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Graphene nanosheets are facilely prepared by electrochemical exfoliation of graphite in sodium tungstate aqueous solution. Through a filtration-transfer procedure and followed by heat treatment, the graphene nanosheets are deposited on the polyethylene terephthalate substrate to form electrothermal films. The graphene electrothermal films exhibit low square resistance of 159 Ω/sq, high in-plane thermal conductivity of 658 W/m/K, and excellent heat propagation with uniform temperature distribution. The steady-state temperature of the films increases from 32 to 139 °C as the applied voltage increases from 5 to 30 V. The electrothermal response of the graphene films is as fast as <20 s. The graphene film heaters also display good flexibility. Even after bending 100 times, the graphene film heaters still exhibit almost the same electrothermal performance. [ABSTRACT FROM AUTHOR]

In this study, the co-precipitation method was adopted to synthesize red phosphor CaO: Eu3+. Sodium carbonate was chosen as the precipitator, and sodium dodecylbenzensulfonate as the surfactant. The structure, morphology, and spectroscopic properties of the samples were characterized by XRD, laser particle size analyzer, SEM, FT-IR, Raman, UV–Vis and PL-PLE spectra, respectively. The results indicated that the Eu3+ ion inhabited the site of Ca2+ as the luminescent center, and the crystal structure of cubic CaO remained unchanged. The particle size of the obtained product was 0.5–2 μm with smooth surface. There was a main intense band with a maximum at 250 nm, which was attributed to the charge transfer transition of Eu3+-O2− and the maximum emission wavelength is 592 nm, corresponding to magnetic dipole transitions 5D0 → 7F1 of Eu3+ in the excitation spectrum. [ABSTRACT FROM AUTHOR]

In this study, the co-precipitation method was adopted to synthesize red phosphor CaO: Eu3+. Sodium carbonate was chosen as the precipitator, and sodium dodecylbenzensulfonate as the surfactant. The structure, morphology, and spectroscopic properties of the samples were characterized by XRD, laser particle size analyzer, SEM, FT-IR, Raman, UV–Vis and PL-PLE spectra, respectively. The results indicated that the Eu3+ ion inhabited the site of Ca2+ as the luminescent center, and the crystal structure of cubic CaO remained unchanged. The particle size of the obtained product was 0.5–2 μm with smooth surface. There was a main intense band with a maximum at 250 nm, which was attributed to the charge transfer transition of Eu3+-O2− and the maximum emission wavelength is 592 nm, corresponding to magnetic dipole transitions 5D0 → 7F1 of Eu3+ in the excitation spectrum. [ABSTRACT FROM AUTHOR]