Completely understanding the working mechanisms of sophisticated supramolecular self-assembly exhibiting competing paths is very important for chemists en route to acquiring the ability of constructing supramolecular systems with controlled structures and designed functions. Here, the self-aggregation behaviors of an N-heterocyclic aromatic dicarboximide molecule 1, boasting two competing paths that give rise to different supramolecular structures and exhibit distinct thermodynamic features, are carefully examined. First, a group of H-aggregates are observed when providing a medium driving force for aromatic stacking, and their formation is manifested as an anticooperative process. When exposed to enhanced strength of aromatic interactions, these H-aggregates are found to transform into J-aggregates via a cooperative assembly mechanism. With the assistance of a mathematic model accommodating two competing polymerization pathways, calculations are conducted to simulate and explain the thermodynamic equilibria of such a unique supramolecular system. The calculation results are highly consistent with the experimental observations, and some important properties are elucidated. Specifically, the anticooperative assembly mechanism generally promotes the formation of low to medium oligomers, whereas the cooperative path is more competent at producing high polymers. If the anticooperative and cooperative routes coexist and compete for the same molecule, the cooperative formations of high polymers are significantly suppressed unless a very high degree of polymerization can be achieved. Such a unique feature of concurring anticooperative and cooperative paths emerges to the H- and J-aggregates of molecule 1 and thus brings about the interesting sequential appearances of the two types of aggregates under conditions of continuously enlarged driving force for self-aggregation. Finally, based on the knowledge acquired from this study and by analyzing the steric features of 1 that influence its supramolecular packing motifs, a slightly modified molecular structure is designed, with which the intermediate H-aggregation state was successfully suppressed, and a single cooperative J-aggregation path is manifested.

Short‐wavelength infrared (SWIR) photodetection and visualization has profound impacts on different applications. In this work, a large‐area organic SWIR photodetector (PD) that is sensitive to SWIR light over a wavelength range from 1000 to 1600 nm and a SWIR visualization device that is capable of upconverting SWIR to visible light are developed. The organic SWIR PD, comprising an organic SWIR sensitive blend of a near‐infrared polymer and a nonfullerene n‐type small molecule SWIR dye, demonstrates an excellent capability for real‐time heart rate monitoring, offering an attractive opportunity for portable and wearable healthcare gadgets. The SWIR‐to‐visible upconversion device is also demonstrated by monolithic integration of an organic SWIR PD and a perovskite light‐emitting diode, converting SWIR (1050 nm) to visible light (516 nm). The most important attribute of the SWIR visualizing device is its solution fabrication capability for large‐area SWIR detection and visualization at a low cost. The results are very encouraging, revealing the exciting large‐area SWIR photodetection and visualization for a plethora of applications in environmental pollution, surveillance, bioimaging, medical, automotive, food, and wellness monitoring.

The overall current literature suggests that smoking was associated with increased risk of ARC, especially NC. Further efforts should be made to confirm these findings and clarify the underlying biological mechanisms.

Hydroazaacene dicarboximide derivatives with red to NIR absorptions are designed and synthesized, which exhibit well-defined J-aggregation behaviors in both solution and thin films. The absorption and emission of an aggregate extend well into the NIR regime (λ(max) = 902 nm), manifesting particularly narrow bandwidth (fwhm = 152 cm(-1)) and is nearly transparent in the visible region.

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Mechanical strength of bioceramic scaffolds is a problem to treat the load bearing bone defects. We developed the Mg-doping wollastonite (CSi-Mg)-based scaffolds with high strength via 3D printing technology. The effect of pore size, β-tricalcium phosphate (β-TCP) content (x%), and heating schedule on the strength of scaffolds were investigated systematically. Incorporation of β-TCP could readily adjust the sintering properties of the CSi-Mg scaffolds and the scaffolds with high (20~30%) and low (10~20%) β-TCP possess much high strength (80~100 MPa or 120~140 MPa) after undergoing one-or two-step sintering. Meanwhile, the CSi-Mg/TCPx (x=10, 20) with medium-pore (~320 µm) had over 100 MPa in compression and ~52% in porosity. In particular, the composite scaffolds maintained appreciable strength (over 50 MPa) after immersion in Tris buffer for a long time stage (6 weeks). These findings demonstrate that the CSi-Mg/TCPx scaffolds are promising for treating some challengeable bone defects, especially for load-bearing bone repair.

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