Two-dimensional (2D) nanomaterials such as graphene, boron nitride (BN), and molybdenum disulfide (MoS 2 ) have been attracting increasing research interest in the past few years due to their unique material properties. However, the lack of a reliable large-scale production method is an inhibiting issue for their practical applications. Here we report a facile, efficient, and scalable method for the fabrication of monolayer and few-layer BN, MoS 2 , and graphene using combined low-energy ball milling and sonication. Ball milling generates two forces on layered materials, shear force and compression force, which can cleave layered materials into 2D nanosheets from the top/bottom surfaces, and the edge of layered materials. Subsequent sonication would further break larger crystallites into smaller crystallites. These fabricated 2D nanosheets can be well dispersed in aqueous solutions at high concentrations, 1.2 mg mL À1 for BN, 0.8 mg mL À1 for MoS 2 , and 0.9 mg mL À1 for graphene, which are highly advantageous over other methods. These advantages render great potential in the construction of high-performance 2D material-based devices at low cost. For example, a prototype gas sensor is demonstrated in our study using graphene and MoS 2 , respectively, which can detect several ppm of ammonia gas.

Molybdenum disulfide (MoS2) nanosheets have been attracting increasing research interests due to their unique material properties. However, the lack of a reliable large‐scale production method impedes their practical applications. Here a facile, efficient, and scalable method for the fabrication of high‐concentration aqueous dispersion of MoS2 nanosheets using combined grinding and sonication is reported. The 26.7 ± 0.7 mg/mL concentration achieved is the highest concentration in an aqueous solution reported up to now. Grinding generates pure shear forces to detach the MoS2 layers from the bulk materials. Subsequent sonication further breaks larger crystallites into smaller crystallites, which promotes the dispersion of MoS2 nanosheets in ethanol/water solutions. The exfoliation process establishes a new paradigm in the top‐down fabrication of 2D nanosheets in aqueous solution. In the meantime, MoS2‐based sensing film produced using this approach has successfully demonstrated the feasibility of a low‐cost and efficient NH3 gas sensor using inkjet printing as a viable method.

ADA + ZnBr2 passivated CsPbBr3 nanocrystals possess high photoluminescence quantum yield and good stability before and after storage for 65 days.

The core of the organic solvent nanofiltration (OSN) technology is solvent-resistant nanofiltration (SRNF) membranes. Till now, relative poor performance of solvent resistance is still the bottleneck of industrial application of SRNF membranes. This work reports a novel polyimide (PI)-based thin-film nanocomposite (TFN) membrane which was embedded with graphene quantum dots (GQDs) and showed an improved solvent resistance for OSN application. This kind of SRNF membrane, termed (PI-GQDs/PI)XA, was synthesized via serial processes of interfacial polymerization (IP), imidization, cross-linking, and solvent activation. The IP process was performed between an aqueous m-phenylenediamine solution doped with GQDs, having an average size of 1.9 nm, and an 1,2,4,5-benzenetetracarboxylic acyl chloride n-hexane solution on the PI substrate surface. The prepared (PI-GQDs-50/PI)X SRNF membranes without organic solvent activation achieved an ethanol permeance of nearly 50% higher than those of the GQD-free membranes under the same preparation conditions, while no compromise of the dye rejection was observed. Further, after the solvent activation using N,N-dimethylformamide (DMF) at 80 °C for 30 min, the ethanol permeance achieved about an 8-folds increment, from 2.84 to 22.6 L m–2 h–1 MPa–1. Interestingly, the rejection of rhodamine B also increased from 97.8 to 98.6%. A long-term permeation test of more than 100 h using rose bengal (RB, 1017 Da)/DMF solution at room temperature demonstrated that the synthesized (PI-GQDs-50/PI)XA membranes could maintain the DMF permeance and the RB rejection as high as 18.3 L m–2 h–1 MPa–1 and 99.9%, respectively. Moreover, the immersion test of the prepared (PI-GQDs-50/PI)XA SRNF membranes in both DMF and ethanol at room temperature for about one year also demonstrated the long-term organic solvent stability, indicating their good potential for OSN application.

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Abstract. Heterogeneous/multiphase oxidation of SO2 by NO2 on solid or aqueous particles is thought to be a potentially important source of sulfate in the atmosphere, for example, during heavily polluted episodes (haze), but the reaction mechanism and rate are uncertain. In this study, in order to assess the importance of the direct oxidation of SO2 by NO2 we investigated the heterogeneous/multiphase reaction of SO2 with NO2 on individual CaCO3 particles in N2 using Micro-Raman spectroscopy. In the SO2 ∕ NO2 ∕ H2O ∕ N2 gas mixture, the CaCO3 solid particle was first converted to the Ca(NO3)2 droplet by the reaction with NO2 and the deliquescence of Ca(NO3)2, and then NO2 oxidized SO2 in the Ca(NO3)2 droplet forming CaSO4, which appeared as needle-shaped crystals. Sulfate was mainly formed after the complete conversion of CaCO3 to Ca(NO3)2, that is, during the multiphase oxidation of SO2 by NO2. The precipitation of CaSO4 from the droplet solution promoted sulfate formation. The reactive uptake coefficient of SO2 for sulfate formation is on the order of 10−8, and RH enhanced the uptake coefficient. We estimate that the direct multiphase oxidation of SO2 by NO2 is not an important source of sulfate in the ambient atmosphere compared with the SO2 oxidation by OH in the gas phase and is not as important as other aqueous-phase pathways, such as the reactions of SO2 with H2O2, O3, and O2, with or without transition metals.

Aberrant FGF19/FGFR4 signaling has been shown to be an oncogenic driver of growth and survival in human hepatocellular carcinoma (HCC) with several pan-FGFR inhibitors and FGFR4-selective inhibitors currently being evaluated in the clinic. However, FGFR4 gatekeeper mutation induced acquired resistance remains an unmet clinical challenge for HCC treatment. Thus, a series of aminoindazole derivatives were designed and synthesized as new irreversible inhibitors of wild-type and gatekeeper mutant FGFR4. One representative compound (7v) exhibited excellent potency against FGFR4, FGFR4V550L, and FGFR4V550M with nanomolar activity in both the biochemical and cellular assays while sparing FGFR1/2/3. While compound 7v demonstrated modest in vivo antitumor efficacy in nude mice bearing the Huh-7 xenograft model consistent with its unfavorable pharmacokinetic properties, it provides a promising new starting point for future drug discovery combating FGFR4 gatekeeper mediated resistance in HCC patients.

Abstract. The reaction of SO2 with NO2 on the surface of aerosol particles has been suggested to be important in sulfate formation during severe air pollution episodes in China. However, we found that the direct oxidation of SO2 by NO2 was slow and might not be the main reason for sulfate formation in ambient air. In this study, we investigated the multiphase reaction of SO2 with an O2 ∕ NO2 mixture on single CaCO3 particles using Micro-Raman spectroscopy. The reaction converted the CaCO3 particle to a Ca(NO3)2 droplet, with CaSO4 ⚫ 2H2O solid particles embedded in it, which constituted a significant fraction of the droplet volume at the end of the reaction. The reactive uptake coefficient of SO2 for sulfate formation was on the order of 10−5, which was higher than that for the multiphase reaction of SO2 directly with NO2 by 2–3 orders of magnitude. According to our observations and the literature, we found that in the multiphase reaction of SO2 with the O2 ∕ NO2 mixture, O2 was the main oxidant of SO2 and was necessary for radical chain propagation. NO2 acted as the initiator of radical formation, but not as the main oxidant. The synergy of NO2 and O2 resulted in much faster sulfate formation than the sum of the reaction rates with NO2 and with O2 alone. We estimated that the multiphase oxidation of SO2 by O2 initiated by NO2 could be an important source of sulfate and a sink of SO2, based on the calculated lifetime of SO2 regarding the loss through the multiphase reaction versus the loss through the gas-phase reaction with OH radicals. Parameterization of the reactive uptake coefficient of the reaction observed in our laboratory for further model simulation is needed, as well as an integrated assessment based on field observations, laboratory study results, and model simulations to evaluate the importance of the reaction in ambient air during severe air pollution episodes, especially in China.