排序方式: 共有15条查询结果,搜索用时 31 毫秒
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(43):13702-13705
We report a dynamic self‐organization of self‐propelled peanut‐shaped hematite motors from non‐equilibrium driving forces where the propulsion can be triggered by blue light. They result in one‐dimensional, active colloid ribbons with a positive phototactic characteristic. The motion of colloid motors is ascribed to the diffusion‐osmotic flow in a chemical gradient by the photocatalytic decomposition of hydrogen peroxide fuel. We show that self‐propelled peanut‐shaped colloids readily form one‐dimensional, slithering ribbon structures under the out‐of‐equilibrium collisions. This self‐organization intrinsically results from the competition among the osmotically driven motion, the phoretic attraction and the inherent magnetic moments. The giant size number fluctuation in colloid ribbons is observed above a critical point 4.1 % of the surface density of colloid motors. Such phototactic colloid ribbons may provide a model system to understand the emergence of function in biological systems and have potential to construct bioinspired active materials based on different active building blocks. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(26):7728-7732
The development of artificial nanomotor systems that are stimuli‐responsive is still posing many challenges. Herein, we demonstrate the self‐assembly of a redox‐responsive stomatocyte nanomotor system, which can be used for triggered drug release under biological reducing conditions. The redox sensitivity was introduced by incorporating a disulfide bridge between the hydrophilic poly(ethylene glycol) block and the hydrophobic polystyrene block. When incubated with the endogenous reducing agent glutathione at a concentration comparable to that within cells, the external PEG shells of these stimuli‐responsive nanomotors are cleaved. The specific bowl‐shaped stomatocytes aggregate after the treatment with glutathione, leading to the loss of motion and triggered drug release. These novel redox‐responsive nanomotors can not only be used for remote transport but also for drug delivery, which is promising for future biomedical applications. 相似文献
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Roberto MaríaHormigos Beatriz JuradoSnchez Alberto Escarpa 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(10):3160-3164
CdS quantum dots/C60 tubular micromotors with chemical/multi‐light‐controlled propulsion and “on‐the‐fly” acceleration capabilities are described. In situ growth of CdS quantum dots on the outer fullerene layer imparts this layer with light‐responsive properties in connection to inner Pt, Pd or MnO2 layers. This is the first time that visible light is used to drive bubble‐propelled tubular micromotors. The micromotors exhibit a broad absorption range from 320 to 670 nm and can be wirelessly controlled by modulating light intensity and peroxide concentration. The built‐in accelerating optical system allows for the control of the velocity over the entire UV/Vis light spectra by modulating the catalyst surface chemistry. The light‐responsive properties have been also exploited to accelerate the chemical dealloying and propulsion of micromotors containing a Cu/Pd layer. Such dual operated hybrid micromotors hold considerable promise for designing smart micromachines for on‐demand operations, motion‐based sensing, and enhanced cargo transportation. 相似文献
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Hailong Che Jianzhi Zhu Shidong Song Alexander F. Mason Shoupeng Cao Imke A. B. Pijpers Loai K. E. A. Abdelmohsen Jan C. M. van Hest 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(37):13247-13252
In nature, dynamic processes are ubiquitous and often characterized by adaptive, transient behavior. Herein, we present the development of a transient bowl‐shaped nanoreactor system, or stomatocyte, the properties of which are mediated by molecular interactions. In a stepwise fashion, we couple motility to a dynamic process, which is maintained by transient events; namely, binding and unbinding of adenosine triphosphate (ATP). The surface of the nanosystem is decorated with polylysine (PLL), and regulation is achieved by addition of ATP. The dynamic interaction between PLL and ATP leads to an increase in the hydrophobicity of the PLL–ATP complex and subsequently to a collapse of the polymer; this causes a narrowing of the opening of the stomatocytes. The presence of the apyrase, which hydrolyzes ATP, leads to a decrease of the ATP concentration, decomplexation of PLL, and reopening of the stomatocyte. The competition between ATP input and consumption gives rise to a transient state that is controlled by the out‐of‐equilibrium process. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(2):530-533
It is highly demanding to design active nanomotors that can move in response to specific signals with controllable rate and direction. A catalysis‐driven nanomotor was constructed by designing catalytically and plasmonically active Janus gold nanoparticles (Au NPs), which generate an asymmetric temperature gradient of local solvent surrounding NPs in catalytic reactions. The self‐thermophoresis behavior of the Janus nanomotor is monitored from its inherent plasmonic response. The diffusion coefficient of the self‐thermophoresis motion is linearly dependent on chemical reaction rate, as described by a stochastic model. 相似文献
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