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Multi‐level memory can greatly improve information density, so it has been widely studied. In this study, a carbazole‐based donor–acceptor polymer poly[2,7‐9‐(heptadecan‐9‐yl)‐9H‐carbazole‐alt‐7H‐benzimidazo[2,1‐a]benz[de]isoquinolin‐7‐one] (PCz‐BB) is synthesized, which exhibits flash‐type ternary memory behavior. Further, CdS nanoparticles (NPs) are embedded into the prepared polymer to enhance the storage performance. The current–voltage (I–V) characteristics of memory devices based on PCz‐BB:CdS composites and the effect of the embedding ratio of CdS NPs on the memory devices are studied. It is verified that the ON2/ON1/OFF current ratios of the devices at low CdS embedding concentrations are improved, and the threshold voltages are also reduced. The memory device based on the optimal embedding concentration (3 wt% CdS) exhibits a high ON2/ON1/OFF current ratio of 18631:72:1, a low threshold voltage of −0.40/−1.20 V, and excellent stability. The mechanism of resistive switching is explained by the theory of charge traps and conductive filaments. This work provides a new avenue for high‐performance multi‐level organic electrical storage materials. [ABSTRACT FROM AUTHOR]

Radio‐photoluminescence (RPL) materials display a distinct radiation‐induced permanent luminescence center, and therefore find application in the detection of ionizing radiation. The current inventory of RPL materials, which were discovered by serendipity, has been limited to a small number of metal‐ion‐doped inorganic materials. Here we document the RPL of a metal–organic framework (MOF) for the first time: X‐ray induced free radicals are accumulated on the organic linker and are subsequently stabilized in the conjugated fragment in the structure, while the metal center acts as the X‐ray attenuator. These radicals afford new emission features in both UV‐excited and X‐ray excited luminescence spectra, making it possible to establish linear relationships between the radiation dose and the normalized intensity of the new emission feature. The MOF‐based RPL materials exhibit advantages in terms of the dose detection range, reusability, emission stability, and energy threshold. Based on a comprehensive electronic structure and energy diagram study, the rational design and a substantial expansion of candidate RPL materials can be anticipated. [ABSTRACT FROM AUTHOR]

In this study, two types of amine‐containing antioxidants composed of 2‐mercaptobenzimidazole zinc (MBZ) and 4,4′‐bis(α, α‐dimethylbenzyl) diphenylamine (445) were used to improve the thermo‐oxidative aging resistance of ethylene propylene diene rubber (EPDM). The synergistic effects on the performances of EPDM and the corresponding aging mechanism were investigated by FTIR, tensile test, differential scanning calorimetry (DSC), rotary rheometer and other equipment. The results showed that the hardness increased gradually with the increasing aging time regardless of the type of antioxidants. Compared with the EPDM without antioxidants, the elongation retention of those samples with MBZ or 445 improved obviously. Additionally, the sample with the MBZ/445 complex showed the highest retention values at the same aging time. The antioxidative mechanisms were further analyzed by carbonyl index, activation energy and oxidation induction time, respectively. Results indicated that the degree of oxidation of EPDM using the MBZ/445 complex was much lower than other control systems during the aging process. As a result, the MBZ/445 complex was a favorable antioxidative additive for EPDM. [ABSTRACT FROM AUTHOR]