共查询到20条相似文献，搜索用时 15 毫秒
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Feika Bian Lingyu Sun Lijun Cai Yu Wang Yuetong Wang Yuanjin Zhao 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(9)
Colloidal crystals are of great interest to researchers because of their excellent optical properties and broad applications in barcodes, sensors, displays, drug delivery, and other fields. Therefore, the preparation of high quality colloidal crystals in large quantities with high speed is worth investigating. After decades of development, microfluidics have been developed that provide new choices for many fields, especially for the generation of functional materials in microscale. Through the design of microfluidic chips, colloidal crystals can be prepared controllably with the advantages of fast speed and low cost. In this Review, research progress on colloidal crystals from microfluidics is discussed. After summarizing the classifications, the generation of colloidal crystals from microfluidics is discussed, including basic colloidal particles preparation, and their assembly inside or outside of microfluidic devices. Then, applications of the achieved colloidal crystals from microfluidics are illustrated. Finally, the future development and prospects of microfluidic‐based colloidal crystals are summarized. 相似文献
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Ma S Thiele J Liu X Bai Y Abell C Huck WT 《Small (Weinheim an der Bergstrasse, Germany)》2012,8(15):2356-2360
Microgel particles are formed from aqueous-two-phase-system (ATPS) droplets in poly(dimethylsiloxane) (PDMS) microfluidic devices. The droplets consist of a dextran core and a photopolymerizable poly(ethylene glycol) diacrylate (PEGDA) shell. Upon UV exposure, the ATPS droplets undergo a shape-transformation yielding PEGDA microgel particles containing a socket. 相似文献
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William S. Y. Wong Noushin Nasiri Guanyu Liu Nicholas Rumsey‐Hill Vincent S. J. Craig David R. Nisbet Antonio Tricoli 《Advanced Materials Interfaces》2015,2(9)
Precise manipulation of water is a key step in numerous natural and synthetic processes. Here, a new flexible and transparent hierarchical structure is determined that allows ultra‐dexterous manipulation and lossless transfer of water droplets. A 3D nanomesh is fabricated in one step by scalable electrospinning of low‐cost polystyrene solutions. Optimal structures are composed of a mesh of dense nanofiber layers vertically separated by isolated mesoporous microbeads. This results in a highly adhesive superhydrophobic wetting that perfectly mimics rose petal‐like structures. Structural–functional correlations are obtained over all key process parameters enabling robust tailoring of the wetting properties from hydrophilic to lotus‐like Cassie‐Baxter and rose‐like Cassie‐impregnating states. A mechanistic model of the droplet adhesion and release dynamics is obtained alongside the first demonstration of a mechanically induced transfer of microdroplets between two superhydrophobic coatings. This low‐temperature reaction‐free material structure demonstrates a facile means to fabricate impenetrable residue‐less rose petal‐like surfaces with superhydrophobic contact angles of 152 ± 2° and effective adhesion strength of 113 ± 20 μN. This is a significant step toward parallel, multistep droplet manipulation with applications ranging from flexible on‐paper devices to microfluidics and portable/wearable biosensors. 相似文献
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《Advanced Materials Interfaces》2018,5(18)
Microcompartments are useful for the storage, controlled reaction, and release of active compounds. However, the useful lifetime of a microcompartment is generally ended when it ruptures. Here, a self‐repairing microcompartment is proposed whose dynamic polymer shell can seal after rupturing, thus extending the lifetime of the capsule and allowing for multiple mechanically‐stimulated release events. The dynamic polymer shell is created in a one‐step approach through the formation of a double network polymer in the oil phase of a double emulsion template made by microfluidics. Of the two networks, a permanently‐crosslinked network is introduced to elastically restore the shape of the microcompartment, while a dynamically‐crosslinked network forms new bonds across crack interfaces. By quantifying the timescales required for the formation of new dynamic bonds within ruptured shells, strong microcompartments with predictable strength recovery and self‐repairing capabilities are successfully prepared and used to demonstrate the possibility of mechanically‐stimulated multiple release of cargo molecules. 相似文献
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Tae Min Choi Gun Ho Lee Young‐Seok Kim Jin‐Gyu Park Hyerim Hwang Shin‐Hyun Kim 《Advanced materials (Deerfield Beach, Fla.)》2019,31(18)
Colloidal particles with a repulsive interparticle potential spontaneously form crystalline lattices, which are used as a motif for photonic materials. It is difficult to predict the crystal arrangement in spherical volume as lattices are incompatible with a spherical surface. Here, the optimum arrangement of charged colloids is experimentally investigated by encapsulating them in double‐emulsion drops. Under conditions of strong interparticle repulsion, the colloidal crystal rapidly grows from the surface toward the center of the microcapsule, forming an onion‐like arrangement. By contrast, for weak repulsion, crystallites slowly grow and fuse through rearrangement to form a single‐crystal phase. Single‐crystal structure is energetically favorable even for strong repulsion. Nevertheless, a high energy barrier to colloidal rearrangement kinetically arrests the onion‐like structure formed by heterogeneous nucleation. Unlike the isotropic onion‐shaped product, the anisotropic single‐crystal‐containing microcapsules selectively display—at certain orientations but not others—one of the distinct colors from the various crystal planes. 相似文献
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Shuo Bai Sisir Debnath Kirsty Gibson Barbara Schlicht Lauren Bayne Michele Zagnoni Rein V. Ulijn 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(2):285-293
Uniformly‐sized, nanostructured peptide microparticles are generated by exploiting the ability of enzymes to serve (i) as catalysts, to control self‐assembly within monodisperse, surfactant‐stabilized water‐in‐oil microdroplets, and (ii) as destabilizers of emulsion interfaces, to enable facile transfer of the produced microparticles to water. This approach combines the advantages of biocatalytic self‐assembly with the compartmentalization properties enabled by droplet microfluidics. Firstly, using microfluidic techniques, precursors of self‐assembling peptide derivatives and enzymes are mixed in the microdroplets which upon catalytic conversion undergo molecular self‐assembly into peptide particles, depending on the chemical nature of the precursors. Due to their amphiphilic nature, enzymes adsorb at the water‐surfactant‐oil interface of the droplets, inducing the transfer of peptide microparticles from the oil to the aqueous phase. Ultimately, through washing steps, enzymes can be removed from the microparticles which results in uniformely‐sized particles composed of nanostructured aromatic peptide amphiphiles. 相似文献
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The use of emulsions as templates for nanomaterial assembly is a versatile method to create controlled microstructures. However, production rates are often low, particularly where the droplet phase solvent must be removed to achieve consolidation. Here, the emulsion templated fabrication of microparticles from multi-walled carbon nanotubes (CNTs) is studied. As an exemplar primary nanoparticle for microparticle assembly, CNTs present particular challenges due to their strong inter-particle interactions and limited dispersion in solvents. Nevertheless, small batches of CNT microparticles have demonstrated promising performances in energy storage, environmental remediation, and sensing due to their controlled structures. Improving CNT microparticle production through emulsion processing is therefore interesting to promote these real-world applications. In this work, it is shown that the slow rate of CNT microparticle formation from water-in-oil emulsions is due to spontaneous emulsification. Then methanol-in-oil emulsions are tested, which rapidly form fragile CNT capsules. Using mixtures of methanol and water, a faster rate of solvent loss can be balanced alongside nanoparticle assembly; CNT microparticle formation is up to twice as fast using 40% methanol compared to aqueous dispersions. In addition to facilitating faster CNT microparticle production, these findings offer more broadly applicable insights into the mechanisms of solvent transport in emulsions. 相似文献
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Zhijie Zhu Ji‐Dong Liu Chang Liu Xingjiang Wu Qing Li Su Chen Xin Zhao David A. Weitz 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(9)
Development of fast curing and easy modeling of colloidal photonic crystals is highly desirable for various applications. Here, a novel type of injectable photonic hydrogel (IPH) is proposed to achieve self‐healable structural color by integrating microfluidics‐derived photonic supraballs with supramolecular hydrogels. The supramolecular hydrogel is engineered via incorporating β‐cyclodextrin/poly(2‐hydroxypropyl acrylate‐co‐N‐vinylimidazole) (CD/poly(HPA‐co‐VI)) with methacrylated gelatin (GelMA), and serves as a scaffold for colloidal crystal arrays. The photonic supraballs derived from the microfluidics techniques, exhibit excellent compatibility with the hydrogel scaffolds, leading to enhanced assembly efficiency. By virtue of hydrogen bonds and host–guest interactions, a series of self‐healable photonic hydrogels (linear, planar, and spiral assemblies) can be facilely assembled. It is demonstrated that the spherical symmetry of the photonic supraballs endows them with identical optical responses independent of viewing angles. In addition, by taking the advantage of angle independent spectrum characteristics, the IPH presents beneficial effects in reflective cooling, which can achieve up to 17.4 °C in passive solar reflective cooling. The strategy represents an easy‐to‐perform platform for the construction of IPH, providing novel insights into macroscopic self‐assembly toward thermal management applications. 相似文献
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Ethan M. Susca Peter A. Beaucage R. Paxton Thedford Andrej Singer Sol M. Gruner Lara A. Estroff Ulrich Wiesner 《Advanced materials (Deerfield Beach, Fla.)》2019,31(40)
Properties arising from ordered periodic mesostructures are often obscured by small, randomly oriented domains and grain boundaries. Bulk macroscopic single crystals with mesoscale periodicity are needed to establish fundamental structure–property correlations for materials ordered at this length scale (10–100 nm). A solvent‐evaporation‐induced crystallization method providing access to large (millimeter to centimeter) single‐crystal mesostructures, specifically bicontinuous gyroids, in thick films (>100 µm) derived from block copolymers is reported. After in‐depth crystallographic characterization of single‐crystal block copolymer–preceramic nanocomposite films, the structures are converted into mesoporous ceramic monoliths, with retention of mesoscale crystallinity. When fractured, these monoliths display single‐crystal‐like cleavage along mesoscale facets. The method can prepare macroscopic bulk single crystals with other block copolymer systems, suggesting that the method is broadly applicable to block copolymer materials assembled by solvent evaporation. It is expected that such bulk single crystals will enable fundamental understanding and control of emergent mesostructure‐based properties in block‐copolymer‐directed metal, semiconductor, and superconductor materials. 相似文献
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Tianjin Yang Alberto Cingolani Tommaso Casalini Abdessalem Aribia Antoine Klaue Hua Wu Stavros Stavrakis Andrew de Mello Massimo Morbidelli 《Advanced Materials Technologies》2019,4(6)
A novel methodology, combining reactive gelation and droplet‐based microfluidics, is described for the synthesis of rigid, porous, and hollow polymeric nanoparticles (NPs). The precursors of such capsules are microfluidically generated latex droplets, with diameters tunable between 20 and 100 µm. The conversion of latex droplets to polymeric capsules involves two steps, namely self‐migration and gelation of the NPs toward the oil–water interface to form a solid‐like shell, and then postpolymerization to covalently fix the shell structure. The hollow structure of the capsules results from the interaction between negatively charged NPs inside the droplet and positive charges present on fluorosurfactant at the droplet interface. Significantly, the porosity and average pore size in the capsule shell can be controlled through variation of the initial NP concentration in the droplet. Based on the analysis of diffusion of fluorescent molecules of known size, it is shown that penetration of molecules into the internal volume of the capsules increases as the initial NP concentration in the droplet decreases, thus the porosity of the formed shell increases. This novel synthetic methodology defines a powerful tool in the generation of hollow capsules of controlled size and morphology, and has significant application in material sciences. 相似文献
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Paolo Falcaro Dario Buso Anita J. Hill Cara M. Doherty 《Advanced materials (Deerfield Beach, Fla.)》2012,24(24):3153-3168
The tuneable pore size and architecture, chemical properties and functionalization make metal organic frameworks (MOFs) attractive versatile stimuli‐responsive materials. In this context, MOFs hold promise for industrial applications and a fervent research field is currently investigating MOF properties for device fabrication. Although the material properties have a crucial role, the ability to precisely locate the functional material is fundamental for device fabrication. In this progress report, advancements in the control of MOF positioning and precise localization of functional materials within MOF crystals are presented. Advantages and limitations of each reviewed technique are critically investigated, and several important gaps in the technological development for device fabrication are highlighted. Finally, promising patterning techniques are presented which are inspired by previous studies in organic and inorganic crystal patterning for the future of MOF lithography. 相似文献
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Paolo Falcaro Dario Buso Anita J. Hill Cara M. Doherty 《Advanced materials (Deerfield Beach, Fla.)》2012,24(24):3145-3145