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Solvent plays a vital role in the syntheses, purifications, and broad applications of upconversion nanoparticles (UCNPs). In this work, the effect of various dispersive solvents, including single solvents and mixed solvents, on the luminescence properties of NaYF:Yb, Er UCNPs was studied systematically. The differences in both upconversion luminescence (UCL) intensities and color outputs of the nanoparticles were observed when dispersing the UCNPs in deuterium oxide, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), ethanol, or water. The attenuation of the excitation and emission light of the UCNPs caused by absorption of the solvents, as well as the high-frequency vibrational groups of the solvents, such as -OH, -CH, and -CH groups, are responsible for the decrease in UCL intensities and increase in the red to green emission intensity ratios (RGR). The changes in water or OH ion contents of ethanol/water mixed solvent triggered similar changes in UCL properties. Interestingly, the quenching of the solvents for the UCL cannot be fully eliminated by changing the dispersive solvents once the UCNPs have touched the solvents containing high-frequency vibrational groups. Our work will facilitate the comprehension of the solvent induced luminescence variations of the nanoparticles and provide guidance for their applications.

A new three-component reaction, namely condensation-anti-Michael addition-aromatization, enabling the construction of benzylic compounds is disclosed. This reaction can not only act as an alternative approach to regioselective Csp-H trifluoromethylation of arenes through an "aromatic to be" strategy, but also provides a simple, convenient, step-economic, and practical strategy for the in situ generation of electrophilic p-(trifluoromethyl)benzyl species under extremely mild conditions.

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The next generation of high-energy-density electrostatic capacitors operable under elevated temperatures is urgently demanded to cope with the development of advanced high-power electronic systems. However, the inherent characteristics of the existing polymer dielectrics, such as poor heat dissipation, narrow band gaps, and high conduction loss, limit their energy density at high temperatures and result in a major hindrance to their applications under harsh conditions. Herein, a class of sandwich-structured dielectric polymer nanocomposites based on high-permittivity barium titanate nanoparticles (BT NPs) and heat-resistant hexagonal boron nitride nanosheets (BNNSs) are reported. In contrast to the traditional single-layer designs, the sandwich-structured configuration could elegantly combine the complementary functionalities of multicomponents in a synergistic fashion. Accordingly, functionalized with BT NPs in the outer layers offering superior permittivity and BNNSs in the central layer impeding the charge injection from electrodes, the properly designed sandwichstructured polymer composite films achieve a superior discharge energy density (U d ) of 11.5 J cm −3 accompanied by an efficiency (η) of 86.2% at room temperature, which is a 570% enhancement of neat polyimide (PI ∼2.00 J cm −3 ) and 960% over biaxially oriented polypropylene (∼1.2 J cm −3 ). Particularly, the composite films exhibit high-temperature performances with U d ∼ 4.072 J cm −3 and η ∼ 83.3% at 150 °C. The remarkable U d and η obtained in this work proved the feasibility of the layered polymer nanocomposite film in high-temperature electrostatic capacitors.

Through a historical analysis of the concept of inertia about its origination, definitions, and interpretations in the marketing context, this article presents the disagreements and debates on consumer inertia. In response, the authors redefine it by proposing clear definitions for two types of consumer inertia (CI1 and CI2). The reconceptualization clarifies the scope of consumer inertia and the role it plays in repeat purchase behavior. The conceptual models indicate the determinant and moderating factors of CI1 and CI2. The sequential development conceptual model of CI2 based on four dimensions (Cognitive Inertia, Affective Inertia, Conative Inertia, Action Inertia) deconstructs its mechanism. As for its relationship with loyalty, while type one inertia (CI1) leads to Spurious Loyalty, type two consumer inertia (CI2) can lead to either Loyalty, Latent Loyalty, Spurious Loyalty or No Loyalty. This study contributes to a better understanding of how consumer inertia works in repeat purchase behavior and provides some implications for future research and marketing practice.

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