共查询到20条相似文献,搜索用时 31 毫秒
1.
Xianbao Li Qi Li Jinbo Fei Yi Jia Huimin Xue Jie Zhao Junbai Li 《Angewandte Chemie (International ed. in English)》2020,59(29):11932-11936
Constructing supramolecular materials with tunable properties and functions is a great challenge due to the complex competition between multiple assembly pathways. Herein, we report that dipeptides can self‐assemble into aerogels with entirely different surface wettability through precisely controlling the assembly pathways. Charged groups or aromatic residues are selectively exposed on the surface of their nanoscale building blocks which results either in a superhydrophilic or highly hydrophobic surface. With this special property, single component dipeptide aerogels can play diverse roles in medical care applications. This study suggests great promise in the synthesis of supramolecular materials with different targeted functions from the same molecular unit. 相似文献
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Dr. Daniel Spitzer Dr. Vincent Marichez Georges J. M. Formon Prof. Dr. Pol Besenius Prof. Dr. Thomas M. Hermans 《Angewandte Chemie (International ed. in English)》2018,57(35):11349-11353
Controlling supramolecular growth at solid surfaces is of great importance to expand the scope of supramolecular materials. A dendritic benzene‐1,3,5‐tricarboxamide peptide conjugate is described in which assembly can be triggered by a pH jump. Stopped‐flow kinetics and mathematical modeling provide a quantitative understanding of the nucleation, elongation, and fragmentation behavior in solution. To assemble the molecule at a solid–liquid interface, we use proton diffusion from the bulk. The latter needs to be slower than the lag phase of nucleation to progressively grow a hydrogel outwards from the surface. Our method of surface‐assisted self‐assembly is generally applicable to other gelators, and can be used to create structured supramolecular materials. 相似文献
3.
Yuxing Xia Chao Gao Weiwei Gao 《Journal of polymer science. Part A, Polymer chemistry》2022,60(15):2239-2261
Graphene aerogels with unique properties, such as ultralow density, super-elasticity, high specific surface area, and excellent thermal stability, have undergone great progress in the past decades. Especially, super-elastic graphene aerogels provide a highly attention-catching platform for developing advanced energy devices, pressure sensors, contaminates adsorbents, and electromagnetic wave shielding and absorption materials, and so forth. In this review, we begin with the introduction and discussion of various fabrication techniques and compare their advantages and disadvantages, focusing on the template-free assembly process and template-assisted assembly process. Then, we summarize the factors influencing the compressibility and elasticity of graphene aerogels, including intrinsic properties of building blocks, constituent materials, and structure design, and their wide applications. At the end, we discuss the current challenges and future prospects of this field. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(36):11045-11050
Aerogel structures have attracted increasing research interest in energy storage and conversion owing to their unique structural features, and a variety of materials have been engineered into aerogels, including carbon‐based materials, metal oxides, linear polymers and even metal chalcogenides. However, manufacture of aerogels from nitride‐based materials, particularly the emerging light‐weight carbon nitride (CN) semiconductors is rarely reported. Here, we develop a facile method based on self‐assembly to produce self‐supported CN aerogels, without using any cross‐linking agents. The combination of large surface area, incorporated functional groups and three‐dimensional (3D) network structure, endows the resulting freestanding aerogels with high photocatalytic activity for hydrogen evolution and H2O2 production under visible light irradiation. This work presents a simple colloid chemistry strategy to construct 3D CN aerogel networks that shows great potential for solar‐to‐chemical energy conversion by artificial photosynthesis. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(40):12342-12346
The design and fabrication of quantum dots (QDs) with circularly polarized luminescence (CPL) has been a great challenge in developing chiroptical materials. We herein propose an alternative to the use of chiral capping reagents on QDs for the fabrication of CPL‐active QDs that is based on the supramolecular self‐assembly of achiral QDs with chiral gelators. Full‐color‐tunable CPL‐active QDs were obtained by simple mixing or gelation of a chiral gelator and achiral 3‐mercaptopropionic acid capped QDs. In addition, the handedness of the CPL can be controlled by the supramolecular chirality of the gels. Moreover, QDs with circularly polarized white light emission were fabricated for the first time by tuning the blending ratio of colorful QDs in the gel. The chirality transfer in the co‐assembly of the achiral QDs with the gelator and the spacer effect of the capping reagents on the QD surface are also discussed. This work provides new insight into the design of functional chiroptical materials. 相似文献
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Photochemical Reactions in Self‐Assembled Organic Monolayers Characterized by using Scanning Tunneling Microscopy
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Research on the supramolecular self‐assembly behavior at interfaces is of great importance to improving the performance of nanodevices that are based on optical functional materials. In this Minireview, several photoinduced isomerization and polymerization reactions in self‐assembled organic monolayers on surfaces are discussed. Typical organic molecules contain azobenzene, alkynyl, or olefins groups. The feature surface base is a highly oriented pyrolytic graphite (HOPG) surface or a gold surface. Scanning tunneling microscopy (STM) is used as a strong tool to characterize new species’ structures before and after illumination. 相似文献
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Felix Rechberger Florian J. Heiligtag Martin J. Süess Prof. Dr. Markus Niederberger 《Angewandte Chemie (International ed. in English)》2014,53(26):6823-6826
Aerogels with their low density and high surface area are fascinating materials. However, their advantageous morphology is still far from being fully exploited owing to their limited compositional variety and low crystallinity. Replacing the sol–gel process by a particle‐based assembly route is a powerful alternative to expand the accessible functionalities of aerogels. A strategy is presented for the controlled destabilization of concentrated dispersions of BaTiO3 nanoparticles, resulting in the assembly of the fully crystalline building blocks into cylindrically shaped monolithic gels, thereby combining the inherent properties of ternary oxides with the highly porous microstructure of aerogels. The obtained aerogels showed an unprecedentedly high surface area of over 300 m2 g?1. 相似文献
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Shuanggen Wu Changyong Cai Fenfang Li Zhijian Tan Shengyi Dong 《Angewandte Chemie (International ed. in English)》2020,59(29):11871-11875
Application of new strategies for supramolecular self‐assembly can significantly impact the properties and/or functions of supramolecular polymers. To realize a facial strategy for the development of solvent‐free supramolecular polymers in bulk, “deep eutectic solvents” were employed. Cyclodextrins and natural acids were used to prepare deep eutectic supramolecular polymers ( DESP s). Deep eutectic solvents have special characteristics that endow DESP s with unique macroscopic properties and excellent processability. DESP s exhibit supramolecular adhesion and temperature‐dependent behavior originating from the combined effects of deep eutectic solvents and supramolecular polymerization. Because DESP s are solvent‐free and display interesting macroscopic properties, they have potential as new adaptive materials. 相似文献
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An Elaborate Supramolecular Assembly for a Smart Nanodevice for Ratiometric Molecular Recognition and Logic Gates
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Yu‐Jie Xie Wen‐Yu Wu Hao Chen Xiang Li Prof. Hao‐Li Zhang Liang‐Liang Liu Xing‐Xin Shao Chang‐Fu Shan Prof. Wei‐Sheng Liu Prof. Yu Tang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(24):8339-8345
Ingenious approaches to supramolecular assembly for fabricating smart nanodevices is one of the more significant topics in nanomaterials research. Herein, by using surface quaternized cationic carbon dots (CDots) as the assembly and fluorescence platform, anionic sulfonatocalix[4]arene with modifiable lower and upper rims as a connector, as well as in situ coordination of Tb3+ ions, we propose an elaborate supramolecular assembly strategy for the facile fabrication of a multifunctional nanodevice. The dynamic equilibrium characteristics of the supramolecular interaction can eventually endow this nanodevice with functions of fluorescent ratiometric molecular recognition and as a nano‐logic gate with two output channels. 相似文献
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Huang Y Hu J Kuang W Wei Z Faul CF 《Chemical communications (Cambridge, England)》2011,47(19):5554-5556
Here we show that it is possible to modulate the supramolecular assembly of designed H-bonding amphiphilic perylene-based materials through simple solvent interactions. These modulated supramolecular interactions have been translated to and observed in macroscopic properties, and provide new pathways to the preparation of switchable interfaces based on designed supramolecular interactions. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(35):10598-10602
Structural colors have profound implications in the fields of pigments, displays and sensors, but none of the current non‐iridescent photonic materials can restore their functions after mechanical damage. Herein, we report the first self‐healable organogel nanocomposites with angle‐independent structural colors. The organogel nanocomposites were prepared through the co‐assembly of oleophilic silica nanoparticles, silicone‐based supramolecular gels, and carbon black. The organogel system enables amorphous aggregation of silica nanoparticles and the angle‐independent structural colors in the nanocomposites. Moreover, the hydrogen bonding in the supramolecular gel provides self‐healing ability to the system, and the structural colored films obtained could heal themselves in tens of seconds to restore storage modulus, structural color, and surface slipperiness from mechanical cuts or shear failure repeatedly. 相似文献
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Dr. Mengjiao Cheng Prof. Feng Shi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(68):15763-15778
Macroscopic supramolecular assembly (MSA) is a new concept in supramolecular science with a focus on interfacial assembly of macroscopic building blocks, which has largely extended the applicable materials of supramolecular assembly and provided new solutions to fabricating tissue scaffolds, soft devices, etc. The precision of the assembled structures is of great interest; unlike molecular assemblies, MSA precision is highly dependent on the matching degree of assembled surfaces because of the large interactive area and group number, which result in remarkably increased kinetic possibilities and metastable assemblies. This Concept introduces the principle, history, and development of MSA, elaborates the low-precision challenge in MSA, summarizes the strategies for precise MSA based on the different thermodynamic stability of precise/imprecise structures and control over assembly kinetics, and finally demonstrates the applications of precise MSA structures in advanced manufacture such as tissue scaffolds. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(24):6932-6936
The properties of supramolecular materials are dictated by both kinetic and thermodynamic aspects, providing opportunities to dynamically regulate morphology and function. Herein, we demonstrate time‐dependent regulation of supramolecular self‐assembly by connected, kinetically competing enzymatic reactions. Starting from Fmoc‐tyrosine phosphate and phenylalanine amide in the presence of an amidase and phosphatase, four distinct self‐assembling molecules may be formed which each give rise to distinct morphologies (spheres, fibers, tubes/tapes and sheets). By varying the sequence or ratio in which the enzymes are added to mixtures of precursors, these structures can be (transiently) accessed and interconverted. The approach provides insights into dynamic self‐assembly using competing pathways that may aid the design of soft nanostructures with tunable dynamic properties and life times. 相似文献
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Dr. Cécile Vigier‐Carrière Dr. Fouzia Boulmedais Prof. Pierre Schaaf Dr. Loïc Jierry 《Angewandte Chemie (International ed. in English)》2018,57(6):1448-1456
Localized molecular self‐assembly processes leading to the growth of nanostructures exclusively from the surface of a material is one of the great challenges in surface chemistry. In the last decade, several works have been reported on the ability of modified or unmodified surfaces to manage the self‐assembly of low‐molecular‐weight hydrogelators (LMWH) resulting in localized supramolecular hydrogel coatings mainly based on nanofiber architectures. This Minireview highlights all strategies that have emerged recently to initiate and localize LMWH supramolecular hydrogel formation, their related fundamental issues and applications. 相似文献
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Precise Macroscopic Supramolecular Assembly by Combining Spontaneous Locomotion Driven by the Marangoni Effect and Molecular Recognition
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Meng Xiao Yiming Xian Prof. Dr. Feng Shi 《Angewandte Chemie (International ed. in English)》2015,54(31):8952-8956
Macroscopic supramolecular assembly bridges fundamental research on molecular recognition and the potential applications as bulk supramolecular materials. However, challenges remain to realize stable precise assembly, which is significant for further functions. To handle this issue, the Marangoni effect is applied to achieve spontaneous locomotion of macroscopic building blocks to reach interactive distance, thus contributing to formation of ordered structures. By increasing the density of the building blocks, the driving force for assembly transforms from a hydrophobic–hydrophobic interaction to hydrophilic–hydrophilic interaction, which is favorable for introducing hydrophilic coatings with supramolecular interactive groups on matched surfaces, consequently realizing the fabrication of stable precise macroscopic supramolecular assemblies. 相似文献
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Ultralow-density nanostructured metal foams: combustion synthesis, morphology, and composition 总被引:1,自引:0,他引:1
Tappan BC Huynh MH Hiskey MA Chavez DE Luther EP Mang JT Son SF 《Journal of the American Chemical Society》2006,128(20):6589-6594
The synthesis of low-density, nanoporous materials has been an active area of study in chemistry and materials science dating back to the initial synthesis of aerogels. These materials, however, are most often limited to metal oxides, e.g., silica and alumina, and organic aerogels, e.g., resorcinol/formaldehyde, or carbon aerogels, produced from the pyrolysis of organic aerogels. The ability to form monolithic metallic nanocellular porous materials is difficult and sometimes elusive using conventional methodology. Here we report a relatively simple method to access unprecedented ultralow-density, nanostructured, monolithic, transition-metal foams, utilizing self-propagating combustion synthesis of novel transition-metal complexes containing high nitrogen energetic ligands. During the investigation of the decomposition behavior of the high-nitrogen transition metal complexes, it was discovered that nanostructured metal monolithic foams were formed in a post flame-front dynamic assembly having remarkably low densities down to 0.011 g cm(-3) and extremely high surface areas as high as 270 m(2) g(-1). We have produced monolithic nanoporous metal foams via this method of iron, cobalt, copper, and silver metals. We expect to be able to apply this to many other metals and to be able to tailor the resulting structure significantly. 相似文献
20.
Dr. Ichiro Hisaki Chen Xin Dr. Kiyonori Takahashi Prof. Takayoshi Nakamura 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(33):11278-11288
Designing organic components that can be used to construct porous materials enables the preparation of tailored functionalized materials. Research into porous materials has seen a resurgence in the past decade as a result of finding of self‐standing porous molecular crystals (PMCs). Particularly, a number of crystalline systems with permanent porosity that are formed by self‐assembly through hydrogen bonding (H‐bonding) have been developed. Such systems are called hydrogen‐bonded organic frameworks (HOFs). Herein we systematically describe H‐bonding patterns (supramolecular synthons) and molecular structures (tectons) that have been used to achieve thermal and chemical durability, a large surface area, and functions, such as selective gas sorption and separation, which can provide design principles for constructing HOFs with permanent porosity. 相似文献