Plasma-Induced Superhydrophobicity as a Green Technology for Enhanced Air Gap Membrane Distillation

Lotus leaf-inspired poly(lactic acid) nanofibrous membranes with enhanced humidity resistance for superefficient PM filtration and high-sensitivity passive monitoring

The biomimetic design principles offer promising solutions to fabrication of multifunctional nanofibrous membranes (NFMs) with on-demand hierarchies and properties. Herein, a combined electrospinningelectrospray approach was employed to firmly anchor MOF nanocrystals onto poly(lactic acid) (PLA) nanofibers, resembling the naturally occurring dense protrusions at the lotus leaf. The formation of unique MOF-protruding superstructures gave rise to an exceptional combination of increased electroactivity, in-situ electret properties and charge regeneration mechanisms, as well as remarkable humidity resistance. With 8 wt% bioinspired MOF-protrusions for the electrospunelectrosprayed PLA NFMs (BM-PLA8), the initial surface potential was elevated to 3.0 kV and slightly decreased to 2.6 kV after 7-day ageing, in clear contrast to only 1.1 and 0.6 kV for the normal PLA, respectively. Moreover, the tribo-output voltage and current were significantly promoted for BM-PLA8 (64.5 V and 151.6 nA), demonstrating high humidity resistance and long-term robustness even at 90 % RH. It conferred distinct improvements in air filtration performance for BM-PLA8 even at the highest airflow velocity of 85 L/min (below 250 Pa, 99.9 % and 95.0 % removal of PM2.5 and PM0.3, respectively), far surpassing the normal PLA counterpart (nearly 350 Pa, 89.5 % and 75.8 %). Arising from the respiration-driven charge regeneration mechanisms, passive respiratory monitoring of high sensitivity was demonstrated for BM-PLA8, showing great promise for efficient healthcare under the challenging circumstances.

An in-depth analysis of membrane distillation research (1990-2023): Exploring trends and future directions through bibliometric approach

This bibliometric analysis offers a comprehensive investigation into membrane distillation (MD) research from 1990 to 2023. Covering 4389 publications, the analysis sheds light on the evolution, trends, and future directions of the field. It delves into authorship patterns, publication trends, prominent journals, and global contributions to reveal collaborative networks, research hotspots, and emerging themes within MD research. The findings demonstrate extensive global participation, with esteemed journals such as Desalination and the Journal of Membrane Science serving as key platforms for disseminating cutting-edge research. The analysis further identifies crucial themes and concepts driving MD research, ranging from membrane properties to strategies for mitigating membrane fouling. Co-occurrence analysis further highlights the interconnectedness of research themes, showcasing advancements in materials, sustainable heating strategies, contaminant treatment, and resource management. Overlay co-occurrence analysis provides temporal perspective on emerging research trends, delineating six key topics that will likely shape the future of MD. These include innovations in materials and surface engineering, sustainable heating strategies, emerging contaminants treatment, sustainable water management, data-driven approaches, and sustainability assessments. Finally, the study serves as a roadmap for researchers and engineers navigating the dynamic landscape of MD research, offering insights into current trends and future trajectories, ultimately aiming to propel MD technology towards enhanced performance, sustainability, and global relevance.

Metal Surface Engineering for Extreme Sustenance of Jumping Droplet Condensation

Water vapor condensation on metallic surfaces is critical to a broad range of applications, ranging from power generation to the chemical and pharmaceutical industries. Enhancing simultaneously the heat transfer efficiency, scalability, and durability of a condenser surface remains a persistent challenge. Coalescence-induced condensing droplet jumping is a capillarity-driven mechanism of self-ejection of microscopic condensate droplets from a surface. This mechanism is highly desired due to the fact that it continuously frees up the surface for new condensate to form directly on the surface, enhancing heat transfer without requiring the presence of the gravitational field. However, this condensate ejection mechanism typically requires the fabrication of surface nanotextures coated by an ultrathin (<10 nm) conformal hydrophobic coating (hydrophobic self-assembled monolayers such as silanes), which results in poor durability. Here, we present a scalable approach for the fabrication of a hierarchically structured superhydrophobic surface on aluminum substrates, which is able to withstand adverse conditions characterized by condensation of superheated steam shear flow at pressure and temperature up to ≈1.42 bar and ≈111 °C, respectively, and velocities in the range ≈3-9 m/s. The synergetic function of micro- and nanotextures, combined with a chemically grafted, robust ultrathin (≈4.0 nm) poly-1H,1H,2H,2H-perfluorodecyl acrylate (pPFDA) coating, which is 1 order of magnitude thinner than the current state of the art, allows the sustenance of long-term coalescence-induced condensate jumping drop condensation for at least 72 h. This yields unprecedented, up to an order of magnitude higher heat transfer coefficients compared to filmwise condensation under the same conditions and significantly outperforms the current state of the art in terms of both durability and performance establishing a new milestone.