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Multi-stimuli Responsive Supramolecular Gels Based on a D-π-A Structural Cyanostilbene Derivative with Aggregation Induced Emission Properties
摘要： Developing multi-stimuli responsive fluorescent gel materials in a single system remains challenging. Gelator molecules with classical fluorophores suffer from aggregation-caused quenching (ACQ) effect, limiting their applications further. Herein, a novel V-shaped cyanostilbene-based molecule (BAPBIA) with aggregation induced emission (AIE) characteristics and great gelation ability was synthesized and was found to exhibit multi-stimuli responsive behaviors. Reversible gel-sol phase transitions together with emission quenching are realized in response to external stimuli including heating, light and fluoride ion. Especially, the introduction of dimethylaniline group (donor) and cyano group (acceptor) generates a D-π-A structure, further leading to an intramolecular charge transfer (ICT) effect, which enlarges the emission contrast with the variations of the distribution of charge. Thus, upon trifluoroacetic acid (TFA) triggered protonation of dimethylaniline group, not only gel-sol transition but also emission color switching (yellow-to-blue) is achieved due to the loss of the ICT effect. This work paves an easy way to construct fully reversible multi-stimuli responsive fluorescence modulation smart materials.
关键词： supramolecular gels,aggregation induced emission,multi-stimuli responsive,fluorescence switching,cyanostilbene derivative
更新于2025-11-14 15:14:40
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Fluorescent Self-Healing Carbon Dot/Polymer Gels
摘要： Multicolor, fluorescent self-healing gels were constructed through reacting carbon dots produced from different aldehyde precursors with branched polyethylenimine. The self-healing gels were formed through Schiff base reaction between the aldehyde units displayed upon the carbon dots' surface and primary amine residues within the polyethylenimine network, generating imine bonds. The dynamic covalent imine bonds between the carbon dots and polymeric matrix endowed the gels with both excellent self-healing properties, as well as high mechanical strength. Moreover, the viscoelastic properties of the gels could be intimately modulated by controlling the ratio between the carbon dots and polymer. The distinct fluorescence emissions of the gels, originating from the specific carbon dot constituents, were employed for fabrication of light emitters at different colors, particularly generating white light.
关键词： imines,carbon dots,aldehydes.,dynamic covalent bonds,self-healing gels,fluorescent gels
更新于2025-09-23 15:23:52
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Self-Assembly of Amphiphilic Schiff Base and Selectively Turn on Circularly Polarized Luminescence by Al3+
摘要： We designed glutamide-derived amphiphilic Schiff bases containing three different aldehyde moieties for the fabrication of circularly polarized luminescence (CPL) emitting materials. Upon self-assembly in acetonitrile, Schiff bases featuring 4-(dimethylamino)-2-hydroxylbenzaldehyde and 1-hydroxy-2-naphthaldehyde groups form supramolecular gels with twist and fiber structures, respectively, while Schiff bases featuring 2-hydroxy-1-naphthaldehyde groups forms precipitation with flakes structures. Although emission and circular dichroism (CD) signals can be detected from the supramolecular gels formed by amphiphilic Schiff bases, none of them exhibits circularly polarized luminescence (CPL). While Mg2+, Zn2+ and Al3+ can both significantly enhance the fluorescence of the Schiff bases, interestingly, only Al3+ ion is able to turn on the CPL emission. This study on the one hand provides a simple method to the fabrication of CPL emitting supramolecular materials, and on the other hand offers a novel way to the sensing of aluminum ion with supramolecular materials.
关键词： Self-assembly,Schiff bases,Circularly polarized luminescence,Al3+,Supramolecular gels
更新于2025-09-23 15:21:21
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Boronic ester-based dynamic covalent ionic liquid gels for self-healable, recyclable and malleable optical devices
摘要： Dynamic covalent ionic liquid (IL) gels have been proved to be promising materials for soft optical devices which possess the advantages of other dynamic gels but avoid shrinking. The focal length of the planoconvex lens made from the gels is tunable and the prism from them shows an excellent beam splitting property. Damaged devices could be re-covered via self-healing or re-molding.
关键词： malleable optical devices,recyclable,Boronic ester,dynamic covalent ionic liquid gels,self-healable
更新于2025-09-23 15:21:21
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Hole transporting properties of discotic liquid-crystalline semiconductor confined in calamitic UV-crosslinked gel
摘要： The influence of polymer network on hole transport in discotic liquid crystal (LC) is investigated by the time of flight charge carrier mobility measurements. Composites of discotic LC and nematic reactive mesogen undergo UV-activated polymerization in columnar phase which yields the formation of chemical gels. Polarized optical microscopy allows us to observe alignment effect, whether scanning electron microscopy helps us to obtain characteristic imprint of polydomain columnar phase in created polymeric network. Hole mobility is improved, presumably due to the stabilization of the alignment of discotic LC. This type of composite is relevant for potential multilayer and flexible device applications.
关键词： reactive mesogens,discotic liquid crystals,photopolymers,gels,organic semiconductors
更新于2025-09-23 15:21:21
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[ACS Symposium Series] Gels and Other Soft Amorphous Solids Volume 1296 || Probe Diffusion Dynamic Light Scattering of Polymer solutions and Gels
摘要： Probe diffusion dynamic light scattering technique is a powerful to investigate the dynamics of polymer chains in polymer solutions and gels. Not only the local dynamics and/or local viscosity but also the gel point and the post-gel dynamics can be investigated. In this chapter, we discuss (1) a conventional probe diffusion of radical polymerization of poly(N-isopropylacrylamide) (PNIPAM) aqueous system, (2) an in-situ isorefractive probe diffusion of tetra-arm poly(ethylene glycol) (Tetra-PEG) undergoing sol-gel transition via cross-end-coupling, and (3) of PNIPAM radical polymerization. It is demonstrated that the gel point is determined as a function of the reaction conversion, which is a more universal measure than the reaction time. The post-gel dynamics explored by the probe particles illuminates the local dynamics in a “pool” of the sol phase surrounded by a gel network. Furthermore, comparison in dynamics is made between well-controlled uniform networks (Tetra-PEG gels) and randomly cross-linked more heterogeneous networks (PNIPAM gels) the probe size from the viewpoints of dependence and scattering angle dependence.
关键词： gel point,Tetra-PEG,post-gel dynamics,Probe diffusion,PNIPAM,gels,polymer solutions,dynamic light scattering
更新于2025-09-23 15:21:21
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Extremely Soft, Conductive, and Transparent Ionic Gels by 3D Optical Printing
摘要： A series of 3D printable multifunctional ionic gels (IGs) are developed incorporating ionic liquid (IL) in the thiol–ene network of thiol-based end-crosslinker and acrylate monomers. The resulted gels, termed as thiol-ionic gels (T-IGs), are highly transparent and very soft with IL content of 70–85 wt%. The mechanical and conductive properties of the T-IGs are found to be largely dependent on the IL content, end-crosslinker functionalities, and chain-length of monomers. Progression of ionic conductivity is observed with an increase in IL content and conductivity as high as 5.40 mS cm?1 is attained for longer acrylate group containing T-IGs at room temperature, while further increase is observed at elevated temperature. T-IGs in all systems are found to exhibit superior thermal stability. Three-dimensional fabrication of these functional T-IGs is achieved by optical 3D printing process with microscale resolution in facile steps.
关键词： multifunctional ionic gels,3D printing,thiol–ene reaction,ionic liquids
更新于2025-09-23 15:21:01
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Photoactive Functional Soft Materials (Preparation, Properties, and Applications) || Soft Materials Driven by Photothermal Effect and Their Applications
摘要： We are surrounded by soft materials. Most organs of the human body are made of soft materials. One defining characteristic of soft materials is that they can be readily deformed by external stimuli and stress. Even the thermal energy available at room temperature is sufficient to cause significant deformation in soft materials. de Gennes in his 1991 Nobel lecture emphasized “flexibility” as a defining characteristic of soft materials. Colloids, polymers, liquid crystals (LCs), gels, and biological materials are categorized as soft materials. Being pervasive in nature, soft materials have been a source of inspiration for scientists and engineers for the design and fabrication of stimuli‐responsive smart materials and systems for scientific investigations to understand the basic principles and technological application in devices and health care. Accordingly, a wide variety of engineered soft materials have been developed, which play a crucial role in modern technology. Soft nanotechnology, soft robotics, and soft lithography are examples that reflect the far‐reaching implications of soft materials in biology and engineering. Soft materials constitute one of the most stimulating interdisciplinary frontiers of modern science and are built on diverse experimental and theoretical foundations. Although soft materials in neat state have found a wide range of applications, fabrication of composites of soft materials by integrating other functional materials has recently become a common practice to realize advanced and tunable materials with enhanced properties for high‐tech applications. Incorporation of photothermal agents into the matrices of soft materials is one such emerging approach.
关键词： nanocomposites,soft materials,liquid crystals,photothermal therapy,polymers,gels,photothermal effect,actuators,drug delivery
更新于2025-09-23 15:21:01
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Metallopolymer Organohydrogels with Photoa??Controlled Coordination Crosslinks Work Properly Below 0 ?°C
摘要： Controlling the structures and functions of gels is important for both fundamental research and technological applications. Introducing photoresponsive units into gels enables remote control of their properties with light. However, existing gels show photoresponsiveness only at room temperature or elevated temperatures. The development of photoresponsive gels that work below 0 °C can expand their usage in cold environments. Here, photoresponsive metallopolymer organohydrogels that function even at ?20 °C are reported. The organohydrogels are prepared using photoresponsive Ru–thioether coordination bonds as reversible crosslinks to form polymer networks. A water/glycerol mixture is used as an anti-freezing solvent. At ?20 °C, the Ru–thioether coordination bonds are dissociated under light irradiation and reformed reversibly in the dark, which result in alternating crosslinking densities in the polymer networks. This process enables inducing reversible gel-to-sol transitions, healing damaged gels, controlling the mechanical properties and volumes of the gels, and rewriting microstructures on the gels below 0 °C.
关键词： photoresponsive materials,gels,crosslinks,anti-freezing,metallopolymers
更新于2025-09-23 15:19:57
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Highly Elastic and >200% Reversibly Stretchable Downa??Conversion White Lighta??Emitting Diodes Based on Quantum Dot Gel Emitters
摘要： Combining the characteristics of different materials offers exciting new opportunities for advanced applications in various fields. Herein, white light-emitting diodes (WLEDs) with >200% reversible stretchability are fabricated using six-color quantum dots (QDs) gel emitters. Stable aqueous-phase alloy core/shell QDs with high quantum yield are obtained via ligand exchange using a ternary solvent system. Transparent and highly stretchable gels with large pores are created by binary-solvent-based gelation at low temperatures. Importantly, the QDs and the gel originate from the same two solvents, which make the QDs highly compatible with the gelation process. Consequently, QDs of six different colors are incorporated into the gel without any property degradation. The excellent optical properties of the QDs in the liquid phase (e.g., 17% higher photoluminescence (PL) intensity) are retained in the gel phase. The QD gel (QDG) exhibits elastic deformation up to 200%, with uniform PL over the entire gel. A down-conversion WLED built using the QDG emitter produces cool white light with a color temperature of 6100 K, a color rendering index of 94, and a luminous efficacy of 72 lm W?1. In addition, the performance of the QDG-based WLED remains unchanged even after more than 1000 bending/stretching cycles.
关键词： white light emitting diodes,gels,mechanical reliability,form factors,quantum dots
更新于2025-09-19 17:13:59