Manipulating 2D Membrane Interlayer Channels with Accelerated Mass-Transfer Behavior to Boost Solar Desalination.

The scarcity of fresh water necessitates sustainable and efficient water desalination strategies. Solar-driven steam generation (SSG), which employs solar energy for water evaporation, has emerged as a promising approach. Graphene oxide (GO)-based membranes possess advantages like capillary action and Marangoni effect, but their stacking defects and dead zones of flexible flakes hinders efficient water transportation, thus the evaporation rate lag behind unobstructed-porous 3D evaporators. Therefore, fundamental mass-transfer approach for optimizing SSG evaporators offers new horizons. Herein, a universal multi-force-fields-based method is presented to regularize membrane channels, which can mechanically eliminate inherent interlayer stackings and defects. Both characterization and simulation demonstrate the effectiveness of this approach across different scales and explain the intrinsic mechanism of mass-transfer enhancement. When combined with a structurally optimized substrate, the 4Laponite@GO-1 achieves evaporation rate of 2.782 kg m-2 h-1 with 94.48% evaporation efficiency, which is comparable with most 3D evaporators. Moreover, the optimized membrane exhibits excellent cycling stability (10 days) and tolerance to extreme conditions (pH 1-14, salinity 1%-15%), verifies the robust structural stability of regularized channels. This optimization strategy provides simple but efficient way to enhance the SSG performance of GO-based membranes, facilitating their extensive application in sustainable water purification technologies.

Dialytic Synthesis of Two-Dimensional Cu-Based Metal-Organic Frameworks for Gas Separation: Designable MOF-Polymer Interface.

We demonstrate a dialytic strategy for the synthesis of congeneric two-dimensional metal-organic framework (2D MOF) nanosheets with a dialysis membrane using 1,4-benzenedicarboxylic acid (BDC), 1,4-naphthalenedicarboxylic acid (NDC), and 9,10-anthracenedicarboxylic acid (ADC) as organic linkers and copper(II) as a metal precursor, respectively. Polyimide (PI) membranes containing these empty 2D MOF nanosheets exhibit distinct molecular sieve effects. Molecular dynamic simulation results reveal that the structures of MOF-polymer interfaces are designable by modifying the MOF interlayer distance and aperture size, which has significant influences on gas permeability and selectivity. As a result, Cu-NDC/PI with the moderate composite interface structure shows superior performance toward H2/CH4 and CO2/CH4 separations with a selectivity of 199 and 63 over Cu-BDC (121 and 53) and Cu-ADC (135 and 54), respectively.

A noteworthy interface-targeting fluorescent probe for long-term tracking mitochondria and visualizing mitophagy.

Mitochondria are crucial for physiological activities, and alterations in mitochondrial function will lead to diverse human diseases. However, the tracking and long-term visualizing mitochondria are still deficient, which limits the research related to mitochondria. Inspired by the exceptional interfacial architecture of mitochondria, we proposed the interface-targeting model for designing fluorescent probes that could track and long-term visualize mitochondria with high selectivity in living cells, tissues, and zebrafish. And (E)-4-(2-(7-(diethylamino)-2-oxo-2H-chromen-3-yl)vinyl)-1-dodecylpyridin-1-ium iodide (CVP) with a cationic pyridinium unit and a C12-chain for targeting mitochondria was synthesized in this work. Thanks to the C12-chain, CVP has excellent permeability in tissues and zebrafish. In comparison to traditional mitochondrial probes, CVP stained mitochondria in short time and long-term track mitochondria without being affected by mitochondrial membrane potential because of the distal long alkyl chain, which enhanced the binding affinity of CVP to mitochondria. The phospholipid-biomimetic structure of CVP endowed it with high selectivity to mitochondria, which decreased the background noise. So CVP could stain mitochondria in tissues and zebrafish with high fidelity through no washing procedures. Particularly, four kinds of mitochondria were visualized by CVP in tissues. In addition, CVP can be applied to track the mitophagy behavior in situ and real-time. All of them demonstrated that the interface-targeting model is an effective strategy for designing mitochondrial probes with high selectivity.

Highly fluorescent triazolopyridine-thiophene D-A-D oligomers for efficient pH sensing both in solution and in the solid state.

Conjugated fluorophores have been extensively used for fluorescence sensing of various substances in the field of life processes and environmental science, due to their noninvasiveness, sensitivity, simplicity and rapidity. Most existing conjugated fluorophores exhibit excellent light-emitting performance in dilute solutions, but their properties substantially decrease or even completely vanish due to severe aggregation quenching in the solid state. Herein, we synthesize a series of triazolopyridine-thiophene donor-acceptor-donor (D-A-D) type conjugated molecules with high absolute fluorescence quantum yields (ΦF) ranging from 80% to 89% in solution. These molecules also show unusual light-emitting properties in the solid state with ΦF of up to 26%. We find that owing to the protonation-deprotonation process of the pyridine ring, these compounds display obvious changes in both fluorescence wavelength and intensity upon addition of acids, and these changes can be readily recovered by the successive introduction of bases. By harnessing this phenomenon, we further show that these fluorophores can be employed for efficient and reversible fluorescence sensing of hydrogen ions in a broad pH range (0.0-7.0). With the fabrication of pH testing papers and ink-printed complex patterns including butterflies and letters on substrates, we demonstrate the application of such sensors to fluorescence indication or solid state pH detection for real samples such as volatile acidic/basic gas and water-quality analysis.