发表论文

The catalytic performance, depending on the surface nature, is ubiquitous in photocatalysis. However, surface engineering for organic photocatalysts through structural modulation has long been neglected. Here, we propose a zone crystallization strategy for covalent organic frameworks (COFs) that enhances surface ordering through regulator-induced amorphous-tocrystalline transformation. Dynamic simulations show that attaching monofunctional regulators to the surface of spherical amorphous precursor improves surface dynamic reversibility, increasing crystallinity from the inside out. The resulting COF microspheres display surface-enhanced crystallinity and uniform spherical morphology. The visible photocatalytic hydrogen evolution rate reaches 126 mmol g–1 h–1 for the simplest β-ketoenamine-linked COF and 350 mmol gCOF–1 h–1 for SiO2@COF with minimal Pt cocatalysts. Mechanism studies indicate that surface crystalline domains build the surface electrical fields to accumulate photogenerated electrons and diminish electron transfer barriers between the COF and Pt interface. This work bridges the gap between microscopic molecules and macroscopic properties, allowing tailored design of crystalline organic photocatalysts.

The study of structure−activity relationships is a top priority in the development of nontraditional luminescent materials. In this work, nonconjugated polyurethanes (PUs) with full-color emission (red, green, and blue) are easily obtained by control of the diol monomer structure and the polymerization conditions. Selected diol monomers introduced single, double, or triple bond repeating units into the main chain of the PUs, in order to understand how unsaturated bonds and H-bonds affect their luminescence from a molecular orbital viewpoint. Detailed experimental and theoretical results show that the PUs have different temperature-dependent behaviors related to the interplay of H-bonding, through-space n−π interactions, and aggregation properties. The potential applications of PUs in colorful displays, covert information transmission, and multifunctional bioimaging have been verified. This work provides a new general protocol for the simple preparation of multifunctional nonconventional fluorescent polymers and deepens the understanding of their luminescence mechanisms.

Unlike one-dimensional polymers, the theoretical framework on the behaviors of two-dimensional (2D) polymers is far from completeness. In this study, we model single-layer flexible 2D polymers of different sizes and examine their scaling behaviors in solution, represented by Rg ∼ Lν, where Rg is the radius of gyration and L is the side length of a 2D polymer. We find that the scaling exponent ν is 0.96 for a good solvent and 0.64 for under poor solvent condition. Interestingly, we observe a previously unnoticed phenomenon:under intermediate solvent conditions, the 2D polymer folds to maintain a flat structure, and as L becomes larger, multiple folded structures emerge. We introduce a shape parameter Q to diagram the relationship of folded structures with the polymer size and solvent condition. Theoretically, we explain the folding transitions by the competition between bending and solvophobic free energies.

Nonconventional chromophores are good candidates for preparing luminous gels because their luminescence is usually enhanced in the aggregated state. In this work, a simple one-pot strategy for polymerization-induced gelation of polymer fluorescent gels was developed, and a self physically crosslinked luminous gel PUHG based on a non-conjugated/nonconventional luminous polyurethane derivative was obtained. Detailed experimental and theoretical studies probed the physical properties and luminescence principles of PUHG’s aggregated state. Molecular dynamics simulations suggest that abundant non-covalent interactions and physical entanglement between polyurethane chains are the main driving forces of gel formation and the source of luminescence. PUHG displays stable photophysical properties, environmental tolerance, good adhesion properties and processability, leading to the validation of patterning applications of PUHG on different organic/inorganic substrates. This work broadens the application range of nonconventional luminous polymers and provides a simple route for large-scale preparation of fluorescent gel soft materials.

Charge-transfer mechanisms in adaptive multicomponent solutions at liquid–solid interfaces with triboelectric probes are crucial for understanding chemistry dynamics. However, liquid–solid charge transfer becomes unpredictable, due to the components or interactions in solutions, restricting its potential application for precise monitoring of liquid environments. This study utilizes triboelectric probes to investigate the charge transfer of chemicals, applying this approach to real-time coolant state monitoring. Analysis of electrical signal dynamics induced by ethylene glycol and its oxidation byproduct, oxalic acid, in ethylene glycol solutions reveals that hydrogen bond and ion adsorption diminishes the efficiency of electron transfer at the liquid–solid interface. These findings promote the engineering of the triboelectric probe that enhances coolant quality with remarkable sensitivity (detection limit:0.0001%) and a broad freezing point operational range (0 to −49 °C). This work advances the precise control of the charge dynamics and demonstrates the potential of triboelectric probes for interdisciplinary applications.

The concentration-in-control strategy is a versatile and powerful approach to construct a variety of low-dimensional nanostructures. However, little is known about the mechanistic aspects of the concentration-dependent formation of oligomers on the solid surface. In this study, we employ molecular dynamics simulation to give insight into the formation of oligomers, involving dimers and zigzag polymers, which are controlled upon adjusting kinetics via monomer concentrations. Our analyses indicate that concentration-dependent nucleation determines the size and topology of oligomers, and the correlation between reactions and diffusion of monomers significantly influences the crystallinity of oligomers. Our study suggests that a highly reversible reaction combined with rapid monomer diffusion can promote the crystalline quality of oligomers.

The collapse or folding of an individual polymer chain into a nanoscale particle gives rise to single‐chain nanoparticles (SCNPs), which share a soft nature with biological protein particles. The precise control of their properties, including morphology, internal structure, size, and deformability, are a long‐standing and challenging pursuit. Herein, a new strategy based on amphiphilic alternating copolymers for producing SCNPs with ultrasmall size and uniform structure is presented. SCNPs are obtained by folding the designed alternating copolymer in N,N‐dimethylformamide (DMF) and fixing it through a photocatalyzed cycloaddition reaction of anthracene units. Molecular dynamics simulation confirms the solvophilic outer corona and solvophobic inner core structure of SCNPs. Furthermore, by adjusting the length of PEG units, precise control over the mean size of SCNPs is achieved within the range of 2.8 to 3.9 nm. These findings highlight a new synthetic strategy that enables enhanced control over morphology and internal structure while achieving ultrasmall and uniform size for SCNPs.

Ensuring effective and controlled zinc ion transportation is crucial for functionality of the solid electrolyte interphase (SEI) and overall performance in zinc‐based battery systems. Herein the first‐ever demonstration of incorporate cation‐π interactions are provided in the SEI to effectively facilitate uniform zinc ion flux. The artificial SEI design involves the immobilization of 4‐amino‐p‐terphenyl (TPA), a strong amphiphilic cation‐π interaction donor, as a monolayer onto a conductive poly(3,4‐ethylenedioxythiophene) (PEDOT) matrix, which enable the establishment of a robust network of cation‐π interactions. Through a carefully‐designed interfacial polymerization process, a high‐quality, large‐area, robust is achieved, thin polymeric TPA/PEDOT (TP) film for the use of artificial SEI. Consequently, this interphase exhibits exceptional cycling stability with low overpotential and enables high reversibility of Zn plating/stripping. Symmetrical cells with TP/Zn electrodes can be cycled for more than 3200 hours at 1 mA cm −2 and 1 mAh cm −2 . And the asymmetric cells can cycle 3000 cycles stably with a high Coulomb efficiency of 99.78%. Also, under the extreme conditions of lean electrolyte and low N/P ratio, the battery with TP protective layer can still achieve ultra‐stable cycle.

The application of liquid crystal technology typically relies on the precise control of molecular orientation at a surface or interface. This control can be achieved through a combination of morphological and chemical methods. Consequently, variations in constrained boundary flexibility can result in a diverse range of phase behaviors. In this study, we delve into the self-assembly of liquid crystals within elastic spatial confinement by using the Gay–Berne model with the aid of molecular dynamics simulations. Our findings reveal that a spherical elastic shell promotes a more regular and orderly alignment of liquid crystals compared to a hard shell. Moreover, during the cooling process, the hard-shell confined system undergoes an isotropic–smectic phase transition. In contrast, the phase behavior within the spherical elastic shell closely mirrors the isotropic–nematic–smectic phase transition observed in bulk systems. This indicates that the orientational arrangement of liquid crystals and the deformations induced by a flexible interface engage in a competitive interplay during the self-assembly process. Importantly, we found that phase behavior could be manipulated by altering the flexibility of the confined boundaries. This insight offers a fresh perspective for the design of innovative materials, particularly in the realm of liquid crystal/polymer composites.

The development of single-component materials with low cytotoxicity and multichannel fluorescence imaging capability is a research hotspot. In the present work, highly electron-deficient pyrazine monomers were covalently connected into a polyurethane backbone using addition polymerization with terminal poly(ethylene glycol) monomethyl ether units containing a high density of electron pairs. Thereby, an amphiphilic polyurethane-pyrazine (PUP) derivative has been synthesized. The polymer displays cluster-induced emission through compact inter- and/or intramolecular noncovalent interactions and extensive through-space electron coupling and delocalization. Molecular rigidity facilitates red-shifted emission. Based on hydrophilic/hydrophobic interactions and excitation dependence emission at low concentrations, PUP has been self-assembled into fluorescent nanoparticles (PUP NPs) without additional surfactant. PUP NPs have been used for cellular multicolor imaging to provide a variety of switchable colors on demand. This work provides a simple molecular design for environmentally sustainable, luminescent materials with excellent photophysical properties, biocompatibility, low cytotoxicity, and color modulation.