Plasmonic dimers not only provide a unique platform for studying fundamental plasmonic behavior and effects but also are functional materials for numerous applications. The efficient creation of well-defined dimers with flexible control of structure parameters and thus tunable optical property is the prerequisite for fully exploiting the potential of this nanostructure. Herein, based on a polymer-assisted self-assembly approach in conjugation with molecular cage chemistry, a strategy was demonstrated for constructing cage-bridged plasmonic dimers with controlled sizes, compositions, shape, symmetry, and interparticle gap separation in a modular and high-yield manner. With a high degree of freedom and controllability, this strategy allows facilely accessing various symmetrical/asymmetrical dimers with sub-5 nm gap distance and tailored optical properties. Importantly, as the linkage of the two constituent elements, the molecular cages embedded in the junction endow the assembled dimers with the ability to precisely and reversibly host rich guest molecules in hotspot regions, offering great potential for creating various plasmon-mediated applications.
Droplet‐based microfluidics enable the production of emulsions and microparticles with spherical shapes, but the high‐throughput fabrication of nonspherical emulsions and microparticles still remains challenging because interfacial tension plays a dominant role during preparation. Herein, ionic liquids (ILs) containing salts, which possess sufficient osmotic pressure to realize water transport and phase separation, are introduced as inner cores of oil‐in‐oil‐in‐water double emulsions and it is shown that nonspherical emulsions can be constructed by osmosis‐driven arrested coalescence of inner cores. Subsequently, ultraviolet polymerization of the nonspherical emulsions leads to nonspherical microparticles. By tailoring the number, composition, and size of inner cores as well as coalescence time, a variety of nonspherical shapes such as dumbbell, rod, spindle, snowman, tumbler, three‐pointed star, triangle, and scalene triangle are created. Importantly, benefitting from excellent solvency of ILs, this system can serve as a general platform to produce nonspherical microparticles made from different materials. Moreover, by controlling the osmotic pressure, programmed coalescence of inner cores in double emulsions is realizable, which indicates the potential to build microreactors. Thus, a simple and high‐throughput strategy to create nonspherical microparticles with arrested coalescence shapes is developed for the first time and can be further used to construct novel materials and microreactors.
Block copolymers (BCPs) have been intensively used as structure-directing agents for the synthesis of mesostructured materials because of their rich microphase separation and excellent thermal stability. Incorporating functional moieties into BCPs to extend the currently dominated monotonic role may open new opportunities in the creation of mesostructured materials using one single BCP system. In this work, we reported a new kind of pyrrole-containing BCP (PPHMA-b-PEO), finding that PPHMA-b-PEO could produce the effect of killing more birds with one stone and efficient fabrication of diverse mesostructured materials could be facilely realized. As a structure-directing agent, different ordered mesoporous silicas were produced as expected by using PPHMA-b-PEO. Importantly, the pyrrole-containing template molecules (PPHMA-b-PEO) confined in silica channels could also be used as a polymerizable monomer or precursor for further chemical transformation, leading to a mesostructured polymer and carbon materials. Moreover, because of the reductive activity of pyrrole, numerous oxidative agents could be explored to carry out the related polymerization process, making it possible to facilely access the diverse-doped mesostructured polymer or carbon materials. In addition to mesostructured silica, polymer, and carbon materials, it is also found that the uniform carbon coating derived from PPHMA-b-PEO could serve as a robust support for realizing the mesoporous metal oxides with high crystallinity, as demonstrated by the formation of high crystalline TiO2. All of our results indicate that the rational incorporation of functional moieties into BCPs will bring new opportunities and show great potential for the efficient fabrication of diverse mesostructured materials.
We report a new type of ABA-type brush-like triblock copolymer (PEGMA-b-PPHMA-b-PEGMA), which is characterized by two hydrophilic end segments (A) and a hydrophobic midblock (B) bearing polymerizable pyrrole moieties. This kind of symmetric triblock copolymers can not only serve as a structure-directing agent for the formation of mesoporous silicates but also function as a polymerizable monomer or carbon source for further chemical conversion to deliver mesostructured polymer or carbon materials within the preformed silicate framework. By utilizing such dual functional macromolecules, rich morphologies of mesostructures are accessible through microphase separation, and the order−order transition among cubic, lamellar, 2D hexagonal, and bicontinuous mesostructures is sensitively achievable by varying the hydrophilic volume fraction of copolymers and TEOS dosage. These features enable facile access to diverse mesostructured silica, polymer, and carbon materials. Remarkably, due to the brush-like polymer architecture and the formation of loop configuration, a widely tunable pore size from mesoscale to macroscale is realizable through using a relatively lower molecular weight copolymer. Importantly, it is found that the brush-like hydrophilic segments of our triblock copolymers can firmly anchor into the silica walls without appreciable escape of copolymer template in commonly used solvents even under reflux extraction, providing a prerequisite for reliable confined chemical transformation into mesostructured polymer and carbon materials. Our work demonstrates that the design and synthesis of functional amphiphilic block copolymers will bring great opportunity for the development of novel mesostructured materials.
synthetic ways, generating a diverse range of multicompartment assemblies. [4,5] Analogous to cellular tissues, multicompartment assemblies on micro or macro scales can be designed with complex morphologies and multiple functions by rationally organizing building blocks, finding wide applications in artificial cells, [6] cascade reactions, [7] responsive materials, [8] signal communication, [9] and therapeutic applications. [10] For the preparation of multicompartment assemblies, bottomup assembly from building blocks is most widely adopted as this approach enables precise and independent control over individual chambers, where the physical and chemical characteristics of multicompartment architectures can be dictated. For example, exploiting surface tension and hydrophobic interactions at the liquidgas interface, A. Khademhosseini and coworkers completed the ordered assembly of cell-loaded hydrogels and obtained biotissue-like structures. [11] S. Chen's group prepared hydrogel microspheres as building blocks by microfluidics and successfully constructed multicompartment ensembles at multidimensional scales through hydrogen bonding and host-guest interactions between microspheres. [12] In another work, they first prepared a Janus microsphere, which was then partially fused with a certain number of other microspheres regulated by a magnetic field. In this way, they fabricated molecule-analog photonic crystal structures. [13] Besides, through introducing dynamic covalent bonding between amino and carbonyl compounds, B. Tang and his co-workers generated magic cube-like assemblies from aggregation-induced fluorescence molecule (AIE) doped hydrogel and studied their luminescence and deformation properties. [14] Although many advances made, there are some limitations within bottom-up processes towards multicompartment assemblies. Above all, the realization of assemblies generally requires elaborately designed building blocks and interactions. Therefore, it is inevitable to synthesize the peripheral bind motif and carefully tailor the variety and number of interaction sites on building blocks, thus bringing disadvantages such as poor tunability and hard extendibility.Multicompartment assemblies attract much attention for their wide applications. However, the fabrication of multicompartment assemblies usually requires elaborately designed building blocks and careful controlling. The emergence of droplet networks has provided a facile way to construct multiple droplet architectures, which can further be converted to multicompartment assemblies. Herein, the bind motif-free building blocks are presented, which consist of the hydrophobic Tf 2 N − -based ionic liquid (IL) dissolving LiTf 2 N salt, that can conjugate via arrested coalescence in confined-space templates to form IL droplet networks. Subsequent ultraviolent polymerization generates robust free-standing multicompartment assemblies. The conjugation of building blocks relies not on the peripheral bind motif but on the interfacial instability-induced arrested coalesc...
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