共查询到20条相似文献，搜索用时 15 毫秒
1.
Yusheng Zhou;Peng Zhang;Zhen Liu;Wenqing Yan;Haiyang Gao;Guodong Liang;Wei Qin; 《Advanced materials (Deerfield Beach, Fla.)》2024,36(16):2312439
Afterglow materials featuring long emission durations ranging from milliseconds to hours have garnered increasing interest owing to their potential applications in sensing, bioimaging, and anti-counterfeiting. Unfortunately, polymeric materials rarely exhibit afterglow properties under ambient conditions because of the rapid nonradiative decay rate of triplet excitons. In this study, hour-long afterglow (HLA) polymer films are fabricated using a facile molecular doping strategy. Flexible and transparent polymer films emitted a bright afterglow lasting over 11 h at room temperature in air, which is one of the best performances among the organic afterglow materials reported to date. Intriguingly, HLA polymer films can be activated by sunlight, and their cyan afterglow in air can be readily observed by the naked eye. Moreover, the HLA color of the polymer films could be tuned from cyan to red through the Förster resonance energy transfer mechanism. Their application in flexible displays and information storage has also been demonstrated. With remarkable advantages, including an hour-long and bright afterglow, tunable afterglow colors, superior flexibility and transparency, and ease of fabrication, the HLA polymer paves the way for the practical application of afterglow materials in the engineering sector. 相似文献
2.
Shen Yu Guo-Long Xing Li-Hua Chen Teng Ben Bao-Lian Su 《Advanced materials (Deerfield Beach, Fla.)》2020,32(44):2003270
Crystalline porous organic salts (CPOSs), as an emerging class of porous organic materials, combining the uniform microporous system and distinct polarized channels, have become a highly evolving field of important current interest. The unique ionic bond of a CPOS endows the confined channels with high polarity, making CPOSs distinct from other organic frameworks. CPOSs show many fascinating properties, such as proton conductivity and fast transport of polar molecules, which involve the interaction between highly polarized guest molecules and host frameworks. Substantial progress has been made in the synthesis and applications of CPOSs. Herein, an overview is provided to impart a comprehensive understanding of the link between the synthetic approaches and the resultant microporous structure, the structure–function correlation and the state-of-the-art applications of CPOSs. The enhanced mass-transport performance of hierarchically porous structure in combination with the intrinsic polarized channels of CPOSs is very promising to create new applications and contribute to a new research upsurge. The perspective to construct porous hierarchy within the crystalline porous organic salts is assessed and will open a new research avenue. In the conclusion, the current challenges on the synthesis, structural regulation, and applications of CPOSs and the future of hierarchically porous crystalline organic salts are discussed. 相似文献
3.
Xiao‐Ning Li Mingxue Yang Xu‐Lin Chen Ji‐Hui Jia Wan‐Wan Zhao Xiao‐Yuan Wu Sa‐Sa Wang Lingyi Meng Can‐Zhong Lu 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(45)
Metal‐free ultralong organic phosphorescence (UOP) materials have attracted significant attention owing to their anomalous photophysical properties and potential applications in various fields. Here, three pyrimidine‐based organic luminogens, 9‐(pyrimidin‐2‐yl)‐9H‐carbazole, 9‐(4,6‐dimethylpyrimidin‐2‐yl)‐9H‐carbazole, and 9‐(5‐bromopyrimidin‐2‐yl)‐9H‐carbazole are designed and synthesized, which show efficient yellow UOP with the longest lifetimes up to 1.37 s and the highest absolute phosphorescence quantum yields up to 23.6% under ambient conditions. Theoretical calculations, crystal structures, and photophysical properties of these compounds reveal that intramolecular hydrogen bonding, intermolecular π–π interactions, and intermolecular electronic coupling are responsible for forming dimers and generating highly efficient UOP. Their efficacy as solid materials for data encryption is demonstrated. 相似文献
4.
Wei Yao;Kai Sun;Chenxiao Li;Shasha Zhang;Kun Liu;Beishen Wu;Yufeng Mao;Huili Ma;Wei Huang;Zhongfu An; 《Small (Weinheim an der Bergstrasse, Germany)》2024,20(24):2309559
Hopper-shaped microcrystals, an unusual type of crystal with a large specific surface area, are promising for use in catalysis, drug delivery, and gas sensors. In contrast to well-studied inorganic hopper-shaped crystals, organic phosphorescent concave hopper-shaped microstructures are rarely reported. This study reports the synthesis of two types of organic stepped indented hopper-shaped microstructures with efficient room temperature phosphorescence (RTP) using a liquid phase self-assembly strategy. The formation mechanism is attributed to the interfacial instability induced by the concentration gradient and selective etching. Compared with flat microstructures, the stepped indented hopper-like RTP microstructures exhibit high sensitivity to oxygen. This work also demonstrates that packing the photochromic material into the concave hopper “vessel” effectively controls the switch of phosphorescence from energy transfer, expanding the potential applications of phosphorescent materials. 相似文献
5.
Jingyue Zhu Dan Xu Wenjing Qian Jinyu Zhang Feng Yan 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(14):1935-1944
A simple strategy for the synthesis of heteroatom‐doped porous carbon materials (CMs) via using ionic liquid (IL)‐doped alkali organic salts as small molecular precursors is developed. Doping of alkali organic salts (such as sodium glutamate, sodium tartrate, and sodium citrate) with heteroatoms containing ILs (including 1‐butyl‐3‐methylimidazolium chlorine and 3‐butyl‐4‐methythiazolebromination) not only incorporates the heteroatoms into the carbon frameworks but also highly improves the carbonization yield, as compared with that of either alkali organic salts or ILs as precursors. The porous structure of CMs can be tuned by adjusting the feed ratio of ILs. The porous CMs derived from 1‐butyl‐3‐methylimidazolium chlorine‐doped sodium glutamate exhibit high charge storage capacity with a specific capacitance of 287 F g?1 and good stability over 5000 cycles in 6 m KOH at a current density of 1 A g?1 for supercapacitors. This strategy opens a simple and efficient method for the synthesis of heteroatom‐doped porous CMs. 相似文献
6.
7.
Sina Naficy Thi Yen Loan Le Farshad Oveissi Aeryne Lee Jui Chien Hung Steven G. Wise David S. Winlaw Fariba Dehghani 《Advanced Materials Interfaces》2020,7(3)
Conventional tough hydrogels offer enhanced mechanical properties and high toughness. Their application scope however is limited by their lack of processability. Here, a new porous tough hydrogel system is introduced which is processable via gel fiber spinning and 3D printing. The tough hydrogels are produced by rehydrating processable organogels developed by induced phase separation between two linear polymer chains capable of intermolecular hydrogen bonding. Through a slow sol–gel phase separation, highly porous gel networks made of hydrogen bonded polymer chains is formed. These organogels can be easily transformed to 3D printed multimaterial constructs or gel fibers, and after rehydration produce highly robust hydrogel structures. Although such hydrogels are highly porous and contain large amount of water, their strength can reach as high as 2000 kPa, with high elongation at break (≈900%), and tunable moduli ranging from 250 to 2000 kPa. The hydrogels have fracture energies larger than cartilage and demonstrate excellent load recovery because of their renewable hydrogen bond crosslinks. Furthermore, the hydrogels exhibit excellent hemocompatibility and in vitro biocompatibility. Such hydrogels can further expand the application of tough hydrogels and may serve as a model to explore the toughening mechanism of hydrogen bonded hybrid, tough hydrogel systems. 相似文献
8.
Porous nanostructured materials are demonstrated to be very promising in catalysis due to their well accessible active sites. Thermally stable metal‐organic frameworks (MOFs) as hard templates are successfully utilized to afford porous metal oxides and subsequently metal sulfides by a nanocasting method. The resultant metal oxides/sulfides show considerable Brunauer–Emmett–Teller (BET) surface areas, by partially inheriting the pore character of MOF templates. Preliminary investigation on the obtained hierarchically porous CdS for water splitting, as a proof of concept, demonstrates its much higher activity than both corresponding bulk and nanosized counterparts, under visible light irradiation. Given the structural diversity and tailorability of MOFs, such synthetic approach may open an avenue to the synthesis of advanced porous materials for functional applications. 相似文献
9.
Zhihui Zeng Hao Jin Mingji Chen Weiwei Li Licheng Zhou Xiao Xue Zhong Zhang 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(34)
Multiwalled carbon nanotube/polymer composites with aligned and isotropic micropores are constructed by a facile ice‐templated freeze‐drying method in a wide density range, with controllable types and contents of the nanoscale building blocks, in order to tune the shielding performance together with the considerable mechanical and electrical properties. Under the mutual promotion of the frame and porous structure, the lightweight high‐performance shielding is achieved: a 2.3 mm thick sample can reach 46.7 and 21.7 dB in the microwave X‐band while the density is merely 32.3 and 9.0 mg cm?3, respectively. The lowest density corresponds to a value of shielding effectiveness divided by both the density and thickness up to 104 dB cm2 g?1, far beyond the conductive polymer composites with other fillers ever reported. The shielding mechanism of the flexible porous materials is further demonstrated by an in situ compression experiment. 相似文献
10.
Markus Einzinger Tianyu Zhu Piotr de Silva Christian Belger Timothy M. Swager Troy Van Voorhis Marc A. Baldo 《Advanced materials (Deerfield Beach, Fla.)》2017,29(40)
Multiexcited‐state phenomena are believed to be the root cause of two exigent challenges in organic light‐emitting diodes; namely, efficiency roll‐off and degradation. The development of novel strategies to reduce exciton densities under heavy load is therefore highly desirable. Here, it is shown that triplet exciton lifetimes of thermally activated delayed‐fluorescence‐emitter molecules can be manipulated in the solid state by exploiting intermolecular interactions. The external heavy‐atom effect of brominated host molecules leads to increased spin–orbit coupling, which in turn enhances intersystem crossing rates in the guest molecule. Wave function overlap between the host and the guest is confirmed by combined molecular dynamics and density functional theory calculations. Shorter triplet exciton lifetimes are observed, while high photoluminescence quantum yields and essentially unaltered emission spectra are maintained. A change in the intersystem crossing rate ratio due to increased dielectric constants leads to almost 50% lower triplet exciton densities in the emissive layer in the steady state and results in an improved onset of the photoluminescence quantum yield roll‐off at high excitation densities. Efficient organic light‐emitting diodes with better roll‐off behavior based on these novel hosts are fabricated, demonstrating the suitability of this concept for real‐world applications. 相似文献
11.
综述了芳香族热固性共聚酯多孔材料的特点与性能,并针对其在航空航天材料、车体结构材料、吸波材料等领域的应用与有机泡沫多孔材料进行了相似的分析与比较。通过对比得出芳香族热固性树脂多孔泡沫是一类高性能树脂泡沫材料,具有优异的耐热性,很高的刚性与强度,且制备成本低廉,因此具有更广阔的应用前景。 相似文献
12.
Joanna Boucard Camille Linot Thibaut Blondy Steven Nedellec Philippe Hulin Christophe Blanquart Lénaïc Lartigue Eléna Ishow 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(38)
Bright supramolecular fluorescent organic nanoassemblies (FONs), based on strongly polar red‐emissive benzothiadiazole fluorophores containing acidic units, are fabricated to serve as theranostic tools with large colloidal stability in the absence of a polymer or surfactant. High architectural cohesion is ensured by the multiple hydrogen‐bonding networks, reinforced by the dipolar and hydrophobic interactions developed between the dyes. Such interactions are harnessed to ensure high payload encapsulation and efficient trapping of hydrophobic and hydrogen‐bonding drugs like doxorubicin, as shown by steady state and time‐resolved measurements. Fine tuning of the drug release in cancer cells is achieved by adjusting the structure and combination of the fluorophore acidic units. Notably delayed drug delivery is observed by confocal microscopy compared to the entrance of hydrosoluble doxorubicin, demonstrating the absence of undesirable burst release outside the cells by using FONs. Since FON‐constituting fluorophores exhibit a large emission shift from red to green when dissociating in contact with the lipid cellular content, drug delivery could advantageously be followed by dual‐color spectral detection, independently of the drug staining potentiality. 相似文献
13.
Ning Li Su-Juan Yao Mei-Jie Wei Jun He Weijie Chi Ya-Qian Lan 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(5):2206724
The discovery and in-depth study of non-biocatalytic applications of active biomolecules are essential for the development of biomimicry. Here, the effect of intermolecular hydrogen-bonding traction on the CO2 photoactivation performance of adenine nucleobase by means of an adenine-containing model system ( AMOF-1−4 ) is uncovered. Remarkably, the hydrogen-bonding schemes around adenines are regularly altered with the increase in the alkyl (methyl, ethyl, isopropyl, and tert-butyl) electron-donating capacity of the coordinated aliphatic carboxylic acids, and thus, lead to a stepwise improvement in CO2 photoreduction activity. Density functional theory calculations demonstrate that strong intermolecular hydrogen-bonding traction surrounding adenine can obviously increase the adenine-CO2 interaction energy and, therefore, result in a smoother CO2 activation process. Significantly, this work also provides new inspiration for expanding the application of adenine to more small-molecule catalytic reactions. 相似文献
14.
Yagai S Seki T Murayama H Wakikawa Y Ikoma T Kikkawa Y Karatsu T Kitamura A Honsho Y Seki S 《Small (Weinheim an der Bergstrasse, Germany)》2010,6(23):2731-2740
Extremely long nanofibers, whose lengths reach the millimeter regime, are generated via co-aggregation of a melamine-appended perylene bisimide semiconductor and a substituted cyanurate, both of which are ditopic triple-hydrogen-bonding building blocks; they co-aggregate in an unexpected stoichiometrically mismatched 1:2 ratio. Various microscopic and X-ray diffraction studies suggest that hydrogen-bonded polymeric chains are formed along the long axis of the nanofibers by the 1:2 complexation of the two components, which further stack along the short axis of the nanofibers. The photocarrier generation mechanism in the nanofibers is investigated by time-of-flight (TOF) experiments under electric and magnetic fields, revealing the birth and efficient recombination of singlet geminate electron-hole pairs. Flash-photolysis time-resolved microwave conductivity (FP-TRMC) measurements revealed intrinsic 1D electron mobilities up to 0.6 cm(2) V(-1) s(-1) within nanofibers. 相似文献
15.
Bald I Wang YG Dong M Rosen CB Ravnsbaek JB Zhuang GL Gothelf KV Wang JG Besenbacher F 《Small (Weinheim an der Bergstrasse, Germany)》2011,7(7):939-949
Methylation of DNA nucleobases is an important control mechanism in biology applied, for example, in the regulation of gene expression. The effect of methylation on the intermolecular interactions between guanine molecules is studied through an interplay between scanning tunneling microscopy (STM) and density functional theory with empirical dispersion correction (DFT-D). The present STM and DFT-D results show that methylation of guanine can have subtle effects on the hydrogen-bond strength with a strong dependence on the position of methylation. It is demonstrated that the methylation of DNA nucleobases is a precise means to tune intermolecular interactions and consequently enables very specific recognition of DNA methylation by enzymes. This scheme is used to generate four different types of artificial 2D nanostructures from methylated guanine. For instance, a 2D guanine windmill motif that is stabilized by cooperative hydrogen bonding is revealed. It forms by self-assembly on a graphite surface under ambient conditions at the liquid-solid interface when the hydrogen-bonding donor at the N1 site of guanine is blocked by a methyl group. 相似文献
16.
The cover shows a recording process using nematic liquid crystal alignment. On p. 692, Kato and co‐workers report that reversibly bistable states have been achieved for nematic liquid crystals incorporating a small amount of self‐assembled fibers. Homeotropic monodomains and non‐aligned multidomains can be fixed and switched by thermal treatment in electric fields. The technique is applied to the formation of rewritable light scattering patterns, as shown on the cover. 相似文献
17.
18.
Briana Aguila Qi Sun Jason A. Perman Lyndsey D. Earl Carter W. Abney Radwan Elzein Rudy Schlaf Shengqian Ma 《Advanced materials (Deerfield Beach, Fla.)》2017,29(31)
The primary challenge in materials design and synthesis is achieving the balance between performance and economy for real‐world application. This issue is addressed by creating a thiol functionalized porous organic polymer (POP) using simple free radical polymerization techniques to prepare a cost‐effective material with a high density of chelating sites designed for mercury capture and therefore environmental remediation. The resulting POP is able to remove aqueous and airborne mercury with uptake capacities of 1216 and 630 mg g?1, respectively. The material demonstrates rapid kinetics, capable of dropping the mercury concentration from 5 ppm to 1 ppb, lower than the US Environmental Protection Agency's drinking water limit (2 ppb), within 10 min. Furthermore, the material has the added benefits of recyclability, stability in a broad pH range, and selectivity for toxic metals. These results are attributed to the material's physical properties, which include hierarchical porosity, a high density of chelating sites, and the material's robustness, which improve the thiol availability to bind with mercury as determined by X‐ray photoelectron spectroscopy and X‐ray absorption fine structure studies. The work provides promising results for POPs as an economical material for multiple environmental remediation applications. 相似文献
19.
20.
A. A. Chialvo P. T. Cummings H. D. Cochran 《International Journal of Thermophysics》1996,17(1):147-156
We review molecular dynamics simulations of infinitely dilute supercritical aqueous NaCl solutions to determine the solvation structure and the soluteinduced effect on water water hydrogen bonding and report new simulation results On the extent of the ion pairing. Our simulation studies indicate that Na+ and Cl ions as a pair or its isolated infinitely dilute ions form strong solvation structures in SCW. even though the water eater hydrogen bonding is not affected Within the context of the models we are using. there is strong indication of a high degree of Na+ CI ion pairing.Paper presented at the Twelfth Symposium on Thermophysical Properties, June 19–24, 1994. Boulder, Colorado. U.S.A. 相似文献