assembled nanostructures and the chemical structures of coil‐rod‐coil molecules is discussed. A series of nonamphiphilic coil‐rod‐coil molecules with different alkyl chains, central mesogenic groups, and chemical linkers were designed and synthesized. The solvent‐mediated supramolecular self‐assembling of these coil‐rod‐coil molecules resulted in rolled‐up nanotubes, nanofibers, submicron sized belts, needle‐like microcrystals, and amorphous structures. The self‐assembling behaviors of these coil‐rod‐coil molecules have been systematically investigated to reveal the relationship between the supramolecularly self‐assembled nanostructures and their chemical structures. With respect to the formation of rolled‐up nanotubes by self‐assembly of coil‐rod‐coil molecules, we have systematically investigated the following three influencing structural factors: 1) the alkyl chain length; 2) the central mesogenic group; (3) the linker type. These studies disclosed the key structural features of coil‐rod‐coil molecules for the formation of rolled‐up nanotubes. 相似文献
7.
Robert Chapman Prof. Gregory G. Warr Prof. Sébastien Perrier Prof. Dr. Katrina A. Jolliffe 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(6):1955-1961
Water‐soluble organic nanotubes were prepared by convergently conjugating polymers of hydroxyethyl acrylate (HEA) and acrylic acid (AA) to self‐assembling cyclic octapeptides of alternating D and L chirality. The structure of the self‐assembled tubes was characterised in a number of polar solvents, and notably water, by using light scattering, TEM and small angle neutron scattering (SANS) techniques. In addition, the self‐assembly into tubes could be controlled by exploiting the pH responsiveness of acrylic acid polymers. 相似文献
8.
Derrick A. Roberts Prof. Timothy W. Schmidt Prof. Maxwell J. Crossley Prof. Sébastien Perrier 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(38):12759-12770
The convergence of supramolecular chemistry and polymer science offers many powerful approaches for building functional nanostructures with well‐defined dynamic behaviour. Herein we report the efficient “click” synthesis and self‐assembly of AB2‐ and AB4‐type multitopic porphyrin–polymer conjugates (PPCs). PPCs were prepared using the copper(I)‐catalysed azide–alkyne cycloaddition (CuAAC) reaction, and consisted of linear polystyrene, poly(butyl acrylate), or poly(tert‐butyl acrylate) arms attached to a zinc(II) porphyrin core via triazole linkages. We exploit the presence of the triazole groups obtained from CuAAC coupling to direct the self‐assembly of the PPCs into short oligomers (2–6 units in length) via intermolecular porphyrinatozinc–triazole coordination. By altering the length and grafting density of the polymer arms, we demonstrate that the association constant of the porphyrinatozinc–triazole complex can be systematically tuned over two orders of magnitude. Self‐assembly of the PPCs also resulted in a 6 K increase in the glass transition temperature of the bulk material compared to a non‐assembling PPC. The modular synthesis and tunable self‐assembly of the triazole‐linked PPCs thus represents a powerful supramolecular platform for building functional nanostructured materials. 相似文献
9.
Ning Xu Rui Wang Fu‐Sheng Du Zi‐Chen Li 《Journal of polymer science. Part A, Polymer chemistry》2009,47(14):3583-3594
Amphiphilic, biodegradable block glycopolymers based on poly(ε‐caprolactone) (PCL) with various pendent saccharides were synthesized by combination of ring‐opening polymerization (ROP) and “click” chemistry. PCL macroinitiators obtained by ROP of ε‐caprolactone were used to initiate the ROP of 2‐bromo‐ε‐caprolactone (BrCL) to get diblock copolymers, PCL‐b‐PBrCL. Reaction of the block copolymers with sodium azide converted the bromine groups in the PBrCL block to azide groups. In the final step, click chemistry of alkynyl saccharides with the pendent azide groups of PCL‐b‐PBrCL led to the formation of the amphiphilic block glycopolymers. These copolymers were characterized by 1H NMR spectroscopy and gel permeation chromatography. The self‐assembly behavior of the amphiphilic block copolymers was investigated using transmission electron microscopy and atomic force microscope, spherical aggregates with saccharide groups on the surface were observed, and the aggregates could bind reversibly with Concanavalin A. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3583–3594, 2009 相似文献
10.
Folding Construction of a Pentacyclic Quadruply fused Polymer Topology with Tailored kyklo‐Telechelic Precursors 下载免费PDF全文
Hiroyuki Heguri Dr. Takuya Yamamoto Prof. Yasuyuki Tezuka 《Angewandte Chemie (International ed. in English)》2015,54(30):8688-8692
A pentacyclic quadruply fused polymer topology has been constructed for the first time through alkyne–azide addition (click) and olefin metathesis (clip) reactions in conjunction with an electrostatic self‐assembly and covalent fixation (ESA‐CF) process. Thus, a spiro‐type, tandem tetracyclic poly(tetrahydrofuran), poly(THF), precursor having two allyloxy groups at the opposite positions of the four ring units was prepared by the click‐linking of one unit of an eight‐shaped precursor having alkyne groups at the opposite positions with two units of a single‐cyclic counterpart having an azide and an alkene group at the opposite positions. Both are obtainable through ESA‐CF. The subsequent metathesis clip‐folding of the tetracyclic precursor could afford a pentacyclic quadruply fused polymer product, of “shippo” form, in 19 % yield. 相似文献
11.
Ning Ren Xiao‐Jun Huang Xu Huang Yue‐Cheng Qian Cang Wang Zhi‐Kang Xu 《Journal of polymer science. Part A, Polymer chemistry》2012,50(15):3149-3157
We describe a versatile approach to synthesize glycosylated polyphosphazenes with controllable density of glycosyl groups. These glycopolymers have been synthesized by the nucleophilic substitution of poly(dichlorophosphazene) with propargylamine and subsequent “thiol–yne” click reaction between poly[di(propargylamine)phosphazene] and 2,3,4,6‐tetra‐O‐acetyl‐1‐thio‐β‐D ‐glucopyranose (SH‐GlcAc4). The polymers were characterized with FTIR and 1H NMR. We found that the high steric hindrance of SH‐GlcAc4 plays a key role in the overall reaction process, and ~55% of the alkyne groups participate in the “thiol–yne” click reaction. About 8% of the alkyne groups convert to alkene groups at the end of click reaction. The substitution of alkyne/alkane mixture was conducted to reduce the alkyne density in the side groups of polyphosphazenes and minimize the influences of this steric effect. Mixed‐substituent polyphosphazene was synthesized with 2:3 ratio of alkyne and alkane. In this case, almost no alkyne group remains after the “thiol–yne” click reaction, and thus the glycosylated polyphosphazene is able to form into micelles through self‐assembly process. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
12.
Wenwen Qu Hongwei Tan Guangju Chen Ruozhuang Liu 《International journal of quantum chemistry》2010,110(9):1648-1659
Cyclic D,L ‐α‐peptides are able to self‐assemble to nanotubes, although the inherent reason of the stability of this kind of nanotube as well as the intrinsic driving force of self‐assembly of the cyclic D ,L ‐α‐peptides still remain elusive. In this work, using several computational approaches, we investigated the structural and energy characteristics of a series of cyclo[(‐L ‐Phe‐D ‐Ala‐)4] and cyclo[(‐L ‐Ala‐D ‐Ala‐)4] oligomers. The results reveal that the thermodynamic stability, cooperativity, and self‐assembly patterns of cyclic D ,L ‐α‐peptide nanotubes are mainly determined by the interactions between cross‐strand side chains instead of those between backbones. For cyclo[(‐L ‐Phe‐D ‐Ala‐)4] oligomers, the steric interaction between cross‐strand side chains, especially the electrostatic repulsion between the phenyls in Phe residues, brings anticooperative effect into parallel stacking mode, which is responsible for the preference of self‐assembling nanotube in antiparallel vs. parallel stacking orientation. Based on our results, a novel self‐assembling mechanism is put forward—it is the L ‐L antiparallel dimer of cyclo[(‐L ‐Phe‐D ‐Ala‐)4], instead of the commonly presumed monomer, that acts as the basic building block in self assembly. It explains why these cyclic peptides uniquely self‐assemble to form antiparallel nanotubes. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 相似文献
13.
Michael J. Strauss Darya Asheghali Austin M. Evans Rebecca L. Li Anton D. Chavez Chao Sun Matthew L. Becker William R. Dichtel 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(41):14850-14856
Nanotubes assembled from macrocyclic precursors offer a unique combination of low dimensionality, structural rigidity, and distinct interior and exterior microenvironments. Usually the weak stacking energies of macrocycles limit the length and mechanical strength of the resultant nanotubes. Imine‐linked macrocycles were recently found to assemble into high‐aspect ratio (>103), lyotropic nanotubes in the presence of excess acid. Yet these harsh conditions are incompatible with many functional groups and processing methods, and lower acid loadings instead catalyze macrocycle degradation. Here we report pyridine‐2,6‐diimine‐linked macrocycles that assemble into high‐aspect ratio nanotubes in the presence of less than 1 equiv of CF3CO2H per macrocycle. Analysis by gel permeation chromatography and fluorescence spectroscopy revealed a cooperative self‐assembly mechanism. The low acid concentrations needed to induce assembly enabled nanofibers to be obtained by touch‐spinning, which exhibit higher Young's moduli (1.33 GPa) than many synthetic polymers and biological filaments. These findings represent a breakthrough in the design of inverse chromonic liquid crystals, as assembly under such mild conditions will enable the design of structurally diverse and mechanically robust nanotubes from synthetically accessible macrocycles. 相似文献
14.
Petra M. Erne Laura S. vanBezouwen Peter tacko Derk Jan vanDijken Jiawen Chen Marc C. A. Stuart Egbert J. Boekema Ben L. Feringa 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(50):15337-15342
The facile assembly of higher‐order nanoarchitectures from simple building blocks is demonstrated by the loading of vesicles into soft amphiphilic nanotubes using osmosis. The nanotubes are constructed from rigid interdigitated bilayers which are capped with vesicles comprising phospholipid‐based flexible bilayers. When a hyperosmotic gradient is applied to these vesicle‐capped nanotubes, the closed system loses water and the more flexible vesicle bilayer is pulled inwards. This leads to inclusion of vesicles inside the nanotubes without affecting the tube structure, showing controlled reorganization of the self‐assembled multicomponent system upon a simple osmotic stimulus. 相似文献
15.
Self‐assembly regulated by hydrogen bonds was successfully achieved in the system of lithocholic acid (LCA) mixed with three organic amines, ethanolamine (EA), diethanolamine (DEA), and triethanolamine (TEA), in aqueous solutions. The mixtures of DEA/LCA exhibit supergelation capability and the hydrogels consist of plenty of network nanotubes with uniform diameters of about 60 nm determined by cryogenic TEM. Interestingly, the sample with the same concentration in a system of EA and LCA is a birefringent solution, in which spherical vesicles and can be transformed into nanotubes as the amount of LCA increases. The formation of hydrogels could be driven by the delicate balance of diverse noncovalent interactions, including electrostatic interactions, hydrophobic interactions, steric effects, van der Waals forces, and mainly hydrogen bonds. The mechanism of self‐assembly from spherical bilayer vesicles into nanotubes was proposed. The dried hydrogels with nanotubes were explored to exhibit the excellent capability for capturing heavy‐metal ions, for example, Cu2+, Co2+, Ni2+, Pb2+, and Hg2+. The superhydrogels of nanotubes from the self‐assembly of low‐molecular‐weight gelators mainly regulated by hydrogen bonds used for the removal of heavy‐metal ions is simple, green, and high efficiency, and provide a strategic approach to removing heavy‐metal ions from industrial sewage. 相似文献
16.
Dr. Partha S. Ghosh Prof. Dr. Andrew D. Hamilton 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(8):2361-2365
We report here the noncovalent synthesis of thermosensitive dendrimers. Short oligoguanosine strands were linked to the focal point of a dendron by using “click chemistry”, and quadruplex formation was used to drive the self‐assembly process in the presence of metal ions. The dynamic nature of these noncovalent assemblies can be exploited to create combinatorial libraries of dendrimers as demonstrated by the co‐assembly of two components. These supramolecular dendrimers showed thermoresponsive behavior that can be tuned by varying the templating cations or the number of guanines in the oligonucleotide strand. 相似文献
17.
Dr. Elise Villemin Dr. Edmond Gravel Dr. Nicolas Izard Dr. Arianna Filoramo Dr. Laurent Vivien Dr. Eric Doris 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(51):18649-18653
A biosensor taking advantage of the optical properties of sorted carbon nanotubes has been developed. A polyfluorene polymer bearing azido groups was synthesized and used for the selective extraction of semi‐conducting nanotubes from the bulk population. The resulting polymer‐decorated nanotubes were then conjugated by click‐chemistry to a ligand unit (biotin), and the sensing properties of the biotinylated nanotubes were investigated by photoluminescence measurements, upon interaction with the streptavidin target. 相似文献
18.
A Carbon Nanotube Confinement Strategy to Implement Homogeneous Asymmetric Catalysis in the Solid Phase 下载免费PDF全文
Kazuki Hashimoto Dr. Naoya Kumagai Prof. Dr. Masakatsu Shibasaki 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(11):4262-4266
A readily recyclable asymmetric catalyst has been developed based on the self‐assembly of a homogeneous catalyst in a fibrous network of multiwalled carbon nanotubes (MWNTs). Dimerization of an amide‐based chiral ligand with a suitable spacer allows for the efficient formation of a heterogeneous catalyst by self‐assembly on addition of Er(OiPr)3. The self‐assembly proceeds in the MWNT fibrous network and small clusters of assembled catalyst are confined in the MWNTs, producing an easily handled solid‐phase catalyst. The resulting MWNT‐confined catalyst exhibits a good catalytic performance in a catalytic asymmetric Mannich‐type reaction, which can be conducted in a repeated batch system and in a continuous‐flow platform. 相似文献
19.
Wei‐Dong Zhang Hong‐Mei Xiao Lu‐Ping Zhu Shao‐Yun Fu Mei‐Xiang Wan 《Journal of polymer science. Part A, Polymer chemistry》2010,48(2):320-326
This article reports a simple self‐assembly process for facile one‐step synthesis of novel electromagnetic functionalized polypyrrole (PPy)/Fe3O4 composite nanotubes using p‐toluenesulfonic acid (p‐TSA) as the dopant and FeCl3 as the oxidant. The key trick of the present method is to use FeCl3 as the oxidant for both PPy and Fe3O4 in the same time to synthesize PPy/Fe3O4 composite nanotubes in one‐step. This facile one‐step method is much simpler than the conventional approach using the Fe3O4 nanoparticles as the additives. Compared to the similar composites synthesized using the conventional method, the as‐prepared PPy‐p‐TSA/Fe3O4 composite nanotubes using the facile one‐step self‐assembly process show much higher room‐temperature conductivity. Moreover, the composite nanotubes display interesting ferromagnetic behavior. The electrical properties of the PPy‐p‐TSA/Fe3O4 composite nanotubes are dominated by the amount of FeCl3 while their magnetic properties are controlled by the amount of FeCl2. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 320–326, 2010 相似文献
20.
Dr. Ming Liang Koh Dr. Paul A. FitzGerald Prof. Gregory G. Warr Prof. Katrina A. Jolliffe Prof. Sébastien Perrier 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(51):18419-18428
We present a fundamental study into the self‐assembly of (cyclic peptide)–polymer conjugates as a versatile supramolecular motif to engineer nanotubes with defined structure and dimensions, as characterised in solution using small‐angle neutron scattering (SANS). This work demonstrates the ability of the grafted polymer to stabilise and/or promote the formation of unaggregated nanotubes by the direct comparison to the unconjugated cyclic peptide precursor. This ideal case permitted a further study into the growth mechanism of self‐assembling cyclic peptides, allowing an estimation of the cooperativity. Furthermore, we show the dependency of the nanostructure on the polymer and peptide chemical functionality in solvent mixtures that vary in the ability to compete with the intermolecular associations between cyclic peptides and ability to solvate the polymer shell. 相似文献