Adjusting and controlling the solid-state photophysical properties of molecule-based fluorophores are crucial for the development of next-generation luminescent materials. In this work, we report the tunable photoemission of a 9-acetylanthracene (ACA) chromophore based on the formation of two-component molecular cocrystals with four different co-assembled building blocks (4-bromotetrafluorobenzene carboxylic acid, 2,3,5,6-tetrafluorohydroquinone, octafluoronaphthalene, and 1,2,4,5-tetracyanobenzene (TCB)), which present wide-range tunability of luminescence properties (such as wavelength, color, fluorescence lifetime, photoluminescence quantum yield and two-photon emission) relative to pristine ACA. In addition, aggregation induced emission (AIE) properties can be further obtained for ACA.TCB cocrystals, which are absent for the pristine ACA solid. Moreover, density functional theory (DFT) calculations suggest that the introduction of TCB can largely influence the energy level structures and orbital distributions of the ACA chromophore in the two-component crystals. Therefore, by the combination of experimental and theoretical studies on the molecular cocrystals, this work not only reports the supramolecular assembly of new types of crystalline two-component ACA systems, but also provides a detailed understanding of the structure–property relationship between molecular aggregation and luminescence behaviors.

Considerable smoke and toxic volatiles generation has compromised the application of thermoplastic polyurethane (TPU) and caused a great threat to human life. Here, nano-MgFe layered double hydroxide (MgFe-LDH) with uniform particle size was synthesized to reduce smoke density and toxic gases of TPU composites using ammonium polyphosphate (APP) as a flame retardant agent. The results show that the combination of 16 wt.% APP and 4 wt.% MgFe-LDH greatly decreased the smoke density (D_20min and D_{s, max}), smoke production rate (SPR) and heat release rate (HRR) of TPU composites. Furthermore, the MgFe-LDH synergist demonstrated high efficiency in decreasing total volatiled products and toxic volatiles evolved, such as the CO, HCN and isocyanates. The reason was mainly attributed to the chemical reaction between MgFe-LDH and APP, which can promote the compactness of char layers with fine microstructure formed in the decomposition process of MgFe-LDH/APP/TPU composites. The protective char layers could act as barriers between combustion zone and matrix to protect the unburned substrate and promote smoke suppression effect.

Recent advances in the detection of HClO/ClO ⁻ in vitro and in vivo using fluorescent, phosphorescent and chemiluminescent probes are reviewed.

Materials for blocking UV light play important roles in a variety of areas such as protecting the human skin and increasing the lifetime of polymers. In this work, a new type of host–guest UV-blocking material has been synthesized by the introduction of a fluorescent anion, 2-[2-[4-[2-(4-carboxyphenyl)vinyl]phenyl]vinyl]benzoate (CPBA), into the interlayer galleries of a ZnAl–NO₃ layered double hydroxide (LDH) precursor by an anion-exchange method. The structure and the thermal and photostability of the intercalated ZnAl–CPBA-LDH were investigated by powder X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermogravimetry and differential thermal analysis (TG-DTA), fluorescence spectroscopy and UV-vis spectroscopy. The supramolecular layered host–guest structure of ZnAl–CPBA-LDH enables both physical shielding and absorption of UV light. Furthermore, in contrast to conventional UV blocking materials—which convert UV light into thermal energy—the CPBA anions in the LDH interlayer galleries convert UV light (in the range 250–380 nm) into lower energy fluorescence emission (λ^em _max = 430 nm), thus reducing the thermal aging of the polymer composite materials. Intercalation of the CPBA anions into the LDH host also markedly enhances the thermal stability of CPBA. In polypropylene (PP) aging performance tests, after adding 1–5 wt% ZnAl–CPBA-LDH to PP, the resistance to UV degradation of the resulting ZnAl–CPBA-LDH/PP composites is higher than that of pristine PP or a CPBA/PP composite. Therefore, this work provides a way to construct a new type of host–guest layered material for UV-blocking applications.