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Water pollution has long been a threat to human sustainability, and the development of nanofiltration membrane materials for water treatment is receiving increasing attention. Graphene oxide (GO) nanomaterials have demonstrated their widespread applicability in molecular separation and water purification technologies in recent years. However, the separation performance of the GO membrane (GOM) will decrease with long-term humidity. In this paper, we report a zeolite imidazole framework-8 (ZIF-8) nanoporous material embedded in a GOM, namely, GOZMs. After the positively charged ZIF-8 is compounded with GO, the separation and permeability of the composite nanofiltration membrane significantly improve, and it can remain stable during the long-term permeation process. Besides, four different ZIF-8 sizes were successfully prepared to investigate the effects of different porous particle sizes on composite nanofiltration membranes. The water permeability of the composite nanofiltration membrane increases monotonically with the increase of the ZIF-8 particle size, reaching 136.4 L m–2 h–1 bar–1, which is about 6 times higher than that of the pure GOM. The composite nanofiltration membrane exhibits decent dye screening performance while ensuring high water permeability. The rejection of rhodamine B and methylene blue was close to 100%, and the rejection of methyl orange was consistently lower. Therefore, the successful preparation of GOZMs paves a unique way for designing and developing novel nanofiltration membranes for water treatment and dye separation. [ABSTRACT FROM AUTHOR]

Abstract A spectrometer employing a silicon photomultiplier (SiPM) based scintillation detector has spectrum drift issues under temperature variations. Although some temperature-dependent compensation methods are reported, spectrum distortions under rapid temperature fluctuations have received little attention. We have developed a SiPM-based CsI(Tl) spectrometer and proposed gain stabilization designs to settle this problem. A temperature sensor was coupled to the SiPM in the detector and wrapped with a thermal insulation foam material to acquire the temperature of the SiPM. Meanwhile, a temperature correction module was applied in the field-programmable gate array (FPGA) within a custom multichannel analyzer (MCA). The effectiveness of the temperature correction module in the FPGA and a specialized detector design were studied and verified under slow and rapid temperature variations. The results prove that the spectrum drifts of the SiPM-based CsI(Tl) spectrometer under rapid temperature variations can be significantly constrained with the proposed gain stabilization designs. [ABSTRACT FROM AUTHOR]

Summary: CsPbBr3 and CsPbBr1.5I1.5 perovskite quantum dots (QDs) are synthesized by hot‐injection with PPO (2,5‐diphenyloxazole) as a fluorescent material for radioluminescent nuclear battery. The results reveal that the fluorescence of the QD/PPO system consists of radioluminescence (4.79%‐5.35%) and photoluminescence (nearly 95%). The addition of QDs leads to more excellent optical and electrical properties of radioluminescent nuclear battery. The peak position of the radioluminescence spectra of QD/PPO can be regulated by controlling the components of QDs. This strategy is suitable for obtaining a satisfactory spectral matching factor for different photovoltaic devices to obtain outstanding output performance. Moreover, good selection of QD/PPO as a fluorescent material can significantly improve the overall output performance of the radioluminescent nuclear battery. The linear relationship between optical and electrical properties was presented. Perovskite QDs exhibit excellent application prospects for the (α, β, γ, and X‐ray sources) radioluminescent nuclear battery and X‐ray imaging technology. [ABSTRACT FROM AUTHOR]

Perfluorohexanoic acid (PFHxA) has been recognized as an alternative to the wide usage of perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) in the fluoropolymer industry for years. PFHxA has been frequently detected in the environment due to its wide application. However, the ecological safety of PFHxA, especially its toxicological effects on aquatic organisms, remains obscure. In the present study, PFHxA at different concentrations (0, 0.48, 2.4, and 12 mg/L) was added to the culture medium for zebrafish embryo/larval exposure at 96 h postfertilization (hpf). Zebrafish larvae showed a slow body growth trend and changes in thyroid hormone levels (THs) upon PFHxA exposure, indicating the interference effect of PFHxA on fish larval development. Moreover, the transcription levels of genes related to the hypothalamic-pituitary-thyroid (HPT) axis were also analyzed. The gene expression level of thyroid hormone receptor β (trβ) was upregulated in a dose-dependent manner. Exposure to 0.48 mg/L PFHxA increased the expression levels of the thyrotrophic-releasing hormone (trh) and thyroid hormone receptor α (trα). Significant increases in corticotrophin-releasing hormone (crh) and transthyretin (ttr) gene expression were also observed when the zebrafish larvae were treated with 12 mg/L PFHxA, except iodothyronine deiodinases (dio1), which decreased obviously at that point. There were significant declines in the transcription of both thyroid-stimulating hormone β (tshβ) and uridinediphosphate-glucuronosyltransferase (ugt1ab) upon exposure to 2.4 mg/L PFHxA. In addition, PFHxA induced a dose-related inhibitory effect on the transcription of sodium/iodide symporter (nis). Finally, the thyroid status will be destroyed after exposure to PFHxA, thus leading to growth impairment in zebrafish larvae. • Zebrafish embryos were exposed to different concentrations of PFHxA for 96 hpf. • PFHxA exposure resulted in decrease of tshβ contents in zebrafish larvae. • Alterations of THs levels indicated thyroid endocrine disruption induced by PFHxA. • Genes involved in HPT axis were also modulated after PFHxA exposure. [ABSTRACT FROM AUTHOR]

Carbon nanomaterials have proven their wide applicability in molecular separation and water purification techniques. Here, an unzipped carbon nanotubes (CNT) embedded graphene oxide (GO) membrane (uCNTm) is reported. The multiwalled CNTs were longitudinally cut into multilayer graphene oxide nanoribbons by a modified Hummer method. To investigate the varying effects of different bandwidths of unzipped CNTs on their properties, four uCNTms were prepared by a vacuum-assisted filtration process. Unzipped-CNTs with different bandwidths were made by unzipping multiwalled CNTs with outer diameters of 0-10, 10-20, 20-30, and 30-50 nm and named uCNTm-1, uCNTm-2, uCNTm-3, and uCNTm-4, respectively. The uCNTms exhibited good stability in different pH solutions, and the water permeability of the composite membranes showed an increasing trend with the increase of the inserted uCNTm's bandwidth up to 107 L·m -2 ·h -1 ·bar -1 , which was more than 10 times greater than that of pure GO membranes. The composite membranes showed decent dye screening performance with the rejection rate of methylene blue and rhodamine B both greater than 99%.

Tunable gating graphene oxide (GO) membranes with high water permeance and precise molecular separation remain highly desired in smart nanofiltration devices. Herein, bioinspired by the filtration function of the renal glomerulus, we report a smart and high-performance graphene oxide membrane constructed via introducing positively charged polyethylenimine-grafted GO (GO-PEI) to negatively charged GO nanosheets. It was found that the additional GO-PEI component changed the surface charge, improved the hydrophilicity, and enlarged the nanochannels. The glomerulus-inspired graphene oxide membrane (G-GOM) shows a water permeance up to 88.57 L m -2 h -1 bar -1 , corresponding to a 4 times enhancement compared with that of a conventional GO membrane due to the enlarged confined nanochannels. Meanwhile, owing to the electrostatic interaction, it can selectively remove positively charged methylene blue at pH 12 and negatively charged methyl orange at pH 2, with a removal rate of over 96%. The high and cyclic water permeance and highly selective organic removal performance can be attributed to the synergic effect of controlled nanochannel size and tunable electrostatic interaction in responding to the environmental pH. This strategy provides insight into designing pH-responsive gating membranes with tunable selectivity, representing a great advancement in smart nanofiltration with a wide range of applications.